Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
author: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-04-19 01:47:29 +0000
committer: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-04-19 01:47:29 +0000
commit: 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch)
tree: a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /testing/web-platform/tests/dom
parent: Initial commit. (diff)
download: firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.tar.xz
firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.zip
593 files changed, 38153 insertions, 0 deletions
diff --git a/testing/web-platform/tests/dom/META.yml b/testing/web-platform/tests/dom/META.yml
new file mode 100644
index 0000000000..6fd5b12664
--- /dev/null
+++ b/testing/web-platform/tests/dom/META.yml
@@ -0,0 +1,5 @@
+spec: https://dom.spec.whatwg.org/
+suggested_reviewers:
+  - jdm
+  - zqzhang
+  - annevk
diff --git a/testing/web-platform/tests/dom/abort/AbortSignal.any.js b/testing/web-platform/tests/dom/abort/AbortSignal.any.js
new file mode 100644
index 0000000000..3bbdc11a92
--- /dev/null
+++ b/testing/web-platform/tests/dom/abort/AbortSignal.any.js
@@ -0,0 +1,40 @@
+test(t => {
+  const signal = AbortSignal.abort();
+  assert_true(signal instanceof AbortSignal, "returned object is an AbortSignal");
+  assert_true(signal.aborted, "returned signal is already aborted");
+}, "the AbortSignal.abort() static returns an already aborted signal");
+
+async_test(t => {
+  const s = AbortSignal.abort();
+  s.addEventListener("abort", t.unreached_func("abort event listener called"));
+  s.onabort = t.unreached_func("abort event handler called");
+  t.step_timeout(() => { t.done(); }, 2000);
+}, "signal returned by AbortSignal.abort() should not fire abort event");
+
+test(t => {
+  const signal = AbortSignal.timeout(0);
+  assert_true(signal instanceof AbortSignal, "returned object is an AbortSignal");
+  assert_false(signal.aborted, "returned signal is not already aborted");
+}, "AbortSignal.timeout() returns a non-aborted signal");
+
+async_test(t => {
+  const signal = AbortSignal.timeout(5);
+  signal.onabort = t.step_func_done(() => {
+    assert_true(signal.aborted, "signal is aborted");
+    assert_true(signal.reason instanceof DOMException, "signal.reason is a DOMException");
+    assert_equals(signal.reason.name, "TimeoutError", "signal.reason is a TimeoutError");
+  });
+}, "Signal returned by AbortSignal.timeout() times out");
+
+async_test(t => {
+  let result = "";
+  for (const value of ["1", "2", "3"]) {
+    const signal = AbortSignal.timeout(5);
+    signal.onabort = t.step_func(() => { result += value; });
+  }
+
+  const signal = AbortSignal.timeout(5);
+  signal.onabort = t.step_func_done(() => {
+    assert_equals(result, "123", "Timeout order should be 123");
+  });
+}, "AbortSignal timeouts fire in order");
diff --git a/testing/web-platform/tests/dom/abort/abort-signal-any.any.js b/testing/web-platform/tests/dom/abort/abort-signal-any.any.js
new file mode 100644
index 0000000000..b4abb14c1a
--- /dev/null
+++ b/testing/web-platform/tests/dom/abort/abort-signal-any.any.js
@@ -0,0 +1,4 @@
+// META: script=./resources/abort-signal-any-tests.js
+
+abortSignalAnySignalOnlyTests(AbortSignal);
+abortSignalAnyTests(AbortSignal, AbortController);
diff --git a/testing/web-platform/tests/dom/abort/abort-signal-timeout.html b/testing/web-platform/tests/dom/abort/abort-signal-timeout.html
new file mode 100644
index 0000000000..2a9c13d614
--- /dev/null
+++ b/testing/web-platform/tests/dom/abort/abort-signal-timeout.html
@@ -0,0 +1,19 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>AbortSignal.timeout frame detach</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe"></iframe>
+<script>
+  async_test(t => {
+    const signal = iframe.contentWindow.AbortSignal.timeout(5);
+    signal.onabort = t.unreached_func("abort must not fire");
+
+    iframe.remove();
+
+    t.step_timeout(() => {
+      assert_false(signal.aborted);
+      t.done();
+    }, 10);
+  }, "Signal returned by AbortSignal.timeout() is not aborted after frame detach");
+</script>
diff --git a/testing/web-platform/tests/dom/abort/crashtests/timeout-close.html b/testing/web-platform/tests/dom/abort/crashtests/timeout-close.html
new file mode 100644
index 0000000000..ee8544a7f5
--- /dev/null
+++ b/testing/web-platform/tests/dom/abort/crashtests/timeout-close.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html class="test-wait">
+<meta charset="utf-8">
+<iframe id="iframe"></iframe>
+<script>
+  const srcdoc = `
+    <!DOCTYPE html>
+    <meta charset="utf-8">
+    <script>
+      const xhr = new XMLHttpRequest()
+      setTimeout(() => {
+        xhr.open('GET', '/', false)
+        xhr.send()
+        AbortSignal.timeout(41.62684667994843)
+      }, 1)
+      setTimeout(() => {
+        location.href = "about:blank"
+        parent.document.documentElement.classList.remove("test-wait")
+      }, 0)
+    </` + "script>";
+  iframe.srcdoc = srcdoc;
+</script>
diff --git a/testing/web-platform/tests/dom/abort/event.any.js b/testing/web-platform/tests/dom/abort/event.any.js
new file mode 100644
index 0000000000..bbbe28b233
--- /dev/null
+++ b/testing/web-platform/tests/dom/abort/event.any.js
@@ -0,0 +1,190 @@
+test(t => {
+  const c = new AbortController(),
+        s = c.signal;
+  let state = "begin";
+
+  assert_false(s.aborted);
+  assert_true("reason" in s, "signal has reason property");
+  assert_equals(s.reason, undefined, "signal.reason is initially undefined");
+
+  s.addEventListener("abort",
+    t.step_func(e => {
+      assert_equals(state, "begin");
+      state = "aborted";
+    })
+  );
+  c.abort();
+
+  assert_equals(state, "aborted");
+  assert_true(s.aborted);
+  assert_true(s.reason instanceof DOMException, "signal.reason is DOMException");
+  assert_equals(s.reason.name, "AbortError", "signal.reason is AbortError");
+
+  c.abort();
+}, "AbortController abort() should fire event synchronously");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  assert_equals(controller.signal, signal,
+                "value of controller.signal should not have changed");
+  controller.abort();
+  assert_equals(controller.signal, signal,
+                "value of controller.signal should still not have changed");
+}, "controller.signal should always return the same object");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  let eventCount = 0;
+  signal.onabort = () => {
+    ++eventCount;
+  };
+  controller.abort();
+  assert_true(signal.aborted);
+  assert_equals(eventCount, 1, "event handler should have been called once");
+  controller.abort();
+  assert_true(signal.aborted);
+  assert_equals(eventCount, 1,
+                "event handler should not have been called again");
+}, "controller.abort() should do nothing the second time it is called");
+
+test(t => {
+  const controller = new AbortController();
+  controller.abort();
+  controller.signal.onabort =
+      t.unreached_func("event handler should not be called");
+}, "event handler should not be called if added after controller.abort()");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  signal.onabort = t.step_func(e => {
+    assert_equals(e.type, "abort", "event type should be abort");
+    assert_equals(e.target, signal, "event target should be signal");
+    assert_false(e.bubbles, "event should not bubble");
+    assert_true(e.isTrusted, "event should be trusted");
+  });
+  controller.abort();
+}, "the abort event should have the right properties");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+
+  assert_true("reason" in signal, "signal has reason property");
+  assert_equals(signal.reason, undefined, "signal.reason is initially undefined");
+
+  const reason = Error("hello");
+  controller.abort(reason);
+
+  assert_true(signal.aborted, "signal.aborted");
+  assert_equals(signal.reason, reason, "signal.reason");
+}, "AbortController abort(reason) should set signal.reason");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+
+  assert_true("reason" in signal, "signal has reason property");
+  assert_equals(signal.reason, undefined, "signal.reason is initially undefined");
+
+  controller.abort();
+
+  assert_true(signal.aborted, "signal.aborted");
+  assert_true(signal.reason instanceof DOMException, "signal.reason is DOMException");
+  assert_equals(signal.reason.name, "AbortError", "signal.reason is AbortError");
+}, "aborting AbortController without reason creates an \"AbortError\" DOMException");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+
+  assert_true("reason" in signal, "signal has reason property");
+  assert_equals(signal.reason, undefined, "signal.reason is initially undefined");
+
+  controller.abort(undefined);
+
+  assert_true(signal.aborted, "signal.aborted");
+  assert_true(signal.reason instanceof DOMException, "signal.reason is DOMException");
+  assert_equals(signal.reason.name, "AbortError", "signal.reason is AbortError");
+}, "AbortController abort(undefined) creates an \"AbortError\" DOMException");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+
+  assert_true("reason" in signal, "signal has reason property");
+  assert_equals(signal.reason, undefined, "signal.reason is initially undefined");
+
+  controller.abort(null);
+
+  assert_true(signal.aborted, "signal.aborted");
+  assert_equals(signal.reason, null, "signal.reason");
+}, "AbortController abort(null) should set signal.reason");
+
+test(t => {
+  const signal = AbortSignal.abort();
+
+  assert_true(signal.aborted, "signal.aborted");
+  assert_true(signal.reason instanceof DOMException, "signal.reason is DOMException");
+  assert_equals(signal.reason.name, "AbortError", "signal.reason is AbortError");
+}, "static aborting signal should have right properties");
+
+test(t => {
+  const reason = Error("hello");
+  const signal = AbortSignal.abort(reason);
+
+  assert_true(signal.aborted, "signal.aborted");
+  assert_equals(signal.reason, reason, "signal.reason");
+}, "static aborting signal with reason should set signal.reason");
+
+test(t => {
+  const signal = AbortSignal.abort();
+
+  assert_true(
+    signal.reason instanceof DOMException,
+    "signal.reason is a DOMException"
+  );
+  assert_equals(
+    signal.reason,
+    signal.reason,
+    "signal.reason returns the same DOMException"
+  );
+}, "AbortSignal.reason returns the same DOMException");
+
+test(t => {
+  const controller = new AbortController();
+  controller.abort();
+
+  assert_true(
+    controller.signal.reason instanceof DOMException,
+    "signal.reason is a DOMException"
+  );
+  assert_equals(
+    controller.signal.reason,
+    controller.signal.reason,
+    "signal.reason returns the same DOMException"
+  );
+}, "AbortController.signal.reason returns the same DOMException");
+
+test(t => {
+  const reason = new Error('boom');
+  const signal = AbortSignal.abort(reason);
+  assert_true(signal.aborted);
+  assert_throws_exactly(reason, () => signal.throwIfAborted());
+}, "throwIfAborted() should throw abort.reason if signal aborted");
+
+test(t => {
+  const signal = AbortSignal.abort('hello');
+  assert_true(signal.aborted);
+  assert_throws_exactly('hello', () => signal.throwIfAborted());
+}, "throwIfAborted() should throw primitive abort.reason if signal aborted");
+
+test(t => {
+  const controller = new AbortController();
+  assert_false(controller.signal.aborted);
+  controller.signal.throwIfAborted();
+}, "throwIfAborted() should not throw if signal not aborted");
+
+done();
diff --git a/testing/web-platform/tests/dom/abort/reason-constructor.html b/testing/web-platform/tests/dom/abort/reason-constructor.html
new file mode 100644
index 0000000000..0515165a0f
--- /dev/null
+++ b/testing/web-platform/tests/dom/abort/reason-constructor.html
@@ -0,0 +1,12 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>AbortSignal.reason constructor</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe"></iframe>
+<script>
+  test(() => {
+    const aborted = iframe.contentWindow.AbortSignal.abort();
+    assert_equals(aborted.reason.constructor, iframe.contentWindow.DOMException, "DOMException is using the correct global");
+  }, "AbortSignal.reason.constructor should be from iframe");
+</script>
diff --git a/testing/web-platform/tests/dom/abort/resources/abort-signal-any-tests.js b/testing/web-platform/tests/dom/abort/resources/abort-signal-any-tests.js
new file mode 100644
index 0000000000..66e4141eac
--- /dev/null
+++ b/testing/web-platform/tests/dom/abort/resources/abort-signal-any-tests.js
@@ -0,0 +1,185 @@
+// Tests for AbortSignal.any() and subclasses that don't use a controller.
+function abortSignalAnySignalOnlyTests(signalInterface) {
+  const desc = `${signalInterface.name}.any()`
+
+  test(t => {
+    const signal = signalInterface.any([]);
+    assert_false(signal.aborted);
+  }, `${desc} works with an empty array of signals`);
+}
+
+// Tests for AbortSignal.any() and subclasses that use a controller.
+function abortSignalAnyTests(signalInterface, controllerInterface) {
+  const suffix = `(using ${controllerInterface.name})`;
+  const desc = `${signalInterface.name}.any()`;
+
+  test(t => {
+    const controller = new controllerInterface();
+    const signal = controller.signal;
+    const cloneSignal = signalInterface.any([signal]);
+    assert_false(cloneSignal.aborted);
+    assert_true("reason" in cloneSignal, "cloneSignal has reason property");
+    assert_equals(cloneSignal.reason, undefined,
+        "cloneSignal.reason is initially undefined");
+    assert_not_equals(signal, cloneSignal,
+        `${desc} returns a new signal.`);
+
+    let eventFired = false;
+    cloneSignal.onabort = t.step_func((e) => {
+      assert_equals(e.target, cloneSignal,
+          `The event target is the signal returned by ${desc}`);
+      eventFired = true;
+    });
+
+    controller.abort("reason string");
+    assert_true(signal.aborted);
+    assert_true(cloneSignal.aborted);
+    assert_true(eventFired);
+    assert_equals(cloneSignal.reason, "reason string",
+        `${desc} propagates the abort reason`);
+  }, `${desc} follows a single signal ${suffix}`);
+
+  test(t => {
+    for (let i = 0; i < 3; ++i) {
+      const controllers = [];
+      for (let j = 0; j < 3; ++j) {
+        controllers.push(new controllerInterface());
+      }
+      const combinedSignal = signalInterface.any(controllers.map(c => c.signal));
+
+      let eventFired = false;
+      combinedSignal.onabort = t.step_func((e) => {
+        assert_equals(e.target, combinedSignal,
+            `The event target is the signal returned by ${desc}`);
+        eventFired = true;
+      });
+
+      controllers[i].abort();
+      assert_true(eventFired);
+      assert_true(combinedSignal.aborted);
+      assert_true(combinedSignal.reason instanceof DOMException,
+          "signal.reason is a DOMException");
+      assert_equals(combinedSignal.reason.name, "AbortError",
+          "signal.reason is a AbortError");
+    }
+  }, `${desc} follows multiple signals ${suffix}`);
+
+  test(t => {
+    const controllers = [];
+    for (let i = 0; i < 3; ++i) {
+      controllers.push(new controllerInterface());
+    }
+    controllers[1].abort("reason 1");
+    controllers[2].abort("reason 2");
+
+    const signal = signalInterface.any(controllers.map(c => c.signal));
+    assert_true(signal.aborted);
+    assert_equals(signal.reason, "reason 1",
+        "The signal should be aborted with the first reason");
+  }, `${desc} returns an aborted signal if passed an aborted signal ${suffix}`);
+
+  test(t => {
+    const controller = new controllerInterface();
+    const signal = signalInterface.any([controller.signal, controller.signal]);
+    assert_false(signal.aborted);
+    controller.abort("reason");
+    assert_true(signal.aborted);
+    assert_equals(signal.reason, "reason");
+  }, `${desc} can be passed the same signal more than once ${suffix}`);
+
+  test(t => {
+    const controller1 = new controllerInterface();
+    controller1.abort("reason 1");
+    const controller2 = new controllerInterface();
+    controller2.abort("reason 2");
+
+    const signal = signalInterface.any([controller1.signal, controller2.signal, controller1.signal]);
+    assert_true(signal.aborted);
+    assert_equals(signal.reason, "reason 1");
+  }, `${desc} uses the first instance of a duplicate signal ${suffix}`);
+
+  test(t => {
+    for (let i = 0; i < 3; ++i) {
+      const controllers = [];
+      for (let j = 0; j < 3; ++j) {
+        controllers.push(new controllerInterface());
+      }
+      const combinedSignal1 =
+          signalInterface.any([controllers[0].signal, controllers[1].signal]);
+      const combinedSignal2 =
+          signalInterface.any([combinedSignal1, controllers[2].signal]);
+
+      let eventFired = false;
+      combinedSignal2.onabort = t.step_func((e) => {
+        eventFired = true;
+      });
+
+      controllers[i].abort();
+      assert_true(eventFired);
+      assert_true(combinedSignal2.aborted);
+      assert_true(combinedSignal2.reason instanceof DOMException,
+          "signal.reason is a DOMException");
+      assert_equals(combinedSignal2.reason.name, "AbortError",
+          "signal.reason is a AbortError");
+    }
+  }, `${desc} signals are composable ${suffix}`);
+
+  async_test(t => {
+    const controller = new controllerInterface();
+    const timeoutSignal = AbortSignal.timeout(5);
+
+    const combinedSignal = signalInterface.any([controller.signal, timeoutSignal]);
+
+    combinedSignal.onabort = t.step_func_done(() => {
+      assert_true(combinedSignal.aborted);
+      assert_true(combinedSignal.reason instanceof DOMException,
+          "combinedSignal.reason is a DOMException");
+      assert_equals(combinedSignal.reason.name, "TimeoutError",
+          "combinedSignal.reason is a TimeoutError");
+    });
+  }, `${desc} works with signals returned by AbortSignal.timeout() ${suffix}`);
+
+  test(t => {
+    const controller = new controllerInterface();
+    let combined = signalInterface.any([controller.signal]);
+    combined = signalInterface.any([combined]);
+    combined = signalInterface.any([combined]);
+    combined = signalInterface.any([combined]);
+
+    let eventFired = false;
+    combined.onabort = () => {
+      eventFired = true;
+    }
+
+    assert_false(eventFired);
+    assert_false(combined.aborted);
+
+    controller.abort("the reason");
+
+    assert_true(eventFired);
+    assert_true(combined.aborted);
+    assert_equals(combined.reason, "the reason");
+  }, `${desc} works with intermediate signals ${suffix}`);
+
+  test(t => {
+    const controller = new controllerInterface();
+    const signals = [];
+    // The first event should be dispatched on the originating signal.
+    signals.push(controller.signal);
+    // All dependents are linked to `controller.signal` (never to another
+    // composite signal), so this is the order events should fire.
+    signals.push(signalInterface.any([controller.signal]));
+    signals.push(signalInterface.any([controller.signal]));
+    signals.push(signalInterface.any([signals[0]]));
+    signals.push(signalInterface.any([signals[1]]));
+
+    let result = "";
+    for (let i = 0; i < signals.length; i++) {
+      signals[i].addEventListener('abort', () => {
+        result += i;
+      });
+    }
+    controller.abort();
+    assert_equals(result, "01234");
+  }, `Abort events for ${desc} signals fire in the right order ${suffix}`);
+}
diff --git a/testing/web-platform/tests/dom/attributes-are-nodes.html b/testing/web-platform/tests/dom/attributes-are-nodes.html
new file mode 100644
index 0000000000..54ff4ccaec
--- /dev/null
+++ b/testing/web-platform/tests/dom/attributes-are-nodes.html
@@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Attributes are Nodes but should not be accepted outside of the `attributes` NamedNodeMap</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-core-changes">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+
+  const attribute = document.createAttribute("newattribute");
+
+  assert_true(attribute instanceof Node, "attribute instances are instances of Node");
+  assert_true(Attr.prototype instanceof Node, "attribute instances are instances of Node");
+
+}, "Attrs are subclasses of Nodes");
+
+test(() => {
+
+  const parent = document.createElement("p");
+
+  const attribute = document.createAttribute("newattribute");
+  assert_throws_dom("HierarchyRequestError", () => {
+    parent.appendChild(attribute);
+  });
+
+}, "appendChild with an attribute as the child should fail");
+
+test(() => {
+
+  const parent = document.createElement("p");
+  parent.appendChild(document.createElement("span"));
+
+  const attribute = document.createAttribute("newattribute");
+  assert_throws_dom("HierarchyRequestError", () => {
+    parent.replaceChild(attribute, parent.firstChild);
+  });
+
+}, "replaceChild with an attribute as the child should fail");
+
+test(() => {
+
+  const parent = document.createElement("p");
+  parent.appendChild(document.createElement("span"));
+
+  const attribute = document.createAttribute("newattribute");
+  assert_throws_dom("HierarchyRequestError", () => {
+    parent.insertBefore(attribute, parent.firstChild);
+  });
+
+}, "insertBefore with an attribute as the child should fail");
+
+</script>
diff --git a/testing/web-platform/tests/dom/collections/HTMLCollection-as-prototype.html b/testing/web-platform/tests/dom/collections/HTMLCollection-as-prototype.html
new file mode 100644
index 0000000000..d572d35c04
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/HTMLCollection-as-prototype.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Objects whose prototype is an HTMLCollection</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+test(function() {
+  var obj = Object.create(document.getElementsByTagName("script"));
+  assert_throws_js(TypeError, function() {
+    obj.length;
+  });
+}, "HTMLCollection as a prototype should not allow getting .length on the base object")
+
+test(function() {
+  var element = document.createElement("p");
+  element.id = "named";
+  document.body.appendChild(element);
+  this.add_cleanup(function() { element.remove() });
+
+  var collection = document.getElementsByTagName("p");
+  assert_equals(collection.named, element);
+  var object = Object.create(collection);
+  assert_equals(object.named, element);
+  object.named = "foo";
+  assert_equals(object.named, "foo");
+  assert_equals(collection.named, element);
+}, "HTMLCollection as a prototype and setting own properties")
+</script>
diff --git a/testing/web-platform/tests/dom/collections/HTMLCollection-delete.html b/testing/web-platform/tests/dom/collections/HTMLCollection-delete.html
new file mode 100644
index 0000000000..99420d4319
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/HTMLCollection-delete.html
@@ -0,0 +1,45 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Deleting properties from HTMLCollection</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<i id=foo></i>
+<script>
+let c, expected;
+setup(() => {
+  // These might be cached anyway, so explicitly use a single object.
+  c = document.getElementsByTagName("i");
+  expected = document.getElementById("foo");
+});
+
+test(() => {
+  assert_equals(c[0], expected, "before");
+  delete c[0];
+  assert_equals(c[0], expected, "after");
+}, "Loose id");
+
+test(() => {
+  assert_equals(c[0], expected, "before");
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    delete c[0];
+  });
+  assert_equals(c[0], expected, "after");
+}, "Strict id");
+
+test(() => {
+  assert_equals(c.foo, expected, "before");
+  delete c.foo;
+  assert_equals(c.foo, expected, "after");
+}, "Loose name");
+
+test(() => {
+  assert_equals(c.foo, expected, "before");
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    delete c.foo;
+  });
+  assert_equals(c.foo, expected, "after");
+}, "Strict name");
+</script>
diff --git a/testing/web-platform/tests/dom/collections/HTMLCollection-empty-name.html b/testing/web-platform/tests/dom/collections/HTMLCollection-empty-name.html
new file mode 100644
index 0000000000..4fc34db7f5
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/HTMLCollection-empty-name.html
@@ -0,0 +1,65 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>HTMLCollection and empty names</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<div id=test>
+<div class=a id></div>
+<div class=a name></div>
+<a class=a name></a>
+</div>
+<script>
+test(function() {
+  var c = document.getElementsByTagName("*");
+  assert_false("" in c, "Empty string should not be in the collection.");
+  assert_equals(c[""], undefined, "Named getter should return undefined for empty string.");
+  assert_equals(c.namedItem(""), null, "namedItem should return null for empty string.");
+}, "Empty string as a name for Document.getElementsByTagName");
+
+test(function() {
+  var div = document.getElementById("test");
+  var c = div.getElementsByTagName("*");
+  assert_false("" in c, "Empty string should not be in the collection.");
+  assert_equals(c[""], undefined, "Named getter should return undefined for empty string.");
+  assert_equals(c.namedItem(""), null, "namedItem should return null for empty string.");
+}, "Empty string as a name for Element.getElementsByTagName");
+
+test(function() {
+  var c = document.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "a");
+  assert_false("" in c, "Empty string should not be in the collection.");
+  assert_equals(c[""], undefined, "Named getter should return undefined for empty string.");
+  assert_equals(c.namedItem(""), null, "namedItem should return null for empty string.");
+}, "Empty string as a name for Document.getElementsByTagNameNS");
+
+test(function() {
+  var div = document.getElementById("test");
+  var c = div.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "a");
+  assert_false("" in c, "Empty string should not be in the collection.");
+  assert_equals(c[""], undefined, "Named getter should return undefined for empty string.");
+  assert_equals(c.namedItem(""), null, "namedItem should return null for empty string.");
+}, "Empty string as a name for Element.getElementsByTagNameNS");
+
+test(function() {
+  var c = document.getElementsByClassName("a");
+  assert_false("" in c, "Empty string should not be in the collection.");
+  assert_equals(c[""], undefined, "Named getter should return undefined for empty string.");
+  assert_equals(c.namedItem(""), null, "namedItem should return null for empty string.");
+}, "Empty string as a name for Document.getElementsByClassName");
+
+test(function() {
+  var div = document.getElementById("test");
+  var c = div.getElementsByClassName("a");
+  assert_false("" in c, "Empty string should not be in the collection.");
+  assert_equals(c[""], undefined, "Named getter should return undefined for empty string.");
+  assert_equals(c.namedItem(""), null, "namedItem should return null for empty string.");
+}, "Empty string as a name for Element.getElementsByClassName");
+
+test(function() {
+  var div = document.getElementById("test");
+  var c = div.children;
+  assert_false("" in c, "Empty string should not be in the collection.");
+  assert_equals(c[""], undefined, "Named getter should return undefined for empty string.");
+  assert_equals(c.namedItem(""), null, "namedItem should return null for empty string.");
+}, "Empty string as a name for Element.children");
+</script>
diff --git a/testing/web-platform/tests/dom/collections/HTMLCollection-iterator.html b/testing/web-platform/tests/dom/collections/HTMLCollection-iterator.html
new file mode 100644
index 0000000000..6296fd1b2d
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/HTMLCollection-iterator.html
@@ -0,0 +1,45 @@
+<!doctype html>
+<meta charset="utf-8">
+<link rel="help" href="https://dom.spec.whatwg.org/#interface-htmlcollection">
+<link rel="help" href="https://webidl.spec.whatwg.org/#es-iterator">
+<title>HTMLCollection @@iterator Test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<p id="1"></p>
+<p id="2"></p>
+<p id="3"></p>
+<p id="4"></p>
+<p id="5"></p>
+<script>
+"use strict";
+
+const paragraphs = document.getElementsByTagName("p");
+
+test(() => {
+  assert_true("length" in paragraphs);
+}, "HTMLCollection has length method.");
+
+test(() => {
+  assert_false("values" in paragraphs);
+}, "HTMLCollection does not have iterable's values method.");
+
+test(() => {
+  assert_false("entries" in paragraphs);
+}, "HTMLCollection does not have iterable's entries method.");
+
+test(() => {
+  assert_false("forEach" in paragraphs);
+}, "HTMLCollection does not have iterable's forEach method.");
+
+test(() => {
+  assert_true(Symbol.iterator in paragraphs);
+}, "HTMLCollection has Symbol.iterator.");
+
+test(() => {
+  const ids = "12345";
+  let idx = 0;
+  for (const element of paragraphs) {
+    assert_equals(element.getAttribute("id"), ids[idx++]);
+  }
+}, "HTMLCollection is iterable via for-of loop.");
+</script>
diff --git a/testing/web-platform/tests/dom/collections/HTMLCollection-live-mutations.window.js b/testing/web-platform/tests/dom/collections/HTMLCollection-live-mutations.window.js
new file mode 100644
index 0000000000..7dbfc6ccf6
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/HTMLCollection-live-mutations.window.js
@@ -0,0 +1,93 @@
+function testHTMLCollection(name, hooks) {
+  test(() => {
+    const nodes = {
+      root: document.createElement("div"),
+      div1: document.createElement("div"),
+      div2: document.createElement("div"),
+      p: document.createElement("p")
+    };
+
+    nodes.div1.id = "div1";
+    nodes.div2.id = "div2";
+
+    const list = nodes.root.getElementsByTagName("div");
+
+    hooks.initial(list, nodes);
+
+    nodes.root.appendChild(nodes.div1);
+    nodes.root.appendChild(nodes.p);
+    nodes.root.appendChild(nodes.div2);
+
+    hooks.afterInsertion(list, nodes);
+
+    nodes.root.removeChild(nodes.div1);
+
+    hooks.afterRemoval(list, nodes);
+  }, `HTMLCollection live mutations: ${name}`);
+}
+
+testHTMLCollection("HTMLCollection.length", {
+  initial(list) {
+    assert_equals(list.length, 0);
+  },
+  afterInsertion(list) {
+    assert_equals(list.length, 2);
+  },
+  afterRemoval(list) {
+    assert_equals(list.length, 1);
+  }
+});
+
+testHTMLCollection("HTMLCollection.item(index)", {
+  initial(list) {
+    assert_equals(list.item(0), null);
+  },
+  afterInsertion(list, nodes) {
+    assert_equals(list.item(0), nodes.div1);
+    assert_equals(list.item(1), nodes.div2);
+  },
+  afterRemoval(list, nodes) {
+    assert_equals(list.item(0), nodes.div2);
+  }
+});
+
+testHTMLCollection("HTMLCollection[index]", {
+  initial(list) {
+    assert_equals(list[0], undefined);
+  },
+  afterInsertion(list, nodes) {
+    assert_equals(list[0], nodes.div1);
+    assert_equals(list[1], nodes.div2);
+  },
+  afterRemoval(list, nodes) {
+    assert_equals(list[0], nodes.div2);
+  }
+});
+
+testHTMLCollection("HTMLCollection.namedItem(index)", {
+  initial(list) {
+    assert_equals(list.namedItem("div1"), null);
+    assert_equals(list.namedItem("div2"), null);
+  },
+  afterInsertion(list, nodes) {
+    assert_equals(list.namedItem("div1"), nodes.div1);
+    assert_equals(list.namedItem("div2"), nodes.div2);
+  },
+  afterRemoval(list, nodes) {
+    assert_equals(list.namedItem("div1"), null);
+    assert_equals(list.namedItem("div2"), nodes.div2);
+  }
+});
+
+testHTMLCollection("HTMLCollection ownPropertyNames", {
+  initial(list) {
+    assert_object_equals(Object.getOwnPropertyNames(list), []);
+  },
+  afterInsertion(list) {
+    assert_object_equals(Object.getOwnPropertyNames(list), ["0", "1", "div1", "div2"]);
+  },
+  afterRemoval(list) {
+    assert_object_equals(Object.getOwnPropertyNames(list), ["0", "div2"]);
+  }
+});
+
diff --git a/testing/web-platform/tests/dom/collections/HTMLCollection-own-props.html b/testing/web-platform/tests/dom/collections/HTMLCollection-own-props.html
new file mode 100644
index 0000000000..99dc425dbe
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/HTMLCollection-own-props.html
@@ -0,0 +1,109 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>HTMLCollection getters and own properties</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+function append(t, tag, name) {
+  var element = document.createElement(tag);
+  if (name) {
+    element.id = name;
+  }
+  document.body.appendChild(element);
+  t.add_cleanup(function() { element.remove(); });
+  return element;
+}
+
+test(function() {
+  var name = "named", tag = "a";
+  var c = document.getElementsByTagName(tag);
+  var element = append(this, tag, name);
+  assert_equals(c[name], element);
+  c[name] = "foo";
+  assert_equals(c[name], element);
+}, "Setting non-array index while named property exists (loose)");
+
+test(function() {
+  "use strict";
+  var name = "named", tag = "b";
+  var c = document.getElementsByTagName(tag);
+  var element = append(this, tag, name);
+  assert_equals(c[name], element);
+  assert_throws_js(TypeError, function() {
+    c[name] = "foo";
+  });
+  assert_equals(c[name], element);
+}, "Setting non-array index while named property exists (strict)");
+
+test(function() {
+  var name = "named", tag = "i";
+  var c = document.getElementsByTagName(tag);
+  assert_equals(c[name], undefined);
+  c[name] = "foo";
+  assert_equals(c[name], "foo");
+
+  var element = append(this, tag, name);
+  assert_equals(c[name], "foo");
+  assert_equals(c.namedItem(name), element);
+}, "Setting non-array index while named property doesn't exist (loose)");
+
+test(function() {
+  "use strict";
+  var name = "named", tag = "p";
+  var c = document.getElementsByTagName(tag);
+  assert_equals(c[name], undefined);
+  c[name] = "foo";
+  assert_equals(c[name], "foo");
+
+  var element = append(this, tag, name);
+  assert_equals(c[name], "foo");
+  assert_equals(c.namedItem(name), element);
+}, "Setting non-array index while named property doesn't exist (strict)");
+
+test(function() {
+  var tag = "q";
+  var c = document.getElementsByTagName(tag);
+  var element = append(this, tag);
+  assert_equals(c[0], element);
+  c[0] = "foo";
+  assert_equals(c[0], element);
+}, "Setting array index while indexed property exists (loose)");
+
+test(function() {
+  "use strict";
+  var tag = "s";
+  var c = document.getElementsByTagName(tag);
+  var element = append(this, tag);
+  assert_equals(c[0], element);
+  assert_throws_js(TypeError, function() {
+    c[0] = "foo";
+  });
+  assert_equals(c[0], element);
+}, "Setting array index while indexed property exists (strict)");
+
+test(function() {
+  var tag = "u";
+  var c = document.getElementsByTagName(tag);
+  assert_equals(c[0], undefined);
+  c[0] = "foo";
+  assert_equals(c[0], undefined);
+
+  var element = append(this, tag);
+  assert_equals(c[0], element);
+}, "Setting array index while indexed property doesn't exist (loose)");
+
+test(function() {
+  "use strict";
+  var tag = "u";
+  var c = document.getElementsByTagName(tag);
+  assert_equals(c[0], undefined);
+  assert_throws_js(TypeError, function() {
+    c[0] = "foo";
+  });
+  assert_equals(c[0], undefined);
+
+  var element = append(this, tag);
+  assert_equals(c[0], element);
+}, "Setting array index while indexed property doesn't exist (strict)");
+</script>
diff --git a/testing/web-platform/tests/dom/collections/HTMLCollection-supported-property-indices.html b/testing/web-platform/tests/dom/collections/HTMLCollection-supported-property-indices.html
new file mode 100644
index 0000000000..5339ec31ea
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/HTMLCollection-supported-property-indices.html
@@ -0,0 +1,179 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<!-- We want to use a tag name that will not interact with our test harness,
+     so just make one up.  "foo" is a good one -->
+
+<!-- Ids that look like negative indices.  These should come first, so we can
+     assert that lookups for nonnegative indices find these by index -->
+<foo id="-2"></foo>
+<foo id="-1"></foo>
+
+<!-- Ids that look like nonnegative indices -->
+<foo id="0"></foo>
+<foo id="1"></foo>
+
+<!-- Ids that look like nonnegative indices near 2^31 = 2147483648 -->
+<foo id="2147483645"></foo> <!-- 2^31 - 3 -->
+<foo id="2147483646"></foo> <!-- 2^31 - 2 -->
+<foo id="2147483647"></foo> <!-- 2^31 - 1 -->
+<foo id="2147483648"></foo> <!-- 2^31 -->
+<foo id="2147483649"></foo> <!-- 2^31 + 1 -->
+
+<!-- Ids that look like nonnegative indices near 2^32 = 4294967296 -->
+<foo id="4294967293"></foo> <!-- 2^32 - 3 -->
+<foo id="4294967294"></foo> <!-- 2^32 - 2 -->
+<foo id="4294967295"></foo> <!-- 2^32 - 1 -->
+<foo id="4294967296"></foo> <!-- 2^32 -->
+<foo id="4294967297"></foo> <!-- 2^32 + 1 -->
+
+<script>
+test(function() {
+  var collection = document.getElementsByTagName("foo");
+  assert_equals(collection.item(-2), null);
+  assert_equals(collection.item(-1), null);
+  assert_equals(collection.namedItem(-2), document.getElementById("-2"));
+  assert_equals(collection.namedItem(-1), document.getElementById("-1"));
+  assert_equals(collection[-2], document.getElementById("-2"));
+  assert_equals(collection[-1], document.getElementById("-1"));
+}, "Handling of property names that look like negative integers");
+
+test(function() {
+  var collection = document.getElementsByTagName("foo");
+  assert_equals(collection.item(0), document.getElementById("-2"));
+  assert_equals(collection.item(1), document.getElementById("-1"));
+  assert_equals(collection.namedItem(0), document.getElementById("0"));
+  assert_equals(collection.namedItem(1), document.getElementById("1"));
+  assert_equals(collection[0], document.getElementById("-2"));
+  assert_equals(collection[1], document.getElementById("-1"));
+}, "Handling of property names that look like small nonnegative integers");
+
+test(function() {
+  var collection = document.getElementsByTagName("foo");
+  assert_equals(collection.item(2147483645), null);
+  assert_equals(collection.item(2147483646), null);
+  assert_equals(collection.item(2147483647), null);
+  assert_equals(collection.item(2147483648), null);
+  assert_equals(collection.item(2147483649), null);
+  assert_equals(collection.namedItem(2147483645),
+                document.getElementById("2147483645"));
+  assert_equals(collection.namedItem(2147483646),
+                document.getElementById("2147483646"));
+  assert_equals(collection.namedItem(2147483647),
+                document.getElementById("2147483647"));
+  assert_equals(collection.namedItem(2147483648),
+                document.getElementById("2147483648"));
+  assert_equals(collection.namedItem(2147483649),
+                document.getElementById("2147483649"));
+  assert_equals(collection[2147483645], undefined);
+  assert_equals(collection[2147483646], undefined);
+  assert_equals(collection[2147483647], undefined);
+  assert_equals(collection[2147483648], undefined);
+  assert_equals(collection[2147483649], undefined);
+}, "Handling of property names that look like integers around 2^31");
+
+test(function() {
+  var collection = document.getElementsByTagName("foo");
+  assert_equals(collection.item(4294967293), null);
+  assert_equals(collection.item(4294967294), null);
+  assert_equals(collection.item(4294967295), null);
+  assert_equals(collection.item(4294967296), document.getElementById("-2"));
+  assert_equals(collection.item(4294967297), document.getElementById("-1"));
+  assert_equals(collection.namedItem(4294967293),
+                document.getElementById("4294967293"));
+  assert_equals(collection.namedItem(4294967294),
+                document.getElementById("4294967294"));
+  assert_equals(collection.namedItem(4294967295),
+                document.getElementById("4294967295"));
+  assert_equals(collection.namedItem(4294967296),
+                document.getElementById("4294967296"));
+  assert_equals(collection.namedItem(4294967297),
+                document.getElementById("4294967297"));
+  assert_equals(collection[4294967293], undefined);
+  assert_equals(collection[4294967294], undefined);
+  assert_equals(collection[4294967295], document.getElementById("4294967295"));
+  assert_equals(collection[4294967296], document.getElementById("4294967296"));
+  assert_equals(collection[4294967297], document.getElementById("4294967297"));
+}, "Handling of property names that look like integers around 2^32");
+
+test(function() {
+  var elements = document.getElementsByTagName("foo");
+  var old_item = elements[0];
+  var old_desc = Object.getOwnPropertyDescriptor(elements, 0);
+  assert_equals(old_desc.value, old_item);
+  assert_true(old_desc.enumerable);
+  assert_true(old_desc.configurable);
+  assert_false(old_desc.writable);
+
+  elements[0] = 5;
+  assert_equals(elements[0], old_item);
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    elements[0] = 5;
+  });
+  assert_throws_js(TypeError, function() {
+    Object.defineProperty(elements, 0, { value: 5 });
+  });
+
+  delete elements[0];
+  assert_equals(elements[0], old_item);
+
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    delete elements[0];
+  });
+  assert_equals(elements[0], old_item);
+}, 'Trying to set an expando that would shadow an already-existing indexed property');
+
+test(function() {
+  var elements = document.getElementsByTagName("foo");
+  var idx = elements.length;
+  var old_item = elements[idx];
+  var old_desc = Object.getOwnPropertyDescriptor(elements, idx);
+  assert_equals(old_item, undefined);
+  assert_equals(old_desc, undefined);
+
+  // [[DefineOwnProperty]] will disallow defining an indexed expando.
+  elements[idx] = 5;
+  assert_equals(elements[idx], undefined);
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    elements[idx] = 5;
+  });
+  assert_throws_js(TypeError, function() {
+    Object.defineProperty(elements, idx, { value: 5 });
+  });
+
+  // Check that deletions out of range do not throw
+  delete elements[idx];
+  (function() {
+    "use strict";
+    delete elements[idx];
+  })();
+}, 'Trying to set an expando with an indexed property name past the end of the list');
+
+test(function(){
+  var elements = document.getElementsByTagName("foo");
+  var old_item = elements[0];
+  var old_desc = Object.getOwnPropertyDescriptor(elements, 0);
+  assert_equals(old_desc.value, old_item);
+  assert_true(old_desc.enumerable);
+  assert_true(old_desc.configurable);
+  assert_false(old_desc.writable);
+
+  Object.prototype[0] = 5;
+  this.add_cleanup(function () { delete Object.prototype[0]; });
+  assert_equals(elements[0], old_item);
+
+  delete elements[0];
+  assert_equals(elements[0], old_item);
+
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    delete elements[0];
+  });
+  assert_equals(elements[0], old_item);
+}, 'Trying to delete an indexed property name should never work');
+</script>
diff --git a/testing/web-platform/tests/dom/collections/HTMLCollection-supported-property-names.html b/testing/web-platform/tests/dom/collections/HTMLCollection-supported-property-names.html
new file mode 100644
index 0000000000..3d21e16692
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/HTMLCollection-supported-property-names.html
@@ -0,0 +1,135 @@
+<!doctype html>
+<meta charset=utf-8>
+<link rel=help href=https://dom.spec.whatwg.org/#interface-htmlcollection>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+
+<div id=log></div>
+
+<!-- with no attribute -->
+<span></span>
+
+<!-- with `id` attribute -->
+<span id=''></span>
+<span id='some-id'></span>
+<span id='some-id'></span><!-- to ensure no duplicates -->
+
+<!-- with `name` attribute -->
+<span name=''></span>
+<span name='some-name'></span>
+<span name='some-name'></span><!-- to ensure no duplicates -->
+
+<!-- with `name` and `id` attribute -->
+<span id='another-id' name='another-name'></span>
+
+<script>
+test(function () {
+  var elements = document.getElementsByTagName("span");
+  assert_array_equals(
+    Object.getOwnPropertyNames(elements),
+    ['0', '1', '2', '3', '4', '5', '6', '7', 'some-id', 'some-name', 'another-id', 'another-name']
+  );
+}, 'Object.getOwnPropertyNames on HTMLCollection');
+
+test(function () {
+  var elem = document.createElementNS('some-random-namespace', 'foo');
+  this.add_cleanup(function () {elem.remove();});
+  elem.setAttribute("name", "some-name");
+  document.body.appendChild(elem);
+
+  var elements = document.getElementsByTagName("foo");
+  assert_array_equals(Object.getOwnPropertyNames(elements), ['0']);
+}, 'Object.getOwnPropertyNames on HTMLCollection with non-HTML namespace');
+
+test(function () {
+  var elem = document.createElement('foo');
+  this.add_cleanup(function () {elem.remove();});
+  document.body.appendChild(elem);
+
+  var elements = document.getElementsByTagName("foo");
+  elements.someProperty = "some value";
+
+  assert_array_equals(Object.getOwnPropertyNames(elements), ['0', 'someProperty']);
+}, 'Object.getOwnPropertyNames on HTMLCollection with expando object');
+
+test(function() {
+  var elements = document.getElementsByTagName("span");
+  var old_item = elements["some-id"];
+  var old_desc = Object.getOwnPropertyDescriptor(elements, "some-id");
+  assert_equals(old_desc.value, old_item);
+  assert_false(old_desc.enumerable);
+  assert_true(old_desc.configurable);
+  assert_false(old_desc.writable);
+
+  elements["some-id"] = 5;
+  assert_equals(elements["some-id"], old_item);
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    elements["some-id"] = 5;
+  });
+  assert_throws_js(TypeError, function() {
+    Object.defineProperty(elements, "some-id", { value: 5 });
+  });
+
+  delete elements["some-id"];
+  assert_equals(elements["some-id"], old_item);
+
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    delete elements["some-id"];
+  });
+  assert_equals(elements["some-id"], old_item);
+
+}, 'Trying to set an expando that would shadow an already-existing named property');
+
+test(function() {
+  var elements = document.getElementsByTagName("span");
+  var old_item = elements["new-id"];
+  var old_desc = Object.getOwnPropertyDescriptor(elements, "new-id");
+  assert_equals(old_item, undefined);
+  assert_equals(old_desc, undefined);
+
+  elements["new-id"] = 5;
+  assert_equals(elements["new-id"], 5);
+
+  var span = document.createElement("span");
+  this.add_cleanup(function () {span.remove();});
+  span.id = "new-id";
+  document.body.appendChild(span);
+
+  assert_equals(elements.namedItem("new-id"), span);
+  assert_equals(elements["new-id"], 5);
+
+  delete elements["new-id"];
+  assert_equals(elements["new-id"], span);
+}, 'Trying to set an expando that shadows a named property that gets added later');
+
+test(function() {
+  var elements = document.getElementsByTagName("span");
+  var old_item = elements["new-id2"];
+  var old_desc = Object.getOwnPropertyDescriptor(elements, "new-id2");
+  assert_equals(old_item, undefined);
+  assert_equals(old_desc, undefined);
+
+  Object.defineProperty(elements, "new-id2", { configurable: false, writable:
+                                              false, value: 5 });
+  assert_equals(elements["new-id2"], 5);
+
+  var span = document.createElement("span");
+  this.add_cleanup(function () {span.remove();});
+  span.id = "new-id2";
+  document.body.appendChild(span);
+
+  assert_equals(elements.namedItem("new-id2"), span);
+  assert_equals(elements["new-id2"], 5);
+
+  delete elements["new-id2"];
+  assert_equals(elements["new-id2"], 5);
+
+  assert_throws_js(TypeError, function() {
+    "use strict";
+    delete elements["new-id2"];
+  });
+  assert_equals(elements["new-id2"], 5);
+}, 'Trying to set a non-configurable expando that shadows a named property that gets added later');
+</script>
diff --git a/testing/web-platform/tests/dom/collections/domstringmap-supported-property-names.html b/testing/web-platform/tests/dom/collections/domstringmap-supported-property-names.html
new file mode 100644
index 0000000000..430aa44c3a
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/domstringmap-supported-property-names.html
@@ -0,0 +1,54 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>DOMStringMap Test: Supported property names</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+
+<div id="edge1" data-="012">Simple</div>
+
+<div id="edge2" data-id-="012">Simple</div>
+
+<div id="user" data-id="1234567890" data-user="johndoe" data-date-of-birth>
+    John Doe
+</div>
+
+<div id="user2" data-unique-id="1234567890"> Jane Doe </div>
+
+<div id="user3" data-unique-id="4324324241"> Jim Doe </div>
+
+<script>
+
+test(function() {
+    var element = document.querySelector('#edge1');
+    assert_array_equals(Object.getOwnPropertyNames(element.dataset),
+        [""]);
+}, "Object.getOwnPropertyNames on DOMStringMap, empty data attribute");
+
+test(function() {
+    var element = document.querySelector('#edge2');
+    assert_array_equals(Object.getOwnPropertyNames(element.dataset),
+        ["id-"]);
+}, "Object.getOwnPropertyNames on DOMStringMap, data attribute trailing hyphen");
+
+test(function() {
+    var element = document.querySelector('#user');
+    assert_array_equals(Object.getOwnPropertyNames(element.dataset),
+        ['id', 'user', 'dateOfBirth']);
+}, "Object.getOwnPropertyNames on DOMStringMap, multiple data attributes");
+
+test(function() {
+    var element = document.querySelector('#user2');
+    element.dataset.middleName = "mark";
+    assert_array_equals(Object.getOwnPropertyNames(element.dataset),
+        ['uniqueId', 'middleName']);
+}, "Object.getOwnPropertyNames on DOMStringMap, attribute set on dataset in JS");
+
+test(function() {
+    var element = document.querySelector('#user3');
+    element.setAttribute("data-age", 30);
+    assert_array_equals(Object.getOwnPropertyNames(element.dataset),
+        ['uniqueId', 'age']);
+}, "Object.getOwnPropertyNames on DOMStringMap, attribute set on element in JS");
+
+</script>
diff --git a/testing/web-platform/tests/dom/collections/namednodemap-supported-property-names.html b/testing/web-platform/tests/dom/collections/namednodemap-supported-property-names.html
new file mode 100644
index 0000000000..2c5dee4efd
--- /dev/null
+++ b/testing/web-platform/tests/dom/collections/namednodemap-supported-property-names.html
@@ -0,0 +1,30 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>NamedNodeMap Test: Supported property names</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="simple" class="fancy">Simple</div>
+<input id="result" type="text" value="" width="200px">
+<script>
+
+test(function() {
+    var elt = document.querySelector('#simple');
+    assert_array_equals(Object.getOwnPropertyNames(elt.attributes),
+        ['0','1','id','class']);
+}, "Object.getOwnPropertyNames on NamedNodeMap");
+
+test(function() {
+    var result = document.getElementById("result");
+    assert_array_equals(Object.getOwnPropertyNames(result.attributes),
+        ['0','1','2','3','id','type','value','width']);
+}, "Object.getOwnPropertyNames on NamedNodeMap of input");
+
+test(function() {
+    var result = document.getElementById("result");
+    result.removeAttribute("width");
+    assert_array_equals(Object.getOwnPropertyNames(result.attributes),
+        ['0','1','2','id','type','value']);
+}, "Object.getOwnPropertyNames on NamedNodeMap after attribute removal");
+
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/common.js b/testing/web-platform/tests/dom/common.js
new file mode 100644
index 0000000000..70367b2eff
--- /dev/null
+++ b/testing/web-platform/tests/dom/common.js
@@ -0,0 +1,1083 @@
+"use strict";
+// Written by Aryeh Gregor <ayg@aryeh.name>
+
+// TODO: iframes, contenteditable/designMode
+
+// Everything is done in functions in this test harness, so we have to declare
+// all the variables before use to make sure they can be reused.
+var testDiv, paras, detachedDiv, detachedPara1, detachedPara2,
+    foreignDoc, foreignPara1, foreignPara2, xmlDoc, xmlElement,
+    detachedXmlElement, detachedTextNode, foreignTextNode,
+    detachedForeignTextNode, xmlTextNode, detachedXmlTextNode,
+    processingInstruction, detachedProcessingInstruction, comment,
+    detachedComment, foreignComment, detachedForeignComment, xmlComment,
+    detachedXmlComment, docfrag, foreignDocfrag, xmlDocfrag, doctype,
+    foreignDoctype, xmlDoctype;
+var testRangesShort, testRanges, testPoints, testNodesShort, testNodes;
+
+function setupRangeTests() {
+    testDiv = document.querySelector("#test");
+    if (testDiv) {
+        testDiv.parentNode.removeChild(testDiv);
+    }
+    testDiv = document.createElement("div");
+    testDiv.id = "test";
+    document.body.insertBefore(testDiv, document.body.firstChild);
+
+    paras = [];
+    paras.push(document.createElement("p"));
+    paras[0].setAttribute("id", "a");
+    // Test some diacritics, to make sure browsers are using code units here
+    // and not something like grapheme clusters.
+    paras[0].textContent = "A\u0308b\u0308c\u0308d\u0308e\u0308f\u0308g\u0308h\u0308\n";
+    testDiv.appendChild(paras[0]);
+
+    paras.push(document.createElement("p"));
+    paras[1].setAttribute("id", "b");
+    paras[1].setAttribute("style", "display:none");
+    paras[1].textContent = "Ijklmnop\n";
+    testDiv.appendChild(paras[1]);
+
+    paras.push(document.createElement("p"));
+    paras[2].setAttribute("id", "c");
+    paras[2].textContent = "Qrstuvwx";
+    testDiv.appendChild(paras[2]);
+
+    paras.push(document.createElement("p"));
+    paras[3].setAttribute("id", "d");
+    paras[3].setAttribute("style", "display:none");
+    paras[3].textContent = "Yzabcdef";
+    testDiv.appendChild(paras[3]);
+
+    paras.push(document.createElement("p"));
+    paras[4].setAttribute("id", "e");
+    paras[4].setAttribute("style", "display:none");
+    paras[4].textContent = "Ghijklmn";
+    testDiv.appendChild(paras[4]);
+
+    detachedDiv = document.createElement("div");
+    detachedPara1 = document.createElement("p");
+    detachedPara1.appendChild(document.createTextNode("Opqrstuv"));
+    detachedPara2 = document.createElement("p");
+    detachedPara2.appendChild(document.createTextNode("Wxyzabcd"));
+    detachedDiv.appendChild(detachedPara1);
+    detachedDiv.appendChild(detachedPara2);
+
+    // Opera doesn't automatically create a doctype for a new HTML document,
+    // contrary to spec.  It also doesn't let you add doctypes to documents
+    // after the fact through any means I've tried.  So foreignDoc in Opera
+    // will have no doctype, foreignDoctype will be null, and Opera will fail
+    // some tests somewhat mysteriously as a result.
+    foreignDoc = document.implementation.createHTMLDocument("");
+    foreignPara1 = foreignDoc.createElement("p");
+    foreignPara1.appendChild(foreignDoc.createTextNode("Efghijkl"));
+    foreignPara2 = foreignDoc.createElement("p");
+    foreignPara2.appendChild(foreignDoc.createTextNode("Mnopqrst"));
+    foreignDoc.body.appendChild(foreignPara1);
+    foreignDoc.body.appendChild(foreignPara2);
+
+    // Now we get to do really silly stuff, which nobody in the universe is
+    // ever going to actually do, but the spec defines behavior, so too bad.
+    // Testing is fun!
+    xmlDoctype = document.implementation.createDocumentType("qorflesnorf", "abcde", "x\"'y");
+    xmlDoc = document.implementation.createDocument(null, null, xmlDoctype);
+    detachedXmlElement = xmlDoc.createElement("everyone-hates-hyphenated-element-names");
+    detachedTextNode = document.createTextNode("Uvwxyzab");
+    detachedForeignTextNode = foreignDoc.createTextNode("Cdefghij");
+    detachedXmlTextNode = xmlDoc.createTextNode("Klmnopqr");
+    // PIs only exist in XML documents, so don't bother with document or
+    // foreignDoc.
+    detachedProcessingInstruction = xmlDoc.createProcessingInstruction("whippoorwill", "chirp chirp chirp");
+    detachedComment = document.createComment("Stuvwxyz");
+    // Hurrah, we finally got to "z" at the end!
+    detachedForeignComment = foreignDoc.createComment("אריה יהודה");
+    detachedXmlComment = xmlDoc.createComment("בן חיים אליעזר");
+
+    // We should also test with document fragments that actually contain stuff
+    // . . . but, maybe later.
+    docfrag = document.createDocumentFragment();
+    foreignDocfrag = foreignDoc.createDocumentFragment();
+    xmlDocfrag = xmlDoc.createDocumentFragment();
+
+    xmlElement = xmlDoc.createElement("igiveuponcreativenames");
+    xmlTextNode = xmlDoc.createTextNode("do re mi fa so la ti");
+    xmlElement.appendChild(xmlTextNode);
+    processingInstruction = xmlDoc.createProcessingInstruction("somePI", 'Did you know that ":syn sync fromstart" is very useful when using vim to edit large amounts of JavaScript embedded in HTML?');
+    xmlDoc.appendChild(xmlElement);
+    xmlDoc.appendChild(processingInstruction);
+    xmlComment = xmlDoc.createComment("I maliciously created a comment that will break incautious XML serializers, but Firefox threw an exception, so all I got was this lousy T-shirt");
+    xmlDoc.appendChild(xmlComment);
+
+    comment = document.createComment("Alphabet soup?");
+    testDiv.appendChild(comment);
+
+    foreignComment = foreignDoc.createComment('"Commenter" and "commentator" mean different things.  I\'ve seen non-native speakers trip up on this.');
+    foreignDoc.appendChild(foreignComment);
+    foreignTextNode = foreignDoc.createTextNode("I admit that I harbor doubts about whether we really need so many things to test, but it's too late to stop now.");
+    foreignDoc.body.appendChild(foreignTextNode);
+
+    doctype = document.doctype;
+    foreignDoctype = foreignDoc.doctype;
+
+    testRangesShort = [
+        // Various ranges within the text node children of different
+        // paragraphs.  All should be valid.
+        "[paras[0].firstChild, 0, paras[0].firstChild, 0]",
+        "[paras[0].firstChild, 0, paras[0].firstChild, 1]",
+        "[paras[0].firstChild, 2, paras[0].firstChild, 8]",
+        "[paras[0].firstChild, 2, paras[0].firstChild, 9]",
+        "[paras[1].firstChild, 0, paras[1].firstChild, 0]",
+        "[paras[1].firstChild, 2, paras[1].firstChild, 9]",
+        "[detachedPara1.firstChild, 0, detachedPara1.firstChild, 0]",
+        "[detachedPara1.firstChild, 2, detachedPara1.firstChild, 8]",
+        "[foreignPara1.firstChild, 0, foreignPara1.firstChild, 0]",
+        "[foreignPara1.firstChild, 2, foreignPara1.firstChild, 8]",
+        // Now try testing some elements, not just text nodes.
+        "[document.documentElement, 0, document.documentElement, 1]",
+        "[document.documentElement, 0, document.documentElement, 2]",
+        "[document.documentElement, 1, document.documentElement, 2]",
+        "[document.head, 1, document.head, 1]",
+        "[document.body, 4, document.body, 5]",
+        "[foreignDoc.documentElement, 0, foreignDoc.documentElement, 1]",
+        "[paras[0], 0, paras[0], 1]",
+        "[detachedPara1, 0, detachedPara1, 1]",
+        // Now try some ranges that span elements.
+        "[paras[0].firstChild, 0, paras[1].firstChild, 0]",
+        "[paras[0].firstChild, 0, paras[1].firstChild, 8]",
+        "[paras[0].firstChild, 3, paras[3], 1]",
+        // How about something that spans a node and its descendant?
+        "[paras[0], 0, paras[0].firstChild, 7]",
+        "[testDiv, 2, paras[4], 1]",
+        // Then a few more interesting things just for good measure.
+        "[document, 0, document, 1]",
+        "[document, 0, document, 2]",
+        "[comment, 2, comment, 3]",
+        "[testDiv, 0, comment, 5]",
+        "[foreignDoc, 1, foreignComment, 2]",
+        "[foreignDoc.body, 0, foreignTextNode, 36]",
+        "[xmlDoc, 1, xmlComment, 0]",
+        "[detachedTextNode, 0, detachedTextNode, 8]",
+        "[detachedForeignTextNode, 0, detachedForeignTextNode, 8]",
+        "[detachedXmlTextNode, 0, detachedXmlTextNode, 8]",
+        "[detachedComment, 3, detachedComment, 4]",
+        "[detachedForeignComment, 0, detachedForeignComment, 1]",
+        "[detachedXmlComment, 2, detachedXmlComment, 6]",
+        "[docfrag, 0, docfrag, 0]",
+        "[processingInstruction, 0, processingInstruction, 4]",
+    ];
+
+    testRanges = testRangesShort.concat([
+        "[paras[1].firstChild, 0, paras[1].firstChild, 1]",
+        "[paras[1].firstChild, 2, paras[1].firstChild, 8]",
+        "[detachedPara1.firstChild, 0, detachedPara1.firstChild, 1]",
+        "[foreignPara1.firstChild, 0, foreignPara1.firstChild, 1]",
+        "[foreignDoc.head, 1, foreignDoc.head, 1]",
+        "[foreignDoc.body, 0, foreignDoc.body, 0]",
+        "[paras[0], 0, paras[0], 0]",
+        "[detachedPara1, 0, detachedPara1, 0]",
+        "[testDiv, 1, paras[2].firstChild, 5]",
+        "[document.documentElement, 1, document.body, 0]",
+        "[foreignDoc.documentElement, 1, foreignDoc.body, 0]",
+        "[document, 1, document, 2]",
+        "[paras[2].firstChild, 4, comment, 2]",
+        "[paras[3], 1, comment, 8]",
+        "[foreignDoc, 0, foreignDoc, 0]",
+        "[xmlDoc, 0, xmlDoc, 0]",
+        "[detachedForeignTextNode, 7, detachedForeignTextNode, 7]",
+        "[detachedXmlTextNode, 7, detachedXmlTextNode, 7]",
+        "[detachedComment, 5, detachedComment, 5]",
+        "[detachedForeignComment, 4, detachedForeignComment, 4]",
+        "[foreignDocfrag, 0, foreignDocfrag, 0]",
+        "[xmlDocfrag, 0, xmlDocfrag, 0]",
+    ]);
+
+    testPoints = [
+        // Various positions within the page, some invalid.  Remember that
+        // paras[0] is visible, and paras[1] is display: none.
+        "[paras[0].firstChild, -1]",
+        "[paras[0].firstChild, 0]",
+        "[paras[0].firstChild, 1]",
+        "[paras[0].firstChild, 2]",
+        "[paras[0].firstChild, 8]",
+        "[paras[0].firstChild, 9]",
+        "[paras[0].firstChild, 10]",
+        "[paras[0].firstChild, 65535]",
+        "[paras[1].firstChild, -1]",
+        "[paras[1].firstChild, 0]",
+        "[paras[1].firstChild, 1]",
+        "[paras[1].firstChild, 2]",
+        "[paras[1].firstChild, 8]",
+        "[paras[1].firstChild, 9]",
+        "[paras[1].firstChild, 10]",
+        "[paras[1].firstChild, 65535]",
+        "[detachedPara1.firstChild, 0]",
+        "[detachedPara1.firstChild, 1]",
+        "[detachedPara1.firstChild, 8]",
+        "[detachedPara1.firstChild, 9]",
+        "[foreignPara1.firstChild, 0]",
+        "[foreignPara1.firstChild, 1]",
+        "[foreignPara1.firstChild, 8]",
+        "[foreignPara1.firstChild, 9]",
+        // Now try testing some elements, not just text nodes.
+        "[document.documentElement, -1]",
+        "[document.documentElement, 0]",
+        "[document.documentElement, 1]",
+        "[document.documentElement, 2]",
+        "[document.documentElement, 7]",
+        "[document.head, 1]",
+        "[document.body, 3]",
+        "[foreignDoc.documentElement, 0]",
+        "[foreignDoc.documentElement, 1]",
+        "[foreignDoc.head, 0]",
+        "[foreignDoc.body, 1]",
+        "[paras[0], 0]",
+        "[paras[0], 1]",
+        "[paras[0], 2]",
+        "[paras[1], 0]",
+        "[paras[1], 1]",
+        "[paras[1], 2]",
+        "[detachedPara1, 0]",
+        "[detachedPara1, 1]",
+        "[testDiv, 0]",
+        "[testDiv, 3]",
+        // Then a few more interesting things just for good measure.
+        "[document, -1]",
+        "[document, 0]",
+        "[document, 1]",
+        "[document, 2]",
+        "[document, 3]",
+        "[comment, -1]",
+        "[comment, 0]",
+        "[comment, 4]",
+        "[comment, 96]",
+        "[foreignDoc, 0]",
+        "[foreignDoc, 1]",
+        "[foreignComment, 2]",
+        "[foreignTextNode, 0]",
+        "[foreignTextNode, 36]",
+        "[xmlDoc, -1]",
+        "[xmlDoc, 0]",
+        "[xmlDoc, 1]",
+        "[xmlDoc, 5]",
+        "[xmlComment, 0]",
+        "[xmlComment, 4]",
+        "[processingInstruction, 0]",
+        "[processingInstruction, 5]",
+        "[processingInstruction, 9]",
+        "[detachedTextNode, 0]",
+        "[detachedTextNode, 8]",
+        "[detachedForeignTextNode, 0]",
+        "[detachedForeignTextNode, 8]",
+        "[detachedXmlTextNode, 0]",
+        "[detachedXmlTextNode, 8]",
+        "[detachedProcessingInstruction, 12]",
+        "[detachedComment, 3]",
+        "[detachedComment, 5]",
+        "[detachedForeignComment, 0]",
+        "[detachedForeignComment, 4]",
+        "[detachedXmlComment, 2]",
+        "[docfrag, 0]",
+        "[foreignDocfrag, 0]",
+        "[xmlDocfrag, 0]",
+        "[doctype, 0]",
+        "[doctype, -17]",
+        "[doctype, 1]",
+        "[foreignDoctype, 0]",
+        "[xmlDoctype, 0]",
+    ];
+
+    testNodesShort = [
+        "paras[0]",
+        "paras[0].firstChild",
+        "paras[1].firstChild",
+        "foreignPara1",
+        "foreignPara1.firstChild",
+        "detachedPara1",
+        "detachedPara1.firstChild",
+        "document",
+        "detachedDiv",
+        "foreignDoc",
+        "foreignPara2",
+        "xmlDoc",
+        "xmlElement",
+        "detachedTextNode",
+        "foreignTextNode",
+        "processingInstruction",
+        "detachedProcessingInstruction",
+        "comment",
+        "detachedComment",
+        "docfrag",
+        "doctype",
+        "foreignDoctype",
+    ];
+
+    testNodes = testNodesShort.concat([
+        "paras[1]",
+        "detachedPara2",
+        "detachedPara2.firstChild",
+        "testDiv",
+        "detachedXmlElement",
+        "detachedForeignTextNode",
+        "xmlTextNode",
+        "detachedXmlTextNode",
+        "xmlComment",
+        "foreignComment",
+        "detachedForeignComment",
+        "detachedXmlComment",
+        "foreignDocfrag",
+        "xmlDocfrag",
+        "xmlDoctype",
+    ]);
+}
+if ("setup" in window) {
+    setup(setupRangeTests);
+} else {
+    // Presumably we're running from within an iframe or something
+    setupRangeTests();
+}
+
+/**
+ * The "length" of a node as defined by the Ranges section of DOM4.
+ */
+function nodeLength(node) {
+    // "The length of a node node depends on node:
+    //
+    // "DocumentType
+    //   "0."
+    if (node.nodeType == Node.DOCUMENT_TYPE_NODE) {
+        return 0;
+    }
+    // "Text
+    // "ProcessingInstruction
+    // "Comment
+    //   "Its length attribute value."
+    // Browsers don't historically support the length attribute on
+    // ProcessingInstruction, so to avoid spurious failures, do
+    // node.data.length instead of node.length.
+    if (node.nodeType == Node.TEXT_NODE || node.nodeType == Node.PROCESSING_INSTRUCTION_NODE || node.nodeType == Node.COMMENT_NODE) {
+        return node.data.length;
+    }
+    // "Any other node
+    //   "Its number of children."
+    return node.childNodes.length;
+}
+
+/**
+ * Returns the furthest ancestor of a Node as defined by the spec.
+ */
+function furthestAncestor(node) {
+    var root = node;
+    while (root.parentNode != null) {
+        root = root.parentNode;
+    }
+    return root;
+}
+
+/**
+ * "The ancestor containers of a Node are the Node itself and all its
+ * ancestors."
+ *
+ * Is node1 an ancestor container of node2?
+ */
+function isAncestorContainer(node1, node2) {
+    return node1 == node2 ||
+        (node2.compareDocumentPosition(node1) & Node.DOCUMENT_POSITION_CONTAINS);
+}
+
+/**
+ * Returns the first Node that's after node in tree order, or null if node is
+ * the last Node.
+ */
+function nextNode(node) {
+    if (node.hasChildNodes()) {
+        return node.firstChild;
+    }
+    return nextNodeDescendants(node);
+}
+
+/**
+ * Returns the last Node that's before node in tree order, or null if node is
+ * the first Node.
+ */
+function previousNode(node) {
+    if (node.previousSibling) {
+        node = node.previousSibling;
+        while (node.hasChildNodes()) {
+            node = node.lastChild;
+        }
+        return node;
+    }
+    return node.parentNode;
+}
+
+/**
+ * Returns the next Node that's after node and all its descendants in tree
+ * order, or null if node is the last Node or an ancestor of it.
+ */
+function nextNodeDescendants(node) {
+    while (node && !node.nextSibling) {
+        node = node.parentNode;
+    }
+    if (!node) {
+        return null;
+    }
+    return node.nextSibling;
+}
+
+/**
+ * Returns the ownerDocument of the Node, or the Node itself if it's a
+ * Document.
+ */
+function ownerDocument(node) {
+    return node.nodeType == Node.DOCUMENT_NODE
+        ? node
+        : node.ownerDocument;
+}
+
+/**
+ * Returns true if ancestor is an ancestor of descendant, false otherwise.
+ */
+function isAncestor(ancestor, descendant) {
+    if (!ancestor || !descendant) {
+        return false;
+    }
+    while (descendant && descendant != ancestor) {
+        descendant = descendant.parentNode;
+    }
+    return descendant == ancestor;
+}
+
+/**
+ * Returns true if ancestor is an inclusive ancestor of descendant, false
+ * otherwise.
+ */
+function isInclusiveAncestor(ancestor, descendant) {
+    return ancestor === descendant || isAncestor(ancestor, descendant);
+}
+
+/**
+ * Returns true if descendant is a descendant of ancestor, false otherwise.
+ */
+function isDescendant(descendant, ancestor) {
+    return isAncestor(ancestor, descendant);
+}
+
+/**
+ * Returns true if descendant is an inclusive descendant of ancestor, false
+ * otherwise.
+ */
+function isInclusiveDescendant(descendant, ancestor) {
+    return descendant === ancestor || isDescendant(descendant, ancestor);
+}
+
+/**
+ * The position of two boundary points relative to one another, as defined by
+ * the spec.
+ */
+function getPosition(nodeA, offsetA, nodeB, offsetB) {
+    // "If node A is the same as node B, return equal if offset A equals offset
+    // B, before if offset A is less than offset B, and after if offset A is
+    // greater than offset B."
+    if (nodeA == nodeB) {
+        if (offsetA == offsetB) {
+            return "equal";
+        }
+        if (offsetA < offsetB) {
+            return "before";
+        }
+        if (offsetA > offsetB) {
+            return "after";
+        }
+    }
+
+    // "If node A is after node B in tree order, compute the position of (node
+    // B, offset B) relative to (node A, offset A). If it is before, return
+    // after. If it is after, return before."
+    if (nodeB.compareDocumentPosition(nodeA) & Node.DOCUMENT_POSITION_FOLLOWING) {
+        var pos = getPosition(nodeB, offsetB, nodeA, offsetA);
+        if (pos == "before") {
+            return "after";
+        }
+        if (pos == "after") {
+            return "before";
+        }
+    }
+
+    // "If node A is an ancestor of node B:"
+    if (nodeB.compareDocumentPosition(nodeA) & Node.DOCUMENT_POSITION_CONTAINS) {
+        // "Let child equal node B."
+        var child = nodeB;
+
+        // "While child is not a child of node A, set child to its parent."
+        while (child.parentNode != nodeA) {
+            child = child.parentNode;
+        }
+
+        // "If the index of child is less than offset A, return after."
+        if (indexOf(child) < offsetA) {
+            return "after";
+        }
+    }
+
+    // "Return before."
+    return "before";
+}
+
+/**
+ * "contained" as defined by DOM Range: "A Node node is contained in a range
+ * range if node's furthest ancestor is the same as range's root, and (node, 0)
+ * is after range's start, and (node, length of node) is before range's end."
+ */
+function isContained(node, range) {
+    var pos1 = getPosition(node, 0, range.startContainer, range.startOffset);
+    var pos2 = getPosition(node, nodeLength(node), range.endContainer, range.endOffset);
+
+    return furthestAncestor(node) == furthestAncestor(range.startContainer)
+        && pos1 == "after"
+        && pos2 == "before";
+}
+
+/**
+ * "partially contained" as defined by DOM Range: "A Node is partially
+ * contained in a range if it is an ancestor container of the range's start but
+ * not its end, or vice versa."
+ */
+function isPartiallyContained(node, range) {
+    var cond1 = isAncestorContainer(node, range.startContainer);
+    var cond2 = isAncestorContainer(node, range.endContainer);
+    return (cond1 && !cond2) || (cond2 && !cond1);
+}
+
+/**
+ * Index of a node as defined by the spec.
+ */
+function indexOf(node) {
+    if (!node.parentNode) {
+        // No preceding sibling nodes, right?
+        return 0;
+    }
+    var i = 0;
+    while (node != node.parentNode.childNodes[i]) {
+        i++;
+    }
+    return i;
+}
+
+/**
+ * extractContents() implementation, following the spec.  If an exception is
+ * supposed to be thrown, will return a string with the name (e.g.,
+ * "HIERARCHY_REQUEST_ERR") instead of a document fragment.  It might also
+ * return an arbitrary human-readable string if a condition is hit that implies
+ * a spec bug.
+ */
+function myExtractContents(range) {
+    // "Let frag be a new DocumentFragment whose ownerDocument is the same as
+    // the ownerDocument of the context object's start node."
+    var ownerDoc = range.startContainer.nodeType == Node.DOCUMENT_NODE
+        ? range.startContainer
+        : range.startContainer.ownerDocument;
+    var frag = ownerDoc.createDocumentFragment();
+
+    // "If the context object's start and end are the same, abort this method,
+    // returning frag."
+    if (range.startContainer == range.endContainer
+    && range.startOffset == range.endOffset) {
+        return frag;
+    }
+
+    // "Let original start node, original start offset, original end node, and
+    // original end offset be the context object's start and end nodes and
+    // offsets, respectively."
+    var originalStartNode = range.startContainer;
+    var originalStartOffset = range.startOffset;
+    var originalEndNode = range.endContainer;
+    var originalEndOffset = range.endOffset;
+
+    // "If original start node is original end node, and they are a Text,
+    // ProcessingInstruction, or Comment node:"
+    if (range.startContainer == range.endContainer
+    && (range.startContainer.nodeType == Node.TEXT_NODE
+    || range.startContainer.nodeType == Node.PROCESSING_INSTRUCTION_NODE
+    || range.startContainer.nodeType == Node.COMMENT_NODE)) {
+        // "Let clone be the result of calling cloneNode(false) on original
+        // start node."
+        var clone = originalStartNode.cloneNode(false);
+
+        // "Set the data of clone to the result of calling
+        // substringData(original start offset, original end offset − original
+        // start offset) on original start node."
+        clone.data = originalStartNode.substringData(originalStartOffset,
+            originalEndOffset - originalStartOffset);
+
+        // "Append clone as the last child of frag."
+        frag.appendChild(clone);
+
+        // "Call deleteData(original start offset, original end offset −
+        // original start offset) on original start node."
+        originalStartNode.deleteData(originalStartOffset,
+            originalEndOffset - originalStartOffset);
+
+        // "Abort this method, returning frag."
+        return frag;
+    }
+
+    // "Let common ancestor equal original start node."
+    var commonAncestor = originalStartNode;
+
+    // "While common ancestor is not an ancestor container of original end
+    // node, set common ancestor to its own parent."
+    while (!isAncestorContainer(commonAncestor, originalEndNode)) {
+        commonAncestor = commonAncestor.parentNode;
+    }
+
+    // "If original start node is an ancestor container of original end node,
+    // let first partially contained child be null."
+    var firstPartiallyContainedChild;
+    if (isAncestorContainer(originalStartNode, originalEndNode)) {
+        firstPartiallyContainedChild = null;
+    // "Otherwise, let first partially contained child be the first child of
+    // common ancestor that is partially contained in the context object."
+    } else {
+        for (var i = 0; i < commonAncestor.childNodes.length; i++) {
+            if (isPartiallyContained(commonAncestor.childNodes[i], range)) {
+                firstPartiallyContainedChild = commonAncestor.childNodes[i];
+                break;
+            }
+        }
+        if (!firstPartiallyContainedChild) {
+            throw "Spec bug: no first partially contained child!";
+        }
+    }
+
+    // "If original end node is an ancestor container of original start node,
+    // let last partially contained child be null."
+    var lastPartiallyContainedChild;
+    if (isAncestorContainer(originalEndNode, originalStartNode)) {
+        lastPartiallyContainedChild = null;
+    // "Otherwise, let last partially contained child be the last child of
+    // common ancestor that is partially contained in the context object."
+    } else {
+        for (var i = commonAncestor.childNodes.length - 1; i >= 0; i--) {
+            if (isPartiallyContained(commonAncestor.childNodes[i], range)) {
+                lastPartiallyContainedChild = commonAncestor.childNodes[i];
+                break;
+            }
+        }
+        if (!lastPartiallyContainedChild) {
+            throw "Spec bug: no last partially contained child!";
+        }
+    }
+
+    // "Let contained children be a list of all children of common ancestor
+    // that are contained in the context object, in tree order."
+    //
+    // "If any member of contained children is a DocumentType, raise a
+    // HIERARCHY_REQUEST_ERR exception and abort these steps."
+    var containedChildren = [];
+    for (var i = 0; i < commonAncestor.childNodes.length; i++) {
+        if (isContained(commonAncestor.childNodes[i], range)) {
+            if (commonAncestor.childNodes[i].nodeType
+            == Node.DOCUMENT_TYPE_NODE) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+            containedChildren.push(commonAncestor.childNodes[i]);
+        }
+    }
+
+    // "If original start node is an ancestor container of original end node,
+    // set new node to original start node and new offset to original start
+    // offset."
+    var newNode, newOffset;
+    if (isAncestorContainer(originalStartNode, originalEndNode)) {
+        newNode = originalStartNode;
+        newOffset = originalStartOffset;
+    // "Otherwise:"
+    } else {
+        // "Let reference node equal original start node."
+        var referenceNode = originalStartNode;
+
+        // "While reference node's parent is not null and is not an ancestor
+        // container of original end node, set reference node to its parent."
+        while (referenceNode.parentNode
+        && !isAncestorContainer(referenceNode.parentNode, originalEndNode)) {
+            referenceNode = referenceNode.parentNode;
+        }
+
+        // "Set new node to the parent of reference node, and new offset to one
+        // plus the index of reference node."
+        newNode = referenceNode.parentNode;
+        newOffset = 1 + indexOf(referenceNode);
+    }
+
+    // "If first partially contained child is a Text, ProcessingInstruction, or
+    // Comment node:"
+    if (firstPartiallyContainedChild
+    && (firstPartiallyContainedChild.nodeType == Node.TEXT_NODE
+    || firstPartiallyContainedChild.nodeType == Node.PROCESSING_INSTRUCTION_NODE
+    || firstPartiallyContainedChild.nodeType == Node.COMMENT_NODE)) {
+        // "Let clone be the result of calling cloneNode(false) on original
+        // start node."
+        var clone = originalStartNode.cloneNode(false);
+
+        // "Set the data of clone to the result of calling substringData() on
+        // original start node, with original start offset as the first
+        // argument and (length of original start node − original start offset)
+        // as the second."
+        clone.data = originalStartNode.substringData(originalStartOffset,
+            nodeLength(originalStartNode) - originalStartOffset);
+
+        // "Append clone as the last child of frag."
+        frag.appendChild(clone);
+
+        // "Call deleteData() on original start node, with original start
+        // offset as the first argument and (length of original start node −
+        // original start offset) as the second."
+        originalStartNode.deleteData(originalStartOffset,
+            nodeLength(originalStartNode) - originalStartOffset);
+    // "Otherwise, if first partially contained child is not null:"
+    } else if (firstPartiallyContainedChild) {
+        // "Let clone be the result of calling cloneNode(false) on first
+        // partially contained child."
+        var clone = firstPartiallyContainedChild.cloneNode(false);
+
+        // "Append clone as the last child of frag."
+        frag.appendChild(clone);
+
+        // "Let subrange be a new Range whose start is (original start node,
+        // original start offset) and whose end is (first partially contained
+        // child, length of first partially contained child)."
+        var subrange = ownerDoc.createRange();
+        subrange.setStart(originalStartNode, originalStartOffset);
+        subrange.setEnd(firstPartiallyContainedChild,
+            nodeLength(firstPartiallyContainedChild));
+
+        // "Let subfrag be the result of calling extractContents() on
+        // subrange."
+        var subfrag = myExtractContents(subrange);
+
+        // "For each child of subfrag, in order, append that child to clone as
+        // its last child."
+        for (var i = 0; i < subfrag.childNodes.length; i++) {
+            clone.appendChild(subfrag.childNodes[i]);
+        }
+    }
+
+    // "For each contained child in contained children, append contained child
+    // as the last child of frag."
+    for (var i = 0; i < containedChildren.length; i++) {
+        frag.appendChild(containedChildren[i]);
+    }
+
+    // "If last partially contained child is a Text, ProcessingInstruction, or
+    // Comment node:"
+    if (lastPartiallyContainedChild
+    && (lastPartiallyContainedChild.nodeType == Node.TEXT_NODE
+    || lastPartiallyContainedChild.nodeType == Node.PROCESSING_INSTRUCTION_NODE
+    || lastPartiallyContainedChild.nodeType == Node.COMMENT_NODE)) {
+        // "Let clone be the result of calling cloneNode(false) on original
+        // end node."
+        var clone = originalEndNode.cloneNode(false);
+
+        // "Set the data of clone to the result of calling substringData(0,
+        // original end offset) on original end node."
+        clone.data = originalEndNode.substringData(0, originalEndOffset);
+
+        // "Append clone as the last child of frag."
+        frag.appendChild(clone);
+
+        // "Call deleteData(0, original end offset) on original end node."
+        originalEndNode.deleteData(0, originalEndOffset);
+    // "Otherwise, if last partially contained child is not null:"
+    } else if (lastPartiallyContainedChild) {
+        // "Let clone be the result of calling cloneNode(false) on last
+        // partially contained child."
+        var clone = lastPartiallyContainedChild.cloneNode(false);
+
+        // "Append clone as the last child of frag."
+        frag.appendChild(clone);
+
+        // "Let subrange be a new Range whose start is (last partially
+        // contained child, 0) and whose end is (original end node, original
+        // end offset)."
+        var subrange = ownerDoc.createRange();
+        subrange.setStart(lastPartiallyContainedChild, 0);
+        subrange.setEnd(originalEndNode, originalEndOffset);
+
+        // "Let subfrag be the result of calling extractContents() on
+        // subrange."
+        var subfrag = myExtractContents(subrange);
+
+        // "For each child of subfrag, in order, append that child to clone as
+        // its last child."
+        for (var i = 0; i < subfrag.childNodes.length; i++) {
+            clone.appendChild(subfrag.childNodes[i]);
+        }
+    }
+
+    // "Set the context object's start and end to (new node, new offset)."
+    range.setStart(newNode, newOffset);
+    range.setEnd(newNode, newOffset);
+
+    // "Return frag."
+    return frag;
+}
+
+/**
+ * insertNode() implementation, following the spec.  If an exception is meant
+ * to be thrown, will return a string with the expected exception name, for
+ * instance "HIERARCHY_REQUEST_ERR".
+ */
+function myInsertNode(range, node) {
+    // "If range's start node is a ProcessingInstruction or Comment node, or is
+    // a Text node whose parent is null, or is node, throw an
+    // "HierarchyRequestError" exception and terminate these steps."
+    if (range.startContainer.nodeType == Node.PROCESSING_INSTRUCTION_NODE
+            || range.startContainer.nodeType == Node.COMMENT_NODE
+            || (range.startContainer.nodeType == Node.TEXT_NODE
+                && !range.startContainer.parentNode)
+            || range.startContainer == node) {
+                    return "HIERARCHY_REQUEST_ERR";
+    }
+
+    // "Let referenceNode be null."
+    var referenceNode = null;
+
+    // "If range's start node is a Text node, set referenceNode to that Text node."
+    if (range.startContainer.nodeType == Node.TEXT_NODE) {
+        referenceNode = range.startContainer;
+
+        // "Otherwise, set referenceNode to the child of start node whose index is
+        // start offset, and null if there is no such child."
+    } else {
+        if (range.startOffset < range.startContainer.childNodes.length) {
+            referenceNode = range.startContainer.childNodes[range.startOffset];
+        } else {
+            referenceNode = null;
+        }
+    }
+
+    // "Let parent be range's start node if referenceNode is null, and
+    // referenceNode's parent otherwise."
+    var parent_ = referenceNode === null ? range.startContainer :
+        referenceNode.parentNode;
+
+    // "Ensure pre-insertion validity of node into parent before
+    // referenceNode."
+    var error = ensurePreInsertionValidity(node, parent_, referenceNode);
+    if (error) {
+        return error;
+    }
+
+    // "If range's start node is a Text node, set referenceNode to the result
+    // of splitting it with offset range's start offset."
+    if (range.startContainer.nodeType == Node.TEXT_NODE) {
+        referenceNode = range.startContainer.splitText(range.startOffset);
+    }
+
+    // "If node is referenceNode, set referenceNode to its next sibling."
+    if (node == referenceNode) {
+        referenceNode = referenceNode.nextSibling;
+    }
+
+    // "If node's parent is not null, remove node from its parent."
+    if (node.parentNode) {
+        node.parentNode.removeChild(node);
+    }
+
+    // "Let newOffset be parent's length if referenceNode is null, and
+    // referenceNode's index otherwise."
+    var newOffset = referenceNode === null ? nodeLength(parent_) :
+        indexOf(referenceNode);
+
+    // "Increase newOffset by node's length if node is a DocumentFragment node,
+    // and one otherwise."
+    newOffset += node.nodeType == Node.DOCUMENT_FRAGMENT_NODE ?
+        nodeLength(node) : 1;
+
+    // "Pre-insert node into parent before referenceNode."
+    parent_.insertBefore(node, referenceNode);
+
+    // "If range's start and end are the same, set range's end to (parent,
+    // newOffset)."
+    if (range.startContainer == range.endContainer
+    && range.startOffset == range.endOffset) {
+        range.setEnd(parent_, newOffset);
+    }
+}
+
+// To make filter() calls more readable
+function isElement(node) {
+    return node.nodeType == Node.ELEMENT_NODE;
+}
+
+function isText(node) {
+    return node.nodeType == Node.TEXT_NODE;
+}
+
+function isDoctype(node) {
+    return node.nodeType == Node.DOCUMENT_TYPE_NODE;
+}
+
+function ensurePreInsertionValidity(node, parent_, child) {
+    // "If parent is not a Document, DocumentFragment, or Element node, throw a
+    // HierarchyRequestError."
+    if (parent_.nodeType != Node.DOCUMENT_NODE
+            && parent_.nodeType != Node.DOCUMENT_FRAGMENT_NODE
+            && parent_.nodeType != Node.ELEMENT_NODE) {
+                return "HIERARCHY_REQUEST_ERR";
+    }
+
+    // "If node is a host-including inclusive ancestor of parent, throw a
+    // HierarchyRequestError."
+    //
+    // XXX Does not account for host
+    if (isInclusiveAncestor(node, parent_)) {
+        return "HIERARCHY_REQUEST_ERR";
+    }
+
+    // "If child is not null and its parent is not parent, throw a NotFoundError
+    // exception."
+    if (child && child.parentNode != parent_) {
+        return "NOT_FOUND_ERR";
+    }
+
+    // "If node is not a DocumentFragment, DocumentType, Element, Text,
+    // ProcessingInstruction, or Comment node, throw a HierarchyRequestError."
+    if (node.nodeType != Node.DOCUMENT_FRAGMENT_NODE
+            && node.nodeType != Node.DOCUMENT_TYPE_NODE
+            && node.nodeType != Node.ELEMENT_NODE
+            && node.nodeType != Node.TEXT_NODE
+            && node.nodeType != Node.PROCESSING_INSTRUCTION_NODE
+            && node.nodeType != Node.COMMENT_NODE) {
+                return "HIERARCHY_REQUEST_ERR";
+    }
+
+    // "If either node is a Text node and parent is a document, or node is a
+    // doctype and parent is not a document, throw a HierarchyRequestError."
+    if ((node.nodeType == Node.TEXT_NODE
+                && parent_.nodeType == Node.DOCUMENT_NODE)
+            || (node.nodeType == Node.DOCUMENT_TYPE_NODE
+                && parent_.nodeType != Node.DOCUMENT_NODE)) {
+                    return "HIERARCHY_REQUEST_ERR";
+    }
+
+    // "If parent is a document, and any of the statements below, switched on
+    // node, are true, throw a HierarchyRequestError."
+    if (parent_.nodeType == Node.DOCUMENT_NODE) {
+        switch (node.nodeType) {
+        case Node.DOCUMENT_FRAGMENT_NODE:
+            // "If node has more than one element child or has a Text node
+            // child.  Otherwise, if node has one element child and either
+            // parent has an element child, child is a doctype, or child is not
+            // null and a doctype is following child."
+            if ([].filter.call(node.childNodes, isElement).length > 1) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+
+            if ([].some.call(node.childNodes, isText)) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+
+            if ([].filter.call(node.childNodes, isElement).length == 1) {
+                if ([].some.call(parent_.childNodes, isElement)) {
+                    return "HIERARCHY_REQUEST_ERR";
+                }
+
+                if (child && child.nodeType == Node.DOCUMENT_TYPE_NODE) {
+                    return "HIERARCHY_REQUEST_ERR";
+                }
+
+                if (child && [].slice.call(parent_.childNodes, indexOf(child) + 1)
+                               .filter(isDoctype)) {
+                    return "HIERARCHY_REQUEST_ERR";
+                }
+            }
+            break;
+
+        case Node.ELEMENT_NODE:
+            // "parent has an element child, child is a doctype, or child is
+            // not null and a doctype is following child."
+            if ([].some.call(parent_.childNodes, isElement)) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+
+            if (child.nodeType == Node.DOCUMENT_TYPE_NODE) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+
+            if (child && [].slice.call(parent_.childNodes, indexOf(child) + 1)
+                           .filter(isDoctype)) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+            break;
+
+        case Node.DOCUMENT_TYPE_NODE:
+            // "parent has a doctype child, an element is preceding child, or
+            // child is null and parent has an element child."
+            if ([].some.call(parent_.childNodes, isDoctype)) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+
+            if (child && [].slice.call(parent_.childNodes, 0, indexOf(child))
+                           .some(isElement)) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+
+            if (!child && [].some.call(parent_.childNodes, isElement)) {
+                return "HIERARCHY_REQUEST_ERR";
+            }
+            break;
+        }
+    }
+}
+
+/**
+ * Asserts that two nodes are equal, in the sense of isEqualNode().  If they
+ * aren't, tries to print a relatively informative reason why not.  TODO: Move
+ * this to testharness.js?
+ */
+function assertNodesEqual(actual, expected, msg) {
+    if (!actual.isEqualNode(expected)) {
+        msg = "Actual and expected mismatch for " + msg + ".  ";
+
+        while (actual && expected) {
+            assert_true(actual.nodeType === expected.nodeType
+                && actual.nodeName === expected.nodeName
+                && actual.nodeValue === expected.nodeValue,
+                "First differing node: expected " + format_value(expected)
+                + ", got " + format_value(actual) + " [" + msg + "]");
+            actual = nextNode(actual);
+            expected = nextNode(expected);
+        }
+
+        assert_unreached("DOMs were not equal but we couldn't figure out why");
+    }
+}
+
+/**
+ * Given a DOMException, return the name (e.g., "HIERARCHY_REQUEST_ERR").
+ */
+function getDomExceptionName(e) {
+    var ret = null;
+    for (var prop in e) {
+        if (/^[A-Z_]+_ERR$/.test(prop) && e[prop] == e.code) {
+            return prop;
+        }
+    }
+
+    throw "Exception seems to not be a DOMException?  " + e;
+}
+
+/**
+ * Given an array of endpoint data [start container, start offset, end
+ * container, end offset], returns a Range with those endpoints.
+ */
+function rangeFromEndpoints(endpoints) {
+    // If we just use document instead of the ownerDocument of endpoints[0],
+    // WebKit will throw on setStart/setEnd.  This is a WebKit bug, but it's in
+    // range, not selection, so we don't want to fail anything for it.
+    var range = ownerDocument(endpoints[0]).createRange();
+    range.setStart(endpoints[0], endpoints[1]);
+    range.setEnd(endpoints[2], endpoints[3]);
+    return range;
+}
diff --git a/testing/web-platform/tests/dom/constants.js b/testing/web-platform/tests/dom/constants.js
new file mode 100644
index 0000000000..397df96fbc
--- /dev/null
+++ b/testing/web-platform/tests/dom/constants.js
@@ -0,0 +1,11 @@
+function testConstants(objects, constants, msg) {
+  objects.forEach(function(arr) {
+    var o = arr[0], desc = arr[1];
+    test(function() {
+      constants.forEach(function(d) {
+        assert_true(d[0] in o, "Object " + o + " doesn't have " + d[0])
+        assert_equals(o[d[0]], d[1], "Object " + o + " value for " + d[0] + " is wrong")
+      })
+    }, "Constants for " + msg + " on " + desc + ".")
+  })
+}
diff --git a/testing/web-platform/tests/dom/eventPathRemoved.html b/testing/web-platform/tests/dom/eventPathRemoved.html
new file mode 100644
index 0000000000..1ed9f88753
--- /dev/null
+++ b/testing/web-platform/tests/dom/eventPathRemoved.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Event.path must be removed</title>
+<!-- Note that this duplicates a test in historical.html for the purposes of
+     using in the Interop-2022 metric -->
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+test(() => {
+    const name = "path";
+    assert_false(name in Event.prototype)
+    assert_equals(Event.prototype[name], undefined)
+    assert_false(name in new Event("test"))
+    assert_equals((new Event("test"))[name], undefined)
+  }, "Event.prototype should not have property named 'path'")
+</script>
diff --git a/testing/web-platform/tests/dom/events/AddEventListenerOptions-once.any.js b/testing/web-platform/tests/dom/events/AddEventListenerOptions-once.any.js
new file mode 100644
index 0000000000..b4edd4345c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/AddEventListenerOptions-once.any.js
@@ -0,0 +1,96 @@
+// META: title=AddEventListenerOptions.once
+
+"use strict";
+
+test(function() {
+  var invoked_once = false;
+  var invoked_normal = false;
+  function handler_once() {
+    invoked_once = true;
+  }
+  function handler_normal() {
+    invoked_normal = true;
+  }
+
+  const et = new EventTarget();
+  et.addEventListener('test', handler_once, {once: true});
+  et.addEventListener('test', handler_normal);
+  et.dispatchEvent(new Event('test'));
+  assert_equals(invoked_once, true, "Once handler should be invoked");
+  assert_equals(invoked_normal, true, "Normal handler should be invoked");
+
+  invoked_once = false;
+  invoked_normal = false;
+  et.dispatchEvent(new Event('test'));
+  assert_equals(invoked_once, false, "Once handler shouldn't be invoked again");
+  assert_equals(invoked_normal, true, "Normal handler should be invoked again");
+  et.removeEventListener('test', handler_normal);
+}, "Once listener should be invoked only once");
+
+test(function() {
+  const et = new EventTarget();
+  var invoked_count = 0;
+  function handler() {
+    invoked_count++;
+    if (invoked_count == 1)
+    et.dispatchEvent(new Event('test'));
+  }
+  et.addEventListener('test', handler, {once: true});
+  et.dispatchEvent(new Event('test'));
+  assert_equals(invoked_count, 1, "Once handler should only be invoked once");
+
+  invoked_count = 0;
+  function handler2() {
+    invoked_count++;
+    if (invoked_count == 1)
+      et.addEventListener('test', handler2, {once: true});
+    if (invoked_count <= 2)
+      et.dispatchEvent(new Event('test'));
+  }
+  et.addEventListener('test', handler2, {once: true});
+  et.dispatchEvent(new Event('test'));
+  assert_equals(invoked_count, 2, "Once handler should only be invoked once after each adding");
+}, "Once listener should be invoked only once even if the event is nested");
+
+test(function() {
+  var invoked_count = 0;
+  function handler() {
+    invoked_count++;
+  }
+
+  const et = new EventTarget();
+
+  et.addEventListener('test', handler, {once: true});
+  et.addEventListener('test', handler);
+  et.dispatchEvent(new Event('test'));
+  assert_equals(invoked_count, 1, "The handler should only be added once");
+
+  invoked_count = 0;
+  et.dispatchEvent(new Event('test'));
+  assert_equals(invoked_count, 0, "The handler was added as a once listener");
+
+  invoked_count = 0;
+  et.addEventListener('test', handler, {once: true});
+  et.removeEventListener('test', handler);
+  et.dispatchEvent(new Event('test'));
+  assert_equals(invoked_count, 0, "The handler should have been removed");
+}, "Once listener should be added / removed like normal listeners");
+
+test(function() {
+  const et = new EventTarget();
+
+  var invoked_count = 0;
+
+  for (let n = 4; n > 0; n--) {
+    et.addEventListener('test', (e) => {
+      invoked_count++;
+      e.stopImmediatePropagation();
+    }, {once: true});
+  }
+
+  for (let n = 4; n > 0; n--) {
+    et.dispatchEvent(new Event('test'));
+  }
+
+  assert_equals(invoked_count, 4, "The listeners should be invoked");
+}, "Multiple once listeners should be invoked even if the stopImmediatePropagation is set");
diff --git a/testing/web-platform/tests/dom/events/AddEventListenerOptions-passive.any.js b/testing/web-platform/tests/dom/events/AddEventListenerOptions-passive.any.js
new file mode 100644
index 0000000000..8e59cf5b37
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/AddEventListenerOptions-passive.any.js
@@ -0,0 +1,134 @@
+// META: title=AddEventListenerOptions.passive
+
+test(function() {
+  var supportsPassive = false;
+  var query_options = {
+    get passive() {
+      supportsPassive = true;
+      return false;
+    },
+    get dummy() {
+      assert_unreached("dummy value getter invoked");
+      return false;
+    }
+  };
+
+  const et = new EventTarget();
+  et.addEventListener('test_event', null, query_options);
+  assert_true(supportsPassive, "addEventListener doesn't support the passive option");
+
+  supportsPassive = false;
+  et.removeEventListener('test_event', null, query_options);
+  assert_false(supportsPassive, "removeEventListener supports the passive option when it should not");
+}, "Supports passive option on addEventListener only");
+
+function testPassiveValue(optionsValue, expectedDefaultPrevented, existingEventTarget) {
+  var defaultPrevented = undefined;
+  var handler = function handler(e) {
+    assert_false(e.defaultPrevented, "Event prematurely marked defaultPrevented");
+    e.preventDefault();
+    defaultPrevented = e.defaultPrevented;
+  }
+  const et = existingEventTarget || new EventTarget();
+  et.addEventListener('test', handler, optionsValue);
+  var uncanceled = et.dispatchEvent(new Event('test', {bubbles: true, cancelable: true}));
+
+  assert_equals(defaultPrevented, expectedDefaultPrevented, "Incorrect defaultPrevented for options: " + JSON.stringify(optionsValue));
+  assert_equals(uncanceled, !expectedDefaultPrevented, "Incorrect return value from dispatchEvent");
+
+  et.removeEventListener('test', handler, optionsValue);
+}
+
+test(function() {
+  testPassiveValue(undefined, true);
+  testPassiveValue({}, true);
+  testPassiveValue({passive: false}, true);
+  testPassiveValue({passive: true}, false);
+  testPassiveValue({passive: 0}, true);
+  testPassiveValue({passive: 1}, false);
+}, "preventDefault should be ignored if-and-only-if the passive option is true");
+
+function testPassiveValueOnReturnValue(test, optionsValue, expectedDefaultPrevented) {
+  var defaultPrevented = undefined;
+  var handler = test.step_func(e => {
+    assert_false(e.defaultPrevented, "Event prematurely marked defaultPrevented");
+    e.returnValue = false;
+    defaultPrevented = e.defaultPrevented;
+  });
+  const et = new EventTarget();
+  et.addEventListener('test', handler, optionsValue);
+  var uncanceled = et.dispatchEvent(new Event('test', {bubbles: true, cancelable: true}));
+
+  assert_equals(defaultPrevented, expectedDefaultPrevented, "Incorrect defaultPrevented for options: " + JSON.stringify(optionsValue));
+  assert_equals(uncanceled, !expectedDefaultPrevented, "Incorrect return value from dispatchEvent");
+
+  et.removeEventListener('test', handler, optionsValue);
+}
+
+async_test(t => {
+  testPassiveValueOnReturnValue(t, undefined, true);
+  testPassiveValueOnReturnValue(t, {}, true);
+  testPassiveValueOnReturnValue(t, {passive: false}, true);
+  testPassiveValueOnReturnValue(t, {passive: true}, false);
+  testPassiveValueOnReturnValue(t, {passive: 0}, true);
+  testPassiveValueOnReturnValue(t, {passive: 1}, false);
+  t.done();
+}, "returnValue should be ignored if-and-only-if the passive option is true");
+
+function testPassiveWithOtherHandlers(optionsValue, expectedDefaultPrevented) {
+  var handlerInvoked1 = false;
+  var dummyHandler1 = function() {
+    handlerInvoked1 = true;
+  };
+  var handlerInvoked2 = false;
+  var dummyHandler2 = function() {
+    handlerInvoked2 = true;
+  };
+
+  const et = new EventTarget();
+  et.addEventListener('test', dummyHandler1, {passive:true});
+  et.addEventListener('test', dummyHandler2);
+
+  testPassiveValue(optionsValue, expectedDefaultPrevented, et);
+
+  assert_true(handlerInvoked1, "Extra passive handler not invoked");
+  assert_true(handlerInvoked2, "Extra non-passive handler not invoked");
+
+  et.removeEventListener('test', dummyHandler1);
+  et.removeEventListener('test', dummyHandler2);
+}
+
+test(function() {
+  testPassiveWithOtherHandlers({}, true);
+  testPassiveWithOtherHandlers({passive: false}, true);
+  testPassiveWithOtherHandlers({passive: true}, false);
+}, "passive behavior of one listener should be unaffected by the presence of other listeners");
+
+function testOptionEquivalence(optionValue1, optionValue2, expectedEquality) {
+  var invocationCount = 0;
+  var handler = function handler(e) {
+    invocationCount++;
+  }
+  const et = new EventTarget();
+  et.addEventListener('test', handler, optionValue1);
+  et.addEventListener('test', handler, optionValue2);
+  et.dispatchEvent(new Event('test', {bubbles: true}));
+  assert_equals(invocationCount, expectedEquality ? 1 : 2, "equivalence of options " +
+    JSON.stringify(optionValue1) + " and " + JSON.stringify(optionValue2));
+  et.removeEventListener('test', handler, optionValue1);
+  et.removeEventListener('test', handler, optionValue2);
+}
+
+test(function() {
+  // Sanity check options that should be treated as distinct handlers
+  testOptionEquivalence({capture:true}, {capture:false, passive:false}, false);
+  testOptionEquivalence({capture:true}, {passive:true}, false);
+
+  // Option values that should be treated as equivalent
+  testOptionEquivalence({}, {passive:false}, true);
+  testOptionEquivalence({passive:true}, {passive:false}, true);
+  testOptionEquivalence(undefined, {passive:true}, true);
+  testOptionEquivalence({capture: true, passive: false}, {capture: true, passive: true}, true);
+
+}, "Equivalence of option values");
+
diff --git a/testing/web-platform/tests/dom/events/AddEventListenerOptions-signal.any.js b/testing/web-platform/tests/dom/events/AddEventListenerOptions-signal.any.js
new file mode 100644
index 0000000000..e6a3426159
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/AddEventListenerOptions-signal.any.js
@@ -0,0 +1,143 @@
+'use strict';
+
+test(function() {
+  let count = 0;
+  function handler() {
+    count++;
+  }
+  const et = new EventTarget();
+  const controller = new AbortController();
+  et.addEventListener('test', handler, { signal: controller.signal });
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 1, "Adding a signal still adds a listener");
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 2, "The listener was not added with the once flag");
+  controller.abort();
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 2, "Aborting on the controller removes the listener");
+  et.addEventListener('test', handler, { signal: controller.signal });
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 2, "Passing an aborted signal never adds the handler");
+}, "Passing an AbortSignal to addEventListener options should allow removing a listener");
+
+test(function() {
+  let count = 0;
+  function handler() {
+    count++;
+  }
+  const et = new EventTarget();
+  const controller = new AbortController();
+  et.addEventListener('test', handler, { signal: controller.signal });
+  et.removeEventListener('test', handler);
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 0, "The listener was still removed");
+}, "Passing an AbortSignal to addEventListener does not prevent removeEventListener");
+
+test(function() {
+  let count = 0;
+  function handler() {
+    count++;
+  }
+  const et = new EventTarget();
+  const controller = new AbortController();
+  et.addEventListener('test', handler, { signal: controller.signal, once: true });
+  controller.abort();
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 0, "The listener was still removed");
+}, "Passing an AbortSignal to addEventListener works with the once flag");
+
+test(function() {
+  let count = 0;
+  function handler() {
+    count++;
+  }
+  const et = new EventTarget();
+  const controller = new AbortController();
+  et.addEventListener('test', handler, { signal: controller.signal, once: true });
+  et.removeEventListener('test', handler);
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 0, "The listener was still removed");
+}, "Removing a once listener works with a passed signal");
+
+test(function() {
+  let count = 0;
+  function handler() {
+    count++;
+  }
+  const et = new EventTarget();
+  const controller = new AbortController();
+  et.addEventListener('first', handler, { signal: controller.signal, once: true });
+  et.addEventListener('second', handler, { signal: controller.signal, once: true });
+  controller.abort();
+  et.dispatchEvent(new Event('first'));
+  et.dispatchEvent(new Event('second'));
+  assert_equals(count, 0, "The listener was still removed");
+}, "Passing an AbortSignal to multiple listeners");
+
+test(function() {
+  let count = 0;
+  function handler() {
+    count++;
+  }
+  const et = new EventTarget();
+  const controller = new AbortController();
+  et.addEventListener('test', handler, { signal: controller.signal, capture: true });
+  controller.abort();
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 0, "The listener was still removed");
+}, "Passing an AbortSignal to addEventListener works with the capture flag");
+
+test(function() {
+  let count = 0;
+  function handler() {
+    count++;
+  }
+  const et = new EventTarget();
+  const controller = new AbortController();
+  et.addEventListener('test', () => {
+    controller.abort();
+  }, { signal: controller.signal });
+  et.addEventListener('test', handler, { signal: controller.signal });
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 0, "The listener was still removed");
+}, "Aborting from a listener does not call future listeners");
+
+test(function() {
+  let count = 0;
+  function handler() {
+    count++;
+  }
+  const et = new EventTarget();
+  const controller = new AbortController();
+  et.addEventListener('test', () => {
+    et.addEventListener('test', handler, { signal: controller.signal });
+    controller.abort();
+  }, { signal: controller.signal });
+  et.dispatchEvent(new Event('test'));
+  assert_equals(count, 0, "The listener was still removed");
+}, "Adding then aborting a listener in another listener does not call it");
+
+test(function() {
+  const et = new EventTarget();
+  const ac = new AbortController();
+  let count = 0;
+  et.addEventListener('foo', () => {
+    et.addEventListener('foo', () => {
+      count++;
+      if (count > 5) ac.abort();
+      et.dispatchEvent(new Event('foo'));
+    }, { signal: ac.signal });
+    et.dispatchEvent(new Event('foo'));
+  }, { once: true });
+  et.dispatchEvent(new Event('foo'));
+}, "Aborting from a nested listener should remove it");
+
+test(function() {
+  const et = new EventTarget();
+  assert_throws_js(TypeError, () => { et.addEventListener("foo", () => {}, { signal: null }); });
+}, "Passing null as the signal should throw");
+
+test(function() {
+  const et = new EventTarget();
+  assert_throws_js(TypeError, () => { et.addEventListener("foo", null, { signal: null }); });
+}, "Passing null as the signal should throw (listener is also null)");
diff --git a/testing/web-platform/tests/dom/events/Body-FrameSet-Event-Handlers.html b/testing/web-platform/tests/dom/events/Body-FrameSet-Event-Handlers.html
new file mode 100644
index 0000000000..3a891158d5
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Body-FrameSet-Event-Handlers.html
@@ -0,0 +1,123 @@
+<!DOCTYPE html>
+<html>
+<title>HTMLBodyElement and HTMLFrameSetElement Event Handler Tests</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+function getObject(interface) {
+    switch(interface) {
+        case "Element":
+            var e = document.createElementNS("http://example.com/", "example");
+            assert_true(e instanceof Element);
+            assert_false(e instanceof HTMLElement);
+            assert_false(e instanceof SVGElement);
+            return e;
+        case "HTMLElement":
+            var e = document.createElement("html");
+            assert_true(e instanceof HTMLElement);
+            return e;
+        case "HTMLBodyElement":
+            var e = document.createElement("body");
+            assert_true(e instanceof HTMLBodyElement);
+            return e;
+        case "HTMLFormElement":
+            var e = document.createElement("form");
+            assert_true(e instanceof HTMLFormElement);
+            return e;
+        case "HTMLFrameSetElement":
+            var e = document.createElement("frameset");
+            assert_true(e instanceof HTMLFrameSetElement);
+            return e;
+        case "SVGElement":
+            var e = document.createElementNS("http://www.w3.org/2000/svg", "rect");
+            assert_true(e instanceof SVGElement);
+            return e;
+        case "Document":
+            assert_true(document instanceof Document);
+            return document;
+        case "Window":
+            assert_true(window instanceof Window);
+            return window;
+    }
+    assert_unreached();
+}
+
+function testSet(interface, attribute) {
+    test(function() {
+        var object = getObject(interface);
+        function nop() {}
+        assert_equals(object[attribute], null, "Initially null");
+        object[attribute] = nop;
+        assert_equals(object[attribute], nop, "Return same function");
+        object[attribute] = "";
+        assert_equals(object[attribute], null, "Return null after setting string");
+        object[attribute] = null;
+        assert_equals(object[attribute], null, "Finally null");
+    }, "Set " + interface + "." + attribute);
+}
+
+function testReflect(interface, attribute) {
+    test(function() {
+        var element = getObject(interface);
+        assert_false(element.hasAttribute(attribute), "Initially missing");
+        element.setAttribute(attribute, "return");
+        assert_equals(element.getAttribute(attribute), "return", "Return same string");
+        assert_equals(typeof element[attribute], "function", "Convert to function");
+        element.removeAttribute(attribute);
+    }, "Reflect " + interface + "." + attribute);
+}
+
+function testForwardToWindow(interface, attribute) {
+    test(function() {
+        var element = getObject(interface);
+        window[attribute] = null;
+        element.setAttribute(attribute, "return");
+        assert_equals(typeof window[attribute], "function", "Convert to function");
+        assert_equals(window[attribute], element[attribute], "Forward content attribute");
+        function nop() {}
+        element[attribute] = nop;
+        assert_equals(window[attribute], nop, "Forward IDL attribute");
+        window[attribute] = null;
+    }, "Forward " + interface + "." + attribute + " to Window");
+}
+
+// Object.propertyIsEnumerable cannot be used because it doesn't
+// work with properties inherited through the prototype chain.
+function getEnumerable(interface) {
+    var enumerable = {};
+    for (var attribute in getObject(interface)) {
+        enumerable[attribute] = true;
+    }
+    return enumerable;
+}
+
+var enumerableCache = {};
+function testEnumerate(interface, attribute) {
+    if (!(interface in enumerableCache)) {
+        enumerableCache[interface] = getEnumerable(interface);
+    }
+    test(function() {
+        assert_true(enumerableCache[interface][attribute]);
+    }, "Enumerate " + interface + "." + attribute);
+}
+
+[
+    "onblur",
+    "onerror",
+    "onfocus",
+    "onload",
+    "onscroll",
+    "onresize"
+].forEach(function(attribute) {
+    testSet("HTMLBodyElement", attribute);
+    testEnumerate("HTMLBodyElement", attribute);
+    testReflect("HTMLBodyElement", attribute);
+    testForwardToWindow("HTMLBodyElement", attribute);
+    testSet("HTMLFrameSetElement", attribute);
+    testEnumerate("HTMLFrameSetElement", attribute);
+    testReflect("HTMLFrameSetElement", attribute);
+    testForwardToWindow("HTMLFrameSetElement", attribute);
+});
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/events/CustomEvent.html b/testing/web-platform/tests/dom/events/CustomEvent.html
new file mode 100644
index 0000000000..87050943f9
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/CustomEvent.html
@@ -0,0 +1,35 @@
+<!doctype html>
+<title>CustomEvent</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var type = "foo";
+
+  var target = document.createElement("div");
+  target.addEventListener(type, this.step_func(function(evt) {
+    assert_equals(evt.type, type);
+  }), true);
+
+  var fooEvent = document.createEvent("CustomEvent");
+  fooEvent.initEvent(type, true, true);
+  target.dispatchEvent(fooEvent);
+}, "CustomEvent dispatching.");
+
+test(function() {
+    var e = document.createEvent("CustomEvent");
+    assert_throws_js(TypeError, function() {
+        e.initCustomEvent();
+    });
+}, "First parameter to initCustomEvent should be mandatory.");
+
+test(function() {
+    var e = document.createEvent("CustomEvent");
+    e.initCustomEvent("foo");
+    assert_equals(e.type, "foo", "type");
+    assert_false(e.bubbles, "bubbles");
+    assert_false(e.cancelable, "cancelable");
+    assert_equals(e.detail, null, "detail");
+}, "initCustomEvent's default parameter values.");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-cancelBubble.html b/testing/web-platform/tests/dom/events/Event-cancelBubble.html
new file mode 100644
index 0000000000..d8d2d7239d
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-cancelBubble.html
@@ -0,0 +1,132 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Event.cancelBubble</title>
+  <link rel="author" title="Chris Rebert" href="http://chrisrebert.com">
+  <link rel="help" href="https://dom.spec.whatwg.org/#dom-event-cancelbubble">
+  <meta name="flags" content="dom">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+  <div id="outer">
+    <div id="middle">
+      <div id="inner"></div>
+    </div>
+  </div>
+  <script>
+test(function () {
+  // See https://dom.spec.whatwg.org/#stop-propagation-flag
+  var e = document.createEvent('Event');
+  assert_false(e.cancelBubble, "cancelBubble must be false after event creation.");
+}, "cancelBubble must be false when an event is initially created.");
+
+test(function () {
+  // See https://dom.spec.whatwg.org/#concept-event-initialize
+
+  // Event which bubbles.
+  var one = document.createEvent('Event');
+  one.cancelBubble = true;
+  one.initEvent('foo', true/*bubbles*/, false/*cancelable*/);
+  assert_false(one.cancelBubble, "initEvent() must set cancelBubble to false. [bubbles=true]");
+  // Re-initialization.
+  one.cancelBubble = true;
+  one.initEvent('foo', true/*bubbles*/, false/*cancelable*/);
+  assert_false(one.cancelBubble, "2nd initEvent() call must set cancelBubble to false. [bubbles=true]");
+
+  // Event which doesn't bubble.
+  var two = document.createEvent('Event');
+  two.cancelBubble = true;
+  two.initEvent('foo', false/*bubbles*/, false/*cancelable*/);
+  assert_false(two.cancelBubble, "initEvent() must set cancelBubble to false. [bubbles=false]");
+  // Re-initialization.
+  two.cancelBubble = true;
+  two.initEvent('foo', false/*bubbles*/, false/*cancelable*/);
+  assert_false(two.cancelBubble, "2nd initEvent() call must set cancelBubble to false. [bubbles=false]");
+}, "Initializing an event must set cancelBubble to false.");
+
+test(function () {
+  // See https://dom.spec.whatwg.org/#dom-event-stoppropagation
+  var e = document.createEvent('Event');
+  e.stopPropagation();
+  assert_true(e.cancelBubble, "stopPropagation() must set cancelBubble to true.");
+}, "stopPropagation() must set cancelBubble to true.");
+
+test(function () {
+  // See https://dom.spec.whatwg.org/#dom-event-stopimmediatepropagation
+  var e = document.createEvent('Event');
+  e.stopImmediatePropagation();
+  assert_true(e.cancelBubble, "stopImmediatePropagation() must set cancelBubble to true.");
+}, "stopImmediatePropagation() must set cancelBubble to true.");
+
+test(function () {
+  var one = document.createEvent('Event');
+  one.stopPropagation();
+  one.cancelBubble = false;
+  assert_true(one.cancelBubble, "cancelBubble must still be true after attempting to set it to false.");
+}, "Event.cancelBubble=false must have no effect.");
+
+test(function (t) {
+  var outer = document.getElementById('outer');
+  var middle = document.getElementById('middle');
+  var inner = document.getElementById('inner');
+
+  outer.addEventListener('barbaz', t.step_func(function () {
+    assert_unreached("Setting Event.cancelBubble=false after setting Event.cancelBubble=true should have no effect.");
+  }), false/*useCapture*/);
+
+  middle.addEventListener('barbaz', function (e) {
+    e.cancelBubble = true;// Stop propagation.
+    e.cancelBubble = false;// Should be a no-op.
+  }, false/*useCapture*/);
+
+  var barbazEvent = document.createEvent('Event');
+  barbazEvent.initEvent('barbaz', true/*bubbles*/, false/*cancelable*/);
+  inner.dispatchEvent(barbazEvent);
+}, "Event.cancelBubble=false must have no effect during event propagation.");
+
+test(function () {
+  // See https://dom.spec.whatwg.org/#concept-event-dispatch
+  // "14. Unset event’s [...] stop propagation flag,"
+  var e = document.createEvent('Event');
+  e.initEvent('foobar', true/*bubbles*/, true/*cancelable*/);
+  document.body.addEventListener('foobar', function listener(e) {
+    e.stopPropagation();
+  });
+  document.body.dispatchEvent(e);
+  assert_false(e.cancelBubble, "cancelBubble must be false after an event has been dispatched.");
+}, "cancelBubble must be false after an event has been dispatched.");
+
+test(function (t) {
+  var outer = document.getElementById('outer');
+  var middle = document.getElementById('middle');
+  var inner = document.getElementById('inner');
+
+  var propagationStopper = function (e) {
+    e.cancelBubble = true;
+  };
+
+  // Bubble phase
+  middle.addEventListener('bar', propagationStopper, false/*useCapture*/);
+  outer.addEventListener('bar', t.step_func(function listenerOne() {
+    assert_unreached("Setting cancelBubble=true should stop the event from bubbling further.");
+  }), false/*useCapture*/);
+
+  var barEvent = document.createEvent('Event');
+  barEvent.initEvent('bar', true/*bubbles*/, false/*cancelable*/);
+  inner.dispatchEvent(barEvent);
+
+  // Capture phase
+  outer.addEventListener('qux', propagationStopper, true/*useCapture*/);
+  middle.addEventListener('qux', t.step_func(function listenerTwo() {
+    assert_unreached("Setting cancelBubble=true should stop the event from propagating further, including during the Capture Phase.");
+  }), true/*useCapture*/);
+
+  var quxEvent = document.createEvent('Event');
+  quxEvent.initEvent('qux', false/*bubbles*/, false/*cancelable*/);
+  inner.dispatchEvent(quxEvent);
+}, "Event.cancelBubble=true must set the stop propagation flag.");
+  </script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/Event-constants.html b/testing/web-platform/tests/dom/events/Event-constants.html
new file mode 100644
index 0000000000..635e9894d9
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-constants.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<title>Event constants</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../constants.js"></script>
+<div id="log"></div>
+<script>
+var objects;
+setup(function() {
+  objects = [
+    [Event, "Event interface object"],
+    [Event.prototype, "Event prototype object"],
+    [document.createEvent("Event"), "Event object"],
+    [document.createEvent("CustomEvent"), "CustomEvent object"]
+  ]
+})
+testConstants(objects, [
+  ["NONE", 0],
+  ["CAPTURING_PHASE", 1],
+  ["AT_TARGET", 2],
+  ["BUBBLING_PHASE", 3]
+], "eventPhase")
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-constructors.any.js b/testing/web-platform/tests/dom/events/Event-constructors.any.js
new file mode 100644
index 0000000000..faa623ea92
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-constructors.any.js
@@ -0,0 +1,120 @@
+// META: title=Event constructors
+
+test(function() {
+  assert_throws_js(
+    TypeError,
+    () => Event(""),
+    "Calling Event constructor without 'new' must throw")
+})
+test(function() {
+  assert_throws_js(TypeError, function() {
+    new Event()
+  })
+})
+test(function() {
+  var test_error = { name: "test" }
+  assert_throws_exactly(test_error, function() {
+    new Event({ toString: function() { throw test_error; } })
+  })
+})
+test(function() {
+  var ev = new Event("")
+  assert_equals(ev.type, "")
+  assert_equals(ev.target, null)
+  assert_equals(ev.srcElement, null)
+  assert_equals(ev.currentTarget, null)
+  assert_equals(ev.eventPhase, Event.NONE)
+  assert_equals(ev.bubbles, false)
+  assert_equals(ev.cancelable, false)
+  assert_equals(ev.defaultPrevented, false)
+  assert_equals(ev.returnValue, true)
+  assert_equals(ev.isTrusted, false)
+  assert_true(ev.timeStamp > 0)
+  assert_true("initEvent" in ev)
+})
+test(function() {
+  var ev = new Event("test")
+  assert_equals(ev.type, "test")
+  assert_equals(ev.target, null)
+  assert_equals(ev.srcElement, null)
+  assert_equals(ev.currentTarget, null)
+  assert_equals(ev.eventPhase, Event.NONE)
+  assert_equals(ev.bubbles, false)
+  assert_equals(ev.cancelable, false)
+  assert_equals(ev.defaultPrevented, false)
+  assert_equals(ev.returnValue, true)
+  assert_equals(ev.isTrusted, false)
+  assert_true(ev.timeStamp > 0)
+  assert_true("initEvent" in ev)
+})
+test(function() {
+  assert_throws_js(TypeError, function() { Event("test") },
+                   'Calling Event constructor without "new" must throw');
+})
+test(function() {
+  var ev = new Event("I am an event", { bubbles: true, cancelable: false})
+  assert_equals(ev.type, "I am an event")
+  assert_equals(ev.bubbles, true)
+  assert_equals(ev.cancelable, false)
+})
+test(function() {
+  var ev = new Event("@", { bubblesIGNORED: true, cancelable: true})
+  assert_equals(ev.type, "@")
+  assert_equals(ev.bubbles, false)
+  assert_equals(ev.cancelable, true)
+})
+test(function() {
+  var ev = new Event("@", { "bubbles\0IGNORED": true, cancelable: true})
+  assert_equals(ev.type, "@")
+  assert_equals(ev.bubbles, false)
+  assert_equals(ev.cancelable, true)
+})
+test(function() {
+  var ev = new Event("Xx", { cancelable: true})
+  assert_equals(ev.type, "Xx")
+  assert_equals(ev.bubbles, false)
+  assert_equals(ev.cancelable, true)
+})
+test(function() {
+  var ev = new Event("Xx", {})
+  assert_equals(ev.type, "Xx")
+  assert_equals(ev.bubbles, false)
+  assert_equals(ev.cancelable, false)
+})
+test(function() {
+  var ev = new Event("Xx", {bubbles: true, cancelable: false, sweet: "x"})
+  assert_equals(ev.type, "Xx")
+  assert_equals(ev.bubbles, true)
+  assert_equals(ev.cancelable, false)
+  assert_equals(ev.sweet, undefined)
+})
+test(function() {
+  var called = []
+  var ev = new Event("Xx", {
+    get cancelable() {
+      called.push("cancelable")
+      return false
+    },
+    get bubbles() {
+      called.push("bubbles")
+      return true;
+    },
+    get sweet() {
+      called.push("sweet")
+      return "x"
+    }
+  })
+  assert_array_equals(called, ["bubbles", "cancelable"])
+  assert_equals(ev.type, "Xx")
+  assert_equals(ev.bubbles, true)
+  assert_equals(ev.cancelable, false)
+  assert_equals(ev.sweet, undefined)
+})
+test(function() {
+  var ev = new CustomEvent("$", {detail: 54, sweet: "x", sweet2: "x", cancelable:true})
+  assert_equals(ev.type, "$")
+  assert_equals(ev.bubbles, false)
+  assert_equals(ev.cancelable, true)
+  assert_equals(ev.sweet, undefined)
+  assert_equals(ev.detail, 54)
+})
diff --git a/testing/web-platform/tests/dom/events/Event-defaultPrevented-after-dispatch.html b/testing/web-platform/tests/dom/events/Event-defaultPrevented-after-dispatch.html
new file mode 100644
index 0000000000..8fef005eb5
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-defaultPrevented-after-dispatch.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Event.defaultPrevented is not reset after dispatchEvent()</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id=log></div>
+<input id="target" type="hidden" value=""/>
+<script>
+test(function() {
+    var EVENT = "foo";
+    var TARGET = document.getElementById("target");
+    var evt = document.createEvent("Event");
+    evt.initEvent(EVENT, true, true);
+
+    TARGET.addEventListener(EVENT, this.step_func(function(e) {
+        e.preventDefault();
+        assert_true(e.defaultPrevented, "during dispatch");
+    }), true);
+    TARGET.dispatchEvent(evt);
+
+    assert_true(evt.defaultPrevented, "after dispatch");
+    assert_equals(evt.target, TARGET);
+    assert_equals(evt.srcElement, TARGET);
+}, "Default prevention via preventDefault");
+
+test(function() {
+    var EVENT = "foo";
+    var TARGET = document.getElementById("target");
+    var evt = document.createEvent("Event");
+    evt.initEvent(EVENT, true, true);
+
+    TARGET.addEventListener(EVENT, this.step_func(function(e) {
+        e.returnValue = false;
+        assert_true(e.defaultPrevented, "during dispatch");
+    }), true);
+    TARGET.dispatchEvent(evt);
+
+    assert_true(evt.defaultPrevented, "after dispatch");
+    assert_equals(evt.target, TARGET);
+    assert_equals(evt.srcElement, TARGET);
+}, "Default prevention via returnValue");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-defaultPrevented.html b/testing/web-platform/tests/dom/events/Event-defaultPrevented.html
new file mode 100644
index 0000000000..2548fa3e06
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-defaultPrevented.html
@@ -0,0 +1,55 @@
+<!doctype html>
+<title>Event.defaultPrevented</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+var ev;
+test(function() {
+  ev = document.createEvent("Event");
+  assert_equals(ev.defaultPrevented, false, "defaultPrevented");
+}, "When an event is created, defaultPrevented should be initialized to false.");
+test(function() {
+  ev.initEvent("foo", true, false);
+  assert_equals(ev.bubbles, true, "bubbles");
+  assert_equals(ev.cancelable, false, "cancelable");
+  assert_equals(ev.defaultPrevented, false, "defaultPrevented");
+}, "initEvent should work correctly (not cancelable).");
+test(function() {
+  assert_equals(ev.cancelable, false, "cancelable (before)");
+  ev.preventDefault();
+  assert_equals(ev.cancelable, false, "cancelable (after)");
+  assert_equals(ev.defaultPrevented, false, "defaultPrevented");
+}, "preventDefault() should not change defaultPrevented if cancelable is false.");
+test(function() {
+  assert_equals(ev.cancelable, false, "cancelable (before)");
+  ev.returnValue = false;
+  assert_equals(ev.cancelable, false, "cancelable (after)");
+  assert_equals(ev.defaultPrevented, false, "defaultPrevented");
+}, "returnValue should not change defaultPrevented if cancelable is false.");
+test(function() {
+  ev.initEvent("foo", true, true);
+  assert_equals(ev.bubbles, true, "bubbles");
+  assert_equals(ev.cancelable, true, "cancelable");
+  assert_equals(ev.defaultPrevented, false, "defaultPrevented");
+}, "initEvent should work correctly (cancelable).");
+test(function() {
+  assert_equals(ev.cancelable, true, "cancelable (before)");
+  ev.preventDefault();
+  assert_equals(ev.cancelable, true, "cancelable (after)");
+  assert_equals(ev.defaultPrevented, true, "defaultPrevented");
+}, "preventDefault() should change defaultPrevented if cancelable is true.");
+test(function() {
+  ev.initEvent("foo", true, true);
+  assert_equals(ev.cancelable, true, "cancelable (before)");
+  ev.returnValue = false;
+  assert_equals(ev.cancelable, true, "cancelable (after)");
+  assert_equals(ev.defaultPrevented, true, "defaultPrevented");
+}, "returnValue should change defaultPrevented if cancelable is true.");
+test(function() {
+  ev.initEvent("foo", true, true);
+  assert_equals(ev.bubbles, true, "bubbles");
+  assert_equals(ev.cancelable, true, "cancelable");
+  assert_equals(ev.defaultPrevented, false, "defaultPrevented");
+}, "initEvent should unset defaultPrevented.");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-bubble-canceled.html b/testing/web-platform/tests/dom/events/Event-dispatch-bubble-canceled.html
new file mode 100644
index 0000000000..20f398f66f
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-bubble-canceled.html
@@ -0,0 +1,59 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Setting cancelBubble=true prior to dispatchEvent()</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"></div>
+
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+
+<script>
+test(function() {
+    var event = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var tbody = document.getElementById("table-body");
+    var table = document.getElementById("table");
+    var body = document.body;
+    var html = document.documentElement;
+    var current_targets = [window, document, html, body, table, tbody, parent, target];
+    var expected_targets = [];
+    var actual_targets = [];
+    var expected_phases = [];
+    var actual_phases = [];
+
+    var test_event = function(evt) {
+        actual_targets.push(evt.currentTarget);
+        actual_phases.push(evt.eventPhase);
+    };
+
+    for (var i = 0; i < current_targets.length; ++i) {
+        current_targets[i].addEventListener(event, test_event, true);
+        current_targets[i].addEventListener(event, test_event, false);
+    }
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event, true, true);
+    evt.cancelBubble = true;
+    target.dispatchEvent(evt);
+
+    assert_array_equals(actual_targets, expected_targets, "actual_targets");
+    assert_array_equals(actual_phases, expected_phases, "actual_phases");
+});
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-bubbles-false.html b/testing/web-platform/tests/dom/events/Event-dispatch-bubbles-false.html
new file mode 100644
index 0000000000..0f43cb0275
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-bubbles-false.html
@@ -0,0 +1,98 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title> Event.bubbles attribute is set to false </title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-event-initevent">
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-dispatch">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+<script>
+function targetsForDocumentChain(document) {
+    return [
+        document,
+        document.documentElement,
+        document.getElementsByTagName("body")[0],
+        document.getElementById("table"),
+        document.getElementById("table-body"),
+        document.getElementById("parent")
+    ];
+}
+
+function testChain(document, targetParents, phases, event_type) {
+    var target = document.getElementById("target");
+    var targets = targetParents.concat(target);
+    var expected_targets = targets.concat(target);
+
+    var actual_targets = [], actual_phases = [];
+    var test_event = function(evt) {
+        actual_targets.push(evt.currentTarget);
+        actual_phases.push(evt.eventPhase);
+    }
+
+    for (var i = 0; i < targets.length; i++) {
+        targets[i].addEventListener(event_type, test_event, true);
+        targets[i].addEventListener(event_type, test_event, false);
+    }
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, false, true);
+
+    target.dispatchEvent(evt);
+
+    assert_array_equals(actual_targets, expected_targets, "targets");
+    assert_array_equals(actual_phases, phases, "phases");
+}
+
+var phasesForDocumentChain = [
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.AT_TARGET,
+    Event.AT_TARGET,
+];
+
+test(function () {
+    var chainWithWindow = [window].concat(targetsForDocumentChain(document));
+    testChain(
+        document, chainWithWindow, [Event.CAPTURING_PHASE].concat(phasesForDocumentChain), "click");
+}, "In window.document with click event");
+
+test(function () {
+    testChain(document, targetsForDocumentChain(document), phasesForDocumentChain, "load");
+}, "In window.document with load event")
+
+test(function () {
+    var documentClone = document.cloneNode(true);
+    testChain(
+        documentClone, targetsForDocumentChain(documentClone), phasesForDocumentChain, "click");
+}, "In window.document.cloneNode(true)");
+
+test(function () {
+    var newDocument = new Document();
+    newDocument.appendChild(document.documentElement.cloneNode(true));
+    testChain(
+        newDocument, targetsForDocumentChain(newDocument), phasesForDocumentChain, "click");
+}, "In new Document()");
+
+test(function () {
+    var HTMLDocument = document.implementation.createHTMLDocument();
+    HTMLDocument.body.appendChild(document.getElementById("table").cloneNode(true));
+    testChain(
+        HTMLDocument, targetsForDocumentChain(HTMLDocument), phasesForDocumentChain, "click");
+}, "In DOMImplementation.createHTMLDocument()");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-bubbles-true.html b/testing/web-platform/tests/dom/events/Event-dispatch-bubbles-true.html
new file mode 100644
index 0000000000..b23605a1eb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-bubbles-true.html
@@ -0,0 +1,108 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title> Event.bubbles attribute is set to false </title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-event-initevent">
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-dispatch">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+<script>
+function concatReverse(a) {
+    return a.concat(a.map(function(x) { return x }).reverse());
+}
+
+function targetsForDocumentChain(document) {
+    return [
+        document,
+        document.documentElement,
+        document.getElementsByTagName("body")[0],
+        document.getElementById("table"),
+        document.getElementById("table-body"),
+        document.getElementById("parent")
+    ];
+}
+
+function testChain(document, targetParents, phases, event_type) {
+    var target = document.getElementById("target");
+    var targets = targetParents.concat(target);
+    var expected_targets = concatReverse(targets);
+
+    var actual_targets = [], actual_phases = [];
+    var test_event = function(evt) {
+        actual_targets.push(evt.currentTarget);
+        actual_phases.push(evt.eventPhase);
+    }
+
+    for (var i = 0; i < targets.length; i++) {
+        targets[i].addEventListener(event_type, test_event, true);
+        targets[i].addEventListener(event_type, test_event, false);
+    }
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, true, true);
+
+    target.dispatchEvent(evt);
+
+    assert_array_equals(actual_targets, expected_targets, "targets");
+    assert_array_equals(actual_phases, phases, "phases");
+}
+
+var phasesForDocumentChain = [
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.CAPTURING_PHASE,
+    Event.AT_TARGET,
+    Event.AT_TARGET,
+    Event.BUBBLING_PHASE,
+    Event.BUBBLING_PHASE,
+    Event.BUBBLING_PHASE,
+    Event.BUBBLING_PHASE,
+    Event.BUBBLING_PHASE,
+    Event.BUBBLING_PHASE,
+];
+
+test(function () {
+    var chainWithWindow = [window].concat(targetsForDocumentChain(document));
+    var phases = [Event.CAPTURING_PHASE].concat(phasesForDocumentChain, Event.BUBBLING_PHASE);
+    testChain(document, chainWithWindow, phases, "click");
+}, "In window.document with click event");
+
+test(function () {
+    testChain(document, targetsForDocumentChain(document), phasesForDocumentChain, "load");
+}, "In window.document with load event")
+
+test(function () {
+    var documentClone = document.cloneNode(true);
+    testChain(
+        documentClone, targetsForDocumentChain(documentClone), phasesForDocumentChain, "click");
+}, "In window.document.cloneNode(true)");
+
+test(function () {
+    var newDocument = new Document();
+    newDocument.appendChild(document.documentElement.cloneNode(true));
+    testChain(
+        newDocument, targetsForDocumentChain(newDocument), phasesForDocumentChain, "click");
+}, "In new Document()");
+
+test(function () {
+    var HTMLDocument = document.implementation.createHTMLDocument();
+    HTMLDocument.body.appendChild(document.getElementById("table").cloneNode(true));
+    testChain(
+        HTMLDocument, targetsForDocumentChain(HTMLDocument), phasesForDocumentChain, "click");
+}, "In DOMImplementation.createHTMLDocument()");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-click.html b/testing/web-platform/tests/dom/events/Event-dispatch-click.html
new file mode 100644
index 0000000000..ab4a24a5ad
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-click.html
@@ -0,0 +1,425 @@
+<!doctype html>
+<title>Synthetic click event "magic"</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<div id=dump style=display:none></div>
+<script>
+var dump = document.getElementById("dump")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  input.onclick = t.step_func_done(function() {
+    assert_true(input.checked)
+  })
+  input.click()
+}, "basic with click()")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  input.onclick = t.step_func_done(function() {
+    assert_true(input.checked)
+  })
+  input.dispatchEvent(new MouseEvent("click", {bubbles:true})) // equivalent to the above
+}, "basic with dispatchEvent()")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  input.onclick = t.step_func_done(function() {
+    assert_false(input.checked)
+  })
+  input.dispatchEvent(new Event("click", {bubbles:true})) // no MouseEvent
+}, "basic with wrong event class")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  var child = input.appendChild(new Text("does not matter"))
+  child.dispatchEvent(new MouseEvent("click")) // does not bubble
+  assert_false(input.checked)
+  t.done()
+}, "look at parents only when event bubbles")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  input.onclick = t.step_func_done(function() {
+    assert_true(input.checked)
+  })
+  var child = input.appendChild(new Text("does not matter"))
+  child.dispatchEvent(new MouseEvent("click", {bubbles:true}))
+}, "look at parents when event bubbles")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  input.onclick = t.step_func(function() {
+    assert_false(input.checked, "input pre-click must not be triggered")
+  })
+  var child = input.appendChild(document.createElement("input"))
+  child.type = "checkbox"
+  child.onclick = t.step_func(function() {
+    assert_true(child.checked, "child pre-click must be triggered")
+  })
+  child.dispatchEvent(new MouseEvent("click", {bubbles:true}))
+  t.done()
+}, "pick the first with activation behavior <input type=checkbox>")
+
+async_test(function(t) { // as above with <a>
+  window.hrefComplete = t.step_func(function(a) {
+    assert_equals(a, 'child');
+    t.done();
+  });
+  var link = document.createElement("a")
+  link.href = "javascript:hrefComplete('link')" // must not be triggered
+  dump.appendChild(link)
+  var child = link.appendChild(document.createElement("a"))
+  child.href = "javascript:hrefComplete('child')"
+  child.dispatchEvent(new MouseEvent("click", {bubbles:true}))
+}, "pick the first with activation behavior <a href>")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "radio"
+  dump.appendChild(input)
+  input.onclick = t.step_func(function() {
+    assert_false(input.checked, "input pre-click must not be triggered")
+  })
+  var child = input.appendChild(document.createElement("input"))
+  child.type = "radio"
+  child.onclick = t.step_func(function() {
+    assert_true(child.checked, "child pre-click must be triggered")
+  })
+  child.dispatchEvent(new MouseEvent("click", {bubbles:true}))
+  t.done()
+}, "pick the first with activation behavior <input type=radio>")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  var clickEvent = new MouseEvent("click")
+  input.onchange = t.step_func_done(function() {
+    assert_false(clickEvent.defaultPrevented)
+    assert_true(clickEvent.returnValue)
+    assert_equals(clickEvent.eventPhase, 0)
+    assert_equals(clickEvent.currentTarget, null)
+    assert_equals(clickEvent.target, input)
+    assert_equals(clickEvent.srcElement, input)
+    assert_equals(clickEvent.composedPath().length, 0)
+  })
+  input.dispatchEvent(clickEvent)
+}, "event state during post-click handling")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  var clickEvent = new MouseEvent("click")
+  var finalTarget = document.createElement("doesnotmatter")
+  finalTarget.onclick = t.step_func_done(function() {
+    assert_equals(clickEvent.target, finalTarget)
+    assert_equals(clickEvent.srcElement, finalTarget)
+  })
+  input.onchange = t.step_func(function() {
+    finalTarget.dispatchEvent(clickEvent)
+  })
+  input.dispatchEvent(clickEvent)
+}, "redispatch during post-click handling")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  dump.appendChild(input)
+  var child = input.appendChild(document.createElement("input"))
+  child.type = "checkbox"
+  child.disabled = true
+  child.click()
+  assert_false(input.checked)
+  assert_false(child.checked)
+  t.done()
+}, "disabled checkbox still has activation behavior")
+
+async_test(function(t) {
+  var state = "start"
+
+  var form = document.createElement("form")
+  form.onsubmit = t.step_func(() => {
+    if(state == "start" || state == "checkbox") {
+      state = "failure"
+    } else if(state == "form") {
+      state = "done"
+    }
+    return false
+  })
+  dump.appendChild(form)
+  var button = form.appendChild(document.createElement("button"))
+  button.type = "submit"
+  var checkbox = button.appendChild(document.createElement("input"))
+  checkbox.type = "checkbox"
+  checkbox.onclick = t.step_func(() => {
+    if(state == "start") {
+      assert_unreached()
+    } else if(state == "checkbox") {
+      assert_true(checkbox.checked)
+    }
+  })
+  checkbox.disabled = true
+  checkbox.click()
+  assert_equals(state, "start")
+
+  state = "checkbox"
+  checkbox.disabled = false
+  checkbox.click()
+  assert_equals(state, "checkbox")
+
+  state = "form"
+  button.click()
+  assert_equals(state, "done")
+
+  t.done()
+}, "disabled checkbox still has activation behavior, part 2")
+
+async_test(function(t) {
+  var state = "start"
+
+  var form = document.createElement("form")
+  form.onsubmit = t.step_func(() => {
+    if(state == "start" || state == "radio") {
+      state = "failure"
+    } else if(state == "form") {
+      state = "done"
+    }
+    return false
+  })
+  dump.appendChild(form)
+  var button = form.appendChild(document.createElement("button"))
+  button.type = "submit"
+  var radio = button.appendChild(document.createElement("input"))
+  radio.type = "radio"
+  radio.onclick = t.step_func(() => {
+    if(state == "start") {
+      assert_unreached()
+    } else if(state == "radio") {
+      assert_true(radio.checked)
+    }
+  })
+  radio.disabled = true
+  radio.click()
+  assert_equals(state, "start")
+
+  state = "radio"
+  radio.disabled = false
+  radio.click()
+  assert_equals(state, "radio")
+
+  state = "form"
+  button.click()
+  assert_equals(state, "done")
+
+  t.done()
+}, "disabled radio still has activation behavior")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "checkbox"
+  input.onclick = t.step_func_done(function() {
+    assert_true(input.checked)
+  })
+  input.click()
+}, "disconnected checkbox should be checked")
+
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "radio"
+  input.onclick = t.step_func_done(function() {
+    assert_true(input.checked)
+  })
+  input.click()
+}, "disconnected radio should be checked")
+
+async_test(t => {
+  const input = document.createElement('input');
+  input.type = 'checkbox';
+  input.onclick = t.step_func_done(() => {
+    assert_true(input.checked);
+  });
+  input.dispatchEvent(new MouseEvent('click'));
+}, `disconnected checkbox should be checked from dispatchEvent(new MouseEvent('click'))`);
+
+async_test(t => {
+  const input = document.createElement('input');
+  input.type = 'radio';
+  input.onclick = t.step_func_done(() => {
+    assert_true(input.checked);
+  });
+  input.dispatchEvent(new MouseEvent('click'));
+}, `disconnected radio should be checked from dispatchEvent(new MouseEvent('click'))`);
+
+test(() => {
+  const input = document.createElement("input");
+  input.type = "checkbox";
+  input.disabled = true;
+  input.dispatchEvent(new MouseEvent("click"));
+  assert_true(input.checked);
+}, `disabled checkbox should be checked from dispatchEvent(new MouseEvent("click"))`);
+
+test(() => {
+  const input = document.createElement("input");
+  input.type = "radio";
+  input.disabled = true;
+  input.dispatchEvent(new MouseEvent("click"));
+  assert_true(input.checked);
+}, `disabled radio should be checked from dispatchEvent(new MouseEvent("click"))`);
+
+async_test(t => {
+  const input = document.createElement("input");
+  input.type = "checkbox";
+  input.disabled = true;
+  input.onclick = t.step_func_done();
+  input.dispatchEvent(new MouseEvent("click"));
+}, `disabled checkbox should fire onclick`);
+
+async_test(t => {
+  const input = document.createElement("input");
+  input.type = "radio";
+  input.disabled = true;
+  input.onclick = t.step_func_done();
+  input.dispatchEvent(new MouseEvent("click"));
+}, `disabled radio should fire onclick`);
+
+async_test(t => {
+  const input = document.createElement("input");
+  input.type = "checkbox";
+  input.disabled = true;
+  input.onclick = t.step_func(ev => {
+    assert_true(input.checked);
+    ev.preventDefault();
+    queueMicrotask(t.step_func_done(() => {
+      assert_false(input.checked);
+    }));
+  });
+  input.dispatchEvent(new MouseEvent("click", { cancelable: true }));
+}, `disabled checkbox should get legacy-canceled-activation behavior`);
+
+async_test(t => {
+  const input = document.createElement("input");
+  input.type = "radio";
+  input.disabled = true;
+  input.onclick = t.step_func(ev => {
+    assert_true(input.checked);
+    ev.preventDefault();
+    queueMicrotask(t.step_func_done(() => {
+      assert_false(input.checked);
+    }));
+  });
+  input.dispatchEvent(new MouseEvent("click", { cancelable: true }));
+}, `disabled radio should get legacy-canceled-activation behavior`);
+
+test(t => {
+  const input = document.createElement("input");
+  input.type = "checkbox";
+  input.disabled = true;
+  const ev = new MouseEvent("click", { cancelable: true });
+  ev.preventDefault();
+  input.dispatchEvent(ev);
+  assert_false(input.checked);
+}, `disabled checkbox should get legacy-canceled-activation behavior 2`);
+
+test(t => {
+  const input = document.createElement("input");
+  input.type = "radio";
+  input.disabled = true;
+  const ev = new MouseEvent("click", { cancelable: true });
+  ev.preventDefault();
+  input.dispatchEvent(ev);
+  assert_false(input.checked);
+}, `disabled radio should get legacy-canceled-activation behavior 2`);
+
+for (const type of ["checkbox", "radio"]) {
+  for (const handler of ["oninput", "onchange"]) {
+    async_test(t => {
+      const input = document.createElement("input");
+      input.type = type;
+      input.onclick = t.step_func(ev => {
+        input.disabled = true;
+      });
+      input[handler] = t.step_func(ev => {
+        assert_equals(input.checked, true);
+        t.done();
+      });
+      dump.append(input);
+      input.click();
+    }, `disabling ${type} in onclick listener shouldn't suppress ${handler}`);
+  }
+}
+
+async_test(function(t) {
+  var form = document.createElement("form")
+  var didSubmit = false
+  form.onsubmit = t.step_func(() => {
+    didSubmit = true
+    return false
+  })
+  var input = form.appendChild(document.createElement("input"))
+  input.type = "submit"
+  input.click()
+  assert_false(didSubmit)
+  t.done()
+}, "disconnected form should not submit")
+
+async_test(t => {
+  const form = document.createElement("form");
+  form.onsubmit = t.step_func(ev => {
+    ev.preventDefault();
+    assert_unreached("The form is unexpectedly submitted.");
+  });
+  dump.append(form);
+  const input = form.appendChild(document.createElement("input"));
+  input.type = "submit"
+  input.disabled = true;
+  input.dispatchEvent(new MouseEvent("click", { cancelable: true }));
+  t.done();
+}, "disabled submit button should not activate");
+
+async_test(t => {
+  const form = document.createElement("form");
+  form.onsubmit = t.step_func(ev => {
+    ev.preventDefault();
+    assert_unreached("The form is unexpectedly submitted.");
+  });
+  dump.append(form);
+  const input = form.appendChild(document.createElement("input"));
+  input.onclick = t.step_func(() => {
+    input.disabled = true;
+  });
+  input.type = "submit"
+  input.dispatchEvent(new MouseEvent("click", { cancelable: true }));
+  t.done();
+}, "submit button should not activate if the event listener disables it");
+
+async_test(t => {
+  const form = document.createElement("form");
+  form.onsubmit = t.step_func(ev => {
+    ev.preventDefault();
+    assert_unreached("The form is unexpectedly submitted.");
+  });
+  dump.append(form);
+  const input = form.appendChild(document.createElement("input"));
+  input.onclick = t.step_func(() => {
+    input.type = "submit"
+    input.disabled = true;
+  });
+  input.click();
+  t.done();
+}, "submit button that morphed from checkbox should not activate");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-click.tentative.html b/testing/web-platform/tests/dom/events/Event-dispatch-click.tentative.html
new file mode 100644
index 0000000000..cfdae55ef2
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-click.tentative.html
@@ -0,0 +1,78 @@
+<!doctype html>
+<title>Clicks on input element</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=dump style=display:none></div>
+<script>
+var dump = document.getElementById("dump")
+
+test(t => {
+  const input = document.createElement("input");
+  input.type = "checkbox";
+  input.disabled = true;
+  const label = document.createElement("label");
+  label.append(input);
+  dump.append(label);
+  label.click();
+  assert_false(input.checked);
+}, "disabled checkbox should not be checked from label click");
+
+test(t => {
+  const input = document.createElement("input");
+  input.type = "radio";
+  input.disabled = true;
+  const label = document.createElement("label");
+  label.append(input);
+  dump.append(label);
+  label.click();
+  assert_false(input.checked);
+}, "disabled radio should not be checked from label click");
+
+test(t => {
+  const input = document.createElement("input");
+  input.type = "checkbox";
+  input.disabled = true;
+  const label = document.createElement("label");
+  label.append(input);
+  dump.append(label);
+  label.dispatchEvent(new MouseEvent("click"));
+  assert_false(input.checked);
+}, "disabled checkbox should not be checked from label click by dispatchEvent");
+
+test(t => {
+  const input = document.createElement("input");
+  input.type = "radio";
+  input.disabled = true;
+  const label = document.createElement("label");
+  label.append(input);
+  dump.append(label);
+  label.dispatchEvent(new MouseEvent("click"));
+  assert_false(input.checked);
+}, "disabled radio should not be checked from label click by dispatchEvent");
+
+test(t => {
+  const checkbox = dump.appendChild(document.createElement("input"));
+  checkbox.type = "checkbox";
+  checkbox.onclick = ev => {
+    checkbox.type = "date";
+    ev.preventDefault();
+  };
+  checkbox.dispatchEvent(new MouseEvent("click", { cancelable: true }));
+  assert_false(checkbox.checked);
+}, "checkbox morphed into another type should not mutate checked state");
+
+test(t => {
+  const radio1 = dump.appendChild(document.createElement("input"));
+  const radio2 = dump.appendChild(radio1.cloneNode());
+  radio1.type = radio2.type = "radio";
+  radio1.name = radio2.name = "foo";
+  radio2.checked = true;
+  radio1.onclick = ev => {
+    radio1.type = "date";
+    ev.preventDefault();
+  };
+  radio1.dispatchEvent(new MouseEvent("click", { cancelable: true }));
+  assert_false(radio1.checked);
+  assert_true(radio2.checked);
+}, "radio morphed into another type should not steal the existing checked state");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-detached-click.html b/testing/web-platform/tests/dom/events/Event-dispatch-detached-click.html
new file mode 100644
index 0000000000..76ea3d78ba
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-detached-click.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<title>Click event on an element not in the document</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+test(function() {
+  var EVENT = "click";
+  var TARGET = document.createElement("somerandomelement");
+  var t = async_test("Click event can be dispatched to an element that is not in the document.")
+  TARGET.addEventListener(EVENT, t.step_func(function(evt) {
+    assert_equals(evt.target, TARGET);
+    assert_equals(evt.srcElement, TARGET);
+    t.done();
+  }), true);
+  var e = document.createEvent("Event");
+  e.initEvent(EVENT, true, true);
+  TARGET.dispatchEvent(e);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-detached-input-and-change.html b/testing/web-platform/tests/dom/events/Event-dispatch-detached-input-and-change.html
new file mode 100644
index 0000000000..a53ae71ac2
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-detached-input-and-change.html
@@ -0,0 +1,190 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="author" title="Joey Arhar" href="mailto:jarhar@chromium.org">
+<title>input and change events for detached checkbox and radio elements</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+<script>
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'checkbox';
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.click();
+  assert_false(inputEventFired);
+  assert_false(changeEventFired);
+}, 'detached checkbox should not emit input or change events on click().');
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'radio';
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.click();
+  assert_false(inputEventFired);
+  assert_false(changeEventFired);
+}, 'detached radio should not emit input or change events on click().');
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'checkbox';
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.dispatchEvent(new MouseEvent('click'));
+  assert_false(inputEventFired);
+  assert_false(changeEventFired);
+}, `detached checkbox should not emit input or change events on dispatchEvent(new MouseEvent('click')).`);
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'radio';
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.dispatchEvent(new MouseEvent('click'));
+  assert_false(inputEventFired);
+  assert_false(changeEventFired);
+}, `detached radio should not emit input or change events on dispatchEvent(new MouseEvent('click')).`);
+
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'checkbox';
+  document.body.appendChild(input);
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.click();
+  assert_true(inputEventFired);
+  assert_true(changeEventFired);
+}, 'attached checkbox should emit input and change events on click().');
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'radio';
+  document.body.appendChild(input);
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.click();
+  assert_true(inputEventFired);
+  assert_true(changeEventFired);
+}, 'attached radio should emit input and change events on click().');
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'checkbox';
+  document.body.appendChild(input);
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.dispatchEvent(new MouseEvent('click'));
+  assert_true(inputEventFired);
+  assert_true(changeEventFired);
+}, `attached checkbox should emit input and change events on dispatchEvent(new MouseEvent('click')).`);
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'radio';
+  document.body.appendChild(input);
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.dispatchEvent(new MouseEvent('click'));
+  assert_true(inputEventFired);
+  assert_true(changeEventFired);
+}, `attached radio should emit input and change events on dispatchEvent(new MouseEvent('click')).`);
+
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'checkbox';
+  const shadowHost = document.createElement('div');
+  document.body.appendChild(shadowHost);
+  const shadowRoot = shadowHost.attachShadow({mode: 'open'});
+  shadowRoot.appendChild(input);
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.click();
+  assert_true(inputEventFired);
+  assert_true(changeEventFired);
+}, 'attached to shadow dom checkbox should emit input and change events on click().');
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'radio';
+  const shadowHost = document.createElement('div');
+  document.body.appendChild(shadowHost);
+  const shadowRoot = shadowHost.attachShadow({mode: 'open'});
+  shadowRoot.appendChild(input);
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.click();
+  assert_true(inputEventFired);
+  assert_true(changeEventFired);
+}, 'attached to shadow dom radio should emit input and change events on click().');
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'checkbox';
+  const shadowHost = document.createElement('div');
+  document.body.appendChild(shadowHost);
+  const shadowRoot = shadowHost.attachShadow({mode: 'open'});
+  shadowRoot.appendChild(input);
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.dispatchEvent(new MouseEvent('click'));
+  assert_true(inputEventFired);
+  assert_true(changeEventFired);
+}, `attached to shadow dom checkbox should emit input and change events on dispatchEvent(new MouseEvent('click')).`);
+
+test(() => {
+  const input = document.createElement('input');
+  input.type = 'radio';
+  const shadowHost = document.createElement('div');
+  document.body.appendChild(shadowHost);
+  const shadowRoot = shadowHost.attachShadow({mode: 'open'});
+  shadowRoot.appendChild(input);
+
+  let inputEventFired = false;
+  input.addEventListener('input', () => inputEventFired = true);
+  let changeEventFired = false;
+  input.addEventListener('change', () => changeEventFired = true);
+  input.dispatchEvent(new MouseEvent('click'));
+  assert_true(inputEventFired);
+  assert_true(changeEventFired);
+}, `attached to shadow dom radio should emit input and change events on dispatchEvent(new MouseEvent('click')).`);
+
+</script>
+</body>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-handlers-changed.html b/testing/web-platform/tests/dom/events/Event-dispatch-handlers-changed.html
new file mode 100644
index 0000000000..24e6fd70cb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-handlers-changed.html
@@ -0,0 +1,91 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title> Dispatch additional events inside an event listener </title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-dispatch">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+
+<script>
+test(function() {
+  var event_type = "bar";
+  var target = document.getElementById("target");
+  var parent = document.getElementById("parent");
+  var tbody = document.getElementById("table-body");
+  var table = document.getElementById("table");
+  var body = document.body;
+  var html = document.documentElement;
+  var targets = [window, document, html, body, table, tbody, parent, target];
+  var expected_targets = [
+    window,
+    document,
+    html,
+    body,
+    table,
+    tbody,
+    parent,
+    target,
+    target,
+    target, // The additional listener for target runs as we copy its listeners twice
+    parent,
+    tbody,
+    table,
+    body,
+    html,
+    document,
+    window
+  ];
+  var expected_listeners = [0,0,0,0,0,0,0,0,1,3,1,1,1,1,1,1,1];
+
+  var actual_targets = [], actual_listeners = [];
+  var test_event_function = function(i) {
+    return this.step_func(function(evt) {
+      actual_targets.push(evt.currentTarget);
+      actual_listeners.push(i);
+
+      if (evt.eventPhase != evt.BUBBLING_PHASE && evt.currentTarget.foo != 1) {
+        evt.currentTarget.removeEventListener(event_type, event_handlers[0], true);
+        evt.currentTarget.addEventListener(event_type, event_handlers[2], true);
+        evt.currentTarget.foo = 1;
+      }
+
+      if (evt.eventPhase != evt.CAPTURING_PHASE && evt.currentTarget.foo != 3) {
+        evt.currentTarget.removeEventListener(event_type, event_handlers[0], false);
+        evt.currentTarget.addEventListener(event_type, event_handlers[3], false);
+        evt.currentTarget.foo = 3;
+      }
+    });
+  }.bind(this);
+  var event_handlers = [
+    test_event_function(0),
+    test_event_function(1),
+    test_event_function(2),
+    test_event_function(3),
+  ];
+
+  for (var i = 0; i < targets.length; ++i) {
+    targets[i].addEventListener(event_type, event_handlers[0], true);
+    targets[i].addEventListener(event_type, event_handlers[1], false);
+  }
+
+  var evt = document.createEvent("Event");
+  evt.initEvent(event_type, true, true);
+  target.dispatchEvent(evt);
+
+  assert_array_equals(actual_targets, expected_targets, "actual_targets");
+  assert_array_equals(actual_listeners, expected_listeners, "actual_listeners");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-listener-order.window.js b/testing/web-platform/tests/dom/events/Event-dispatch-listener-order.window.js
new file mode 100644
index 0000000000..a01a472872
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-listener-order.window.js
@@ -0,0 +1,20 @@
+test(t => {
+  const hostParent = document.createElement("section"),
+        host = hostParent.appendChild(document.createElement("div")),
+        shadowRoot = host.attachShadow({ mode: "closed" }),
+        targetParent = shadowRoot.appendChild(document.createElement("p")),
+        target = targetParent.appendChild(document.createElement("span")),
+        path = [hostParent, host, shadowRoot, targetParent, target],
+        expected = [],
+        result = [];
+  path.forEach((node, index) => {
+    expected.splice(index, 0, "capturing " + node.nodeName);
+    expected.splice(index + 1, 0, "bubbling " + node.nodeName);
+  });
+  path.forEach(node => {
+    node.addEventListener("test", () => { result.push("bubbling " + node.nodeName) });
+    node.addEventListener("test", () => { result.push("capturing " + node.nodeName) }, true);
+  });
+  target.dispatchEvent(new CustomEvent('test', { detail: {}, bubbles: true, composed: true }));
+  assert_array_equals(result, expected);
+});
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-multiple-cancelBubble.html b/testing/web-platform/tests/dom/events/Event-dispatch-multiple-cancelBubble.html
new file mode 100644
index 0000000000..2873fd7794
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-multiple-cancelBubble.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Multiple dispatchEvent() and cancelBubble</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id=log></div>
+
+<div id="parent" style="display: none">
+    <input id="target" type="hidden" value=""/>
+</div>
+
+<script>
+test(function() {
+    var event_type = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var actual_result;
+    var test_event = function(evt) {
+        actual_result.push(evt.currentTarget);
+
+        if (parent == evt.currentTarget) {
+            evt.cancelBubble = true;
+        }
+    };
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, true, true);
+
+    target.addEventListener(event_type, test_event, false);
+    parent.addEventListener(event_type, test_event, false);
+    document.addEventListener(event_type, test_event, false);
+    window.addEventListener(event_type, test_event, false);
+
+    actual_result = [];
+    target.dispatchEvent(evt);
+    assert_array_equals(actual_result, [target, parent]);
+
+    actual_result = [];
+    parent.dispatchEvent(evt);
+    assert_array_equals(actual_result, [parent]);
+
+    actual_result = [];
+    document.dispatchEvent(evt);
+    assert_array_equals(actual_result, [document, window]);
+});
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-multiple-stopPropagation.html b/testing/web-platform/tests/dom/events/Event-dispatch-multiple-stopPropagation.html
new file mode 100644
index 0000000000..72644bd861
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-multiple-stopPropagation.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title> Multiple dispatchEvent() and stopPropagation() </title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id=log></div>
+
+<div id="parent" style="display: none">
+    <input id="target" type="hidden" value=""/>
+</div>
+
+<script>
+test(function() {
+    var event_type = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var actual_result;
+    var test_event = function(evt) {
+        actual_result.push(evt.currentTarget);
+
+        if (parent == evt.currentTarget) {
+            evt.stopPropagation();
+        }
+    };
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, true, true);
+
+    target.addEventListener(event_type, test_event, false);
+    parent.addEventListener(event_type, test_event, false);
+    document.addEventListener(event_type, test_event, false);
+    window.addEventListener(event_type, test_event, false);
+
+    actual_result = [];
+    target.dispatchEvent(evt);
+    assert_array_equals(actual_result, [target, parent]);
+
+    actual_result = [];
+    parent.dispatchEvent(evt);
+    assert_array_equals(actual_result, [parent]);
+
+    actual_result = [];
+    document.dispatchEvent(evt);
+    assert_array_equals(actual_result, [document, window]);
+});
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-omitted-capture.html b/testing/web-platform/tests/dom/events/Event-dispatch-omitted-capture.html
new file mode 100644
index 0000000000..77074d9a3e
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-omitted-capture.html
@@ -0,0 +1,70 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>EventTarget.addEventListener: capture argument omitted</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-eventtarget-addeventlistener">
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-dispatch">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+<script>
+test(function() {
+    var event_type = "foo";
+    var target = document.getElementById("target");
+    var targets = [
+        target,
+        document.getElementById("parent"),
+        document.getElementById("table-body"),
+        document.getElementById("table"),
+        document.body,
+        document.documentElement,
+        document,
+        window
+    ];
+    var phases = [
+        Event.AT_TARGET,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE
+    ];
+
+    var actual_targets = [], actual_phases = [];
+    var test_event = function(evt) {
+        actual_targets.push(evt.currentTarget);
+        actual_phases.push(evt.eventPhase);
+    }
+
+    for (var i = 0; i < targets.length; i++) {
+        targets[i].addEventListener(event_type, test_event);
+    }
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, true, true);
+
+    target.dispatchEvent(evt);
+
+    for (var i = 0; i < targets.length; i++) {
+        targets[i].removeEventListener(event_type, test_event);
+    }
+
+    target.dispatchEvent(evt);
+
+    assert_array_equals(actual_targets, targets, "targets");
+    assert_array_equals(actual_phases, phases, "phases");
+}, "EventTarget.addEventListener with the capture argument omitted");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-on-disabled-elements.html b/testing/web-platform/tests/dom/events/Event-dispatch-on-disabled-elements.html
new file mode 100644
index 0000000000..e7d6b455bb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-on-disabled-elements.html
@@ -0,0 +1,251 @@
+<!doctype html>
+<meta charset="utf8">
+<meta name="timeout" content="long">
+<title>Events must dispatch on disabled elements</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<style>
+  @keyframes fade {
+    0% {
+      opacity: 1;
+    }
+    100% {
+      opacity: 0;
+    }
+  }
+</style>
+<body>
+<script>
+// HTML elements that can be disabled
+const formElements = ["button", "input", "select", "textarea"];
+
+test(() => {
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+    elem.disabled = true;
+    // pass becomes true if the event is called and it's the right type.
+    let pass = false;
+    const listener = ({ type }) => {
+      pass = type === "click";
+    };
+    elem.addEventListener("click", listener, { once: true });
+    elem.dispatchEvent(new Event("click"));
+    assert_true(
+      pass,
+      `Untrusted "click" Event didn't dispatch on ${elem.constructor.name}.`
+    );
+  }
+}, "Can dispatch untrusted 'click' Events at disabled HTML elements.");
+
+test(() => {
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+    elem.disabled = true;
+    // pass becomes true if the event is called and it's the right type.
+    let pass = false;
+    const listener = ({ type }) => {
+      pass = type === "pass";
+    };
+    elem.addEventListener("pass", listener, { once: true });
+    elem.dispatchEvent(new Event("pass"));
+    assert_true(
+      pass,
+      `Untrusted "pass" Event didn't dispatch on ${elem.constructor.name}`
+    );
+  }
+}, "Can dispatch untrusted Events at disabled HTML elements.");
+
+test(() => {
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+    elem.disabled = true;
+    // pass becomes true if the event is called and it's the right type.
+    let pass = false;
+    const listener = ({ type }) => {
+      pass = type === "custom-pass";
+    };
+    elem.addEventListener("custom-pass", listener, { once: true });
+    elem.dispatchEvent(new CustomEvent("custom-pass"));
+    assert_true(
+      pass,
+      `CustomEvent "custom-pass" didn't dispatch on ${elem.constructor.name}`
+    );
+  }
+}, "Can dispatch CustomEvents at disabled HTML elements.");
+
+test(() => {
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+
+    // Element is disabled... so this click() MUST NOT fire an event.
+    elem.disabled = true;
+    let pass = true;
+    elem.onclick = e => {
+      pass = false;
+    };
+    elem.click();
+    assert_true(
+      pass,
+      `.click() must not dispatch "click" event on disabled ${
+        elem.constructor.name
+      }.`
+    );
+
+    // Element is (re)enabled... so this click() fires an event.
+    elem.disabled = false;
+    pass = false;
+    elem.onclick = e => {
+      pass = true;
+    };
+    elem.click();
+    assert_true(
+      pass,
+      `.click() must dispatch "click" event on enabled ${
+        elem.constructor.name
+      }.`
+    );
+  }
+}, "Calling click() on disabled elements must not dispatch events.");
+
+promise_test(async () => {
+  // For each form element type, set up transition event handlers.
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+    elem.disabled = true;
+    document.body.appendChild(elem);
+    const eventPromises = [
+      "transitionrun",
+      "transitionstart",
+      "transitionend",
+    ].map(eventType => {
+      return new Promise(r => {
+        elem.addEventListener(eventType, r);
+      });
+    });
+    // Flushing style triggers transition.
+    getComputedStyle(elem).opacity;
+    elem.style.transition = "opacity .1s";
+    elem.style.opacity = 0;
+    getComputedStyle(elem).opacity;
+    // All the events fire...
+    await Promise.all(eventPromises);
+    elem.remove();
+  }
+}, "CSS Transitions transitionrun, transitionstart, transitionend events fire on disabled form elements");
+
+promise_test(async () => {
+  // For each form element type, set up transition event handlers.
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+    elem.disabled = true;
+    document.body.appendChild(elem);
+    getComputedStyle(elem).opacity;
+    elem.style.transition = "opacity 100s";
+    // We use ontransitionstart to cancel the event.
+    elem.ontransitionstart = () => {
+      elem.style.display = "none";
+    };
+    const promiseToCancel = new Promise(r => {
+      elem.ontransitioncancel = r;
+    });
+    // Flushing style triggers the transition.
+    elem.style.opacity = 0;
+    getComputedStyle(elem).opacity;
+    await promiseToCancel;
+    // And we are done with this element.
+    elem.remove();
+  }
+}, "CSS Transitions transitioncancel event fires on disabled form elements");
+
+promise_test(async () => {
+  // For each form element type, set up transition event handlers.
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+    document.body.appendChild(elem);
+    elem.disabled = true;
+    const animationStartPromise = new Promise(r => {
+      elem.addEventListener("animationstart", () => {
+        // Seek to the second iteration to trigger the animationiteration event
+        elem.style.animationDelay = "-100s"
+        r();
+      });
+    });
+    const animationIterationPromise = new Promise(r => {
+      elem.addEventListener("animationiteration", ()=>{
+        elem.style.animationDelay = "-200s"
+        r();
+      });
+    });
+    const animationEndPromise = new Promise(r => {
+      elem.addEventListener("animationend", r);
+    });
+    elem.style.animation = "fade 100s 2";
+    elem.classList.add("animate");
+    // All the events fire...
+    await Promise.all([
+      animationStartPromise,
+      animationIterationPromise,
+      animationEndPromise,
+    ]);
+    elem.remove();
+  }
+}, "CSS Animation animationstart, animationiteration, animationend fire on disabled form elements");
+
+promise_test(async () => {
+  // For each form element type, set up transition event handlers.
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+    document.body.appendChild(elem);
+    elem.disabled = true;
+
+    const promiseToCancel = new Promise(r => {
+      elem.addEventListener("animationcancel", r);
+    });
+
+    elem.addEventListener("animationstart", () => {
+      // Cancel the animation by hiding it.
+      elem.style.display = "none";
+    });
+
+    // Trigger the animation
+    elem.style.animation = "fade 100s";
+    elem.classList.add("animate");
+    await promiseToCancel;
+    // And we are done with this element.
+    elem.remove();
+  }
+}, "CSS Animation's animationcancel event fires on disabled form elements");
+
+promise_test(async () => {
+  for (const localName of formElements) {
+    const elem = document.createElement(localName);
+    elem.disabled = true;
+    document.body.appendChild(elem);
+    // Element is disabled, so clicking must not fire events
+    let pass = true;
+    elem.onclick = e => {
+      pass = false;
+    };
+    // Disabled elements are not clickable.
+    await test_driver.click(elem);
+    assert_true(
+      pass,
+      `${elem.constructor.name} is disabled, so onclick must not fire.`
+    );
+    // Element is (re)enabled... so this click() will fire an event.
+    pass = false;
+    elem.disabled = false;
+    elem.onclick = () => {
+      pass = true;
+    };
+    await test_driver.click(elem);
+    assert_true(
+      pass,
+      `${elem.constructor.name} is enabled, so onclick must fire.`
+    );
+    elem.remove();
+  }
+}, "Real clicks on disabled elements must not dispatch events.");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-order-at-target.html b/testing/web-platform/tests/dom/events/Event-dispatch-order-at-target.html
new file mode 100644
index 0000000000..79673c3256
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-order-at-target.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Listeners are invoked in correct order (AT_TARGET phase)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+"use strict";
+
+test(() => {
+    const el = document.createElement("div");
+    const expectedOrder = ["capturing", "bubbling"];
+
+    let actualOrder = [];
+    el.addEventListener("click", evt => {
+        assert_equals(evt.eventPhase, Event.AT_TARGET);
+        actualOrder.push("bubbling");
+    }, false);
+    el.addEventListener("click", evt => {
+        assert_equals(evt.eventPhase, Event.AT_TARGET);
+        actualOrder.push("capturing");
+    }, true);
+
+    el.dispatchEvent(new Event("click", {bubbles: true}));
+    assert_array_equals(actualOrder, expectedOrder, "bubbles: true");
+
+    actualOrder = [];
+    el.dispatchEvent(new Event("click", {bubbles: false}));
+    assert_array_equals(actualOrder, expectedOrder, "bubbles: false");
+}, "Listeners are invoked in correct order (AT_TARGET phase)");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-order.html b/testing/web-platform/tests/dom/events/Event-dispatch-order.html
new file mode 100644
index 0000000000..ca94434595
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-order.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<title>Event phases order</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+async_test(function() {
+    document.addEventListener('DOMContentLoaded', this.step_func_done(function() {
+        var parent = document.getElementById('parent');
+        var child = document.getElementById('child');
+
+        var order = [];
+
+        parent.addEventListener('click', this.step_func(function(){ order.push(1) }), true);
+        child.addEventListener('click', this.step_func(function(){ order.push(2) }), false);
+        parent.addEventListener('click', this.step_func(function(){ order.push(3) }), false);
+
+        child.dispatchEvent(new Event('click', {bubbles: true}));
+
+        assert_array_equals(order, [1, 2, 3]);
+    }));
+}, "Event phases order");
+</script>
+<div id="parent">
+    <div id="child"></div>
+</div>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-other-document.html b/testing/web-platform/tests/dom/events/Event-dispatch-other-document.html
new file mode 100644
index 0000000000..689b48087a
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-other-document.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<title>Custom event on an element in another document</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+test(function() {
+  var doc = document.implementation.createHTMLDocument("Demo");
+  var element = doc.createElement("div");
+  var called = false;
+  element.addEventListener("foo", this.step_func(function(ev) {
+    assert_false(called);
+    called = true;
+    assert_equals(ev.target, element);
+    assert_equals(ev.srcElement, element);
+  }));
+  doc.body.appendChild(element);
+
+  var event = new Event("foo");
+  element.dispatchEvent(event);
+  assert_true(called);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-propagation-stopped.html b/testing/web-platform/tests/dom/events/Event-dispatch-propagation-stopped.html
new file mode 100644
index 0000000000..889f8cfe11
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-propagation-stopped.html
@@ -0,0 +1,59 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title> Calling stopPropagation() prior to dispatchEvent() </title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id=log></div>
+
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+
+<script>
+test(function() {
+    var event = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var tbody = document.getElementById("table-body");
+    var table = document.getElementById("table");
+    var body = document.body;
+    var html = document.documentElement;
+    var current_targets = [window, document, html, body, table, tbody, parent, target];
+    var expected_targets = [];
+    var actual_targets = [];
+    var expected_phases = [];
+    var actual_phases = [];
+
+    var test_event = function(evt) {
+        actual_targets.push(evt.currentTarget);
+        actual_phases.push(evt.eventPhase);
+    };
+
+    for (var i = 0; i < current_targets.length; ++i) {
+        current_targets[i].addEventListener(event, test_event, true);
+        current_targets[i].addEventListener(event, test_event, false);
+    }
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event, true, true);
+    evt.stopPropagation();
+    target.dispatchEvent(evt);
+
+    assert_array_equals(actual_targets, expected_targets, "actual_targets");
+    assert_array_equals(actual_phases, expected_phases, "actual_phases");
+});
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-redispatch.html b/testing/web-platform/tests/dom/events/Event-dispatch-redispatch.html
new file mode 100644
index 0000000000..cf861ca177
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-redispatch.html
@@ -0,0 +1,124 @@
+<!DOCTYPE html>
+<meta charset=urf-8>
+<title>EventTarget#dispatchEvent(): redispatching a native event</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<button>click me!</button>
+<div id=log></div>
+<script>
+var test_contentLoaded_redispatching = async_test("Redispatching DOMContentLoaded event after being dispatched");
+var test_mouseup_redispatching = async_test("Redispatching mouseup event whose default action dispatches a click event");
+var test_redispatching_of_dispatching_event = async_test("Redispatching event which is being dispatched");
+
+var buttonElement = document.querySelector("button");
+var contentLoadedEvent;
+
+var waitForLoad = new Promise(resolve => {
+  window.addEventListener("load", () => { requestAnimationFrame(resolve); }, {capture: false, once: true});
+});
+
+document.addEventListener("DOMContentLoaded", event => {
+  contentLoadedEvent = event;
+  test_redispatching_of_dispatching_event.step(() => {
+    assert_throws_dom("InvalidStateError", () => {
+      document.dispatchEvent(contentLoadedEvent);
+    }, "Trusted DOMContentLoaded event");
+  });
+}, {capture: true, once: true});
+
+window.addEventListener("load", loadEvent => {
+  let untrustedContentLoadedEvent;
+  buttonElement.addEventListener("DOMContentLoaded", event => {
+    untrustedContentLoadedEvent = event;
+    test_contentLoaded_redispatching.step(() => {
+      assert_false(untrustedContentLoadedEvent.isTrusted, "Redispatched DOMContentLoaded event shouldn't be trusted");
+    });
+    test_redispatching_of_dispatching_event.step(() => {
+      assert_throws_dom("InvalidStateError", () => {
+        document.dispatchEvent(untrustedContentLoadedEvent);
+      }, "Untrusted DOMContentLoaded event");
+    });
+  });
+
+  test_contentLoaded_redispatching.step(() => {
+    assert_true(contentLoadedEvent.isTrusted, "Received DOMContentLoaded event should be trusted before redispatching");
+    buttonElement.dispatchEvent(contentLoadedEvent);
+    assert_false(contentLoadedEvent.isTrusted, "Received DOMContentLoaded event shouldn't be trusted after redispatching");
+    assert_not_equals(untrustedContentLoadedEvent, undefined, "Untrusted DOMContentLoaded event should've been fired");
+    test_contentLoaded_redispatching.done();
+  });
+}, {capture: true, once: true});
+
+async function testMouseUpAndClickEvent() {
+  let mouseupEvent;
+  buttonElement.addEventListener("mouseup", event => {
+    mouseupEvent = event;
+    test_mouseup_redispatching.step(() => {
+      assert_true(mouseupEvent.isTrusted, "First mouseup event should be trusted");
+    });
+    test_redispatching_of_dispatching_event.step(() => {
+      assert_throws_dom("InvalidStateError", () => {
+        buttonElement.dispatchEvent(mouseupEvent);
+      }, "Trusted mouseup event");
+    });
+  }, {once: true});
+
+  let clickEvent;
+  buttonElement.addEventListener("click", event => {
+    clickEvent = event;
+    test_mouseup_redispatching.step(() => {
+      assert_true(clickEvent.isTrusted, "First click event should be trusted");
+    });
+    test_redispatching_of_dispatching_event.step(() => {
+      assert_throws_dom("InvalidStateError", function() {
+        buttonElement.dispatchEvent(event);
+      }, "Trusted click event");
+    });
+    buttonElement.addEventListener("mouseup", event => {
+      test_mouseup_redispatching.step(() => {
+        assert_false(event.isTrusted, "Redispatched mouseup event shouldn't be trusted");
+      });
+      test_redispatching_of_dispatching_event.step(() => {
+        assert_throws_dom("InvalidStateError", function() {
+          buttonElement.dispatchEvent(event);
+        }, "Untrusted mouseup event");
+      });
+    }, {once: true});
+    function onClick() {
+      test_mouseup_redispatching.step(() => {
+        assert_true(false, "click event shouldn't be fired for dispatched mouseup event");
+      });
+    }
+    test_mouseup_redispatching.step(() => {
+      assert_true(mouseupEvent.isTrusted, "Received mouseup event should be trusted before redispatching from click event listener");
+      buttonElement.addEventListener("click", onClick);
+      buttonElement.dispatchEvent(mouseupEvent);
+      buttonElement.removeEventListener("click", onClick);
+      assert_false(mouseupEvent.isTrusted, "Received mouseup event shouldn't be trusted after redispatching");
+      assert_true(clickEvent.isTrusted, "First click event should still be trusted even after redispatching mouseup event");
+    });
+  }, {once: true});
+
+  await waitForLoad;
+  let bounds = buttonElement.getBoundingClientRect();
+  test(() => { assert_true(true); }, `Synthesizing click on button...`);
+  new test_driver.click(buttonElement)
+      .then(() => {
+        test_mouseup_redispatching.step(() => {
+          assert_not_equals(clickEvent, undefined, "mouseup and click events should've been fired");
+        });
+        test_mouseup_redispatching.done();
+        test_redispatching_of_dispatching_event.done();
+      }, (reason) => {
+        test_mouseup_redispatching.step(() => {
+          assert_true(false, `Failed to send mouse click due to ${reason}`);
+        });
+        test_mouseup_redispatching.done();
+        test_redispatching_of_dispatching_event.done();
+      });
+}
+testMouseUpAndClickEvent();
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-reenter.html b/testing/web-platform/tests/dom/events/Event-dispatch-reenter.html
new file mode 100644
index 0000000000..71f8517bdd
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-reenter.html
@@ -0,0 +1,66 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title> Dispatch additional events inside an event listener </title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+<script>
+test(function() {
+    var event_type = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var tbody = document.getElementById("table-body");
+    var table = document.getElementById("table");
+    var body = document.body;
+    var html = document.documentElement;
+    var targets = [window, document, html, body, table, tbody, parent, target];
+    var expected_targets = [
+        window, document, html, body, table,
+        target, parent, tbody,
+        table, body, html, document, window,
+        tbody, parent, target];
+    var actual_targets = [];
+    var expected_types = [
+        "foo", "foo", "foo", "foo", "foo",
+        "bar", "bar", "bar",
+        "bar", "bar", "bar", "bar", "bar",
+        "foo", "foo", "foo"
+    ];
+
+    var actual_targets = [], actual_types = [];
+    var test_event = this.step_func(function(evt) {
+        actual_targets.push(evt.currentTarget);
+        actual_types.push(evt.type);
+
+        if (table == evt.currentTarget && event_type == evt.type) {
+            var e = document.createEvent("Event");
+            e.initEvent("bar", true, true);
+            target.dispatchEvent(e);
+        }
+    });
+
+    for (var i = 0; i < targets.length; ++i) {
+        targets[i].addEventListener(event_type, test_event, true);
+        targets[i].addEventListener("bar", test_event, false);
+    }
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, false, true);
+    target.dispatchEvent(evt);
+
+    assert_array_equals(actual_targets, expected_targets, "actual_targets");
+    assert_array_equals(actual_types, expected_types, "actual_types");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-target-moved.html b/testing/web-platform/tests/dom/events/Event-dispatch-target-moved.html
new file mode 100644
index 0000000000..facb2c7b95
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-target-moved.html
@@ -0,0 +1,73 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title> Determined event propagation path - target moved </title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-dispatch">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+<script>
+test(function() {
+    var event_type = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var tbody = document.getElementById("table-body");
+    var table = document.getElementById("table");
+    var body = document.body;
+    var html = document.documentElement;
+    var targets = [window, document, html, body, table, tbody, parent, target];
+    var expected_targets = targets.concat([target, parent, tbody, table, body, html, document, window]);
+    var phases = [
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.AT_TARGET,
+        Event.AT_TARGET,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+    ];
+
+    var actual_targets = [], actual_phases = [];
+    var test_event = this.step_func(function(evt) {
+        if (parent === target.parentNode) {
+            var table_row = document.getElementById("table-row");
+            table_row.appendChild(parent.removeChild(target));
+        }
+
+        actual_targets.push(evt.currentTarget);
+        actual_phases.push(evt.eventPhase);
+    });
+
+    for (var i = 0; i < targets.length; i++) {
+        targets[i].addEventListener(event_type, test_event, true);
+        targets[i].addEventListener(event_type, test_event, false);
+    }
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, true, true);
+    target.dispatchEvent(evt);
+
+    assert_array_equals(actual_targets, expected_targets, "targets");
+    assert_array_equals(actual_phases, phases, "phases");
+}, "Event propagation path when an element in it is moved within the DOM");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-target-removed.html b/testing/web-platform/tests/dom/events/Event-dispatch-target-removed.html
new file mode 100644
index 0000000000..531799c3ad
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-target-removed.html
@@ -0,0 +1,72 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Determined event propagation path - target removed</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-dispatch">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+<script>
+test(function() {
+    var event_type = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var tbody = document.getElementById("table-body");
+    var table = document.getElementById("table");
+    var body = document.body;
+    var html = document.documentElement;
+    var targets = [window, document, html, body, table, tbody, parent, target];
+    var expected_targets = targets.concat([target, parent, tbody, table, body, html, document, window]);
+    var phases = [
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.CAPTURING_PHASE,
+        Event.AT_TARGET,
+        Event.AT_TARGET,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+        Event.BUBBLING_PHASE,
+    ];
+
+    var actual_targets = [], actual_phases = [];
+    var test_event = this.step_func(function(evt) {
+        if (parent === target.parentNode) {
+            parent.removeChild(target);
+        }
+
+        actual_targets.push(evt.currentTarget);
+        actual_phases.push(evt.eventPhase);
+    });
+
+    for (var i = 0; i < targets.length; i++) {
+        targets[i].addEventListener(event_type, test_event, true);
+        targets[i].addEventListener(event_type, test_event, false);
+    }
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, true, true);
+    target.dispatchEvent(evt);
+
+    assert_array_equals(actual_targets, expected_targets, "targets");
+    assert_array_equals(actual_phases, phases, "phases");
+}, "Event propagation path when an element in it is removed from the DOM");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-dispatch-throwing.html b/testing/web-platform/tests/dom/events/Event-dispatch-throwing.html
new file mode 100644
index 0000000000..7d1c0d94a0
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-dispatch-throwing.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>Throwing in event listeners</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+setup({allow_uncaught_exception:true})
+
+test(function() {
+    var errorEvents = 0;
+    window.onerror = this.step_func(function(e) {
+        assert_equals(typeof e, 'string');
+        ++errorEvents;
+    });
+
+    var element = document.createElement('div');
+
+    element.addEventListener('click', function() {
+        throw new Error('Error from only listener');
+    });
+
+    element.dispatchEvent(new Event('click'));
+
+    assert_equals(errorEvents, 1);
+}, "Throwing in event listener with a single listeners");
+
+test(function() {
+    var errorEvents = 0;
+    window.onerror = this.step_func(function(e) {
+        assert_equals(typeof e, 'string');
+        ++errorEvents;
+    });
+
+    var element = document.createElement('div');
+
+    var secondCalled = false;
+
+    element.addEventListener('click', function() {
+        throw new Error('Error from first listener');
+    });
+    element.addEventListener('click', this.step_func(function() {
+        secondCalled = true;
+    }), false);
+
+    element.dispatchEvent(new Event('click'));
+
+    assert_equals(errorEvents, 1);
+    assert_true(secondCalled);
+}, "Throwing in event listener with multiple listeners");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-init-while-dispatching.html b/testing/web-platform/tests/dom/events/Event-init-while-dispatching.html
new file mode 100644
index 0000000000..2aa1f6701c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-init-while-dispatching.html
@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Re-initializing events while dispatching them</title>
+<link rel="author" title="Josh Matthews" href="mailto:josh@joshmatthews.net">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+var events = {
+  'KeyboardEvent': {
+    'constructor': function() { return new KeyboardEvent("type", {key: "A"}); },
+    'init': function(ev) { ev.initKeyboardEvent("type2", true, true, null, "a", 1, "", true, "") },
+    'check': function(ev) {
+       assert_equals(ev.key, "A", "initKeyboardEvent key setter should short-circuit");
+       assert_false(ev.repeat, "initKeyboardEvent repeat setter should short-circuit");
+       assert_equals(ev.location, 0, "initKeyboardEvent location setter should short-circuit");
+     }
+  },
+  'MouseEvent': {
+    'constructor': function() { return new MouseEvent("type"); },
+    'init': function(ev) { ev.initMouseEvent("type2", true, true, null, 0, 1, 1, 1, 1, true, true, true, true, 1, null) },
+    'check': function(ev) {
+      assert_equals(ev.screenX, 0, "initMouseEvent screenX setter should short-circuit");
+      assert_equals(ev.screenY, 0, "initMouseEvent screenY setter should short-circuit");
+      assert_equals(ev.clientX, 0, "initMouseEvent clientX setter should short-circuit");
+      assert_equals(ev.clientY, 0, "initMouseEvent clientY setter should short-circuit");
+      assert_false(ev.ctrlKey, "initMouseEvent ctrlKey setter should short-circuit");
+      assert_false(ev.altKey, "initMouseEvent altKey setter should short-circuit");
+      assert_false(ev.shiftKey, "initMouseEvent shiftKey setter should short-circuit");
+      assert_false(ev.metaKey, "initMouseEvent metaKey setter should short-circuit");
+      assert_equals(ev.button, 0, "initMouseEvent button setter should short-circuit");
+    }
+  },
+  'CustomEvent': {
+    'constructor': function() { return new CustomEvent("type") },
+    'init': function(ev) { ev.initCustomEvent("type2", true, true, 1) },
+    'check': function(ev) {
+      assert_equals(ev.detail, null, "initCustomEvent detail setter should short-circuit");
+    }
+  },
+  'UIEvent': {
+    'constructor': function() { return new UIEvent("type") },
+    'init': function(ev) { ev.initUIEvent("type2", true, true, window, 1) },
+    'check': function(ev) {
+      assert_equals(ev.view, null, "initUIEvent view setter should short-circuit");
+      assert_equals(ev.detail, 0, "initUIEvent detail setter should short-circuit");
+    }
+  },
+  'Event': {
+    'constructor': function() { return new Event("type") },
+    'init': function(ev) { ev.initEvent("type2", true, true) },
+    'check': function(ev) {
+      assert_equals(ev.bubbles, false, "initEvent bubbles setter should short-circuit");
+      assert_equals(ev.cancelable, false, "initEvent cancelable setter should short-circuit");
+      assert_equals(ev.type, "type", "initEvent type setter should short-circuit");
+    }
+  }
+};
+
+var names = Object.keys(events);
+for (var i = 0; i < names.length; i++) {
+  var t = async_test("Calling init" + names[i] + " while dispatching.");
+  t.step(function() {
+    var e = events[names[i]].constructor();
+
+    var target = document.createElement("div")
+    target.addEventListener("type", t.step_func(function() {
+      events[names[i]].init(e);
+
+      var o = e;
+      while ((o = Object.getPrototypeOf(o))) {
+        if (!(o.constructor.name in events)) {
+          break;
+        }
+        events[o.constructor.name].check(e);
+      }
+    }), false);
+
+    assert_equals(target.dispatchEvent(e), true, "dispatchEvent must return true")
+  });
+  t.done();
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-initEvent.html b/testing/web-platform/tests/dom/events/Event-initEvent.html
new file mode 100644
index 0000000000..ad1018d4da
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-initEvent.html
@@ -0,0 +1,136 @@
+<!DOCTYPE html>
+<title>Event.initEvent</title>
+<link rel="author" title="Ms2ger" href="mailto:Ms2ger@gmail.com">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+var booleans = [true, false];
+booleans.forEach(function(bubbles) {
+  booleans.forEach(function(cancelable) {
+    test(function() {
+      var e = document.createEvent("Event")
+      e.initEvent("type", bubbles, cancelable)
+
+      // Step 2.
+      // Stop (immediate) propagation flag is tested later
+      assert_equals(e.defaultPrevented, false, "defaultPrevented")
+      assert_equals(e.returnValue, true, "returnValue")
+      // Step 3.
+      assert_equals(e.isTrusted, false, "isTrusted")
+      // Step 4.
+      assert_equals(e.target, null, "target")
+      assert_equals(e.srcElement, null, "srcElement")
+      // Step 5.
+      assert_equals(e.type, "type", "type")
+      // Step 6.
+      assert_equals(e.bubbles, bubbles, "bubbles")
+      // Step 7.
+      assert_equals(e.cancelable, cancelable, "cancelable")
+    }, "Properties of initEvent(type, " + bubbles + ", " + cancelable + ")")
+  })
+})
+
+test(function() {
+  var e = document.createEvent("Event")
+  e.initEvent("type 1", true, false)
+  assert_equals(e.type, "type 1", "type (first init)")
+  assert_equals(e.bubbles, true, "bubbles (first init)")
+  assert_equals(e.cancelable, false, "cancelable (first init)")
+
+  e.initEvent("type 2", false, true)
+  assert_equals(e.type, "type 2", "type (second init)")
+  assert_equals(e.bubbles, false, "bubbles (second init)")
+  assert_equals(e.cancelable, true, "cancelable (second init)")
+}, "Calling initEvent multiple times (getting type).")
+
+test(function() {
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=998809
+  var e = document.createEvent("Event")
+  e.initEvent("type 1", true, false)
+  assert_equals(e.bubbles, true, "bubbles (first init)")
+  assert_equals(e.cancelable, false, "cancelable (first init)")
+
+  e.initEvent("type 2", false, true)
+  assert_equals(e.type, "type 2", "type (second init)")
+  assert_equals(e.bubbles, false, "bubbles (second init)")
+  assert_equals(e.cancelable, true, "cancelable (second init)")
+}, "Calling initEvent multiple times (not getting type).")
+
+// Step 2.
+async_test(function() {
+  // https://www.w3.org/Bugs/Public/show_bug.cgi?id=17715
+
+  var e = document.createEvent("Event")
+  e.initEvent("type", false, false)
+  assert_equals(e.type, "type", "type (first init)")
+  assert_equals(e.bubbles, false, "bubbles (first init)")
+  assert_equals(e.cancelable, false, "cancelable (first init)")
+
+  var target = document.createElement("div")
+  target.addEventListener("type", this.step_func(function() {
+    e.initEvent("fail", true, true)
+    assert_equals(e.type, "type", "type (second init)")
+    assert_equals(e.bubbles, false, "bubbles (second init)")
+    assert_equals(e.cancelable, false, "cancelable (second init)")
+  }), false)
+
+  assert_equals(target.dispatchEvent(e), true, "dispatchEvent must return true")
+
+  this.done()
+}, "Calling initEvent must not have an effect during dispatching.")
+
+test(function() {
+  var e = document.createEvent("Event")
+  e.stopPropagation()
+  e.initEvent("type", false, false)
+  var target = document.createElement("div")
+  var called = false
+  target.addEventListener("type", function() { called = true }, false)
+  assert_false(e.cancelBubble, "cancelBubble must be false")
+  assert_true(target.dispatchEvent(e), "dispatchEvent must return true")
+  assert_true(called, "Listener must be called")
+}, "Calling initEvent must unset the stop propagation flag.")
+
+test(function() {
+  var e = document.createEvent("Event")
+  e.stopImmediatePropagation()
+  e.initEvent("type", false, false)
+  var target = document.createElement("div")
+  var called = false
+  target.addEventListener("type", function() { called = true }, false)
+  assert_true(target.dispatchEvent(e), "dispatchEvent must return true")
+  assert_true(called, "Listener must be called")
+}, "Calling initEvent must unset the stop immediate propagation flag.")
+
+async_test(function() {
+  var e = document.createEvent("Event")
+  e.initEvent("type", false, false)
+
+  var target = document.createElement("div")
+  target.addEventListener("type", this.step_func(function() {
+    e.initEvent("type2", true, true);
+    assert_equals(e.type, "type", "initEvent type setter should short-circuit");
+    assert_false(e.bubbles, "initEvent bubbles setter should short-circuit");
+    assert_false(e.cancelable, "initEvent cancelable setter should short-circuit");
+  }), false)
+  assert_equals(target.dispatchEvent(e), true, "dispatchEvent must return true")
+
+  this.done()
+}, "Calling initEvent during propagation.")
+
+test(function() {
+  var e = document.createEvent("Event")
+  assert_throws_js(TypeError, function() {
+    e.initEvent()
+  })
+}, "First parameter to initEvent should be mandatory.")
+
+test(function() {
+  var e = document.createEvent("Event")
+  e.initEvent("type")
+  assert_equals(e.type, "type", "type")
+  assert_false(e.bubbles, "bubbles")
+  assert_false(e.cancelable, "cancelable")
+}, "Tests initEvent's default parameter values.")
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-isTrusted.any.js b/testing/web-platform/tests/dom/events/Event-isTrusted.any.js
new file mode 100644
index 0000000000..00bcecd0ed
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-isTrusted.any.js
@@ -0,0 +1,11 @@
+test(function() {
+  var desc1 = Object.getOwnPropertyDescriptor(new Event("x"), "isTrusted");
+  assert_not_equals(desc1, undefined);
+  assert_equals(typeof desc1.get, "function");
+
+  var desc2 = Object.getOwnPropertyDescriptor(new Event("x"), "isTrusted");
+  assert_not_equals(desc2, undefined);
+  assert_equals(typeof desc2.get, "function");
+
+  assert_equals(desc1.get, desc2.get);
+});
diff --git a/testing/web-platform/tests/dom/events/Event-propagation.html b/testing/web-platform/tests/dom/events/Event-propagation.html
new file mode 100644
index 0000000000..33989eb4bf
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-propagation.html
@@ -0,0 +1,48 @@
+<!doctype html>
+<title>Event propagation tests</title>
+<link rel=author title="Aryeh Gregor" href=ayg@aryeh.name>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+"use strict";
+
+function testPropagationFlag(ev, expected, desc) {
+  test(function() {
+    var called = false;
+    var callback = function() { called = true };
+    this.add_cleanup(function() {
+      document.head.removeEventListener("foo", callback)
+    });
+    document.head.addEventListener("foo", callback);
+    document.head.dispatchEvent(ev);
+    assert_equals(called, expected, "Propagation flag");
+    // dispatchEvent resets the propagation flags so it will happily dispatch
+    // the event the second time around.
+    document.head.dispatchEvent(ev);
+    assert_equals(called, true, "Propagation flag after first dispatch");
+  }, desc);
+}
+
+var ev = document.createEvent("Event");
+ev.initEvent("foo", true, false);
+testPropagationFlag(ev, true, "Newly-created Event");
+ev.stopPropagation();
+testPropagationFlag(ev, false, "After stopPropagation()");
+ev.initEvent("foo", true, false);
+testPropagationFlag(ev, true, "Reinitialized after stopPropagation()");
+
+var ev = document.createEvent("Event");
+ev.initEvent("foo", true, false);
+ev.stopImmediatePropagation();
+testPropagationFlag(ev, false, "After stopImmediatePropagation()");
+ev.initEvent("foo", true, false);
+testPropagationFlag(ev, true, "Reinitialized after stopImmediatePropagation()");
+
+var ev = document.createEvent("Event");
+ev.initEvent("foo", true, false);
+ev.cancelBubble = true;
+testPropagationFlag(ev, false, "After cancelBubble=true");
+ev.initEvent("foo", true, false);
+testPropagationFlag(ev, true, "Reinitialized after cancelBubble=true");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-returnValue.html b/testing/web-platform/tests/dom/events/Event-returnValue.html
new file mode 100644
index 0000000000..08df2d4141
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-returnValue.html
@@ -0,0 +1,64 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Event.returnValue</title>
+  <link rel="author" title="Chris Rebert" href="http://chrisrebert.com">
+  <link rel="help" href="https://dom.spec.whatwg.org/#dom-event-returnvalue">
+  <meta name="flags" content="dom">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+  <div id="log"></div>
+  <script>
+test(function() {
+  var ev = new Event("foo");
+  assert_true(ev.returnValue, "returnValue");
+}, "When an event is created, returnValue should be initialized to true.");
+test(function() {
+  var ev = new Event("foo", {"cancelable": false});
+  assert_false(ev.cancelable, "cancelable (before)");
+  ev.preventDefault();
+  assert_false(ev.cancelable, "cancelable (after)");
+  assert_true(ev.returnValue, "returnValue");
+}, "preventDefault() should not change returnValue if cancelable is false.");
+test(function() {
+  var ev = new Event("foo", {"cancelable": false});
+  assert_false(ev.cancelable, "cancelable (before)");
+  ev.returnValue = false;
+  assert_false(ev.cancelable, "cancelable (after)");
+  assert_true(ev.returnValue, "returnValue");
+}, "returnValue=false should have no effect if cancelable is false.");
+test(function() {
+  var ev = new Event("foo", {"cancelable": true});
+  assert_true(ev.cancelable, "cancelable (before)");
+  ev.preventDefault();
+  assert_true(ev.cancelable, "cancelable (after)");
+  assert_false(ev.returnValue, "returnValue");
+}, "preventDefault() should change returnValue if cancelable is true.");
+test(function() {
+  var ev = new Event("foo", {"cancelable": true});
+  assert_true(ev.cancelable, "cancelable (before)");
+  ev.returnValue = false;
+  assert_true(ev.cancelable, "cancelable (after)");
+  assert_false(ev.returnValue, "returnValue");
+}, "returnValue should change returnValue if cancelable is true.");
+test(function() {
+  var ev = document.createEvent("Event");
+  ev.returnValue = false;
+  ev.initEvent("foo", true, true);
+  assert_true(ev.bubbles, "bubbles");
+  assert_true(ev.cancelable, "cancelable");
+  assert_true(ev.returnValue, "returnValue");
+}, "initEvent should unset returnValue.");
+test(function() {
+  var ev = new Event("foo", {"cancelable": true});
+  ev.preventDefault();
+  ev.returnValue = true;// no-op
+  assert_true(ev.defaultPrevented);
+  assert_false(ev.returnValue);
+}, "returnValue=true should have no effect once the canceled flag was set.");
+  </script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/Event-stopImmediatePropagation.html b/testing/web-platform/tests/dom/events/Event-stopImmediatePropagation.html
new file mode 100644
index 0000000000..b75732257a
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-stopImmediatePropagation.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Event's stopImmediatePropagation</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-event-stopimmediatepropagation">
+<link rel="author" href="mailto:d@domenic.me" title="Domenic Denicola">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<div id="target"></div>
+
+<script>
+"use strict";
+
+setup({ single_test: true });
+
+const target = document.querySelector("#target");
+
+let timesCalled = 0;
+target.addEventListener("test", e => {
+  ++timesCalled;
+  e.stopImmediatePropagation();
+  assert_equals(e.cancelBubble, true, "The stop propagation flag must have been set");
+});
+target.addEventListener("test", () => {
+  ++timesCalled;
+});
+
+const e = new Event("test");
+target.dispatchEvent(e);
+assert_equals(timesCalled, 1, "The second listener must not have been called");
+
+done();
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-stopPropagation-cancel-bubbling.html b/testing/web-platform/tests/dom/events/Event-stopPropagation-cancel-bubbling.html
new file mode 100644
index 0000000000..5c2c49f338
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-stopPropagation-cancel-bubbling.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="author" title="Joey Arhar" href="mailto:jarhar@chromium.org">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<script>
+test(t => {
+  const element = document.createElement('div');
+
+  element.addEventListener('click', () => {
+    event.stopPropagation();
+  }, { capture: true });
+
+  element.addEventListener('click',
+    t.unreached_func('stopPropagation in the capture handler should have canceled this bubble handler.'));
+
+  element.dispatchEvent(new MouseEvent('click', { bubbles: true, cancelable: true }));
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-subclasses-constructors.html b/testing/web-platform/tests/dom/events/Event-subclasses-constructors.html
new file mode 100644
index 0000000000..08a5ded011
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-subclasses-constructors.html
@@ -0,0 +1,179 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Event constructors</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function assert_props(iface, event, defaults) {
+  assert_true(event instanceof self[iface]);
+  expected[iface].properties.forEach(function(p) {
+    var property = p[0], value = p[defaults ? 1 : 2];
+    assert_true(property in event,
+                "Event " + format_value(event) + " should have a " +
+                property + " property");
+    assert_equals(event[property], value,
+                  "The value of the " + property + " property should be " +
+                  format_value(value));
+  });
+  if ("parent" in expected[iface]) {
+    assert_props(expected[iface].parent, event, defaults);
+  }
+}
+
+// Class declarations don't go on the global by default, so put it there ourselves:
+
+self.SubclassedEvent = class SubclassedEvent extends Event {
+  constructor(name, props) {
+    super(name, props);
+    if (props && typeof(props) == "object" && "customProp" in props) {
+      this.customProp = props.customProp;
+    } else {
+      this.customProp = 5;
+    }
+  }
+
+  get fixedProp() {
+    return 17;
+  }
+}
+
+var EventModifierInit = [
+  ["ctrlKey", false, true],
+  ["shiftKey", false, true],
+  ["altKey", false, true],
+  ["metaKey", false, true],
+];
+var expected = {
+  "Event": {
+    "properties": [
+      ["bubbles", false, true],
+      ["cancelable", false, true],
+      ["isTrusted", false, false],
+    ],
+  },
+
+  "UIEvent": {
+    "parent": "Event",
+    "properties": [
+      ["view", null, window],
+      ["detail", 0, 7],
+    ],
+  },
+
+  "FocusEvent": {
+    "parent": "UIEvent",
+    "properties": [
+      ["relatedTarget", null, document],
+    ],
+  },
+
+  "MouseEvent": {
+    "parent": "UIEvent",
+    "properties": EventModifierInit.concat([
+      ["screenX", 0, 40],
+      ["screenY", 0, 40],
+      ["clientX", 0, 40],
+      ["clientY", 0, 40],
+      ["button", 0, 40],
+      ["buttons", 0, 40],
+      ["relatedTarget", null, document],
+    ]),
+  },
+
+  "WheelEvent": {
+    "parent": "MouseEvent",
+    "properties": [
+      ["deltaX", 0.0, 3.1],
+      ["deltaY", 0.0, 3.1],
+      ["deltaZ", 0.0, 3.1],
+      ["deltaMode", 0, 40],
+    ],
+  },
+
+  "KeyboardEvent": {
+    "parent": "UIEvent",
+    "properties": EventModifierInit.concat([
+      ["key", "", "string"],
+      ["code", "", "string"],
+      ["location", 0, 7],
+      ["repeat", false, true],
+      ["isComposing", false, true],
+      ["charCode", 0, 7],
+      ["keyCode", 0, 7],
+      ["which", 0, 7],
+    ]),
+  },
+
+  "CompositionEvent": {
+    "parent": "UIEvent",
+    "properties": [
+      ["data", "", "string"],
+    ],
+  },
+
+  "SubclassedEvent": {
+    "parent": "Event",
+    "properties": [
+      ["customProp", 5, 8],
+      ["fixedProp", 17, 17],
+    ],
+  },
+};
+
+Object.keys(expected).forEach(function(iface) {
+  test(function() {
+    var event = new self[iface]("type");
+    assert_props(iface, event, true);
+  }, iface + " constructor (no argument)");
+
+  test(function() {
+    var event = new self[iface]("type", undefined);
+    assert_props(iface, event, true);
+  }, iface + " constructor (undefined argument)");
+
+  test(function() {
+    var event = new self[iface]("type", null);
+    assert_props(iface, event, true);
+  }, iface + " constructor (null argument)");
+
+  test(function() {
+    var event = new self[iface]("type", {});
+    assert_props(iface, event, true);
+  }, iface + " constructor (empty argument)");
+
+  test(function() {
+    var dictionary = {};
+    expected[iface].properties.forEach(function(p) {
+      var property = p[0], value = p[1];
+      dictionary[property] = value;
+    });
+    var event = new self[iface]("type", dictionary);
+    assert_props(iface, event, true);
+  }, iface + " constructor (argument with default values)");
+
+  test(function() {
+    function fill_in(iface, dictionary) {
+      if ("parent" in expected[iface]) {
+        fill_in(expected[iface].parent, dictionary)
+      }
+      expected[iface].properties.forEach(function(p) {
+        var property = p[0], value = p[2];
+        dictionary[property] = value;
+      });
+    }
+
+    var dictionary = {};
+    fill_in(iface, dictionary);
+
+    var event = new self[iface]("type", dictionary);
+    assert_props(iface, event, false);
+  }, iface + " constructor (argument with non-default values)");
+});
+
+test(function () {
+  assert_throws_js(TypeError, function() {
+    new UIEvent("x", { view: 7 })
+  });
+}, "UIEvent constructor (view argument with wrong type)")
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-timestamp-cross-realm-getter.html b/testing/web-platform/tests/dom/events/Event-timestamp-cross-realm-getter.html
new file mode 100644
index 0000000000..45823de26b
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-timestamp-cross-realm-getter.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>event.timeStamp is initialized using event's relevant global object</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#ref-for-dom-event-timestamp%E2%91%A1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+<script>
+const t = async_test();
+t.step_timeout(() => {
+  const iframeDelayed = document.createElement("iframe");
+  iframeDelayed.onload = t.step_func_done(() => {
+    // Use eval() to eliminate false-positive test result for WebKit builds before r280256,
+    // which invoked WebIDL accessors in context of lexical (caller) global object.
+    const timeStampExpected = iframeDelayed.contentWindow.eval(`new Event("foo").timeStamp`);
+    const eventDelayed = new iframeDelayed.contentWindow.Event("foo");
+
+    const {get} = Object.getOwnPropertyDescriptor(Event.prototype, "timeStamp");
+    assert_approx_equals(get.call(eventDelayed), timeStampExpected, 5, "via Object.getOwnPropertyDescriptor");
+
+    Object.setPrototypeOf(eventDelayed, Event.prototype);
+    assert_approx_equals(eventDelayed.timeStamp, timeStampExpected, 5, "via Object.setPrototypeOf");
+  });
+  document.body.append(iframeDelayed);
+}, 1000);
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-timestamp-high-resolution.html b/testing/web-platform/tests/dom/events/Event-timestamp-high-resolution.html
new file mode 100644
index 0000000000..a049fef64b
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-timestamp-high-resolution.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script type="text/javascript">
+'use strict';
+for (let eventType of ["MouseEvent", "KeyboardEvent", "WheelEvent", "FocusEvent"]) {
+    test(function() {
+        let before = performance.now();
+        let e = new window[eventType]('test');
+        let after = performance.now();
+        assert_greater_than_equal(e.timeStamp, before, "Event timestamp should be greater than performance.now() timestamp taken before its creation");
+        assert_less_than_equal(e.timeStamp, after, "Event timestamp should be less than performance.now() timestamp taken after its creation");
+    }, `Constructed ${eventType} timestamp should be high resolution and have the same time origin as performance.now()`);
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-timestamp-high-resolution.https.html b/testing/web-platform/tests/dom/events/Event-timestamp-high-resolution.https.html
new file mode 100644
index 0000000000..70f9742947
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-timestamp-high-resolution.https.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script type="text/javascript">
+'use strict';
+for (let eventType of ["GamepadEvent"]) {
+    test(function() {
+        let before = performance.now();
+        let e = new window[eventType]('test');
+        let after = performance.now();
+        assert_greater_than_equal(e.timeStamp, before, "Event timestamp should be greater than performance.now() timestamp taken before its creation");
+        assert_less_than_equal(e.timeStamp, after, "Event timestamp should be less than performance.now() timestamp taken after its creation");
+    }, `Constructed ${eventType} timestamp should be high resolution and have the same time origin as performance.now()`);
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html b/testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html
new file mode 100644
index 0000000000..24f2dec93c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html
@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script type="text/javascript">
+'use strict';
+
+// Computes greatest common divisor of a and b using Euclid's algorithm
+function computeGCD(a, b) {
+  if (!Number.isInteger(a) || !Number.isInteger(b)) {
+    throw new Error('Parameters must be integer numbers');
+  }
+
+  var r;
+  while (b != 0) {
+    r = a % b;
+    a = b;
+    b = r;
+  }
+  return (a < 0) ? -a : a;
+}
+
+// Finds minimum resolution Δ given a set of samples which are known to be in the form of N*Δ.
+// We use GCD of all samples as a simple estimator.
+function estimateMinimumResolution(samples) {
+  var gcd;
+  for (const sample of samples) {
+    gcd = gcd ? computeGCD(gcd, sample) : sample;
+  }
+
+  return gcd;
+}
+
+test(function() {
+  const samples = [];
+  for (var i = 0; i < 1e3; i++) {
+    var deltaInMicroSeconds = 0;
+    const e1 = new MouseEvent('test1');
+    do {
+      const e2 = new MouseEvent('test2');
+      deltaInMicroSeconds = Math.round((e2.timeStamp - e1.timeStamp) * 1000);
+    } while (deltaInMicroSeconds == 0) // only collect non-zero samples
+
+    samples.push(deltaInMicroSeconds);
+  }
+
+  const minResolution = estimateMinimumResolution(samples);
+  assert_greater_than_equal(minResolution, 5);
+}, 'Event timestamp should not have a resolution better than 5 microseconds');
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/events/Event-type-empty.html b/testing/web-platform/tests/dom/events/Event-type-empty.html
new file mode 100644
index 0000000000..225b85a613
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-type-empty.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<title>Event.type set to the empty string</title>
+<link rel="author" title="Ms2ger" href="mailto:Ms2ger@gmail.com">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-event-type">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function do_test(t, e) {
+  assert_equals(e.type, "", "type");
+  assert_equals(e.bubbles, false, "bubbles");
+  assert_equals(e.cancelable, false, "cancelable");
+
+  var target = document.createElement("div");
+  var handled = false;
+  target.addEventListener("", t.step_func(function(e) {
+    handled = true;
+  }));
+  assert_true(target.dispatchEvent(e));
+  assert_true(handled);
+}
+
+async_test(function() {
+  var e = document.createEvent("Event");
+  e.initEvent("", false, false);
+  do_test(this, e);
+  this.done();
+}, "initEvent");
+
+async_test(function() {
+  var e = new Event("");
+  do_test(this, e);
+  this.done();
+}, "Constructor");
+</script>
diff --git a/testing/web-platform/tests/dom/events/Event-type.html b/testing/web-platform/tests/dom/events/Event-type.html
new file mode 100644
index 0000000000..22792f5c6c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/Event-type.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<title>Event.type</title>
+<link rel="author" title="Ms2ger" href="mailto:Ms2ger@gmail.com">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-event-type">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var e = document.createEvent("Event")
+  assert_equals(e.type, "");
+}, "Event.type should initially be the empty string");
+test(function() {
+  var e = document.createEvent("Event")
+  e.initEvent("foo", false, false)
+  assert_equals(e.type, "foo")
+}, "Event.type should be initialized by initEvent");
+test(function() {
+  var e = new Event("bar")
+  assert_equals(e.type, "bar")
+}, "Event.type should be initialized by the constructor");
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListener-addEventListener.sub.window.js b/testing/web-platform/tests/dom/events/EventListener-addEventListener.sub.window.js
new file mode 100644
index 0000000000..b44bc33285
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-addEventListener.sub.window.js
@@ -0,0 +1,9 @@
+async_test(function(t) {
+  let crossOriginFrame = document.createElement('iframe');
+  crossOriginFrame.src = 'https://{{hosts[alt][]}}:{{ports[https][0]}}/common/blank.html';
+  document.body.appendChild(crossOriginFrame);
+  crossOriginFrame.addEventListener('load', t.step_func_done(function() {
+    let crossOriginWindow = crossOriginFrame.contentWindow;
+    window.addEventListener('click', crossOriginWindow);
+  }));
+}, "EventListener.addEventListener doesn't throw when a cross origin object is passed in.");
diff --git a/testing/web-platform/tests/dom/events/EventListener-handleEvent-cross-realm.html b/testing/web-platform/tests/dom/events/EventListener-handleEvent-cross-realm.html
new file mode 100644
index 0000000000..663d04213f
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-handleEvent-cross-realm.html
@@ -0,0 +1,75 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Cross-realm EventListener throws TypeError of its associated Realm</title>
+<link rel="help" href="https://webidl.spec.whatwg.org/#ref-for-prepare-to-run-script">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<iframe name="eventListenerGlobalObject" src="resources/empty-document.html"></iframe>
+
+<script>
+setup({ allow_uncaught_exception: true });
+
+test_onload(() => {
+    const eventTarget = new EventTarget;
+    const eventListener = new eventListenerGlobalObject.Object;
+
+    eventTarget.addEventListener("foo", eventListener);
+    assert_reports_exception(eventListenerGlobalObject.TypeError, () => { eventTarget.dispatchEvent(new Event("foo")); });
+}, "EventListener is cross-realm plain object without 'handleEvent' property");
+
+test_onload(() => {
+    const eventTarget = new EventTarget;
+    const eventListener = new eventListenerGlobalObject.Object;
+    eventListener.handleEvent = {};
+
+    eventTarget.addEventListener("foo", eventListener);
+    assert_reports_exception(eventListenerGlobalObject.TypeError, () => { eventTarget.dispatchEvent(new Event("foo")); });
+}, "EventListener is cross-realm plain object with non-callable 'handleEvent' property");
+
+test_onload(() => {
+    const eventTarget = new EventTarget;
+    const { proxy, revoke } = Proxy.revocable(() => {}, {});
+    revoke();
+
+    const eventListener = new eventListenerGlobalObject.Object;
+    eventListener.handleEvent = proxy;
+
+    eventTarget.addEventListener("foo", eventListener);
+    assert_reports_exception(eventListenerGlobalObject.TypeError, () => { eventTarget.dispatchEvent(new Event("foo")); });
+}, "EventListener is cross-realm plain object with revoked Proxy as 'handleEvent' property");
+
+test_onload(() => {
+    const eventTarget = new EventTarget;
+    const { proxy, revoke } = eventListenerGlobalObject.Proxy.revocable({}, {});
+    revoke();
+
+    eventTarget.addEventListener("foo", proxy);
+    assert_reports_exception(eventListenerGlobalObject.TypeError, () => { eventTarget.dispatchEvent(new Event("foo")); });
+}, "EventListener is cross-realm non-callable revoked Proxy");
+
+test_onload(() => {
+    const eventTarget = new EventTarget;
+    const { proxy, revoke } = eventListenerGlobalObject.Proxy.revocable(() => {}, {});
+    revoke();
+
+    eventTarget.addEventListener("foo", proxy);
+    assert_reports_exception(eventListenerGlobalObject.TypeError, () => { eventTarget.dispatchEvent(new Event("foo")); });
+}, "EventListener is cross-realm callable revoked Proxy");
+
+function test_onload(fn, desc) {
+    async_test(t => { window.addEventListener("load", t.step_func_done(fn)); }, desc);
+}
+
+function assert_reports_exception(expectedConstructor, fn) {
+    let error;
+    const onErrorHandler = event => { error = event.error; };
+
+    eventListenerGlobalObject.addEventListener("error", onErrorHandler);
+    fn();
+    eventListenerGlobalObject.removeEventListener("error", onErrorHandler);
+
+    assert_equals(typeof error, "object");
+    assert_equals(error.constructor, expectedConstructor);
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListener-handleEvent.html b/testing/web-platform/tests/dom/events/EventListener-handleEvent.html
new file mode 100644
index 0000000000..06bc1f6e2a
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-handleEvent.html
@@ -0,0 +1,102 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>EventListener::handleEvent()</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<link rel="help" href="https://dom.spec.whatwg.org/#callbackdef-eventlistener">
+<div id=log></div>
+<script>
+setup({ allow_uncaught_exception: true });
+
+test(function(t) {
+    var type = "foo";
+    var target = document.createElement("div");
+    var eventListener = {
+        handleEvent: function(evt) {
+            var that = this;
+            t.step(function() {
+                assert_equals(evt.type, type);
+                assert_equals(evt.target, target);
+                assert_equals(evt.srcElement, target);
+                assert_equals(that, eventListener);
+            });
+        },
+    };
+
+    target.addEventListener(type, eventListener);
+    target.dispatchEvent(new Event(type));
+}, "calls `handleEvent` method of `EventListener`");
+
+test(function(t) {
+    var type = "foo";
+    var target = document.createElement("div");
+    var calls = 0;
+
+    target.addEventListener(type, {
+        get handleEvent() {
+            calls++;
+            return function() {};
+        },
+    });
+
+    assert_equals(calls, 0);
+    target.dispatchEvent(new Event(type));
+    target.dispatchEvent(new Event(type));
+    assert_equals(calls, 2);
+}, "performs `Get` every time event is dispatched");
+
+test(function(t) {
+    var type = "foo";
+    var target = document.createElement("div");
+    var calls = 0;
+    var eventListener = function() { calls++; };
+    eventListener.handleEvent = t.unreached_func("`handleEvent` method should not be called on functions");
+
+    target.addEventListener(type, eventListener);
+    target.dispatchEvent(new Event(type));
+    assert_equals(calls, 1);
+}, "doesn't call `handleEvent` method on callable `EventListener`");
+
+const uncaught_error_test = async (t, getHandleEvent) => {
+    const type = "foo";
+    const target = document.createElement("div");
+
+    let calls = 0;
+    target.addEventListener(type, {
+        get handleEvent() {
+            calls++;
+            return getHandleEvent();
+        },
+    });
+
+    const timeout = () => {
+        return new Promise(resolve => {
+            t.step_timeout(resolve, 0);
+        });
+    };
+
+    const eventWatcher = new EventWatcher(t, window, "error", timeout);
+    const errorPromise = eventWatcher.wait_for("error");
+
+    target.dispatchEvent(new Event(type));
+
+    const event = await errorPromise;
+    assert_equals(calls, 1, "handleEvent property was not looked up");
+    throw event.error;
+};
+
+promise_test(t => {
+    const error = { name: "test" };
+
+    return promise_rejects_exactly(t, error,
+        uncaught_error_test(t, () => { throw error; }));
+}, "rethrows errors when getting `handleEvent`");
+
+promise_test(t => {
+    return promise_rejects_js(t, TypeError, uncaught_error_test(t, () => null));
+}, "throws if `handleEvent` is falsy and not callable");
+
+promise_test(t => {
+    return promise_rejects_js(t, TypeError, uncaught_error_test(t, () => 42));
+}, "throws if `handleEvent` is thruthy and not callable");
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListener-incumbent-global-1.sub.html b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-1.sub.html
new file mode 100644
index 0000000000..9d941385cb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-1.sub.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<iframe src="{{location[scheme]}}://{{domains[www1]}}:{{ports[http][0]}}{{location[path]}}/../EventListener-incumbent-global-subframe-1.sub.html"></iframe>
+<script>
+
+var t = async_test("Check the incumbent global EventListeners  are called with");
+
+onload = t.step_func(function() {
+  onmessage = t.step_func_done(function(e) {
+    var d = e.data;
+    assert_equals(d.actual, d.expected, d.reason);
+  });
+
+  frames[0].postMessage("start", "*");
+});
+
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListener-incumbent-global-2.sub.html b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-2.sub.html
new file mode 100644
index 0000000000..4433c098d7
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-2.sub.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<iframe src="{{location[scheme]}}://{{domains[www1]}}:{{ports[http][0]}}{{location[path]}}/../EventListener-incumbent-global-subframe-2.sub.html"></iframe>
+<script>
+
+var t = async_test("Check the incumbent global EventListeners  are called with");
+
+onload = t.step_func(function() {
+  onmessage = t.step_func_done(function(e) {
+    var d = e.data;
+    assert_equals(d.actual, d.expected, d.reason);
+  });
+
+  frames[0].postMessage("start", "*");
+});
+
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subframe-1.sub.html b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subframe-1.sub.html
new file mode 100644
index 0000000000..25487cc5e0
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subframe-1.sub.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<iframe src="{{location[scheme]}}://{{domains[www2]}}:{{ports[http][0]}}{{location[path]}}/../EventListener-incumbent-global-subsubframe.sub.html"></iframe>
+<script>
+  document.domain = "{{host}}";
+  onmessage = function(e) {
+    if (e.data == "start") {
+      frames[0].document.body.addEventListener("click", frames[0].postMessage.bind(frames[0], "respond", "*", undefined));
+      frames[0].postMessage("sendclick", "*");
+    } else {
+      parent.postMessage(e.data, "*");
+    }
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subframe-2.sub.html b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subframe-2.sub.html
new file mode 100644
index 0000000000..9c7235e2ad
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subframe-2.sub.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<iframe src="{{location[scheme]}}://{{domains[www2]}}:{{ports[http][0]}}{{location[path]}}/../EventListener-incumbent-global-subsubframe.sub.html"></iframe>
+<script>
+  document.domain = "{{host}}";
+  onmessage = function(e) {
+    if (e.data == "start") {
+      frames[0].document.body.addEventListener("click", frames[0].getTheListener());
+      frames[0].postMessage("sendclick", "*");
+    } else {
+      parent.postMessage(e.data, "*");
+    }
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subsubframe.sub.html b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subsubframe.sub.html
new file mode 100644
index 0000000000..dd683f6f65
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-incumbent-global-subsubframe.sub.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<script>
+  function getTheListener() {
+    return postMessage.bind(this, "respond", "*", undefined)
+  }
+  document.domain = "{{host}}";
+  onmessage = function (e) {
+    if (e.data == "sendclick") {
+      document.body.click();
+    } else {
+      parent.postMessage(
+        {
+          actual: e.origin,
+          expected: parent.location.origin,
+          reason: "Incumbent should have been the caller of addEventListener()"
+        },
+        "*")
+    };
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListener-invoke-legacy.html b/testing/web-platform/tests/dom/events/EventListener-invoke-legacy.html
new file mode 100644
index 0000000000..a01afcd8d1
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListener-invoke-legacy.html
@@ -0,0 +1,66 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Invoke legacy event listener</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style>
+  @keyframes test {
+    0% { color: red; }
+    100% { color: green; }
+  }
+</style>
+<div id="log"></div>
+<script>
+function runLegacyEventTest(type, legacyType, ctor, setup) {
+  function createTestElem(t) {
+    var elem = document.createElement('div');
+    document.body.appendChild(elem);
+    t.add_cleanup(function() {
+      document.body.removeChild(elem);
+    });
+    return elem;
+  }
+
+  async_test(function(t) {
+    var elem = createTestElem(t);
+    var gotEvent = false;
+    elem.addEventListener(legacyType,
+      t.unreached_func("listener of " + legacyType + " should not be invoked"));
+    elem.addEventListener(type, t.step_func(function() {
+      assert_false(gotEvent, "unexpected " + type + " event");
+      gotEvent = true;
+      t.step_timeout(function() { t.done(); }, 100);
+    }));
+    setup(elem);
+  }, "Listener of " + type);
+
+  async_test(function(t) {
+    var elem = createTestElem(t);
+    var count = 0;
+    elem.addEventListener(legacyType, t.step_func(function() {
+      ++count;
+      if (count > 1) {
+        assert_unreached("listener of " + legacyType + " should not be invoked again");
+        return;
+      }
+      elem.dispatchEvent(new window[ctor](type));
+      t.done();
+    }));
+    setup(elem);
+  }, "Legacy listener of " + type);
+}
+
+function setupTransition(elem) {
+  getComputedStyle(elem).color;
+  elem.style.color = 'green';
+  elem.style.transition = 'color 30ms';
+}
+
+function setupAnimation(elem) {
+  elem.style.animation = 'test 30ms';
+}
+
+runLegacyEventTest('transitionend', 'webkitTransitionEnd', "TransitionEvent", setupTransition);
+runLegacyEventTest('animationend', 'webkitAnimationEnd', "AnimationEvent", setupAnimation);
+runLegacyEventTest('animationstart', 'webkitAnimationStart', "AnimationEvent", setupAnimation);
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventListenerOptions-capture.html b/testing/web-platform/tests/dom/events/EventListenerOptions-capture.html
new file mode 100644
index 0000000000..f72cf3ca54
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventListenerOptions-capture.html
@@ -0,0 +1,98 @@
+<!DOCTYPE HTML>
+<meta charset="utf-8">
+<title>EventListenerOptions.capture</title>
+<link rel="author" title="Rick Byers" href="mailto:rbyers@chromium.org">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-eventlisteneroptions-capture">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+
+<script>
+
+function testCaptureValue(captureValue, expectedValue) {
+  var handlerPhase = undefined;
+  var handler = function handler(e) {
+    assert_equals(handlerPhase, undefined, "Handler invoked after remove");
+    handlerPhase = e.eventPhase;
+  }
+  document.addEventListener('test', handler, captureValue);
+  document.body.dispatchEvent(new Event('test', {bubbles: true}));
+  document.removeEventListener('test', handler, captureValue);
+  document.body.dispatchEvent(new Event('test', {bubbles: true}));
+  assert_equals(handlerPhase, expectedValue, "Incorrect event phase for value: " + JSON.stringify(captureValue));
+}
+
+test(function() {
+  testCaptureValue(true, Event.CAPTURING_PHASE);
+  testCaptureValue(false, Event.BUBBLING_PHASE);
+  testCaptureValue(null, Event.BUBBLING_PHASE);
+  testCaptureValue(undefined, Event.BUBBLING_PHASE);
+  testCaptureValue(2.3, Event.CAPTURING_PHASE);
+  testCaptureValue(-1000.3, Event.CAPTURING_PHASE);
+  testCaptureValue(NaN, Event.BUBBLING_PHASE);
+  testCaptureValue(+0.0, Event.BUBBLING_PHASE);
+  testCaptureValue(-0.0, Event.BUBBLING_PHASE);
+  testCaptureValue("", Event.BUBBLING_PHASE);
+  testCaptureValue("AAAA", Event.CAPTURING_PHASE);
+}, "Capture boolean should be honored correctly");
+
+test(function() {
+  testCaptureValue({}, Event.BUBBLING_PHASE);
+  testCaptureValue({capture:true}, Event.CAPTURING_PHASE);
+  testCaptureValue({capture:false}, Event.BUBBLING_PHASE);
+  testCaptureValue({capture:2}, Event.CAPTURING_PHASE);
+  testCaptureValue({capture:0}, Event.BUBBLING_PHASE);
+}, "Capture option should be honored correctly");
+
+test(function() {
+  var supportsCapture = false;
+  var query_options = {
+    get capture() {
+      supportsCapture = true;
+      return false;
+    },
+    get dummy() {
+      assert_unreached("dummy value getter invoked");
+      return false;
+    }
+  };
+
+  document.addEventListener('test_event', null, query_options);
+  assert_true(supportsCapture, "addEventListener doesn't support the capture option");
+  supportsCapture = false;
+  document.removeEventListener('test_event', null, query_options);
+  assert_true(supportsCapture, "removeEventListener doesn't support the capture option");
+}, "Supports capture option");
+
+function testOptionEquality(addOptionValue, removeOptionValue, expectedEquality) {
+  var handlerInvoked = false;
+  var handler = function handler(e) {
+    assert_equals(handlerInvoked, false, "Handler invoked multiple times");
+    handlerInvoked = true;
+  }
+  document.addEventListener('test', handler, addOptionValue);
+  document.removeEventListener('test', handler, removeOptionValue);
+  document.body.dispatchEvent(new Event('test', {bubbles: true}));
+  assert_equals(!handlerInvoked, expectedEquality, "equivalence of options " +
+    JSON.stringify(addOptionValue) + " and " + JSON.stringify(removeOptionValue));
+  if (handlerInvoked)
+    document.removeEventListener('test', handler, addOptionValue);
+}
+
+test(function() {
+  // Option values that should be treated as equivalent
+  testOptionEquality({}, false, true);
+  testOptionEquality({capture: false}, false, true);
+  testOptionEquality(true, {capture: true}, true);
+  testOptionEquality({capture: null}, undefined, true);
+  testOptionEquality({capture: true}, {dummy: false, capture: 1}, true);
+  testOptionEquality({dummy: true}, false, true);
+
+  // Option values that should be treated as distinct
+  testOptionEquality(true, false, false);
+  testOptionEquality(true, {capture:false}, false);
+  testOptionEquality({}, true, false);
+
+}, "Equivalence of option values");
+
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventTarget-add-listener-platform-object.html b/testing/web-platform/tests/dom/events/EventTarget-add-listener-platform-object.html
new file mode 100644
index 0000000000..d5565c22b3
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-add-listener-platform-object.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>addEventListener with a platform object</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+</script>
+<my-custom-click id=click>Click me!</my-custom-click>
+<script>
+"use strict";
+setup({ single_test: true });
+
+class MyCustomClick extends HTMLElement {
+  connectedCallback() {
+    this.addEventListener("click", this);
+  }
+
+  handleEvent(event) {
+    if (event.target === this) {
+      this.dataset.yay = "It worked!";
+    }
+  }
+}
+window.customElements.define("my-custom-click", MyCustomClick);
+
+const customElement = document.getElementById("click");
+customElement.click();
+
+assert_equals(customElement.dataset.yay, "It worked!");
+
+done();
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventTarget-add-remove-listener.any.js b/testing/web-platform/tests/dom/events/EventTarget-add-remove-listener.any.js
new file mode 100644
index 0000000000..b1d7ffb3e0
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-add-remove-listener.any.js
@@ -0,0 +1,21 @@
+// META: title=EventTarget's addEventListener + removeEventListener
+
+"use strict";
+
+function listener(evt) {
+  evt.preventDefault();
+  return false;
+}
+
+test(() => {
+  const et = new EventTarget();
+  et.addEventListener("x", listener, false);
+  let event = new Event("x", { cancelable: true });
+  let ret = et.dispatchEvent(event);
+  assert_false(ret);
+
+  et.removeEventListener("x", listener);
+  event = new Event("x", { cancelable: true });
+  ret = et.dispatchEvent(event);
+  assert_true(ret);
+}, "Removing an event listener without explicit capture arg should succeed");
diff --git a/testing/web-platform/tests/dom/events/EventTarget-addEventListener.any.js b/testing/web-platform/tests/dom/events/EventTarget-addEventListener.any.js
new file mode 100644
index 0000000000..e22da4aff8
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-addEventListener.any.js
@@ -0,0 +1,9 @@
+// META: title=EventTarget.addEventListener
+
+// Step 1.
+test(function() {
+  const et = new EventTarget();
+  assert_equals(et.addEventListener("x", null, false), undefined);
+  assert_equals(et.addEventListener("x", null, true), undefined);
+  assert_equals(et.addEventListener("x", null), undefined);
+}, "Adding a null event listener should succeed");
diff --git a/testing/web-platform/tests/dom/events/EventTarget-constructible.any.js b/testing/web-platform/tests/dom/events/EventTarget-constructible.any.js
new file mode 100644
index 0000000000..b0e7614e62
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-constructible.any.js
@@ -0,0 +1,62 @@
+"use strict";
+
+test(() => {
+  const target = new EventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  function listener(e) {
+    assert_equals(e, event);
+    ++callCount;
+  }
+
+  target.addEventListener("foo", listener);
+
+  target.dispatchEvent(event);
+  assert_equals(callCount, 1);
+
+  target.dispatchEvent(event);
+  assert_equals(callCount, 2);
+
+  target.removeEventListener("foo", listener);
+  target.dispatchEvent(event);
+  assert_equals(callCount, 2);
+}, "A constructed EventTarget can be used as expected");
+
+test(() => {
+  class NicerEventTarget extends EventTarget {
+    on(...args) {
+      this.addEventListener(...args);
+    }
+
+    off(...args) {
+      this.removeEventListener(...args);
+    }
+
+    dispatch(type, detail) {
+      this.dispatchEvent(new CustomEvent(type, { detail }));
+    }
+  }
+
+  const target = new NicerEventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  const detail = "some data";
+  let callCount = 0;
+
+  function listener(e) {
+    assert_equals(e.detail, detail);
+    ++callCount;
+  }
+
+  target.on("foo", listener);
+
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 1);
+
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 2);
+
+  target.off("foo", listener);
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 2);
+}, "EventTarget can be subclassed");
diff --git a/testing/web-platform/tests/dom/events/EventTarget-dispatchEvent-returnvalue.html b/testing/web-platform/tests/dom/events/EventTarget-dispatchEvent-returnvalue.html
new file mode 100644
index 0000000000..c4466e0d6c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-dispatchEvent-returnvalue.html
@@ -0,0 +1,71 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>EventTarget.dispatchEvent: return value</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-dispatch">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-event-preventdefault">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-event-returnvalue">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-event-defaultprevented">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<table id="table" border="1" style="display: none">
+    <tbody id="table-body">
+    <tr id="table-row">
+        <td id="table-cell">Shady Grove</td>
+        <td>Aeolian</td>
+    </tr>
+    <tr id="parent">
+        <td id="target">Over the river, Charlie</td>
+        <td>Dorian</td>
+    </tr>
+    </tbody>
+</table>
+<script>
+test(function() {
+    var event_type = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var default_prevented;
+    var return_value;
+
+    parent.addEventListener(event_type, function(e) {}, true);
+    target.addEventListener(event_type, function(e) {
+        evt.preventDefault();
+        default_prevented = evt.defaultPrevented;
+        return_value = evt.returnValue;
+    }, true);
+    target.addEventListener(event_type, function(e) {}, true);
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, true, true);
+
+    assert_true(parent.dispatchEvent(evt));
+    assert_false(target.dispatchEvent(evt));
+    assert_true(default_prevented);
+    assert_false(return_value);
+}, "Return value of EventTarget.dispatchEvent() affected by preventDefault().");
+
+test(function() {
+    var event_type = "foo";
+    var target = document.getElementById("target");
+    var parent = document.getElementById("parent");
+    var default_prevented;
+    var return_value;
+
+    parent.addEventListener(event_type, function(e) {}, true);
+    target.addEventListener(event_type, function(e) {
+        evt.returnValue = false;
+        default_prevented = evt.defaultPrevented;
+        return_value = evt.returnValue;
+    }, true);
+    target.addEventListener(event_type, function(e) {}, true);
+
+    var evt = document.createEvent("Event");
+    evt.initEvent(event_type, true, true);
+
+    assert_true(parent.dispatchEvent(evt));
+    assert_false(target.dispatchEvent(evt));
+    assert_true(default_prevented);
+    assert_false(return_value);
+}, "Return value of EventTarget.dispatchEvent() affected by returnValue.");
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventTarget-dispatchEvent.html b/testing/web-platform/tests/dom/events/EventTarget-dispatchEvent.html
new file mode 100644
index 0000000000..783561f5fb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-dispatchEvent.html
@@ -0,0 +1,104 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>EventTarget.dispatchEvent</title>
+<link rel="author" title="Olli Pettay" href="mailto:Olli.Pettay@gmail.com">
+<link rel="author" title="Ms2ger" href="mailto:Ms2ger@gmail.com">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-eventtarget-dispatchevent">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/dom/nodes/Document-createEvent.js"></script>
+<div id="log"></div>
+<script>
+setup({
+  "allow_uncaught_exception": true,
+})
+
+test(function() {
+  assert_throws_js(TypeError, function() { document.dispatchEvent(null) })
+}, "Calling dispatchEvent(null).")
+
+for (var alias in aliases) {
+  test(function() {
+    var e = document.createEvent(alias)
+    assert_equals(e.type, "", "Event type should be empty string before initialization")
+    assert_throws_dom("InvalidStateError", function() { document.dispatchEvent(e) })
+  }, "If the event's initialized flag is not set, an InvalidStateError must be thrown (" + alias + ").")
+}
+
+var dispatch_dispatch = async_test("If the event's dispatch flag is set, an InvalidStateError must be thrown.")
+dispatch_dispatch.step(function() {
+  var e = document.createEvent("Event")
+  e.initEvent("type", false, false)
+
+  var target = document.createElement("div")
+  target.addEventListener("type", dispatch_dispatch.step_func(function() {
+    assert_throws_dom("InvalidStateError", function() {
+      target.dispatchEvent(e)
+    })
+    assert_throws_dom("InvalidStateError", function() {
+      document.dispatchEvent(e)
+    })
+  }), false)
+
+  assert_equals(target.dispatchEvent(e), true, "dispatchEvent must return true")
+
+  dispatch_dispatch.done()
+})
+
+test(function() {
+  // https://www.w3.org/Bugs/Public/show_bug.cgi?id=17713
+  // https://www.w3.org/Bugs/Public/show_bug.cgi?id=17714
+
+  var e = document.createEvent("Event")
+  e.initEvent("type", false, false)
+
+  var called = []
+
+  var target = document.createElement("div")
+  target.addEventListener("type", function() {
+    called.push("First")
+    throw new Error()
+  }, false)
+
+  target.addEventListener("type", function() {
+    called.push("Second")
+  }, false)
+
+  assert_equals(target.dispatchEvent(e), true, "dispatchEvent must return true")
+  assert_array_equals(called, ["First", "Second"],
+                      "Should have continued to call other event listeners")
+}, "Exceptions from event listeners must not be propagated.")
+
+async_test(function() {
+  var results = []
+  var outerb = document.createElement("b")
+  var middleb = outerb.appendChild(document.createElement("b"))
+  var innerb = middleb.appendChild(document.createElement("b"))
+  outerb.addEventListener("x", this.step_func(function() {
+    middleb.addEventListener("x", this.step_func(function() {
+      results.push("middle")
+    }), true)
+    results.push("outer")
+  }), true)
+  innerb.dispatchEvent(new Event("x"))
+  assert_array_equals(results, ["outer", "middle"])
+  this.done()
+}, "Event listeners added during dispatch should be called");
+
+async_test(function() {
+  var results = []
+  var b = document.createElement("b")
+  b.addEventListener("x", this.step_func(function() {
+    results.push(1)
+  }), true)
+  b.addEventListener("x", this.step_func(function() {
+    results.push(2)
+  }), false)
+  b.addEventListener("x", this.step_func(function() {
+    results.push(3)
+  }), true)
+  b.dispatchEvent(new Event("x"))
+  assert_array_equals(results, [1, 3, 2])
+  this.done()
+}, "Capturing event listeners should be called before non-capturing ones")
+</script>
diff --git a/testing/web-platform/tests/dom/events/EventTarget-removeEventListener.any.js b/testing/web-platform/tests/dom/events/EventTarget-removeEventListener.any.js
new file mode 100644
index 0000000000..289dfcfbab
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-removeEventListener.any.js
@@ -0,0 +1,8 @@
+// META: title=EventTarget.removeEventListener
+
+// Step 1.
+test(function() {
+  assert_equals(globalThis.removeEventListener("x", null, false), undefined);
+  assert_equals(globalThis.removeEventListener("x", null, true), undefined);
+  assert_equals(globalThis.removeEventListener("x", null), undefined);
+}, "removing a null event listener should succeed");
diff --git a/testing/web-platform/tests/dom/events/EventTarget-this-of-listener.html b/testing/web-platform/tests/dom/events/EventTarget-this-of-listener.html
new file mode 100644
index 0000000000..506564c413
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/EventTarget-this-of-listener.html
@@ -0,0 +1,182 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>EventTarget listeners this value</title>
+<link rel="author" title="Domenic Denicola" href="mailto:d@domenic.me">
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-listener-invoke">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+
+  const nodes = [
+    document.createElement("p"),
+    document.createTextNode("some text"),
+    document.createDocumentFragment(),
+    document.createComment("a comment"),
+    document.createProcessingInstruction("target", "data")
+  ];
+
+  let callCount = 0;
+  for (const node of nodes) {
+    node.addEventListener("someevent", function () {
+      ++callCount;
+      assert_equals(this, node);
+    });
+
+    node.dispatchEvent(new CustomEvent("someevent"));
+  }
+
+  assert_equals(callCount, nodes.length);
+
+}, "the this value inside the event listener callback should be the node");
+
+test(() => {
+
+  const nodes = [
+    document.createElement("p"),
+    document.createTextNode("some text"),
+    document.createDocumentFragment(),
+    document.createComment("a comment"),
+    document.createProcessingInstruction("target", "data")
+  ];
+
+  let callCount = 0;
+  for (const node of nodes) {
+    const handler = {
+      handleEvent() {
+        ++callCount;
+        assert_equals(this, handler);
+      }
+    };
+
+    node.addEventListener("someevent", handler);
+
+    node.dispatchEvent(new CustomEvent("someevent"));
+  }
+
+  assert_equals(callCount, nodes.length);
+
+}, "the this value inside the event listener object handleEvent should be the object");
+
+test(() => {
+
+  const nodes = [
+    document.createElement("p"),
+    document.createTextNode("some text"),
+    document.createDocumentFragment(),
+    document.createComment("a comment"),
+    document.createProcessingInstruction("target", "data")
+  ];
+
+  let callCount = 0;
+  for (const node of nodes) {
+    const handler = {
+      handleEvent() {
+        assert_unreached("should not call the old handleEvent method");
+      }
+    };
+
+    node.addEventListener("someevent", handler);
+    handler.handleEvent = function () {
+      ++callCount;
+      assert_equals(this, handler);
+    };
+
+    node.dispatchEvent(new CustomEvent("someevent"));
+  }
+
+  assert_equals(callCount, nodes.length);
+
+}, "dispatchEvent should invoke the current handleEvent method of the object");
+
+test(() => {
+
+  const nodes = [
+    document.createElement("p"),
+    document.createTextNode("some text"),
+    document.createDocumentFragment(),
+    document.createComment("a comment"),
+    document.createProcessingInstruction("target", "data")
+  ];
+
+  let callCount = 0;
+  for (const node of nodes) {
+    const handler = {};
+
+    node.addEventListener("someevent", handler);
+    handler.handleEvent = function () {
+      ++callCount;
+      assert_equals(this, handler);
+    };
+
+    node.dispatchEvent(new CustomEvent("someevent"));
+  }
+
+  assert_equals(callCount, nodes.length);
+
+}, "addEventListener should not require handleEvent to be defined on object listeners");
+
+test(() => {
+
+  const nodes = [
+    document.createElement("p"),
+    document.createTextNode("some text"),
+    document.createDocumentFragment(),
+    document.createComment("a comment"),
+    document.createProcessingInstruction("target", "data")
+  ];
+
+  let callCount = 0;
+  for (const node of nodes) {
+    function handler() {
+      ++callCount;
+      assert_equals(this, node);
+    }
+
+    handler.handleEvent = () => {
+      assert_unreached("should not call the handleEvent method on a function");
+    };
+
+    node.addEventListener("someevent", handler);
+
+    node.dispatchEvent(new CustomEvent("someevent"));
+  }
+
+  assert_equals(callCount, nodes.length);
+
+}, "handleEvent properties added to a function before addEventListener are not reached");
+
+test(() => {
+
+  const nodes = [
+    document.createElement("p"),
+    document.createTextNode("some text"),
+    document.createDocumentFragment(),
+    document.createComment("a comment"),
+    document.createProcessingInstruction("target", "data")
+  ];
+
+  let callCount = 0;
+  for (const node of nodes) {
+    function handler() {
+      ++callCount;
+      assert_equals(this, node);
+    }
+
+    node.addEventListener("someevent", handler);
+
+    handler.handleEvent = () => {
+      assert_unreached("should not call the handleEvent method on a function");
+    };
+
+    node.dispatchEvent(new CustomEvent("someevent"));
+  }
+
+  assert_equals(callCount, nodes.length);
+
+}, "handleEvent properties added to a function after addEventListener are not reached");
+
+</script>
diff --git a/testing/web-platform/tests/dom/events/KeyEvent-initKeyEvent.html b/testing/web-platform/tests/dom/events/KeyEvent-initKeyEvent.html
new file mode 100644
index 0000000000..3fffaba014
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/KeyEvent-initKeyEvent.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>KeyEvent.initKeyEvent</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+// The legacy KeyEvent.initKeyEvent shouldn't be defined in the wild anymore.
+// https://www.w3.org/TR/1999/WD-DOM-Level-2-19990923/events.html#Events-Event-initKeyEvent
+test(function() {
+  const event = document.createEvent("KeyboardEvent");
+  assert_true(event?.initKeyEvent === undefined);
+}, "KeyboardEvent.initKeyEvent shouldn't be defined (created by createEvent(\"KeyboardEvent\")");
+
+test(function() {
+  const event = new KeyboardEvent("keypress");
+  assert_true(event?.initKeyEvent === undefined);
+}, "KeyboardEvent.initKeyEvent shouldn't be defined (created by constructor)");
+
+test(function() {
+  assert_true(KeyboardEvent.prototype.initKeyEvent === undefined);
+}, "KeyboardEvent.prototype.initKeyEvent shouldn't be defined");
+</script>
diff --git a/testing/web-platform/tests/dom/events/event-disabled-dynamic.html b/testing/web-platform/tests/dom/events/event-disabled-dynamic.html
new file mode 100644
index 0000000000..3f995b02f1
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/event-disabled-dynamic.html
@@ -0,0 +1,21 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Test that disabled is honored immediately in presence of dynamic changes</title>
+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
+<link rel="author" title="Andreas Farre" href="mailto:afarre@mozilla.com">
+<link rel="help" href="https://html.spec.whatwg.org/multipage/#enabling-and-disabling-form-controls:-the-disabled-attribute">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1405087">
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<input type="button" value="Click" disabled>
+<script>
+async_test(t => {
+  // NOTE: This test will timeout if it fails.
+  window.addEventListener('load', t.step_func(() => {
+    let e = document.querySelector('input');
+    e.disabled = false;
+    e.onclick = t.step_func_done(() => {});
+    e.click();
+  }));
+}, "disabled is honored properly in presence of dynamic changes");
+</script>
diff --git a/testing/web-platform/tests/dom/events/event-global-extra.window.js b/testing/web-platform/tests/dom/events/event-global-extra.window.js
new file mode 100644
index 0000000000..0f14961c40
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/event-global-extra.window.js
@@ -0,0 +1,90 @@
+const otherWindow = document.body.appendChild(document.createElement("iframe")).contentWindow;
+
+["EventTarget", "XMLHttpRequest"].forEach(constructorName => {
+  async_test(t => {
+    const eventTarget = new otherWindow[constructorName]();
+    eventTarget.addEventListener("hi", t.step_func_done(e => {
+      assert_equals(otherWindow.event, undefined);
+      assert_equals(e, window.event);
+    }));
+    eventTarget.dispatchEvent(new Event("hi"));
+  }, "window.event for constructors from another global: " + constructorName);
+});
+
+// XXX: It would be good to test a subclass of EventTarget once we sort out
+// https://github.com/heycam/webidl/issues/540
+
+async_test(t => {
+  const element = document.body.appendChild(otherWindow.document.createElement("meh"));
+  element.addEventListener("yo", t.step_func_done(e => {
+    assert_equals(e, window.event);
+  }));
+  element.dispatchEvent(new Event("yo"));
+}, "window.event and element from another document");
+
+async_test(t => {
+  const doc = otherWindow.document,
+        element = doc.body.appendChild(doc.createElement("meh")),
+        child = element.appendChild(doc.createElement("bleh"));
+  element.addEventListener("yoyo", t.step_func(e => {
+    document.body.appendChild(element);
+    assert_equals(element.ownerDocument, document);
+    assert_equals(window.event, e);
+    assert_equals(otherWindow.event, undefined);
+  }), true);
+  element.addEventListener("yoyo", t.step_func(e => {
+    assert_equals(element.ownerDocument, document);
+    assert_equals(window.event, e);
+    assert_equals(otherWindow.event, undefined);
+  }), true);
+  child.addEventListener("yoyo", t.step_func_done(e => {
+    assert_equals(child.ownerDocument, document);
+    assert_equals(window.event, e);
+    assert_equals(otherWindow.event, undefined);
+  }));
+  child.dispatchEvent(new Event("yoyo"));
+}, "window.event and moving an element post-dispatch");
+
+test(t => {
+  const host = document.createElement("div"),
+        shadow = host.attachShadow({ mode: "open" }),
+        child = shadow.appendChild(document.createElement("trala")),
+        furtherChild = child.appendChild(document.createElement("waddup"));
+  let counter = 0;
+  host.addEventListener("hi", t.step_func(e => {
+    assert_equals(window.event, e);
+    assert_equals(counter++, 3);
+  }));
+  child.addEventListener("hi", t.step_func(e => {
+    assert_equals(window.event, undefined);
+    assert_equals(counter++, 2);
+  }));
+  furtherChild.addEventListener("hi", t.step_func(e => {
+    host.appendChild(child);
+    assert_equals(window.event, undefined);
+    assert_equals(counter++, 0);
+  }));
+  furtherChild.addEventListener("hi", t.step_func(e => {
+    assert_equals(window.event, undefined);
+    assert_equals(counter++, 1);
+  }));
+  furtherChild.dispatchEvent(new Event("hi", { composed: true, bubbles: true }));
+  assert_equals(counter, 4);
+}, "window.event should not be affected by nodes moving post-dispatch");
+
+async_test(t => {
+  const frame = document.body.appendChild(document.createElement("iframe"));
+  frame.src = "resources/event-global-extra-frame.html";
+  frame.onload = t.step_func_done((load_event) => {
+    const event = new Event("hi");
+    document.addEventListener("hi", frame.contentWindow.listener); // listener intentionally not wrapped in t.step_func
+    document.addEventListener("hi", t.step_func(e => {
+      assert_equals(event, e);
+      assert_equals(window.event, e);
+    }));
+    document.dispatchEvent(event);
+    assert_equals(frameState.event, event);
+    assert_equals(frameState.windowEvent, event);
+    assert_equals(frameState.parentEvent, load_event);
+  });
+}, "Listener from a different global");
diff --git a/testing/web-platform/tests/dom/events/event-global-is-still-set-when-coercing-beforeunload-result.html b/testing/web-platform/tests/dom/events/event-global-is-still-set-when-coercing-beforeunload-result.html
new file mode 100644
index 0000000000..a64c8b6b8b
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/event-global-is-still-set-when-coercing-beforeunload-result.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>window.event is still set when 'beforeunload' result is coerced to string</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#ref-for-window-current-event%E2%91%A1">
+<link rel="help" href="https://webidl.spec.whatwg.org/#call-a-user-objects-operation">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<iframe id="iframe" src="resources/event-global-is-still-set-when-coercing-beforeunload-result-frame.html"></iframe>
+<body>
+<script>
+window.onload = () => {
+  async_test(t => {
+    iframe.onload = t.step_func_done(() => {
+      assert_equals(typeof window.currentEventInToString, "object");
+      assert_equals(window.currentEventInToString.type, "beforeunload");
+    });
+
+    iframe.contentWindow.location.href = "about:blank";
+  });
+};
+</script>
diff --git a/testing/web-platform/tests/dom/events/event-global-is-still-set-when-reporting-exception-onerror.html b/testing/web-platform/tests/dom/events/event-global-is-still-set-when-reporting-exception-onerror.html
new file mode 100644
index 0000000000..ceaac4fe2b
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/event-global-is-still-set-when-reporting-exception-onerror.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>window.onerror handler restores window.event after it reports an exception</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-listener-inner-invoke">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+<iframe src="resources/empty-document.html"></iframe>
+<iframe src="resources/empty-document.html"></iframe>
+
+<script>
+setup({ allow_uncaught_exception: true });
+
+async_test(t => {
+    window.onload = t.step_func_done(onLoadEvent => {
+        frames[0].onerror = new frames[1].Function(`
+            top.eventDuringSecondOnError = top.window.event;
+            top.frames[0].eventDuringSecondOnError = top.frames[0].event;
+            top.frames[1].eventDuringSecondOnError = top.frames[1].event;
+        `);
+
+        window.onerror = new frames[0].Function(`
+            top.eventDuringFirstOnError = top.window.event;
+            top.frames[0].eventDuringFirstOnError = top.frames[0].event;
+            top.frames[1].eventDuringFirstOnError = top.frames[1].event;
+
+            foo; // cause second onerror
+        `);
+
+        const myEvent = new ErrorEvent("error", { error: new Error("myError") });
+        window.dispatchEvent(myEvent);
+
+        assert_equals(top.eventDuringFirstOnError, onLoadEvent);
+        assert_equals(frames[0].eventDuringFirstOnError, myEvent);
+        assert_equals(frames[1].eventDuringFirstOnError, undefined);
+
+        assert_equals(top.eventDuringSecondOnError, onLoadEvent);
+        assert_equals(frames[0].eventDuringSecondOnError, myEvent);
+        assert_equals(frames[1].eventDuringSecondOnError.error.name, "ReferenceError");
+    });
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/event-global-set-before-handleEvent-lookup.window.js b/testing/web-platform/tests/dom/events/event-global-set-before-handleEvent-lookup.window.js
new file mode 100644
index 0000000000..8f934bcea9
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/event-global-set-before-handleEvent-lookup.window.js
@@ -0,0 +1,19 @@
+// https://dom.spec.whatwg.org/#concept-event-listener-inner-invoke (steps 8.2 - 12)
+// https://webidl.spec.whatwg.org/#call-a-user-objects-operation (step 10.1)
+
+test(() => {
+  const eventTarget = new EventTarget;
+
+  let currentEvent;
+  eventTarget.addEventListener("foo", {
+    get handleEvent() {
+      currentEvent = window.event;
+      return () => {};
+    }
+  });
+
+  const event = new Event("foo");
+  eventTarget.dispatchEvent(event);
+
+  assert_equals(currentEvent, event);
+}, "window.event is set before 'handleEvent' lookup");
diff --git a/testing/web-platform/tests/dom/events/event-global.html b/testing/web-platform/tests/dom/events/event-global.html
new file mode 100644
index 0000000000..3e8d25ecb5
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/event-global.html
@@ -0,0 +1,117 @@
+<!DOCTYPE html>
+<title>window.event tests</title>
+<link rel="author" title="Mike Taylor" href="mailto:miketaylr@gmail.com">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+setup({allow_uncaught_exception: true});
+
+test(t => {
+  assert_own_property(window, "event");
+  assert_equals(window.event, undefined);
+}, "event exists on window, which is initially set to undefined");
+
+async_test(t => {
+  let target = document.createElement("div");
+  assert_equals(window.event, undefined, "undefined before dispatch");
+
+  let clickEvent = new Event("click");
+  target.addEventListener("click", t.step_func_done(e => {
+    assert_equals(window.event, clickEvent, "window.event set to current event during dispatch");
+  }));
+
+  target.dispatchEvent(clickEvent);
+  assert_equals(window.event, undefined, "undefined after dispatch");
+}, "window.event is only defined during dispatch");
+
+async_test(t => {
+  let parent = document.createElement("div");
+  let root = parent.attachShadow({mode: "closed"});
+  let span = document.createElement("span");
+  root.appendChild(span);
+
+  span.addEventListener("test", t.step_func(e => {
+    assert_equals(window.event, undefined);
+    assert_not_equals(window.event, e);
+  }));
+
+  parent.addEventListener("test", t.step_func_done(e => {
+    assert_equals(window.event, e);
+    assert_not_equals(window.event, undefined);
+  }));
+
+  parent.dispatchEvent(new Event("test", {composed: true}));
+}, "window.event is undefined if the target is in a shadow tree (event dispatched outside shadow tree)");
+
+async_test(t => {
+  let parent = document.createElement("div");
+  let root = parent.attachShadow({mode: "closed"});
+  let span = document.createElement("span");
+  root.appendChild(span);
+  let shadowNode = root.firstElementChild;
+
+  shadowNode.addEventListener("test", t.step_func((e) => {
+    assert_not_equals(window.event, e);
+    assert_equals(window.event, undefined);
+  }));
+
+  parent.addEventListener("test", t.step_func_done(e => {
+    assert_equals(window.event, e);
+    assert_not_equals(window.event, undefined);
+  }));
+
+  shadowNode.dispatchEvent(new Event("test", {composed: true, bubbles: true}));
+}, "window.event is undefined if the target is in a shadow tree (event dispatched inside shadow tree)");
+
+async_test(t => {
+  let parent = document.createElement("div");
+  let root = parent.attachShadow({mode: "open"});
+  document.body.append(parent)
+  let span = document.createElement("span");
+  root.append(span);
+  let shadowNode = root.firstElementChild;
+
+  shadowNode.addEventListener("error", t.step_func(e => {
+    assert_not_equals(window.event, e);
+    assert_equals(window.event, undefined);
+  }));
+
+  let windowOnErrorCalled = false;
+  window.onerror = t.step_func_done(() => {
+    windowOnErrorCalled = true;
+    assert_equals(typeof window.event, "object");
+    assert_equals(window.event.type, "error");
+  });
+
+  shadowNode.dispatchEvent(new ErrorEvent("error", {composed: true, bubbles: true}));
+  assert_true(windowOnErrorCalled);
+}, "window.event is undefined inside window.onerror if the target is in a shadow tree (ErrorEvent dispatched inside shadow tree)");
+
+async_test(t => {
+  let target1 = document.createElement("div");
+  let target2 = document.createElement("div");
+
+  target2.addEventListener("dude", t.step_func(() => {
+    assert_equals(window.event.type, "dude");
+  }));
+
+  target1.addEventListener("cool", t.step_func_done(() => {
+    assert_equals(window.event.type, "cool", "got expected event from global event during dispatch");
+    target2.dispatchEvent(new Event("dude"));
+    assert_equals(window.event.type, "cool", "got expected event from global event after handling a different event handler callback");
+  }));
+
+  target1.dispatchEvent(new Event("cool"));
+}, "window.event is set to the current event during dispatch");
+
+async_test(t => {
+  let target = document.createElement("div");
+
+  target.addEventListener("click", t.step_func_done(e => {
+    assert_equals(e, window.event);
+  }));
+
+  target.dispatchEvent(new Event("click"));
+}, "window.event is set to the current event, which is the event passed to dispatch");
+</script>
diff --git a/testing/web-platform/tests/dom/events/event-global.worker.js b/testing/web-platform/tests/dom/events/event-global.worker.js
new file mode 100644
index 0000000000..116cf32932
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/event-global.worker.js
@@ -0,0 +1,14 @@
+importScripts("/resources/testharness.js");
+test(t => {
+  let seen = false;
+  const event = new Event("hi");
+  assert_equals(self.event, undefined);
+  self.addEventListener("hi", t.step_func(e => {
+    seen = true;
+    assert_equals(self.event, undefined);
+    assert_equals(e, event);
+  }));
+  self.dispatchEvent(event);
+  assert_true(seen);
+}, "There's no self.event (that's why we call it window.event) in workers");
+done();
diff --git a/testing/web-platform/tests/dom/events/focus-event-document-move.html b/testing/web-platform/tests/dom/events/focus-event-document-move.html
new file mode 100644
index 0000000000..2943761ce1
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/focus-event-document-move.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<link rel="author" href="mailto:masonf@chromium.org">
+<link rel="help" href="https://crbug.com/747207">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+
+<script>
+  function handleDown(node) {
+    var d2 = new Document();
+    d2.appendChild(node);
+  }
+</script>
+
+<!-- No crash should occur if a node is moved during mousedown. -->
+<div id='click' onmousedown='handleDown(this)'>Click me</div>
+
+<script>
+  const target = document.getElementById('click');
+  async_test(t => {
+    let actions = new test_driver.Actions()
+      .pointerMove(0, 0, {origin: target})
+      .pointerDown()
+      .pointerUp()
+      .send()
+      .then(t.step_func_done(() => {
+        assert_equals(null,document.getElementById('click'));
+      }))
+      .catch(e => t.step_func(() => assert_unreached('Error')));
+  },'Moving a node during mousedown should not crash');
+</script>
diff --git a/testing/web-platform/tests/dom/events/keypress-dispatch-crash.html b/testing/web-platform/tests/dom/events/keypress-dispatch-crash.html
new file mode 100644
index 0000000000..3207adbd8c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/keypress-dispatch-crash.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<link rel="author" title="Robert Flack" href="mailto:flackr@chromium.org">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1209098">
+
+<!-- No crash should occur if a keypress is dispatched to a constructed document. -->
+
+<script>
+var newDoc = document.implementation.createDocument( "", null);
+var testNode = newDoc.createElement('div');
+newDoc.append(testNode);
+
+var syntheticEvent = document.createEvent('KeyboardEvents');
+syntheticEvent.initKeyboardEvent("keypress");
+testNode.dispatchEvent(syntheticEvent)
+</script>
diff --git a/testing/web-platform/tests/dom/events/legacy-pre-activation-behavior.window.js b/testing/web-platform/tests/dom/events/legacy-pre-activation-behavior.window.js
new file mode 100644
index 0000000000..e9e84bfad1
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/legacy-pre-activation-behavior.window.js
@@ -0,0 +1,10 @@
+test(t => {
+  const input = document.body.appendChild(document.createElement('input'));
+  input.type = "radio";
+  t.add_cleanup(() => input.remove());
+  const clickEvent = new MouseEvent('click', { button: 0, which: 1 });
+  input.addEventListener('change', t.step_func(() => {
+    assert_equals(clickEvent.eventPhase, Event.NONE);
+  }));
+  input.dispatchEvent(clickEvent);
+}, "Use NONE phase during legacy-pre-activation behavior");
diff --git a/testing/web-platform/tests/dom/events/mouse-event-retarget.html b/testing/web-platform/tests/dom/events/mouse-event-retarget.html
new file mode 100644
index 0000000000..c9ce6240d4
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/mouse-event-retarget.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html>
+<title>Script created MouseEvent properly retargets and adjusts offsetX</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<style>
+body {
+  margin: 8px;
+  padding: 0;
+}
+</style>
+
+<div id="target">Hello</div>
+
+<script>
+async_test(t => {
+  target.addEventListener('click', ev => {
+    t.step(() => assert_equals(ev.offsetX, 42));
+    t.done();
+  });
+
+  const ev = new MouseEvent('click', { clientX: 50 });
+  target.dispatchEvent(ev);
+}, "offsetX is correctly adjusted");
+</script>
diff --git a/testing/web-platform/tests/dom/events/no-focus-events-at-clicking-editable-content-in-link.html b/testing/web-platform/tests/dom/events/no-focus-events-at-clicking-editable-content-in-link.html
new file mode 100644
index 0000000000..dc08636c46
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/no-focus-events-at-clicking-editable-content-in-link.html
@@ -0,0 +1,80 @@
+<!doctype html>
+<html>
+<head>
+<meta chareset="utf-8">
+<title>Clicking editable content in link shouldn't cause redundant focus related events</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+</head>
+<body>
+<a href="#"><span contenteditable>Hello</span></a>
+<a href="#" contenteditable><span>Hello</span></a>
+<script>
+function promiseTicks() {
+  return new Promise(resolve => {
+    requestAnimationFrame(() => {
+      requestAnimationFrame(resolve);
+    });
+  });
+}
+
+async function clickElementAndCollectFocusEvents(x, y, options) {
+  await promiseTicks();
+  let events = [];
+  for (const eventType of ["focus", "blur", "focusin", "focusout"]) {
+    document.addEventListener(eventType, event => {
+      events.push(`type: ${event.type}, target: ${event.target.nodeName}`);
+    }, {capture: true});
+  }
+
+  const waitForClickEvent = new Promise(resolve => {
+    addEventListener("click", resolve, {capture: true, once: true});
+  });
+
+  await new test_driver
+    .Actions()
+    .pointerMove(x, y, options)
+    .pointerDown()
+    .pointerUp()
+    .send();
+
+  await waitForClickEvent;
+  await promiseTicks();
+  return events;
+}
+
+promise_test(async t => {
+  document.activeElement?.blur();
+  const editingHost = document.querySelector("span[contenteditable]");
+  editingHost.blur();
+  const focusEvents =
+    await clickElementAndCollectFocusEvents(5, 5, {origin: editingHost});
+  assert_array_equals(
+    focusEvents,
+    [
+      "type: focus, target: SPAN",
+      "type: focusin, target: SPAN",
+    ],
+    "Click event shouldn't cause redundant focus events");
+}, "Click editable element in link");
+
+promise_test(async t => {
+  document.activeElement?.blur();
+  const editingHost = document.querySelector("a[contenteditable]");
+  editingHost.blur();
+  const focusEvents =
+    await clickElementAndCollectFocusEvents(5, 5, {origin: editingHost});
+  assert_array_equals(
+    focusEvents,
+    [
+      "type: focus, target: A",
+      "type: focusin, target: A",
+    ],
+    "Click event shouldn't cause redundant focus events");
+}, "Click editable link");
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-body.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-body.html
new file mode 100644
index 0000000000..5574fe0acb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-body.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>non-passive mousewheel event listener on body</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.body,
+    eventName: 'mousewheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-div.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-div.html
new file mode 100644
index 0000000000..6fbf692cd7
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-div.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<title>non-passive mousewheel event listener on div</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<style>
+  html, body {
+    overflow: hidden;
+    margin: 0;
+  }
+  #div {
+    position: fixed;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    overflow: scroll;
+  }
+</style>
+<div class=remove-on-cleanup id=div>
+  <div style="height: 200vh"></div>
+</div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.getElementById('div'),
+    eventName: 'mousewheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-document.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-document.html
new file mode 100644
index 0000000000..7d07393c69
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-document.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>non-passive mousewheel event listener on document</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document,
+    eventName: 'mousewheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-root.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-root.html
new file mode 100644
index 0000000000..e85fbacaba
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-root.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>non-passive mousewheel event listener on root</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.documentElement,
+    eventName: 'mousewheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-window.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-window.html
new file mode 100644
index 0000000000..29b09f8561
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-mousewheel-event-listener-on-window.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>non-passive mousewheel event listener on window</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: window,
+    eventName: 'mousewheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-body.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-body.html
new file mode 100644
index 0000000000..f417bdd0a6
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-body.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchmove event listener on body</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.body,
+    eventName: 'touchmove',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-div.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-div.html
new file mode 100644
index 0000000000..11c9345407
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-div.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchmove event listener on div</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.getElementById('touchDiv'),
+    eventName: 'touchmove',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-document.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-document.html
new file mode 100644
index 0000000000..8b95a8d492
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-document.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchmove event listener on document</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document,
+    eventName: 'touchmove',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-root.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-root.html
new file mode 100644
index 0000000000..c41ab72bd8
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-root.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchmove event listener on root</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.documentElement,
+    eventName: 'touchmove',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-window.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-window.html
new file mode 100644
index 0000000000..3d6675c566
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchmove-event-listener-on-window.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<link rel="help" href="https://github.com/WICG/interventions/issues/35">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: window,
+    eventName: 'touchstart',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-body.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-body.html
new file mode 100644
index 0000000000..f6e6ecb06d
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-body.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchstart event listener on body</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.body,
+    eventName: 'touchstart',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-div.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-div.html
new file mode 100644
index 0000000000..2e7c6e6b3b
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-div.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchstart event listener on div</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.getElementById('touchDiv'),
+    eventName: 'touchstart',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-document.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-document.html
new file mode 100644
index 0000000000..22fcbdc322
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-document.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchstart event listener on document</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document,
+    eventName: 'touchstart',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-root.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-root.html
new file mode 100644
index 0000000000..56c51349a0
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-root.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchstart event listener on root</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.documentElement,
+    eventName: 'touchstart',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-window.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-window.html
new file mode 100644
index 0000000000..4e9d424a9d
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-touchstart-event-listener-on-window.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>non-passive touchstart event listener on window</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: window,
+    eventName: 'touchstart',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-body.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-body.html
new file mode 100644
index 0000000000..070cadc291
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-body.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>non-passive wheel event listener on body</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.body,
+    eventName: 'wheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-div.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-div.html
new file mode 100644
index 0000000000..c49d18ac13
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-div.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<title>non-passive wheel event listener on div</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<style>
+  html, body {
+    overflow: hidden;
+    margin: 0;
+  }
+  #div {
+    position: fixed;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    overflow: scroll;
+  }
+</style>
+<div class=remove-on-cleanup id=div>
+  <div style="height: 200vh"></div>
+</div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.getElementById('div'),
+    eventName: 'wheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-document.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-document.html
new file mode 100644
index 0000000000..31a55cad43
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-document.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>non-passive wheel event listener on document</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document,
+    eventName: 'wheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-root.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-root.html
new file mode 100644
index 0000000000..b7bacbfc7c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-root.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>non-passive wheel event listener on root</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.documentElement,
+    eventName: 'wheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-window.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-window.html
new file mode 100644
index 0000000000..c236059df4
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/non-passive-wheel-event-listener-on-window.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>non-passive wheel event listener on window</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: window,
+    eventName: 'wheel',
+    passive: false,
+    expectCancelable: true,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-body.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-body.html
new file mode 100644
index 0000000000..9db12cfbdc
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-body.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>passive mousewheel event listener on body</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.body,
+    eventName: 'mousewheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-div.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-div.html
new file mode 100644
index 0000000000..373670856b
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-div.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<title>passive mousewheel event listener on div</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<style>
+  html, body {
+    overflow: hidden;
+    margin: 0;
+  }
+  #div {
+    position: fixed;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    overflow: scroll;
+  }
+</style>
+<div class=remove-on-cleanup id=div>
+  <div style="height: 200vh"></div>
+</div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.getElementById('div'),
+    eventName: 'mousewheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-document.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-document.html
new file mode 100644
index 0000000000..71262280b6
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-document.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>passive mousewheel event listener on document</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document,
+    eventName: 'mousewheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-root.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-root.html
new file mode 100644
index 0000000000..fc641d172e
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-root.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>passive mousewheel event listener on root</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.documentElement,
+    eventName: 'mousewheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-window.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-window.html
new file mode 100644
index 0000000000..f60955c7c4
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-mousewheel-event-listener-on-window.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>passive mousewheel event listener on window</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<link rel="help" href="https://github.com/w3c/uievents/issues/331">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: window,
+    eventName: 'mousewheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-body.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-body.html
new file mode 100644
index 0000000000..2349bad258
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-body.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchmove event listener on body</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.body,
+    eventName: 'touchmove',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-div.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-div.html
new file mode 100644
index 0000000000..a61b34851e
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-div.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchmove event listener on div</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.getElementById('touchDiv'),
+    eventName: 'touchmove',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-document.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-document.html
new file mode 100644
index 0000000000..b49971b5b0
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-document.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchmove event listener on document</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document,
+    eventName: 'touchmove',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-root.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-root.html
new file mode 100644
index 0000000000..b851704590
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-root.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchmove event listener on root</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.documentElement,
+    eventName: 'touchmove',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-window.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-window.html
new file mode 100644
index 0000000000..351d6ace84
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchmove-event-listener-on-window.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchmove event listener on window</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: window,
+    eventName: 'touchstart',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-body.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-body.html
new file mode 100644
index 0000000000..c3d2b577fd
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-body.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchstart event listener on body</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.body,
+    eventName: 'touchstart',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-div.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-div.html
new file mode 100644
index 0000000000..103e7f0d23
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-div.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchstart event listener on div</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.getElementById('touchDiv'),
+    eventName: 'touchstart',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-document.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-document.html
new file mode 100644
index 0000000000..2e4de2405f
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-document.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchstart event listener on document</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document,
+    eventName: 'touchstart',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-root.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-root.html
new file mode 100644
index 0000000000..0f52e9a16f
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-root.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchstart event listener on root</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.documentElement,
+    eventName: 'touchstart',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-window.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-window.html
new file mode 100644
index 0000000000..c47af8101f
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-touchstart-event-listener-on-window.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<title>passive touchstart event listener on window</title>
+<link rel="help" href="https://w3c.github.io/touch-events/#cancelability">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/wait-for.js"></script>
+<script src="resources/touching.js"></script>
+<style>
+#touchDiv {
+  width: 100px;
+  height: 100px;
+}
+</style>
+<div id="touchDiv"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: window,
+    eventName: 'touchstart',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-body.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-body.html
new file mode 100644
index 0000000000..fe0869b022
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-body.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>passive wheel event listener on body</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.body,
+    eventName: 'wheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-div.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-div.html
new file mode 100644
index 0000000000..e2ca6e795a
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-div.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<title>passive wheel event listener on div</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<style>
+  html, body {
+    overflow: hidden;
+    margin: 0;
+  }
+  #div {
+    position: fixed;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    overflow: scroll;
+  }
+</style>
+<div class=remove-on-cleanup id=div>
+  <div style="height: 200vh"></div>
+</div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.getElementById('div'),
+    eventName: 'wheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-document.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-document.html
new file mode 100644
index 0000000000..61b716f7bb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-document.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>passive wheel event listener on document</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document,
+    eventName: 'wheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-root.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-root.html
new file mode 100644
index 0000000000..6b383bc871
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-root.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>passive wheel event listener on root</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: document.documentElement,
+    eventName: 'wheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-window.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-window.html
new file mode 100644
index 0000000000..a1e901f552
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/passive-wheel-event-listener-on-window.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>passive wheel event listener on window</title>
+<link rel="help" href="https://w3c.github.io/uievents/#cancelability-of-wheel-events">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="resources/scrolling.js"></script>
+<div class=remove-on-cleanup style="height: 200vh"></div>
+<script>
+  document.body.onload = () => runTest({
+    target: window,
+    eventName: 'wheel',
+    passive: true,
+    expectCancelable: false,
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/scrolling.js b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/scrolling.js
new file mode 100644
index 0000000000..88e10f5efd
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/scrolling.js
@@ -0,0 +1,34 @@
+function raf() {
+  return new Promise((resolve) => {
+    // rAF twice.
+    window.requestAnimationFrame(() => {
+      window.requestAnimationFrame(resolve);
+    });
+  });
+}
+
+async function runTest({target, eventName, passive, expectCancelable}) {
+  await raf();
+
+  let cancelable = null;
+  let arrived = false;
+  target.addEventListener(eventName, function (event) {
+    cancelable = event.cancelable;
+    arrived = true;
+  }, {passive:passive, once:true});
+
+  promise_test(async (t) => {
+    t.add_cleanup(() => {
+      document.querySelector('.remove-on-cleanup')?.remove();
+    });
+    const pos_x = Math.floor(window.innerWidth / 2);
+    const pos_y = Math.floor(window.innerHeight / 2);
+    const delta_x = 0;
+    const delta_y = 100;
+
+    await new test_driver.Actions()
+      .scroll(pos_x, pos_y, delta_x, delta_y).send();
+    await t.step_wait(() => arrived, `Didn't get event ${eventName} on ${target.localName}`);
+    assert_equals(cancelable, expectCancelable);
+  });
+}
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/touching.js b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/touching.js
new file mode 100644
index 0000000000..620d26804b
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/touching.js
@@ -0,0 +1,34 @@
+function waitForCompositorCommit() {
+  return new Promise((resolve) => {
+    // rAF twice.
+    window.requestAnimationFrame(() => {
+      window.requestAnimationFrame(resolve);
+    });
+  });
+}
+
+function injectInput(touchDiv) {
+  return new test_driver.Actions()
+    .addPointer("touch_pointer", "touch")
+    .pointerMove(0, 0, {origin: touchDiv})
+    .pointerDown()
+    .pointerMove(30, 30)
+    .pointerUp()
+    .send();
+}
+
+function runTest({target, eventName, passive, expectCancelable}) {
+  let touchDiv = document.getElementById("touchDiv");
+  let cancelable = null;
+  let arrived = false;
+  target.addEventListener(eventName, function (event) {
+    cancelable = event.cancelable;
+    arrived = true;
+  }, {passive});
+  promise_test(async () => {
+    await waitForCompositorCommit();
+    await injectInput(touchDiv);
+    await waitFor(() => arrived);
+    assert_equals(cancelable, expectCancelable);
+  });
+}
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/wait-for.js b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/wait-for.js
new file mode 100644
index 0000000000..0bf3e55834
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/resources/wait-for.js
@@ -0,0 +1,15 @@
+function waitFor(condition, MAX_FRAME = 500) {
+  return new Promise((resolve, reject) => {
+    function tick(frames) {
+      // We requestAnimationFrame either for MAX_FRAME frames or until condition is
+      // met.
+      if (frames >= MAX_FRAME)
+        reject(new Error(`Condition did not become true after ${MAX_FRAME} frames`));
+      else if (condition())
+        resolve();
+      else
+        requestAnimationFrame(() => tick(frames + 1));
+    }
+    tick(0);
+  });
+}
diff --git a/testing/web-platform/tests/dom/events/non-cancelable-when-passive/synthetic-events-cancelable.html b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/synthetic-events-cancelable.html
new file mode 100644
index 0000000000..4287770b8d
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/non-cancelable-when-passive/synthetic-events-cancelable.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<title>Synthetic events are always cancelable by default</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dictdef-eventinit">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+const eventsMap = {
+  wheel: 'WheelEvent',
+  mousewheel: 'WheelEvent',
+  touchstart: 'TouchEvent',
+  touchmove: 'TouchEvent',
+  touchend: 'TouchEvent',
+  touchcancel: 'TouchEvent',
+}
+function isCancelable(eventName, interfaceName) {
+  test(() => {
+    assert_implements(interfaceName in self, `${interfaceName} should be supported`);
+    let defaultPrevented = null;
+    addEventListener(eventName, event => {
+      event.preventDefault();
+      defaultPrevented = event.defaultPrevented;
+    });
+    const event = new self[interfaceName](eventName);
+    assert_false(event.cancelable, 'cancelable');
+    const dispatchEventReturnValue = dispatchEvent(event);
+    assert_false(defaultPrevented, 'defaultPrevented');
+    assert_true(dispatchEventReturnValue, 'dispatchEvent() return value');
+  }, `Synthetic ${eventName} event with interface ${interfaceName} is not cancelable`);
+}
+for (const eventName in eventsMap) {
+  isCancelable(eventName, eventsMap[eventName]);
+  isCancelable(eventName, 'Event');
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/passive-by-default.html b/testing/web-platform/tests/dom/events/passive-by-default.html
new file mode 100644
index 0000000000..02029f4dac
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/passive-by-default.html
@@ -0,0 +1,50 @@
+<!DOCTYPE html>
+<title>Default passive event listeners on window, document, document element, body</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#default-passive-value">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+  <div id="div"></div>
+<script>
+  function isListenerPassive(eventName, eventTarget, passive, expectPassive) {
+    test(() => {
+      let defaultPrevented = null;
+      let handler = event => {
+        event.preventDefault();
+        defaultPrevented = event.defaultPrevented;
+        eventTarget.removeEventListener(eventName, handler);
+      };
+      if (passive === 'omitted') {
+        eventTarget.addEventListener(eventName, handler);
+      } else {
+        eventTarget.addEventListener(eventName, handler, {passive});
+      }
+      let dispatchEventReturnValue = eventTarget.dispatchEvent(new Event(eventName, {cancelable: true}));
+      assert_equals(defaultPrevented, !expectPassive, 'defaultPrevented');
+      assert_equals(dispatchEventReturnValue, expectPassive, 'dispatchEvent() return value');
+    }, `${eventName} listener is ${expectPassive ? '' : 'non-'}passive ${passive === 'omitted' ? 'by default' : `with {passive:${passive}}`} for ${eventTarget.constructor.name}`);
+  }
+
+  const eventNames = {
+    touchstart: true,
+    touchmove: true,
+    wheel: true,
+    mousewheel: true,
+    touchend: false
+  };
+  const passiveEventTargets = [window, document, document.documentElement, document.body];
+  const div = document.getElementById('div');
+
+  for (const eventName in eventNames) {
+    for (const eventTarget of passiveEventTargets) {
+      isListenerPassive(eventName, eventTarget, 'omitted', eventNames[eventName]);
+      isListenerPassive(eventName, eventTarget, undefined, eventNames[eventName]);
+      isListenerPassive(eventName, eventTarget, false, false);
+      isListenerPassive(eventName, eventTarget, true, true);
+    }
+    isListenerPassive(eventName, div, 'omitted', false);
+    isListenerPassive(eventName, div, undefined, false);
+    isListenerPassive(eventName, div, false, false);
+    isListenerPassive(eventName, div, true, true);
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/preventDefault-during-activation-behavior.html b/testing/web-platform/tests/dom/events/preventDefault-during-activation-behavior.html
new file mode 100644
index 0000000000..9287403134
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/preventDefault-during-activation-behavior.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<title>preventDefault during activation behavior</title>
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1197032">
+<link rel="help" href="https://html.spec.whatwg.org/multipage/C#the-button-element">
+<link rel="help" href="https://dom.spec.whatwg.org/#dispatching-events">
+<link rel="author" title="L. David Baron" href="https://dbaron.org/">
+<link rel="author" title="Google" href="http://www.google.com/">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<form id="f">
+  <input type="submit" id="b">
+</form>
+
+<script>
+
+promise_test(async () => {
+  let form = document.getElementById("f");
+  let button = document.getElementById("b");
+
+  let cached_event;
+  let submit_fired = false;
+
+  let click_promise = new Promise((resolve, reject) => {
+    button.addEventListener("click", event => {
+      assert_false(submit_fired);
+      cached_event = event;
+      resolve();
+    });
+  });
+
+  form.addEventListener("submit", event => {
+    assert_false(submit_fired);
+    assert_true(!!cached_event, "click should have fired");
+
+    // Call preventDefault on the click event during its activation
+    // behavior, to test the bug that we're trying to test.
+    cached_event.preventDefault();
+
+    // prevent the form submission from navigating the page
+    event.preventDefault();
+
+    submit_fired = true;
+  });
+
+  assert_false(submit_fired);
+  button.click();
+  await click_promise;
+  assert_true(submit_fired);
+}, "behavior of preventDefault during activation behavior");
+
+</script>
diff --git a/testing/web-platform/tests/dom/events/relatedTarget.window.js b/testing/web-platform/tests/dom/events/relatedTarget.window.js
new file mode 100644
index 0000000000..ebc83ceb20
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/relatedTarget.window.js
@@ -0,0 +1,81 @@
+// https://dom.spec.whatwg.org/#concept-event-dispatch
+
+const host = document.createElement("div"),
+      child = host.appendChild(document.createElement("p")),
+      shadow = host.attachShadow({ mode: "closed" }),
+      slot = shadow.appendChild(document.createElement("slot"));
+
+test(() => {
+  for (target of [shadow, slot]) {
+    for (relatedTarget of [new XMLHttpRequest(), self, host]) {
+      const event = new FocusEvent("demo", { relatedTarget: relatedTarget });
+      target.dispatchEvent(event);
+      assert_equals(event.target, null);
+      assert_equals(event.relatedTarget, null);
+    }
+  }
+}, "Reset if target pointed to a shadow tree");
+
+test(() => {
+  for (relatedTarget of [shadow, slot]) {
+    for (target of [new XMLHttpRequest(), self, host]) {
+      const event = new FocusEvent("demo", { relatedTarget: relatedTarget });
+      target.dispatchEvent(event);
+      assert_equals(event.target, target);
+      assert_equals(event.relatedTarget, host);
+    }
+  }
+}, "Retarget a shadow-tree relatedTarget");
+
+test(t => {
+  const shadowChild = shadow.appendChild(document.createElement("div"));
+  shadowChild.addEventListener("demo", t.step_func(() => document.body.appendChild(shadowChild)));
+  const event = new FocusEvent("demo", { relatedTarget: new XMLHttpRequest() });
+  shadowChild.dispatchEvent(event);
+  assert_equals(shadowChild.parentNode, document.body);
+  assert_equals(event.target, null);
+  assert_equals(event.relatedTarget, null);
+  shadowChild.remove();
+}, "Reset if target pointed to a shadow tree pre-dispatch");
+
+test(t => {
+  const shadowChild = shadow.appendChild(document.createElement("div"));
+  document.body.addEventListener("demo", t.step_func(() => document.body.appendChild(shadowChild)));
+  const event = new FocusEvent("demo", { relatedTarget: shadowChild });
+  document.body.dispatchEvent(event);
+  assert_equals(shadowChild.parentNode, document.body);
+  assert_equals(event.target, document.body);
+  assert_equals(event.relatedTarget, host);
+  shadowChild.remove();
+}, "Retarget a shadow-tree relatedTarget, part 2");
+
+test(t => {
+  const event = new FocusEvent("heya", { relatedTarget: shadow, cancelable: true }),
+        callback = t.unreached_func();
+  host.addEventListener("heya", callback);
+  t.add_cleanup(() => host.removeEventListener("heya", callback));
+  event.preventDefault();
+  assert_true(event.defaultPrevented);
+  assert_false(host.dispatchEvent(event));
+  assert_equals(event.target, null);
+  assert_equals(event.relatedTarget, null);
+  // Check that the dispatch flag is cleared
+  event.initEvent("x");
+  assert_equals(event.type, "x");
+}, "Reset targets on early return");
+
+test(t => {
+  const input = document.body.appendChild(document.createElement("input")),
+        event = new MouseEvent("click", { relatedTarget: shadow });
+  let seen = false;
+  t.add_cleanup(() => input.remove());
+  input.type = "checkbox";
+  input.oninput = t.step_func(() => {
+    assert_equals(event.target, null);
+    assert_equals(event.relatedTarget, null);
+    assert_equals(event.composedPath().length, 0);
+    seen = true;
+  });
+  assert_true(input.dispatchEvent(event));
+  assert_true(seen);
+}, "Reset targets before activation behavior");
diff --git a/testing/web-platform/tests/dom/events/replace-event-listener-null-browsing-context-crash.html b/testing/web-platform/tests/dom/events/replace-event-listener-null-browsing-context-crash.html
new file mode 100644
index 0000000000..f41955eedd
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/replace-event-listener-null-browsing-context-crash.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Event listeners: replace listener after moving between documents</title>
+<link rel="author" title="Nate Chapin" href="mailto:japhet@chromium.org">
+<link rel="help" href="https://w3c.github.io/touch-events/#dom-globaleventhandlers-ontouchcancel">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1083793">
+<meta name="assert" content="Overwriting an attribute event listener after adopting the owning node to a different document should not crash"/>
+<progress id="p">
+<iframe id="i"></iframe>
+<script>
+var p = document.getElementById("p");
+i.contentDocument.adoptNode(p);
+p.setAttribute("ontouchcancel", "");
+document.body.appendChild(p);
+p.setAttribute("ontouchcancel", "");
+</script>
+
diff --git a/testing/web-platform/tests/dom/events/resources/empty-document.html b/testing/web-platform/tests/dom/events/resources/empty-document.html
new file mode 100644
index 0000000000..b9cd130a07
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/resources/empty-document.html
@@ -0,0 +1,3 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<body>
diff --git a/testing/web-platform/tests/dom/events/resources/event-global-extra-frame.html b/testing/web-platform/tests/dom/events/resources/event-global-extra-frame.html
new file mode 100644
index 0000000000..241dda8b66
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/resources/event-global-extra-frame.html
@@ -0,0 +1,9 @@
+<script>
+function listener(e) {
+  parent.frameState = {
+    event: e,
+    windowEvent: window.event,
+    parentEvent: parent.event
+  }
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/resources/event-global-is-still-set-when-coercing-beforeunload-result-frame.html b/testing/web-platform/tests/dom/events/resources/event-global-is-still-set-when-coercing-beforeunload-result-frame.html
new file mode 100644
index 0000000000..5df4fa2793
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/resources/event-global-is-still-set-when-coercing-beforeunload-result-frame.html
@@ -0,0 +1,6 @@
+<!doctype html>
+<meta charset="utf-8">
+<body>
+<script>
+window.onbeforeunload = () => ({ toString: () => { parent.currentEventInToString = window.event; } });
+</script>
diff --git a/testing/web-platform/tests/dom/events/resources/prefixed-animation-event-tests.js b/testing/web-platform/tests/dom/events/resources/prefixed-animation-event-tests.js
new file mode 100644
index 0000000000..021b6bb9df
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/resources/prefixed-animation-event-tests.js
@@ -0,0 +1,366 @@
+'use strict'
+
+// Runs a set of tests for a given prefixed/unprefixed animation event (e.g.
+// animationstart/webkitAnimationStart).
+//
+// The eventDetails object must have the following form:
+// {
+//   isTransition: false, <-- can be omitted, default false
+//   unprefixedType: 'animationstart',
+//   prefixedType: 'webkitAnimationStart',
+//   animationCssStyle: '1ms',  <-- must NOT include animation name or
+//                                  transition property
+// }
+function runAnimationEventTests(eventDetails) {
+  const {
+    isTransition,
+    unprefixedType,
+    prefixedType,
+    animationCssStyle
+  } = eventDetails;
+
+  // Derive the DOM event handler names, e.g. onanimationstart.
+  const unprefixedHandler = `on${unprefixedType}`;
+  const prefixedHandler = `on${prefixedType.toLowerCase()}`;
+
+  const style = document.createElement('style');
+  document.head.appendChild(style);
+  if (isTransition) {
+    style.sheet.insertRule(
+      `.baseStyle { width: 100px; transition: width ${animationCssStyle}; }`);
+    style.sheet.insertRule('.transition { width: 200px !important; }');
+  } else {
+    style.sheet.insertRule('@keyframes anim {}');
+  }
+
+  function triggerAnimation(div) {
+    if (isTransition) {
+      div.classList.add('transition');
+    } else {
+      div.style.animation = `anim ${animationCssStyle}`;
+    }
+  }
+
+  test(t => {
+    const div = createDiv(t);
+
+    assert_equals(div[unprefixedHandler], null,
+        `${unprefixedHandler} should initially be null`);
+    assert_equals(div[prefixedHandler], null,
+        `${prefixedHandler} should initially be null`);
+
+    // Setting one should not affect the other.
+    div[unprefixedHandler] = () => { };
+
+    assert_not_equals(div[unprefixedHandler], null,
+        `setting ${unprefixedHandler} should make it non-null`);
+    assert_equals(div[prefixedHandler], null,
+        `setting ${unprefixedHandler} should not affect ${prefixedHandler}`);
+
+    div[prefixedHandler] = () => { };
+
+    assert_not_equals(div[prefixedHandler], null,
+        `setting ${prefixedHandler} should make it non-null`);
+    assert_not_equals(div[unprefixedHandler], div[prefixedHandler],
+        'the setters should be different');
+  }, `${unprefixedHandler} and ${prefixedHandler} are not aliases`);
+
+  // The below tests primarily test the interactions of prefixed animation
+  // events in the algorithm for invoking events:
+  // https://dom.spec.whatwg.org/#concept-event-listener-invoke
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedEventCount = 0;
+    addTestScopedEventHandler(t, div, prefixedHandler, () => {
+      receivedEventCount++;
+    });
+    addTestScopedEventListener(t, div, prefixedType, () => {
+      receivedEventCount++;
+    });
+
+    // The HTML spec[0] specifies that the prefixed event handlers have an
+    // 'Event handler event type' of the appropriate prefixed event type. E.g.
+    // onwebkitanimationend creates a listener for the event type
+    // 'webkitAnimationEnd'.
+    //
+    // [0]: https://html.spec.whatwg.org/multipage/webappapis.html#event-handlers-on-elements,-document-objects,-and-window-objects
+    div.dispatchEvent(new AnimationEvent(prefixedType));
+    assert_equals(receivedEventCount, 2,
+                'prefixed listener and handler received event');
+  }, `dispatchEvent of a ${prefixedType} event does trigger a ` +
+      `prefixed event handler or listener`);
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedEvent = false;
+    addTestScopedEventHandler(t, div, unprefixedHandler, () => {
+      receivedEvent = true;
+    });
+    addTestScopedEventListener(t, div, unprefixedType, () => {
+      receivedEvent = true;
+    });
+
+    div.dispatchEvent(new AnimationEvent(prefixedType));
+    assert_false(receivedEvent,
+                'prefixed listener or handler received event');
+  }, `dispatchEvent of a ${prefixedType} event does not trigger an ` +
+    `unprefixed event handler or listener`);
+
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedEvent = false;
+    addTestScopedEventHandler(t, div, prefixedHandler, () => {
+      receivedEvent = true;
+    });
+    addTestScopedEventListener(t, div, prefixedType, () => {
+      receivedEvent = true;
+    });
+
+    // The rewrite rules from
+    // https://dom.spec.whatwg.org/#concept-event-listener-invoke step 8 do not
+    // apply because isTrusted will be false.
+    div.dispatchEvent(new AnimationEvent(unprefixedType));
+    assert_false(receivedEvent, 'prefixed listener or handler received event');
+  }, `dispatchEvent of an ${unprefixedType} event does not trigger a ` +
+      `prefixed event handler or listener`);
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedEvent = false;
+    addTestScopedEventHandler(t, div, prefixedHandler, () => {
+      receivedEvent = true;
+    });
+
+    triggerAnimation(div);
+    await waitForEventThenAnimationFrame(t, unprefixedType);
+    assert_true(receivedEvent, `received ${prefixedHandler} event`);
+  }, `${prefixedHandler} event handler should trigger for an animation`);
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedPrefixedEvent = false;
+    addTestScopedEventHandler(t, div, prefixedHandler, () => {
+      receivedPrefixedEvent = true;
+    });
+    let receivedUnprefixedEvent = false;
+    addTestScopedEventHandler(t, div, unprefixedHandler, () => {
+      receivedUnprefixedEvent = true;
+    });
+
+    triggerAnimation(div);
+    await waitForEventThenAnimationFrame(t, unprefixedType);
+    assert_true(receivedUnprefixedEvent, `received ${unprefixedHandler} event`);
+    assert_false(receivedPrefixedEvent, `received ${prefixedHandler} event`);
+  }, `${prefixedHandler} event handler should not trigger if an unprefixed ` +
+      `event handler also exists`);
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedPrefixedEvent = false;
+    addTestScopedEventHandler(t, div, prefixedHandler, () => {
+      receivedPrefixedEvent = true;
+    });
+    let receivedUnprefixedEvent = false;
+    addTestScopedEventListener(t, div, unprefixedType, () => {
+      receivedUnprefixedEvent = true;
+    });
+
+    triggerAnimation(div);
+    await waitForEventThenAnimationFrame(t, unprefixedHandler);
+    assert_true(receivedUnprefixedEvent, `received ${unprefixedHandler} event`);
+    assert_false(receivedPrefixedEvent, `received ${prefixedHandler} event`);
+  }, `${prefixedHandler} event handler should not trigger if an unprefixed ` +
+      `listener also exists`);
+
+  promise_test(async t => {
+    // We use a parent/child relationship to be able to register both prefixed
+    // and unprefixed event handlers without the deduplication logic kicking in.
+    const parent = createDiv(t);
+    const child = createDiv(t);
+    parent.appendChild(child);
+    // After moving the child, we have to clean style again.
+    getComputedStyle(child).transition;
+    getComputedStyle(child).width;
+
+    let observedUnprefixedType;
+    addTestScopedEventHandler(t, parent, unprefixedHandler, e => {
+      observedUnprefixedType = e.type;
+    });
+    let observedPrefixedType;
+    addTestScopedEventHandler(t, child, prefixedHandler, e => {
+      observedPrefixedType = e.type;
+    });
+
+    triggerAnimation(child);
+    await waitForEventThenAnimationFrame(t, unprefixedType);
+
+    assert_equals(observedUnprefixedType, unprefixedType);
+    assert_equals(observedPrefixedType, prefixedType);
+  }, `event types for prefixed and unprefixed ${unprefixedType} event ` +
+    `handlers should be named appropriately`);
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedEvent = false;
+    addTestScopedEventListener(t, div, prefixedType, () => {
+      receivedEvent = true;
+    });
+
+    triggerAnimation(div);
+    await waitForEventThenAnimationFrame(t, unprefixedHandler);
+    assert_true(receivedEvent, `received ${prefixedType} event`);
+  }, `${prefixedType} event listener should trigger for an animation`);
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedPrefixedEvent = false;
+    addTestScopedEventListener(t, div, prefixedType, () => {
+      receivedPrefixedEvent = true;
+    });
+    let receivedUnprefixedEvent = false;
+    addTestScopedEventListener(t, div, unprefixedType, () => {
+      receivedUnprefixedEvent = true;
+    });
+
+    triggerAnimation(div);
+    await waitForEventThenAnimationFrame(t, unprefixedHandler);
+    assert_true(receivedUnprefixedEvent, `received ${unprefixedType} event`);
+    assert_false(receivedPrefixedEvent, `received ${prefixedType} event`);
+  }, `${prefixedType} event listener should not trigger if an unprefixed ` +
+      `listener also exists`);
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedPrefixedEvent = false;
+    addTestScopedEventListener(t, div, prefixedType, () => {
+      receivedPrefixedEvent = true;
+    });
+    let receivedUnprefixedEvent = false;
+    addTestScopedEventHandler(t, div, unprefixedHandler, () => {
+      receivedUnprefixedEvent = true;
+    });
+
+    triggerAnimation(div);
+    await waitForEventThenAnimationFrame(t, unprefixedHandler);
+    assert_true(receivedUnprefixedEvent, `received ${unprefixedType} event`);
+    assert_false(receivedPrefixedEvent, `received ${prefixedType} event`);
+  }, `${prefixedType} event listener should not trigger if an unprefixed ` +
+       `event handler also exists`);
+
+  promise_test(async t => {
+    // We use a parent/child relationship to be able to register both prefixed
+    // and unprefixed event listeners without the deduplication logic kicking in.
+    const parent = createDiv(t);
+    const child = createDiv(t);
+    parent.appendChild(child);
+    // After moving the child, we have to clean style again.
+    getComputedStyle(child).transition;
+    getComputedStyle(child).width;
+
+    let observedUnprefixedType;
+    addTestScopedEventListener(t, parent, unprefixedType, e => {
+      observedUnprefixedType = e.type;
+    });
+    let observedPrefixedType;
+    addTestScopedEventListener(t, child, prefixedType, e => {
+      observedPrefixedType = e.type;
+    });
+
+    triggerAnimation(child);
+    await waitForEventThenAnimationFrame(t, unprefixedHandler);
+
+    assert_equals(observedUnprefixedType, unprefixedType);
+    assert_equals(observedPrefixedType, prefixedType);
+  }, `event types for prefixed and unprefixed ${unprefixedType} event ` +
+      `listeners should be named appropriately`);
+
+  promise_test(async t => {
+    const div = createDiv(t);
+
+    let receivedEvent = false;
+    addTestScopedEventListener(t, div, prefixedType.toLowerCase(), () => {
+      receivedEvent = true;
+    });
+    addTestScopedEventListener(t, div, prefixedType.toUpperCase(), () => {
+      receivedEvent = true;
+    });
+
+    triggerAnimation(div);
+    await waitForEventThenAnimationFrame(t, unprefixedHandler);
+    assert_false(receivedEvent, `received ${prefixedType} event`);
+  }, `${prefixedType} event listener is case sensitive`);
+}
+
+// Below are utility functions.
+
+// Creates a div element, appends it to the document body and removes the
+// created element during test cleanup.
+function createDiv(test) {
+  const element = document.createElement('div');
+  element.classList.add('baseStyle');
+  document.body.appendChild(element);
+  test.add_cleanup(() => {
+    element.remove();
+  });
+
+  // Flush style before returning. Some browsers only do partial style re-calc,
+  // so ask for all important properties to make sure they are applied.
+  getComputedStyle(element).transition;
+  getComputedStyle(element).width;
+
+  return element;
+}
+
+// Adds an event handler for |handlerName| (calling |callback|) to the given
+// |target|, that will automatically be cleaned up at the end of the test.
+function addTestScopedEventHandler(test, target, handlerName, callback) {
+  assert_regexp_match(
+      handlerName, /^on/, 'Event handler names must start with "on"');
+  assert_equals(target[handlerName], null,
+                `${handlerName} must be supported and not previously set`);
+  target[handlerName] = callback;
+  // We need this cleaned up even if the event handler doesn't run.
+  test.add_cleanup(() => {
+    if (target[handlerName])
+      target[handlerName] = null;
+  });
+}
+
+// Adds an event listener for |type| (calling |callback|) to the given
+// |target|, that will automatically be cleaned up at the end of the test.
+function addTestScopedEventListener(test, target, type, callback) {
+  target.addEventListener(type, callback);
+  // We need this cleaned up even if the event handler doesn't run.
+  test.add_cleanup(() => {
+    target.removeEventListener(type, callback);
+  });
+}
+
+// Returns a promise that will resolve once the passed event (|eventName|) has
+// triggered and one more animation frame has happened. Automatically chooses
+// between an event handler or event listener based on whether |eventName|
+// begins with 'on'.
+//
+// We always listen on window as we don't want to interfere with the test via
+// triggering the prefixed event deduplication logic.
+function waitForEventThenAnimationFrame(test, eventName) {
+  return new Promise((resolve, _) => {
+    const eventFunc = eventName.startsWith('on')
+        ? addTestScopedEventHandler : addTestScopedEventListener;
+    eventFunc(test, window, eventName, () => {
+      // rAF once to give the event under test time to come through.
+      requestAnimationFrame(resolve);
+    });
+  });
+}
diff --git a/testing/web-platform/tests/dom/events/scrolling/iframe-chains.html b/testing/web-platform/tests/dom/events/scrolling/iframe-chains.html
new file mode 100644
index 0000000000..fb7d674aae
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/iframe-chains.html
@@ -0,0 +1,48 @@
+<!DOCTYPE html>
+<html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<style>
+
+body { margin: 0; padding: 10px; }
+.space { height: 2000px; }
+
+#scroller {
+  border: 3px solid green;
+  position: absolute;
+  z-index: 0;
+  overflow: auto;
+  padding: 10px;
+  width: 250px;
+  height: 150px;
+}
+
+.ifr {
+  border: 3px solid blue;
+  width: 200px;
+  height: 100px;
+}
+
+</style>
+</head>
+<body>
+<div id=scroller>
+  <iframe srcdoc="SCROLL ME" class=ifr></iframe>
+  <div class=space></div>
+</div>
+<div class=space></div>
+<script>
+
+promise_test(async t => {
+  await new test_driver.Actions().scroll(50, 50, 0, 50).send();
+  // Allow the possibility the scroll is not fully synchronous
+  await t.step_wait(() => scroller.scrollTop === 50);
+}, "Wheel scroll in iframe chains to containing element.");
+
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/scrolling/input-text-scroll-event-when-using-arrow-keys.html b/testing/web-platform/tests/dom/events/scrolling/input-text-scroll-event-when-using-arrow-keys.html
new file mode 100644
index 0000000000..f84e446527
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/input-text-scroll-event-when-using-arrow-keys.html
@@ -0,0 +1,71 @@
+<!doctype html>
+<html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+
+</head>
+<body onload=runTest()>
+    <p>Moving the cursor using the arrow keys into an
+        input element fires scroll events when text has to scroll into view.
+        Uses arrow keys to move forward and backwards in the input
+        element.</p>
+    <input type="text" style='width: 50px'
+    value="Fooooooooooooooooooooooooooooooooooooooooooooooooo"/>
+    <textarea rows="4" cols="4">
+        Fooooooooooooooooooooooooooooooooooooooooooooooooo
+    </textarea>
+
+    <script>
+      async function moveCursorRightInsideElement(element, value){
+          var arrowRight = '\uE014';
+          for(var i=0;i<value;i++){
+            await test_driver.send_keys(element, arrowRight);
+          }
+      }
+
+      function runTest(){
+          promise_test(async(t) => { return new Promise(async (resolve, reject) => {
+            var input = document.getElementsByTagName('input')[0];
+            function handleScroll(){
+              resolve("Scroll Event successfully fired!");
+            }
+            input.addEventListener('scroll', handleScroll, false);
+            // move cursor to the right until the text scrolls
+            while(input.scrollLeft === 0){
+              await moveCursorRightInsideElement(input, 1);
+            }
+            // if there is no scroll event fired then test will fail by timeout
+          })},
+             /*
+               Moving the cursor using the arrow keys into an input element
+               fires scroll events when text has to scroll into view.
+               Uses arrow keys to move right in the input element.
+             */
+           "Scroll event fired for <input> element.");
+
+          promise_test(async(t) => { return new Promise(async (resolve, reject) => {
+            var textarea = document.getElementsByTagName('textarea')[0];
+            function handleScroll(){
+              resolve("Scroll Event successfully fired!");
+            }
+            textarea.addEventListener('scroll', handleScroll, false);
+            // move cursor to the right until the text scrolls
+            while(textarea.scrollLeft === 0){
+              await moveCursorRightInsideElement(textarea, 1);
+            }
+            // if there is no scroll event fired then test will fail by timeout
+          })},
+             /*
+              Moving the cursor using the arrow keys into a textarea element
+              fires scroll events when text has to scroll into view.
+              Uses arrow keys to move right in the textarea element.
+            */
+              "Scroll event fired for <textarea> element.");
+      }
+    </script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/events/scrolling/overscroll-deltas.html b/testing/web-platform/tests/dom/events/scrolling/overscroll-deltas.html
new file mode 100644
index 0000000000..2158632250
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/overscroll-deltas.html
@@ -0,0 +1,147 @@
+<!DOCTYPE HTML>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+  #hspacer {
+    height: 100px;
+    width: 100vw;
+    top: 0;
+    /* on the right edge of targetDiv */
+    left: 200px;
+    position: absolute;
+  }
+
+  #vspacer {
+    height: 100vh;
+    width: 100px;
+    position: absolute;
+  }
+
+  #targetDiv {
+    width: 200px;
+    height: 200px;
+    overflow: scroll;
+  }
+
+  #innerDiv {
+    width: 400px;
+    height: 400px;
+  }
+</style>
+
+<body style="margin:0" onload=runTest()>
+  <div id="targetDiv">
+    <div id="innerDiv"></div>
+  </div>
+  <div id="hspacer"></div>
+  <div id="vspacer"></div>
+</body>
+
+<script>
+  var target_div = document.getElementById('targetDiv');
+  var overscrolled_x_deltas = [];
+  var overscrolled_y_deltas = [];
+  var scrollend_received = false;
+
+  function onOverscroll(event) {
+    overscrolled_x_deltas.push(event.deltaX);
+    overscrolled_y_deltas.push(event.deltaY);
+  }
+
+  async function resetScrollers(test) {
+    await waitForScrollReset(test, target_div);
+    await waitForScrollReset(test, document.scrollingElement);
+  }
+
+  function resetOverScrollDeltas() {
+    overscrolled_x_deltas = [];
+    overscrolled_y_deltas = [];
+  }
+
+  function fail() {
+    assert_true(false);
+  }
+
+  document.addEventListener("overscroll", onOverscroll);
+
+  function runTest() {
+    promise_test(async (t) => {
+      await resetScrollers(t);
+      await waitForCompositorCommit();
+      resetOverScrollDeltas();
+
+      assert_equals(document.scrollingElement.scrollTop, 0,
+        "document should not be scrolled");
+
+      let scrollend_promise = waitForScrollendEvent(t, target_div);
+      let max_target_div_scroll_top = target_div.scrollHeight - target_div.clientHeight;
+      target_div.scrollTop = target_div.scrollHeight;
+      await scrollend_promise;
+      assert_equals(target_div.scrollTop, max_target_div_scroll_top,
+      "target_div should be fully scrolled down");
+
+      let overscroll_promise = waitForOverscrollEvent(t, document, 2000);
+      scrollend_promise = waitForScrollendEvent(t, document, 2000);
+      target_div.addEventListener("scrollend", fail);
+      // Scroll target div vertically and wait for the doc to get scrollend event.
+      await scrollElementDown(target_div, target_div.clientHeight + 300);
+      await waitForCompositorCommit();
+      await overscroll_promise;
+      await scrollend_promise;
+
+      target_div.removeEventListener("scrollend", fail);
+      // Even though we request 300 extra pixels of scroll, the API above doesn't
+      // guarantee how much scroll delta will be generated - different browsers
+      // can consume different amounts for "touch slop" (for example). Ensure the
+      // overscroll reaches at least 50 pixels which is a fairly conservative
+      // value.
+      assert_greater_than(overscrolled_y_deltas.length, 0, "There should be at least one overscroll events when overscrolling.");
+      assert_equals(overscrolled_x_deltas.filter(function (x) { return x != 0; }).length, 0, "The deltaX attribute must be 0 when there is no scrolling in x direction.");
+      assert_greater_than_equal(Math.min(...overscrolled_y_deltas), 50, "The deltaY attribute must be the number of pixels overscrolled.");
+      assert_less_than_equal(Math.max(...overscrolled_y_deltas), 300, "The deltaY attribute must be <= the number of pixels overscrolled (300)");
+      assert_greater_than(document.scrollingElement.scrollTop, target_div.clientHeight - 1,
+        "document is scrolled by the height of target_div");
+    }, "testing, vertical");
+
+    promise_test(async (t) => {
+      await resetScrollers(t);
+      await waitForCompositorCommit();
+      resetOverScrollDeltas();
+
+      assert_equals(document.scrollingElement.scrollLeft, 0,
+        "document should not be scrolled");
+
+      let scrollend_promise = waitForScrollendEvent(t, target_div);
+      let max_target_div_scroll_left = target_div.scrollWidth - target_div.clientWidth;
+      target_div.scrollLeft = target_div.scrollWidth;
+      await scrollend_promise;
+      assert_equals(target_div.scrollLeft, max_target_div_scroll_left,
+        "target_div should be fully scrolled right");
+
+      let overscroll_promise = waitForOverscrollEvent(t, document, 2000);
+      scrollend_promise = waitForScrollendEvent(t, document, 2000);
+      target_div.addEventListener("scrollend", fail);
+      // Scroll target div horizontally and wait for the doc to get scrollend event.
+      await scrollElementLeft(target_div, target_div.clientWidth + 300);
+      await waitForCompositorCommit();
+      await overscroll_promise;
+      await scrollend_promise;
+
+      target_div.removeEventListener("scrollend", fail);
+      assert_greater_than(document.scrollingElement.scrollLeft, target_div.clientWidth - 1,
+        "document is scrolled by the height of target_div");
+      // TODO(bokan): It looks like Chrome inappropriately filters some scroll
+      // events despite |overscroll-behavior| being set to none. The overscroll
+      // amount here has been loosened but this should be fixed in Chrome.
+      // https://crbug.com/1112183.
+      assert_greater_than(overscrolled_x_deltas.length, 0, "There should be at least one overscroll events when overscrolling.");
+      assert_equals(overscrolled_y_deltas.filter(function(x){ return x!=0; }).length, 0, "The deltaY attribute must be 0 when there is no scrolling in y direction.");
+      assert_less_than_equal(Math.max(...overscrolled_x_deltas), 300, "The deltaX attribute must be <= number of pixels overscrolled (300)");
+      assert_greater_than_equal(Math.min(...overscrolled_x_deltas),50, "The deltaX attribute must be the number of pixels overscrolled.");
+    }, "testing, horizontal");
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-document.html b/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-document.html
new file mode 100644
index 0000000000..c054ffca9c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-document.html
@@ -0,0 +1,62 @@
+<!DOCTYPE HTML>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+#targetDiv {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+}
+
+#innerDiv {
+  width: 400px;
+  height: 400px;
+}
+</style>
+
+<body style="margin:0" onload=runTest()>
+<div id="targetDiv">
+  <div id="innerDiv">
+  </div>
+</div>
+</body>
+
+<script>
+var target_div = document.getElementById('targetDiv');
+var overscrolled_x_delta = 0;
+var overscrolled_y_delta = 0;
+function onOverscroll(event) {
+  assert_false(event.cancelable);
+  // overscroll events are bubbled when the target node is document.
+  assert_true(event.bubbles);
+  overscrolled_x_delta = event.deltaX;
+  overscrolled_y_delta = event.deltaY;
+}
+document.addEventListener("overscroll", onOverscroll);
+
+function runTest() {
+  promise_test (async (t) => {
+    // Make sure that no overscroll event is sent to target_div.
+    target_div.addEventListener("overscroll",
+        t.unreached_func("target_div got unexpected overscroll event."));
+    await waitForCompositorCommit();
+
+    // Scroll up on target div and wait for the doc to get overscroll event.
+    await touchScrollInTarget(300, target_div, 'up');
+    await waitFor(() => { return overscrolled_y_delta < 0; },
+        'Document did not receive overscroll event after scroll up on target.');
+    assert_equals(target_div.scrollTop, 0);
+
+    // Scroll left on target div and wait for the doc to get overscroll event.
+    await touchScrollInTarget(300, target_div, 'left');
+    await waitFor(() => { return overscrolled_x_delta < 0; },
+        'Document did not receive overscroll event after scroll left on target.');
+    assert_equals(target_div.scrollLeft, 0);
+  }, 'Tests that the document gets overscroll event when no element scrolls ' +
+      'after touch scrolling.');
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-element-with-overscroll-behavior.html b/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-element-with-overscroll-behavior.html
new file mode 100644
index 0000000000..750080e656
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-element-with-overscroll-behavior.html
@@ -0,0 +1,92 @@
+<!DOCTYPE HTML>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+#overscrollXDiv {
+  width: 600px;
+  height: 600px;
+  overflow: scroll;
+  overscroll-behavior-x: contain;
+}
+#overscrollYDiv {
+  width: 500px;
+  height: 500px;
+  overflow: scroll;
+  overscroll-behavior-y: none;
+}
+#targetDiv {
+  width: 400px;
+  height: 400px;
+  overflow: scroll;
+}
+.content {
+  width:800px;
+  height:800px;
+}
+</style>
+
+<body style="margin:0" onload=runTest()>
+<div id="overscrollXDiv">
+  <div class=content>
+    <div id="overscrollYDiv">
+      <div class=content>
+        <div id="targetDiv">
+          <div class="content">
+          </div>
+        </div>
+      </div>
+    </div>
+  </div>
+</div>
+</body>
+
+<script>
+var target_div = document.getElementById('targetDiv');
+var overscrolled_x_delta = 0;
+var overscrolled_y_delta = 0;
+function onOverscrollX(event) {
+  assert_false(event.cancelable);
+  assert_false(event.bubbles);
+  overscrolled_x_delta = event.deltaX;
+}
+function onOverscrollY(event) {
+  assert_false(event.cancelable);
+  assert_false(event.bubbles);
+  overscrolled_y_delta = event.deltaY;
+}
+// Test that both "onoverscroll" and addEventListener("overscroll"... work.
+document.getElementById('overscrollXDiv').onoverscroll = onOverscrollX;
+document.getElementById('overscrollYDiv').
+    addEventListener("overscroll", onOverscrollY);
+
+function runTest() {
+  promise_test (async (t) => {
+    // Make sure that no overscroll event is sent to document or target_div.
+    document.addEventListener("overscroll",
+        t.unreached_func("Document got unexpected overscroll event."));
+    target_div.addEventListener("overscroll",
+        t.unreached_func("target_div got unexpected overscroll event."));
+    await waitForCompositorCommit();
+    // Scroll up on target div and wait for the element with overscroll-y to get
+    // overscroll event.
+    await touchScrollInTarget(300, target_div, 'up');
+    await waitFor(() => { return overscrolled_y_delta < 0; },
+        'Expected element did not receive overscroll event after scroll up on ' +
+        'target.');
+    assert_equals(target_div.scrollTop, 0);
+
+    // Scroll left on target div and wait for the element with overscroll-x to
+    // get overscroll event.
+    await touchScrollInTarget(300, target_div, 'left');
+    await waitFor(() => { return overscrolled_x_delta < 0; },
+        'Expected element did not receive overscroll event after scroll left ' +
+        'on target.');
+    assert_equals(target_div.scrollLeft, 0);
+  }, 'Tests that the last element in the cut scroll chain gets overscroll ' +
+     'event when no element scrolls by touch.');
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-scrolled-element.html b/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-scrolled-element.html
new file mode 100644
index 0000000000..cfc782a809
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-scrolled-element.html
@@ -0,0 +1,65 @@
+<!DOCTYPE HTML>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+#scrollableDiv {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+}
+
+#innerDiv {
+  width: 400px;
+  height: 400px;
+}
+</style>
+
+<body style="margin:0" onload=runTest()>
+<div id="scrollableDiv">
+  <div id="innerDiv">
+  </div>
+</div>
+</body>
+
+<script>
+var scrolling_div = document.getElementById('scrollableDiv');
+var overscrolled_x_delta = 0;
+var overscrolled_y_delta = 0;
+function onOverscroll(event) {
+  assert_false(event.cancelable);
+  assert_false(event.bubbles);
+  overscrolled_x_delta = event.deltaX;
+  overscrolled_y_delta = event.deltaY;
+}
+scrolling_div.addEventListener("overscroll", onOverscroll);
+
+function runTest() {
+  promise_test (async (t) => {
+    // Make sure that no overscroll event is sent to document.
+    document.addEventListener("overscroll",
+        t.unreached_func("Document got unexpected overscroll event."));
+    await waitForCompositorCommit();
+
+    // Do a horizontal scroll and wait for overscroll event.
+    await touchScrollInTarget(300, scrolling_div , 'right');
+    await waitFor(() => { return overscrolled_x_delta > 0; },
+        'Scroller did not receive overscroll event after horizontal scroll.');
+    assert_equals(scrolling_div.scrollWidth - scrolling_div.scrollLeft,
+                scrolling_div.clientWidth);
+
+    overscrolled_x_delta = 0;
+    overscrolled_y_delta = 0;
+
+    // Do a vertical scroll and wait for overscroll event.
+    await touchScrollInTarget(300, scrolling_div, 'down');
+    await waitFor(() => { return overscrolled_y_delta > 0; },
+        'Scroller did not receive overscroll event after vertical scroll.');
+    assert_equals(scrolling_div.scrollHeight - scrolling_div.scrollTop,
+                scrolling_div.clientHeight);
+  }, 'Tests that the scrolled element gets overscroll event after fully scrolling by touch.');
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-window.html b/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-window.html
new file mode 100644
index 0000000000..ef5ae3daef
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/overscroll-event-fired-to-window.html
@@ -0,0 +1,52 @@
+<!DOCTYPE HTML>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+#targetDiv {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+}
+
+#innerDiv {
+  width: 400px;
+  height: 400px;
+}
+</style>
+
+<body style="margin:0" onload=runTest()>
+<div id="targetDiv">
+  <div id="innerDiv">
+  </div>
+</div>
+</body>
+
+<script>
+var target_div = document.getElementById('targetDiv');
+var window_received_overscroll = false;
+
+function onOverscroll(event) {
+  assert_false(event.cancelable);
+  // overscroll events targetting document are bubbled to the window.
+  assert_true(event.bubbles);
+  window_received_overscroll = true;
+}
+window.addEventListener("overscroll", onOverscroll);
+
+function runTest() {
+  promise_test (async (t) => {
+    // Make sure that no overscroll event is sent to target_div.
+    target_div.addEventListener("overscroll",
+        t.unreached_func("target_div got unexpected overscroll event."));
+    // Scroll up on target div and wait for the window to get overscroll event.
+    await touchScrollInTarget(300, target_div, 'up');
+    await waitFor(() => { return window_received_overscroll; },
+        'Window did not receive overscroll event after scroll up on target.');
+  }, 'Tests that the window gets overscroll event when no element scrolls' +
+     'after touch scrolling.');
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scroll_support.js b/testing/web-platform/tests/dom/events/scrolling/scroll_support.js
new file mode 100644
index 0000000000..52c2f58723
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scroll_support.js
@@ -0,0 +1,278 @@
+async function waitForEvent(eventName, test, target, timeoutMs = 500) {
+  return new Promise((resolve, reject) => {
+    const timeoutCallback = test.step_timeout(() => {
+      reject(`No ${eventName} event received for target ${target}`);
+    }, timeoutMs);
+    target.addEventListener(eventName, (evt) => {
+      clearTimeout(timeoutCallback);
+      resolve(evt);
+    }, { once: true });
+  });
+}
+
+async function waitForScrollendEvent(test, target, timeoutMs = 500) {
+  return waitForEvent("scrollend", test, target, timeoutMs);
+}
+
+async function waitForOverscrollEvent(test, target, timeoutMs = 500) {
+  return waitForEvent("overscroll", test, target, timeoutMs);
+}
+
+async function waitForPointercancelEvent(test, target, timeoutMs = 500) {
+  return waitForEvent("pointercancel", test, target, timeoutMs);
+}
+
+// Resets the scroll position to (0,0).  If a scroll is required, then the
+// promise is not resolved until the scrollend event is received.
+async function waitForScrollReset(test, scroller, timeoutMs = 500) {
+  return new Promise(resolve => {
+    if (scroller.scrollTop == 0 &&
+        scroller.scrollLeft == 0) {
+      resolve();
+    } else {
+      const eventTarget =
+        scroller == document.scrollingElement ? document : scroller;
+      scroller.scrollTop = 0;
+      scroller.scrollLeft = 0;
+      waitForScrollendEvent(test, eventTarget, timeoutMs).then(resolve);
+    }
+  });
+}
+
+async function createScrollendPromiseForTarget(test,
+                                               target_div,
+                                               timeoutMs = 500) {
+  return waitForScrollendEvent(test, target_div, timeoutMs).then(evt => {
+    assert_false(evt.cancelable, 'Event is not cancelable');
+    assert_false(evt.bubbles, 'Event targeting element does not bubble');
+  });
+}
+
+function verifyNoScrollendOnDocument(test) {
+  const callback =
+      test.unreached_func("window got unexpected scrollend event.");
+  window.addEventListener('scrollend', callback);
+  test.add_cleanup(() => {
+    window.removeEventListener('scrollend', callback);
+  });
+}
+
+async function verifyScrollStopped(test, target_div) {
+  const unscaled_pause_time_in_ms = 100;
+  const x = target_div.scrollLeft;
+  const y = target_div.scrollTop;
+  return new Promise(resolve => {
+    test.step_timeout(() => {
+      assert_equals(target_div.scrollLeft, x);
+      assert_equals(target_div.scrollTop, y);
+      resolve();
+    }, unscaled_pause_time_in_ms);
+  });
+}
+
+async function resetTargetScrollState(test, target_div) {
+  if (target_div.scrollTop != 0 || target_div.scrollLeft != 0) {
+    target_div.scrollTop = 0;
+    target_div.scrollLeft = 0;
+    return waitForScrollendEvent(test, target_div);
+  }
+}
+
+const MAX_FRAME = 700;
+const MAX_UNCHANGED_FRAMES = 20;
+
+// Returns a promise that resolves when the given condition is met or rejects
+// after MAX_FRAME animation frames.
+// TODO(crbug.com/1400399): deprecate. We should not use frame based waits in
+// WPT as frame rates may vary greatly in different testing environments.
+function waitFor(condition, error_message = 'Reaches the maximum frames.') {
+  return new Promise((resolve, reject) => {
+    function tick(frames) {
+      // We requestAnimationFrame either for MAX_FRAM frames or until condition
+      // is met.
+      if (frames >= MAX_FRAME)
+        reject(error_message);
+      else if (condition())
+        resolve();
+      else
+        requestAnimationFrame(tick.bind(this, frames + 1));
+    }
+    tick(0);
+  });
+}
+
+// TODO(crbug.com/1400446): Test driver should defer sending events until the
+// browser is ready. Also the term compositor-commit is misleading as not all
+// user-agents use a compositor process.
+function waitForCompositorCommit() {
+  return new Promise((resolve) => {
+    // rAF twice.
+    window.requestAnimationFrame(() => {
+      window.requestAnimationFrame(resolve);
+    });
+  });
+}
+
+// Please don't remove this. This is necessary for chromium-based browsers.
+// This shouldn't be necessary if the test harness deferred running the tests
+// until after paint holding. This can be a no-op on user-agents that do not
+// have a separate compositor thread.
+async function waitForCompositorReady() {
+  const animation =
+      document.body.animate({ opacity: [ 1, 1 ] }, {duration: 1 });
+  return animation.finished;
+}
+
+function waitForNextFrame() {
+  const startTime = performance.now();
+  return new Promise(resolve => {
+    window.requestAnimationFrame((frameTime) => {
+      if (frameTime < startTime) {
+        window.requestAnimationFrame(resolve);
+      } else {
+        resolve();
+      }
+    });
+  });
+}
+
+// TODO(crbug.com/1400399): Deprecate as frame rates may vary greatly in
+// different test environments.
+function waitForAnimationEnd(getValue) {
+  var last_changed_frame = 0;
+  var last_position = getValue();
+  return new Promise((resolve, reject) => {
+    function tick(frames) {
+    // We requestAnimationFrame either for MAX_FRAME or until
+    // MAX_UNCHANGED_FRAMES with no change have been observed.
+      if (frames >= MAX_FRAME || frames - last_changed_frame > MAX_UNCHANGED_FRAMES) {
+        resolve();
+      } else {
+        current_value = getValue();
+        if (last_position != current_value) {
+          last_changed_frame = frames;
+          last_position = current_value;
+        }
+        requestAnimationFrame(tick.bind(this, frames + 1));
+      }
+    }
+    tick(0);
+  })
+}
+
+// Scrolls in target according to move_path with pauses in between
+// The move_path should contains coordinates that are within target boundaries.
+// Keep in mind that 0,0 is the center of the target element and is also
+// the pointerDown position.
+// pointerUp() is fired after sequence of moves.
+function touchScrollInTargetSequentiallyWithPause(target, move_path, pause_time_in_ms = 100) {
+  const test_driver_actions = new test_driver.Actions()
+    .addPointer("pointer1", "touch")
+    .pointerMove(0, 0, {origin: target})
+    .pointerDown();
+
+  const substeps = 5;
+  let x = 0;
+  let y = 0;
+  // Do each move in 5 steps
+  for(let move of move_path) {
+    let step_x = (move.x - x) / substeps;
+    let step_y = (move.y - y) / substeps;
+    for(let step = 0; step < substeps; step++) {
+      x += step_x;
+      y += step_y;
+      test_driver_actions.pointerMove(x, y, {origin: target});
+    }
+    test_driver_actions.pause(pause_time_in_ms); // To prevent inertial scroll
+  }
+
+  return test_driver_actions.pointerUp().send();
+}
+
+function touchScrollInTarget(pixels_to_scroll, target, direction, pause_time_in_ms = 100) {
+  var x_delta = 0;
+  var y_delta = 0;
+  const num_movs = 5;
+  if (direction == "down") {
+    y_delta = -1 * pixels_to_scroll / num_movs;
+  } else if (direction == "up") {
+    y_delta = pixels_to_scroll / num_movs;
+  } else if (direction == "right") {
+    x_delta = -1 * pixels_to_scroll / num_movs;
+  } else if (direction == "left") {
+    x_delta = pixels_to_scroll / num_movs;
+  } else {
+    throw("scroll direction '" + direction + "' is not expected, direction should be 'down', 'up', 'left' or 'right'");
+  }
+  return new test_driver.Actions()
+      .addPointer("pointer1", "touch")
+      .pointerMove(0, 0, {origin: target})
+      .pointerDown()
+      .pointerMove(x_delta, y_delta, {origin: target})
+      .pointerMove(2 * x_delta, 2 * y_delta, {origin: target})
+      .pointerMove(3 * x_delta, 3 * y_delta, {origin: target})
+      .pointerMove(4 * x_delta, 4 * y_delta, {origin: target})
+      .pointerMove(5 * x_delta, 5 * y_delta, {origin: target})
+      .pause(pause_time_in_ms)
+      .pointerUp()
+      .send();
+}
+
+// Trigger fling by doing pointerUp right after pointerMoves.
+function touchFlingInTarget(pixels_to_scroll, target, direction) {
+  touchScrollInTarget(pixels_to_scroll, target, direction, 0 /* pause_time */);
+}
+
+function mouseActionsInTarget(target, origin, delta, pause_time_in_ms = 100) {
+  return new test_driver.Actions()
+    .addPointer("pointer1", "mouse")
+    .pointerMove(origin.x, origin.y, { origin: target })
+    .pointerDown()
+    .pointerMove(origin.x + delta.x, origin.y + delta.y, { origin: target })
+    .pointerMove(origin.x + delta.x * 2, origin.y + delta.y * 2, { origin: target })
+    .pause(pause_time_in_ms)
+    .pointerUp()
+    .send();
+}
+
+// Returns a promise that resolves when the given condition holds for 10
+// animation frames or rejects if the condition changes to false within 10
+// animation frames.
+// TODO(crbug.com/1400399): Deprecate as frame rates may very greatly in
+// different test environments.
+function conditionHolds(condition, error_message = 'Condition is not true anymore.') {
+  const MAX_FRAME = 10;
+  return new Promise((resolve, reject) => {
+    function tick(frames) {
+      // We requestAnimationFrame either for 10 frames or until condition is
+      // violated.
+      if (frames >= MAX_FRAME)
+        resolve();
+      else if (!condition())
+        reject(error_message);
+      else
+        requestAnimationFrame(tick.bind(this, frames + 1));
+    }
+    tick(0);
+  });
+}
+
+function scrollElementDown(element, scroll_amount) {
+  let x = 0;
+  let y = 0;
+  let delta_x = 0;
+  let delta_y = scroll_amount;
+  let actions = new test_driver.Actions()
+  .scroll(x, y, delta_x, delta_y, {origin: element});
+  return  actions.send();
+}
+
+function scrollElementLeft(element, scroll_amount) {
+  let x = 0;
+  let y = 0;
+  let delta_x = scroll_amount;
+  let delta_y = 0;
+  let actions = new test_driver.Actions()
+  .scroll(x, y, delta_x, delta_y, {origin: element});
+  return  actions.send();
+}
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-after-sequence-of-scrolls.tentative.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-after-sequence-of-scrolls.tentative.html
new file mode 100644
index 0000000000..dab6dcc9bd
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-after-sequence-of-scrolls.tentative.html
@@ -0,0 +1,91 @@
+<!DOCTYPE HTML>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+#targetDiv {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+}
+
+#innerDiv {
+  width: 4000px;
+  height: 4000px;
+}
+</style>
+
+<body style="margin:0" onload=runTest()>
+<div id="targetDiv">
+  <div id="innerDiv">
+  </div>
+</div>
+</body>
+
+<script>
+const target_div = document.getElementById('targetDiv');
+
+async function testWithMovePath(t, move_path) {
+  // Skip the test on a Mac as they do not support touch screens.
+  const isMac = navigator.platform.toUpperCase().indexOf('MAC')>=0;
+  if (isMac)
+    return;
+
+  await resetTargetScrollState(t, target_div);
+  await waitForCompositorReady();
+
+  verifyNoScrollendOnDocument(t);
+
+  let scrollend_count = 0;
+  const scrollend_listener = () => { scrollend_count += 1; };
+  target_div.addEventListener("scrollend", scrollend_listener);
+  t.add_cleanup(() => { target_div.removeEventListener('scrollend', scrollend_listener); });
+
+  const pointercancel_listener = () => {
+    assert_equals(scrollend_count, 0, 'scrollend should happen after pointercancel.');
+  };
+  target_div.addEventListener("pointercancel", pointercancel_listener);
+  t.add_cleanup(() => { target_div.removeEventListener('pointercancel', pointercancel_listener); });
+
+  // Because we have several pointer moves, we choose bigger timeout.
+  const timeoutMs = 3000;
+  const targetPointercancelPromise = waitForPointercancelEvent(t, target_div, timeoutMs);
+  const targetScrollendPromise = createScrollendPromiseForTarget(t, target_div, timeoutMs);
+
+  await touchScrollInTargetSequentiallyWithPause(target_div, move_path);
+
+  // Because we start scrolling after pointerdown, there is no pointerup, instead the target
+  // will receive a pointercancel, so we wait for pointercancel, and then continue.
+  await targetPointercancelPromise;
+  await targetScrollendPromise;
+  await verifyScrollStopped(t, target_div);
+  assert_equals(scrollend_count, 1, 'Only one scrollend event should be fired');
+}
+
+function runTest() {
+  promise_test (async (t) => {
+    // Scroll down & up & down on target div and wait for the target_div to get scrollend event.
+    const move_path = [
+      { x: 0, y: -80 }, // Scroll down
+      { x: 0, y: -40 }, // Scroll up
+      { x: 0, y: -80 }, // Scroll down
+    ];
+    await testWithMovePath(t, move_path);
+  }, "Move down, up and down again, receive scrollend event only once");
+
+  promise_test (async (t) => {
+    // Scroll right & left & right on target div and wait for the target_div to get scrollend event.
+    const move_path = [
+      { x: -80, y: 0 }, // Scroll right
+      { x: -40, y: 0 }, // Scroll left
+      { x: -80, y: 0 }, // Scroll right
+    ];
+    await testWithMovePath(t, move_path);
+  }, "Move right, left and right again, receive scrollend event only once");
+
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-after-snap.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-after-snap.html
new file mode 100644
index 0000000000..03079ddc6c
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-after-snap.html
@@ -0,0 +1,87 @@
+<!DOCTYPE html>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+div {
+  position: absolute;
+}
+#scroller {
+  width: 500px;
+  height: 500px;
+  overflow: scroll;
+  scroll-snap-type: both mandatory;
+  border: solid black 5px;
+}
+#space {
+  width: 2000px;
+  height: 2000px;
+}
+.target {
+  width: 200px;
+  height: 200px;
+  scroll-snap-align: start;
+  background-color: blue;
+}
+</style>
+
+<body style="margin:0" onload=runTests()>
+  <div id="scroller">
+    <div id="space"></div>
+    <div class="target" style="left: 0px; top: 0px;"></div>
+    <div class="target" style="left: 80px; top: 80px;"></div>
+    <div class="target" style="left: 200px; top: 200px;"></div>
+  </div>
+</body>
+
+<script>
+var scroller = document.getElementById("scroller");
+var space = document.getElementById("space");
+const MAX_FRAME_COUNT = 700;
+const MAX_UNCHANGED_FRAME = 20;
+
+function scrollTop() {
+  return scroller.scrollTop;
+}
+
+var scroll_arrived_after_scroll_end = false;
+var scroll_end_arrived = false;
+scroller.addEventListener("scroll", () => {
+  if (scroll_end_arrived)
+    scroll_arrived_after_scroll_end = true;
+});
+scroller.addEventListener("scrollend", () => {
+  scroll_end_arrived = true;
+});
+
+function runTests() {
+  promise_test (async () => {
+    await waitForCompositorCommit();
+    await touchScrollInTarget(100, scroller, 'down');
+    // Wait for the scroll snap animation to finish.
+    await waitForAnimationEnd(scrollTop);
+    await waitFor(() => { return scroll_end_arrived; });
+    // Verify that scroll snap animation has finished before firing scrollend event.
+    assert_false(scroll_arrived_after_scroll_end);
+  }, "Tests that scrollend is fired after scroll snap animation completion.");
+
+  promise_test (async () => {
+    // Reset scroll state.
+    scroller.scrollTo(0, 0);
+    await waitForCompositorCommit();
+    scroll_end_arrived = false;
+    scroll_arrived_after_scroll_end = false;
+
+    await touchFlingInTarget(50, scroller, 'down');
+    // Wait for the scroll snap animation to finish.
+    await waitForAnimationEnd(scrollTop);
+    await waitFor(() => { return scroll_end_arrived; });
+    // Verify that scroll snap animation has finished before firing scrollend event.
+    assert_false(scroll_arrived_after_scroll_end);
+  }, "Tests that scrollend is fired after fling snap animation completion.");
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-mandatory-snap-point-after-load.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-mandatory-snap-point-after-load.html
new file mode 100644
index 0000000000..f379113420
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-mandatory-snap-point-after-load.html
@@ -0,0 +1,87 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="scroll_support.js"></script>
+  <title>scrollend + mandatory scroll snap test</title>
+
+  <style>
+    #root {
+      width: 400px;
+      height: 400px;
+      overflow: auto;
+      scroll-snap-type: y mandatory;
+      border: 1px solid black;
+      --page-height: 400px;
+    }
+
+    #scroller {
+      height: 200px;
+      width: 200px;
+      overflow: auto;
+      border: 1px solid black;
+      --page-height: 200px;
+    }
+
+    .page {
+      height: var(--page-height);
+      scroll-snap-align: start;
+    }
+
+    .hidden {
+      display: none;
+    }
+  </style>
+</head>
+
+<body onload="runTests()">
+<div id="root" class="hidden">
+  <h1>scrollend + mandatory scroll snap test</h1>
+  <div id="scroller">
+    <div class="page">
+      <p>Page 1</p>
+    </div>
+    <div class="page">
+      <p>Page 2</p>
+    </div>
+    <div class="page">
+      <p>Page 3</p>
+    </div>
+  </div>
+
+  <div class="page">
+    <p>Page A</p>
+  </div>
+  <div class="page">
+    <p>Page B</p>
+  </div>
+  <div class="page">
+    <p>Page C</p>
+  </div>
+</div>
+
+<script>
+  function runTests() {
+    const root_div = document.getElementById("root");
+
+    promise_test(async (t) => {
+      const targetScrollendPromise = createScrollendPromiseForTarget(t, root_div);
+
+      await waitForNextFrame();
+      root_div.classList.remove("hidden");
+      await waitForNextFrame();
+
+      await targetScrollendPromise;
+      await verifyScrollStopped(t, root_div);
+    }, "scrollend event fired after load for mandatory snap point");
+  }
+</script>
+</body>
+
+</html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-programmatic-scroll.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-programmatic-scroll.html
new file mode 100644
index 0000000000..c6569e0beb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-programmatic-scroll.html
@@ -0,0 +1,135 @@
+<!DOCTYPE HTML>
+<meta name="timeout" content="long">
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+html {
+  height: 3000px;
+  width: 3000px;
+}
+#targetDiv {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+}
+
+#innerDiv {
+  width: 400px;
+  height: 400px;
+}
+</style>
+
+<body style="margin:0" onload=runTest()>
+<div id="targetDiv">
+  <div id="innerDiv">
+  </div>
+</div>
+</body>
+<script>
+var element_scrollend_arrived = false;
+var document_scrollend_arrived = false;
+
+function onElementScrollEnd(event) {
+  assert_false(event.cancelable);
+  assert_false(event.bubbles);
+  element_scrollend_arrived = true;
+}
+
+function onDocumentScrollEnd(event) {
+  assert_false(event.cancelable);
+  // scrollend events are bubbled when the target node is document.
+  assert_true(event.bubbles);
+  document_scrollend_arrived = true;
+}
+
+function callScrollFunction([scrollTarget, scrollFunction, args]) {
+  scrollTarget[scrollFunction](args);
+}
+
+function runTest() {
+  let root_element = document.scrollingElement;
+  let target_div = document.getElementById("targetDiv");
+
+  promise_test (async (t) => {
+    await waitForCompositorCommit();
+    target_div.addEventListener("scrollend", onElementScrollEnd);
+    document.addEventListener("scrollend", onDocumentScrollEnd);
+
+    let test_cases = [
+      [target_div, 200, 200, [target_div, "scrollTo", { top: 200, left: 200, behavior: "auto" }]],
+      [target_div, 0, 0, [target_div, "scrollTo", { top: 0, left: 0, behavior: "smooth" }]],
+      [root_element, 200, 200, [root_element, "scrollTo", { top: 200, left: 200, behavior: "auto" }]],
+      [root_element, 0, 0, [root_element, "scrollTo", { top: 0, left: 0, behavior: "smooth" }]],
+      [target_div, 200, 200, [target_div, "scrollBy", { top: 200, left: 200, behavior: "auto" }]],
+      [target_div, 0, 0, [target_div, "scrollBy", { top: -200, left: -200, behavior: "smooth" }]],
+      [root_element, 200, 200, [root_element, "scrollBy", { top: 200, left: 200, behavior: "auto" }]],
+      [root_element, 0, 0, [root_element, "scrollBy", { top: -200, left: -200, behavior: "smooth" }]]
+    ];
+
+    for(i = 0; i < test_cases.length; i++) {
+      let t = test_cases[i];
+      let target = t[0];
+      let expected_x = t[1];
+      let expected_y = t[2];
+      let scroll_datas = t[3];
+
+      callScrollFunction(scroll_datas);
+      await waitFor(() => { return element_scrollend_arrived || document_scrollend_arrived; }, target.tagName + "." + scroll_datas[1] + " did not receive scrollend event.");
+      if (target == root_element)
+        assert_false(element_scrollend_arrived);
+      else
+        assert_false(document_scrollend_arrived);
+      assert_equals(target.scrollLeft, expected_x, target.tagName + "." + scroll_datas[1] + " scrollLeft");
+      assert_equals(target.scrollTop, expected_y, target.tagName + "." + scroll_datas[1] + " scrollTop");
+
+      element_scrollend_arrived = false;
+      document_scrollend_arrived = false;
+    }
+  }, "Tests scrollend event for calling scroll functions.");
+
+  promise_test(async (t) => {
+    await waitForCompositorCommit();
+
+    let test_cases = [
+      [target_div, "scrollTop"],
+      [target_div, "scrollLeft"],
+      [root_element, "scrollTop"],
+      [root_element, "scrollLeft"]
+    ];
+    for (i = 0; i < test_cases.length; i++) {
+      let t = test_cases[i];
+      let target = t[0];
+      let attribute = t[1];
+      let position = 200;
+
+      target.style.scrollBehavior = "smooth";
+      target[attribute] = position;
+      await waitFor(() => { return element_scrollend_arrived || document_scrollend_arrived; }, target.tagName + "." + attribute + " did not receive scrollend event.");
+      if (target == root_element)
+        assert_false(element_scrollend_arrived);
+      else
+        assert_false(document_scrollend_arrived);
+      assert_equals(target[attribute], position, target.tagName + "." + attribute + " ");
+      element_scrollend_arrived = false;
+      document_scrollend_arrived = false;
+
+      await waitForCompositorCommit();
+      target.style.scrollBehavior = "auto";
+      target[attribute] = 0;
+      await waitFor(() => { return element_scrollend_arrived || document_scrollend_arrived; }, target.tagName + "." + attribute + " did not receive scrollend event.");
+      if (target == root_element)
+        assert_false(element_scrollend_arrived);
+      else
+        assert_false(document_scrollend_arrived);
+      assert_equals(target[attribute], 0, target.tagName + "." + attribute + " ");
+      element_scrollend_arrived = false;
+      document_scrollend_arrived = false;
+    }
+  }, "Tests scrollend event for changing scroll attributes.");
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-scrollIntoView.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-scrollIntoView.html
new file mode 100644
index 0000000000..8782b1dfee
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-for-scrollIntoView.html
@@ -0,0 +1,124 @@
+<!DOCTYPE HTML>
+<meta name="timeout" content="long">
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+html {
+  height: 3000px;
+  width: 3000px;
+}
+#targetDiv {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+}
+
+#innerDiv {
+  width: 400px;
+  height: 400px;
+}
+</style>
+
+<body style="margin:0" onload=runTest()>
+<div id="targetDiv">
+  <div id="innerDiv">
+  </div>
+</div>
+</body>
+<script>
+var element_scrollend_arrived = false;
+var document_scrollend_arrived = false;
+
+function onElementScrollEnd(event) {
+  assert_false(event.cancelable);
+  assert_false(event.bubbles);
+  element_scrollend_arrived = true;
+}
+
+function onDocumentScrollEnd(event) {
+  assert_false(event.cancelable);
+  // scrollend events are bubbled when the target node is document.
+  assert_true(event.bubbles);
+  document_scrollend_arrived = true;
+}
+
+function callScrollFunction([scrollTarget, scrollFunction, args]) {
+  scrollTarget[scrollFunction](args);
+}
+
+function runTest() {
+  let root_element = document.scrollingElement;
+  let target_div = document.getElementById("targetDiv");
+  let inner_div = document.getElementById("innerDiv");
+
+  // Get expected position for root_element scrollIntoView.
+  root_element.scrollTo(10000, 10000);
+  let max_root_x = root_element.scrollLeft;
+  let max_root_y = root_element.scrollTop;
+  root_element.scrollTo(0, 0);
+
+  target_div.scrollTo(10000, 10000);
+  let max_element_x = target_div.scrollLeft;
+  let max_element_y = target_div.scrollTop;
+  target_div.scrollTo(0, 0);
+
+  promise_test (async (t) => {
+    await waitForCompositorCommit();
+    target_div.addEventListener("scrollend", onElementScrollEnd);
+    document.addEventListener("scrollend", onDocumentScrollEnd);
+
+    let test_cases = [
+      [target_div, max_element_x, max_element_y, [inner_div, "scrollIntoView", { inline: "end", block: "end", behavior: "auto" }]],
+      [target_div, 0, 0, [inner_div, "scrollIntoView", { inline: "start", block: "start", behavior: "smooth" }]],
+      [root_element, max_root_x, max_root_y, [root_element, "scrollIntoView", { inline: "end", block: "end", behavior: "smooth" }]],
+      [root_element, 0, 0, [root_element, "scrollIntoView", { inline: "start", block: "start", behavior: "smooth" }]]
+    ];
+
+    for(i = 0; i < test_cases.length; i++) {
+      let t = test_cases[i];
+      let target = t[0];
+      let expected_x = t[1];
+      let expected_y = t[2];
+      let scroll_datas = t[3];
+
+      callScrollFunction(scroll_datas);
+      await waitFor(() => { return element_scrollend_arrived || document_scrollend_arrived; }, target.tagName + ".scrollIntoView  did not receive scrollend event.");
+      if (target == root_element)
+        assert_false(element_scrollend_arrived);
+      else
+        assert_false(document_scrollend_arrived);
+      assert_equals(target.scrollLeft, expected_x, target.tagName + ".scrollIntoView scrollLeft");
+      assert_equals(target.scrollTop, expected_y, target.tagName + ".scrollIntoView scrollTop");
+
+      element_scrollend_arrived = false;
+      document_scrollend_arrived = false;
+    }
+  }, "Tests scrollend event for scrollIntoView.");
+
+  promise_test(async (t) => {
+    document.body.removeChild(target_div);
+    let out_div = document.createElement("div");
+    out_div.style = "width: 100px; height:100px; overflow:scroll; scroll-behavior:smooth;";
+    out_div.appendChild(target_div);
+    document.body.appendChild(out_div);
+    await waitForCompositorCommit();
+
+    element_scrollend_arrived = false;
+    document_scrollend_arrived = false;
+    inner_div.scrollIntoView({ inline: "end", block: "end", behavior: "auto" });
+    await waitFor(() => { return element_scrollend_arrived || document_scrollend_arrived; }, "Nested scrollIntoView did not receive scrollend event.");
+    assert_equals(root_element.scrollLeft, 0, "Nested scrollIntoView root_element scrollLeft");
+    assert_equals(root_element.scrollTop, 0, "Nested scrollIntoView root_element scrollTop");
+    assert_equals(out_div.scrollLeft, 100, "Nested scrollIntoView out_div scrollLeft");
+    assert_equals(out_div.scrollTop, 100, "Nested scrollIntoView out_div scrollTop");
+    assert_equals(target_div.scrollLeft, max_element_x, "Nested scrollIntoView target_div scrollLeft");
+    assert_equals(target_div.scrollTop, max_element_y, "Nested scrollIntoView target_div scrollTop");
+    assert_false(document_scrollend_arrived);
+  }, "Tests scrollend event for nested scrollIntoView.");
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-document.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-document.html
new file mode 100644
index 0000000000..797c2eb53d
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-document.html
@@ -0,0 +1,106 @@
+<!DOCTYPE HTML>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+  #hspacer {
+    height: 100px;
+    width: 100vw;
+    top: 0;
+    left: 200px;
+    /* on the right edge od targetDiv */
+    position: absolute;
+  }
+
+  #vspacer {
+    height: 100vh;
+    width: 100px;
+    position: absolute;
+  }
+
+  #targetDiv {
+    width: 200px;
+    height: 200px;
+    overflow: scroll;
+  }
+
+  #innerDiv {
+    width: 400px;
+    height: 400px;
+  }
+</style>
+
+<body style="margin:0" onload=runTest()>
+  <div id="targetDiv">
+    <div id="innerDiv"></div>
+  </div>
+  <div id="hspacer"></div>
+  <div id="vspacer"></div>
+</body>
+
+<script>
+  var target_div = document.getElementById('targetDiv');
+  async function resetScrollers(test) {
+    await waitForScrollReset(test, target_div);
+    await waitForScrollReset(test, document.scrollingElement);
+  }
+
+  function fail() {
+    assert_true(false);
+  }
+
+  function runTest() {
+    promise_test(async (t) => {
+      await resetScrollers(t);
+      await waitForCompositorCommit();
+
+      assert_equals(document.scrollingElement.scrollTop, 0,
+        "document should not be scrolled");
+
+      let scrollend_promise = waitForScrollendEvent(t, target_div);
+      let max_target_div_scroll_top = target_div.scrollHeight - target_div.clientHeight;
+      target_div.scrollTo({ top: target_div.scrollHeight, left: 0 });
+      await scrollend_promise;
+      assert_approx_equals(target_div.scrollTop, max_target_div_scroll_top, 1,
+        "target_div should be fully scrolled down");
+
+      scrollend_promise = waitForScrollendEvent(t, document, 2000);
+      target_div.addEventListener("scrollend", fail);
+      // Scroll up on target div and wait for the doc to get scrollend event.
+      await scrollElementDown(target_div, target_div.clientHeight + 25);
+      await scrollend_promise;
+
+      target_div.removeEventListener("scrollend", fail);
+      assert_greater_than(document.scrollingElement.scrollTop, target_div.clientHeight - 1,
+        "document is scrolled by the height of target_div");
+    }, "testing, vertical");
+
+    promise_test(async (t) => {
+      await resetScrollers(t);
+      await waitForCompositorCommit();
+
+      assert_equals(document.scrollingElement.scrollLeft, 0,
+        "document should not be scrolled");
+
+      let scrollend_promise = waitForScrollendEvent(t, target_div);
+      let max_target_div_scroll_left = target_div.scrollWidth - target_div.clientWidth;
+      target_div.scrollTo({ left: target_div.scrollWidth, top: 0 });
+      await scrollend_promise;
+      assert_approx_equals(target_div.scrollLeft, max_target_div_scroll_left, 1,
+        "target_div should be fully scrolled right");
+
+      scrollend_promise = waitForScrollendEvent(t, document, 2000);
+      target_div.addEventListener("scrollend", fail);
+      await scrollElementLeft(target_div, target_div.clientWidth + 25);
+      await scrollend_promise;
+
+      target_div.removeEventListener("scrollend", fail);
+      assert_greater_than(document.scrollingElement.scrollLeft, target_div.clientWidth - 1,
+        "document is scrolled by the height of target_div");
+    }, "testing, horizontal");
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-element-with-overscroll-behavior.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-element-with-overscroll-behavior.html
new file mode 100644
index 0000000000..edda88e7cb
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-element-with-overscroll-behavior.html
@@ -0,0 +1,173 @@
+<!DOCTYPE HTML>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+  #overscrollXDiv {
+    width: 200px;
+    height: 200px;
+    overflow: scroll;
+    overscroll-behavior-x: contain;
+    border: solid 1px black;
+    display: grid;
+    /* Places content and targetXDiv beside each other. */
+    grid-template-columns: 500px 100px;
+  }
+
+  #overscrollYDiv {
+    width: 200px;
+    height: 200px;
+    overflow: scroll;
+    overscroll-behavior-y: none;
+    border: solid 1px black;
+  }
+
+  #targetXDiv {
+    width: 100px;
+    height: 100px;
+    overflow: scroll;
+    border: solid 1px black;
+  }
+
+  #targetYDiv {
+    width: 100px;
+    height: 100px;
+    overflow: scroll;
+    border: solid 1px black;
+  }
+
+  .content {
+    width: 500px;
+    height: 500px;
+  }
+
+  #spacer {
+    height: 200vh;
+    width: 200vw;
+    border: solid 1px black;
+  }
+</style>
+
+<body style="margin:0" onload=runTest()>
+  <div id="overscrollXDiv">
+    <div class="content"></div>
+    <div id="targetXDiv">
+      <div class="content">
+      </div>
+    </div>
+  </div>
+  <div id="overscrollYDiv">
+    <div class="content"></div>
+    <!-- Place targetYDiv below content so that is in view when
+         overscrollYDiv is scrolled all the way down -->
+    <div id="targetYDiv">
+      <div class="content">
+      </div>
+    </div>
+  </div>
+  <div id="spacer"></div>
+</body>
+
+<script>
+  var horizontal_scrollend_arrived = false;
+  var vertical_scrollend_arrived = false;
+  let scrollers = [document.scrollingElement, targetXDiv, targetYDiv,
+                   overscrollXDiv, overscrollYDiv];
+
+  async function resetScrollers(test) {
+    for (const scroller of scrollers) {
+      await resetTargetScrollState(test, scroller);
+    }
+  }
+  function onHorizontalScrollEnd(event) {
+    assert_false(event.cancelable);
+    assert_false(event.bubbles);
+    horizontal_scrollend_arrived = true;
+  }
+  function onVerticalScrollEnd(event) {
+    assert_false(event.cancelable);
+    assert_false(event.bubbles);
+    vertical_scrollend_arrived = true;
+  }
+  // Test that both "onscrollend" and addEventListener("scrollend"... work.
+  document.getElementById('overscrollXDiv').onscrollend = onHorizontalScrollEnd;
+  document.getElementById('overscrollYDiv').
+    addEventListener("scrollend", onVerticalScrollEnd);
+
+  function runTest() {
+    promise_test(async (t) => {
+      await resetScrollers(t);
+      await waitForCompositorCommit();
+
+      // Make sure that no scrollend event is sent to document.
+      document.addEventListener("scrollend",
+      t.unreached_func("Document got unexpected scrollend event."));
+      let scrollend_promise;
+
+      scrollend_promise = waitForScrollendEvent(t, targetXDiv, 2000);
+      targetXDiv.scrollLeft = targetXDiv.scrollWidth;
+      await scrollend_promise;
+
+      scrollend_promise = waitForScrollendEvent(t, overscrollXDiv, 2000);
+      overscrollXDiv.scrollLeft = overscrollXDiv.scrollWidth;
+      await scrollend_promise;
+      horizontal_scrollend_arrived = false;
+
+      assert_equals(targetXDiv.scrollLeft,
+                    targetXDiv.scrollWidth - targetXDiv.clientWidth);
+      assert_equals(overscrollXDiv.scrollLeft,
+                    overscrollXDiv.scrollWidth - overscrollXDiv.clientWidth);
+      // Attempt to scroll targetXDiv further to the right.
+      // targetXDiv and overscrollXDiv are already fully scrolled right but the
+      // scroll should not propagate to the document because of
+      // overscroll-behavior-x: contain on overscrollXDiv.
+      let touchEndPromise = new Promise((resolve) => {
+        targetXDiv.addEventListener("touchend", resolve);
+      });
+      await touchScrollInTarget(100, targetXDiv, 'right');
+      // The scrollend event should never be fired before the gesture has
+      // completed.
+      await touchEndPromise;
+
+      scrollend_promise = waitForScrollendEvent(t, targetYDiv, 2000);
+      targetYDiv.scrollTop = targetXDiv.scrollHeight;
+      await scrollend_promise;
+
+      scrollend_promise = waitForScrollendEvent(t, overscrollYDiv, 2000);
+      overscrollYDiv.scrollTop = overscrollYDiv.scrollHeight;
+      await scrollend_promise;
+      vertical_scrollend_arrived = false;
+
+      assert_equals(targetYDiv.scrollTop,
+                    targetYDiv.scrollHeight - targetYDiv.clientHeight);
+      assert_equals(overscrollYDiv.scrollTop,
+                    overscrollYDiv.scrollHeight - overscrollYDiv.clientHeight);
+      // Attempt to scroll targetYDiv further down.
+      // targetYDiv and overscrollYDiv are already fully scrolled down but the
+      // scroll should not propagate to the document because of
+      // overscroll-behavior-y: none on overscrollYDiv.
+      touchEndPromise = new Promise((resolve) => {
+        targetYDiv.addEventListener("touchend", resolve);
+      });
+      await touchScrollInTarget(50, targetYDiv, 'down');
+      // The scrollend event should never be fired before the gesture has
+      // completed.
+      await touchEndPromise;
+
+      // Ensure we wait at least a tick after the touch end.
+      await waitForCompositorCommit();
+
+      // We should not trigger a scrollend event for a scroll that did not
+      // change the scroll position.
+      assert_equals(horizontal_scrollend_arrived, false,
+                    "overscrollXDiv should not receive scrollend");
+      assert_equals(vertical_scrollend_arrived, false,
+                    "overscrollYDiv should not receive scrollend");
+    }, "Tests that the scroll is not propagated beyond div with non-auto " +
+       "overscroll-behavior.");
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-window.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-window.html
new file mode 100644
index 0000000000..faacf7e572
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-fired-to-window.html
@@ -0,0 +1,69 @@
+<!DOCTYPE HTML>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+  #spacer {
+    height: 100vh;
+    width: 100px;
+  }
+  #targetDiv {
+    width: 200px;
+    height: 200px;
+    overflow: scroll;
+  }
+  #innerDiv {
+    width: 400px;
+    height: 400px;
+  }
+</style>
+
+<body style="margin:0" onload=runTest()>
+  <div id="targetDiv">
+    <div id="innerDiv"></div>
+  </div>
+  <div id="spacer"></div>
+</body>
+
+<script>
+  var target_div = document.getElementById('targetDiv');
+  async function resetScrollers(test) {
+    await waitForScrollReset(test, target_div);
+    await waitForScrollReset(test, document.scrollingElement);
+  }
+
+  function fail() {
+    assert_true(false);
+  }
+
+  function runTest() {
+    promise_test(async (t) => {
+      await resetScrollers(t);
+      await waitForCompositorCommit();
+
+      assert_equals(document.scrollingElement.scrollTop, 0,
+        "document should not be scrolled");
+
+      let scrollend_promise = waitForScrollendEvent(t, target_div);
+      let max_target_div_scroll_top = target_div.scrollHeight - target_div.clientHeight;
+      target_div.scrollTo({ top: target_div.scrollHeight, left: 0 });
+      await scrollend_promise;
+      assert_approx_equals(target_div.scrollTop, max_target_div_scroll_top, 1,
+        "target_div should be fully scrolled down");
+
+      scrollend_promise = waitForScrollendEvent(t, window, 2000);
+      target_div.addEventListener("scrollend", fail);
+      // Scroll up on target div and wait for the doc to get scrollend event.
+      await scrollElementDown(target_div, target_div.clientHeight + 25);
+      await scrollend_promise;
+
+      target_div.removeEventListener("scrollend", fail);
+      assert_greater_than(document.scrollingElement.scrollTop, target_div.clientHeight - 1,
+        "document is scrolled by the height of target_div");
+    }, "testing, vertical");
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-for-user-scroll.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-for-user-scroll.html
new file mode 100644
index 0000000000..561c90ca94
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-for-user-scroll.html
@@ -0,0 +1,187 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+    #targetDiv {
+        width: 200px;
+        height: 200px;
+        overflow: scroll;
+    }
+
+    #innerDiv {
+        width: 400px;
+        height: 400px;
+    }
+</style>
+</head>
+<body style="margin:0" onload=runTest()>
+    <div id="targetDiv">
+        <div id="innerDiv">
+        </div>
+    </div>
+</body>
+
+<script>
+var target_div = document.getElementById('targetDiv');
+
+function runTest() {
+  promise_test(async (t) => {
+    // Skip the test on a Mac as they do not support touch screens.
+    const isMac = navigator.platform.toUpperCase().indexOf('MAC')>=0;
+    if (isMac)
+      return;
+
+    await resetTargetScrollState(t, target_div);
+    await waitForCompositorReady();
+
+    const timeout = 3000; // Because we have two pauses we need longer timeout
+    const targetScrollendPromise = createScrollendPromiseForTarget(t, target_div, timeout);
+    verifyNoScrollendOnDocument(t);
+
+    let scrollend_count = 0;
+    const scrollend_listener = () => {
+      scrollend_count += 1;
+    };
+    target_div.addEventListener("scrollend", scrollend_listener);
+    t.add_cleanup(() => {
+      target_div.removeEventListener('scrollend', scrollend_listener);
+    });
+
+    // Perform a touch drag on target div and wait for target_div to get
+    // a scrollend event.
+    await new test_driver.Actions()
+        .addPointer('TestPointer', 'touch')
+        .pointerMove(0, 0, {origin: target_div}) // 0, 0 is center of element.
+        .pointerDown()
+        .addTick()
+        .pointerMove(0, -40, {origin: target_div}) //  Drag up to move down.
+        .addTick()
+        .pause(200) //  Prevent inertial scroll.
+        .pointerMove(0, -60, {origin: target_div})
+        .addTick()
+        .pause(200) //  Prevent inertial scroll.
+        .pointerUp()
+        .send();
+
+    await targetScrollendPromise;
+
+    assert_true(target_div.scrollTop > 0);
+    await verifyScrollStopped(t, target_div);
+    assert_equals(scrollend_count, 1);
+  }, 'Tests that the target_div gets scrollend event when touch dragging.');
+
+  promise_test(async (t) => {
+    // Skip test on platforms that do not have a visible scrollbar (e.g.
+    // overlay scrollbar).
+    const scrollbar_width = target_div.offsetWidth - target_div.clientWidth;
+    if (scrollbar_width == 0)
+      return;
+
+    await resetTargetScrollState(t, target_div);
+    await waitForCompositorReady();
+
+    const targetScrollendPromise = createScrollendPromiseForTarget(t, target_div);
+    verifyNoScrollendOnDocument(t);
+
+    const bounds = target_div.getBoundingClientRect();
+    // Some versions of webdriver have been known to frown at non-int arguments
+    // to pointerMove.
+    const x = bounds.right - Math.round(scrollbar_width / 2);
+    const y = bounds.bottom - 20;
+    await new test_driver.Actions()
+        .addPointer('TestPointer', 'mouse')
+        .pointerMove(x, y, {origin: 'viewport'})
+        .pointerDown()
+        .addTick()
+        .pointerUp()
+        .send();
+
+    await targetScrollendPromise;
+    assert_true(target_div.scrollTop > 0);
+    await verifyScrollStopped(t, target_div);
+  }, 'Tests that the target_div gets scrollend event when clicking ' +
+     'scrollbar.');
+
+  // Same issue as previous test.
+  promise_test(async (t) => {
+    // Skip test on platforms that do not have a visible scrollbar (e.g.
+    // overlay scrollbar).
+    const scrollbar_width = target_div.offsetWidth - target_div.clientWidth;
+    if (scrollbar_width == 0)
+      return;
+
+    await resetTargetScrollState(t, target_div);
+    await waitForCompositorReady();
+
+    const targetScrollendPromise = createScrollendPromiseForTarget(t, target_div, 1000);
+    verifyNoScrollendOnDocument(t);
+
+    const bounds = target_div.getBoundingClientRect();
+    // Some versions of webdriver have been known to frown at non-int arguments
+    // to pointerMove.
+    const x = bounds.right - Math.round(scrollbar_width / 2);
+    const y = bounds.top + 30;
+    const dy = 30;
+    await new test_driver.Actions()
+        .addPointer('TestPointer', 'mouse')
+        .pointerMove(x, y, { origin: 'viewport' })
+        .pointerDown()
+        .pointerMove(x, y + dy, { origin: 'viewport' })
+        .addTick()
+        .pointerUp()
+        .send();
+
+    await targetScrollendPromise;
+    assert_true(target_div.scrollTop > 0);
+    await verifyScrollStopped(t, target_div);
+  }, 'Tests that the target_div gets scrollend event when dragging the ' +
+      'scrollbar thumb.');
+
+  promise_test(async (t) => {
+    await resetTargetScrollState(t, target_div);
+    await waitForCompositorReady();
+
+    const targetScrollendPromise = createScrollendPromiseForTarget(t, target_div);
+    verifyNoScrollendOnDocument(t);
+
+    const x = 0;
+    const y = 0;
+    const dx = 0;
+    const dy = 40;
+    const duration_ms = 10;
+    await new test_driver.Actions()
+        .scroll(x, y, dx, dy, { origin: target_div }, duration_ms)
+        .send();
+
+    await targetScrollendPromise;
+    assert_true(target_div.scrollTop > 0);
+    await verifyScrollStopped(t, target_div);
+  }, 'Tests that the target_div gets scrollend event when mouse wheel ' +
+     'scrolling.');
+
+  promise_test(async (t) => {
+    await resetTargetScrollState(t, target_div);
+    await waitForCompositorReady();
+
+    verifyNoScrollendOnDocument(t);
+    const targetScrollendPromise = createScrollendPromiseForTarget(t, target_div);
+
+    target_div.focus();
+    window.test_driver.send_keys(target_div, '\ue015');
+
+    await targetScrollendPromise;
+    assert_true(target_div.scrollTop > 0);
+    await verifyScrollStopped(t, target_div);
+  }, 'Tests that the target_div gets scrollend event when sending DOWN key ' +
+     'to the target.');
+}
+
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-handler-content-attributes.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-handler-content-attributes.html
new file mode 100644
index 0000000000..47f563c39b
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-handler-content-attributes.html
@@ -0,0 +1,108 @@
+<!DOCTYPE HTML>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+html, body {
+  margin: 0
+}
+
+body {
+  height: 3000px;
+  width: 3000px;
+}
+
+#targetDiv {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+}
+
+#innerDiv {
+  width: 400px;
+  height: 400px;
+}
+</style>
+
+<body onload=runTest() onscrollend="failOnScrollEnd(event)">
+<div id="targetDiv" onscrollend="onElementScrollEnd(event)">
+  <div id="innerDiv">
+  </div>
+</div>
+</body>
+<script>
+let element_scrollend_arrived = false;
+
+function onElementScrollEnd(event) {
+  assert_false(event.cancelable);
+  assert_false(event.bubbles);
+  element_scrollend_arrived = true;
+}
+
+function failOnScrollEnd(event) {
+  assert_true(false, "Scrollend should not be called on: " + event.target);
+}
+
+function runTest() {
+  let target_div = document.getElementById("targetDiv");
+
+  promise_test (async (t) => {
+    await waitForCompositorCommit();
+
+    target_div.scrollTo({top: 200, left: 200});
+    await waitFor(() => { return element_scrollend_arrived; },
+                  target_div.tagName + " did not receive scrollend event.");
+    assert_equals(target_div.scrollLeft, 200, target_div.tagName + " scrollLeft");
+    assert_equals(target_div.scrollTop, 200, target_div.tagName + " scrollTop");
+  }, "Tests scrollend event is handled by event handler content attribute.");
+
+  promise_test (async (t) => {
+    await waitForCompositorCommit();
+
+    document.scrollingElement.scrollTo({top: 200, left: 200});
+    // The document body onscrollend event handler content attribute will fail
+    // here, if it is fired.
+    await waitForCompositorCommit();
+    assert_equals(document.scrollingElement.scrollLeft, 200,
+                  "Document scrolled on horizontal axis");
+    assert_equals(document.scrollingElement.scrollTop, 200,
+                  "Document scrolled on vertical axis");
+  }, "Tests scrollend event is not fired to document body event handler content attribute.");
+
+  promise_test (async (t) => {
+    await waitForCompositorCommit();
+
+    // Reset the scroll position.
+    document.scrollingElement.scrollTo({top: 0, left: 0});
+
+    let scrollend_event = new Promise(resolve => document.onscrollend = resolve);
+    document.scrollingElement.scrollTo({top: 200, left: 200});
+    await scrollend_event;
+
+    assert_equals(document.scrollingElement.scrollTop, 200,
+                  "Document scrolled on horizontal axis");
+    assert_equals(document.scrollingElement.scrollLeft, 200,
+                  "Document scrolled on vertical axis");
+  }, "Tests scrollend event is fired to document event handler property");
+
+  promise_test (async (t) => {
+    await waitForCompositorCommit();
+
+    // Reset the scroll position.
+    target_div.scrollTo({top: 0, left: 0});
+
+    let scrollend_event = new Promise(resolve => target_div.onscrollend = resolve);
+    target_div.scrollTo({top: 200, left: 200});
+    await scrollend_event;
+
+    assert_equals(target_div.scrollLeft, 200,
+                  target_div.tagName + " scrolled on horizontal axis");
+    assert_equals(target_div.scrollLeft, 200,
+                  target_div.tagName + " scrolled on vertical axis");
+  }, "Tests scrollend event is fired to element event handler property");
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-not-fired-after-removing-scroller.tentative.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-not-fired-after-removing-scroller.tentative.html
new file mode 100644
index 0000000000..95447fbd12
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-not-fired-after-removing-scroller.tentative.html
@@ -0,0 +1,84 @@
+<!DOCTYPE HTML>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+#rootDiv {
+  width: 500px;
+  height: 500px;
+}
+
+#targetDiv {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+}
+
+#innerDiv {
+  width: 500px;
+  height: 4000px;
+}
+</style>
+
+<body style="margin:0" onload=runTest()>
+</body>
+
+<script>
+let scrollend_arrived = false;
+
+async function setupHtmlAndScrollAndRemoveElement(element_to_remove_id) {
+  document.body.innerHTML=`
+    <div id="rootDiv">
+      <div id="targetDiv">
+        <div id="innerDiv">
+        </div>
+      </div>
+    </div>
+  `;
+  await waitForCompositorCommit();
+
+  const target_div = document.getElementById('targetDiv');
+  const element_to_remove = document.getElementById(element_to_remove_id);
+  let reached_half_scroll = false;
+  scrollend_arrived = false;
+
+  target_div.addEventListener("scrollend", () => {
+    scrollend_arrived = true;
+  });
+
+  target_div.onscroll = () => {
+    // Remove the element after reached half of the scroll offset,
+    if(target_div.scrollTop >= 1000) {
+      reached_half_scroll = true;
+      element_to_remove.remove();
+    }
+  };
+
+  target_div.scrollTo({top:2000, left:0, behavior:"smooth"});
+  await waitFor(() => {return reached_half_scroll; },
+    "target_div never reached scroll offset of 1000");
+  await waitForCompositorCommit();
+}
+
+function runTest() {
+  promise_test (async (t) => {
+    await setupHtmlAndScrollAndRemoveElement("rootDiv");
+    await conditionHolds(() => { return !scrollend_arrived; });
+  }, "No scrollend is received after removing parent div");
+
+  promise_test (async (t) => {
+    await setupHtmlAndScrollAndRemoveElement("targetDiv");
+    await conditionHolds(() => { return !scrollend_arrived; });
+  }, "No scrollend is received after removing scrolling element");
+
+  promise_test (async (t) => {
+    await setupHtmlAndScrollAndRemoveElement("innerDiv");
+    await waitFor(() => { return scrollend_arrived; },
+        'target_div did not receive scrollend event after vertical scroll.');
+  }, "scrollend is received after removing descendant div");
+}
+</script>
diff --git a/testing/web-platform/tests/dom/events/scrolling/scrollend-event-not-fired-on-no-scroll.html b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-not-fired-on-no-scroll.html
new file mode 100644
index 0000000000..eaa345aee9
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/scrolling/scrollend-event-not-fired-on-no-scroll.html
@@ -0,0 +1,114 @@
+<!DOCTYPE HTML>
+<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-actions.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="scroll_support.js"></script>
+<style>
+  #spacer {
+    height: 100vh;
+    width: 100px;
+    position: relative;
+  }
+
+  #targetDiv {
+    width: 200px;
+    height: 200px;
+    overflow: scroll;
+  }
+
+  #innerDiv {
+    width: 400px;
+    height: 400px;
+  }
+</style>
+
+<body style="margin:0" onload=runTest()>
+  <div id="targetDiv">
+    <!-- This test uses button elements as a consistent mechanism for
+      ensuring that focus is on the correct scrolling element when
+      scrolling via keys -->
+    <button id="targetButton">target</button>
+    <div id="innerDiv"></div>
+  </div>
+  <button id="docButton">doc</button>
+  <div id="spacer"></div>
+</body>
+
+<script>
+  var target_div = document.getElementById('targetDiv');
+
+  async function resetScrollers(test) {
+    await waitForScrollReset(test, target_div);
+    await waitForScrollReset(test, document.scrollingElement);
+  }
+
+  function getBoundingClientRect(element) {
+    if (element == document) {
+      return document.documentElement.getBoundingClientRect();
+    }
+    return element.getBoundingClientRect();
+  }
+
+  async function upwardScroll(scrolling_element, button_element, scroll_type) {
+    if (scroll_type == "wheel") {
+      let x = 0;
+      let y = 0;
+      let delta_x = 0;
+      let delta_y = -50;
+      let actions = new test_driver.Actions()
+      .scroll(x, y, delta_x, delta_y, {origin: scrolling_element});
+      await actions.send();
+    } else if (scroll_type == "keys") {
+      const num_keydowns = 5;
+      const arrowUp = '\uE013';
+      for (let i = 0; i < num_keydowns; i++) {
+        await test_driver.send_keys(button_element, arrowUp);
+      }
+    }
+  }
+
+  async function testScrollendNotFiredOnNoScroll(test, scrolling_element,
+                                                 listening_element,
+                                                 button_element, scroll_type) {
+    await resetScrollers(test);
+    await waitForCompositorCommit();
+
+    assert_greater_than(scrolling_element.scrollHeight,
+                        scrolling_element.clientHeight);
+    assert_equals(scrolling_element.scrollTop, 0);
+
+    let scrollend_promise = waitForScrollendEvent(test, listening_element);
+    await upwardScroll(scrolling_element, button_element, scroll_type);
+    await scrollend_promise.then(
+      (/*resolve*/) => {
+        assert_true(false, "no scroll, so no scrollend expected");
+      },
+      (/*reject*/) => { /* Did not see scrollend, which is okay. */ }
+    );
+  }
+
+  function runTest() {
+    promise_test(async (t) => {
+      await testScrollendNotFiredOnNoScroll(t, target_div, target_div,
+                                            targetButton, "wheel");
+    }, "No scroll via wheel on div shouldn't fire scrollend.");
+
+    promise_test(async (t) => {
+      await testScrollendNotFiredOnNoScroll(t, target_div, target_div,
+                                            targetButton, "keys");
+    }, "No scroll via keys on div shouldn't fire scrollend.");
+
+    promise_test(async (t) => {
+      await testScrollendNotFiredOnNoScroll(t, document.scrollingElement,
+                                            document, docButton, "wheel");
+    }, "No scroll via wheel on document shouldn't fire scrollend.");
+
+    promise_test(async (t) => {
+      await testScrollendNotFiredOnNoScroll(t, document.scrollingElement,
+                                            document, docButton, "keys");
+    }, "No scroll via keys on document shouldn't fire scrollend.")
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/events/shadow-relatedTarget.html b/testing/web-platform/tests/dom/events/shadow-relatedTarget.html
new file mode 100644
index 0000000000..713555b7d8
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/shadow-relatedTarget.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!--
+  This test is adopted from Olli Pettay's test case at
+  http://mozilla.pettay.fi/shadow_focus.html
+-->
+<div id="host"></div>
+<input id="lightInput">
+<script>
+const root = host.attachShadow({ mode: "closed" });
+root.innerHTML = "<input id='shadowInput'>";
+
+async_test((test) => {
+  root.getElementById("shadowInput").focus();
+  window.addEventListener("focus", test.step_func_done((e) => {
+    assert_equals(e.relatedTarget, host);
+  }, "relatedTarget should be pointing to shadow host."), true);
+  lightInput.focus();
+}, "relatedTarget should not leak at capturing phase, at window object.");
+
+async_test((test) => {
+  root.getElementById("shadowInput").focus();
+  lightInput.addEventListener("focus", test.step_func_done((e) => {
+    assert_equals(e.relatedTarget, host);
+  }, "relatedTarget should be pointing to shadow host."), true);
+  lightInput.focus();
+}, "relatedTarget should not leak at target.");
+
+</script>
diff --git a/testing/web-platform/tests/dom/events/webkit-animation-end-event.html b/testing/web-platform/tests/dom/events/webkit-animation-end-event.html
new file mode 100644
index 0000000000..4186f6b7a9
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/webkit-animation-end-event.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Prefixed CSS Animation end events</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-listener-invoke">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="resources/prefixed-animation-event-tests.js"></script>
+<script>
+'use strict';
+
+runAnimationEventTests({
+  unprefixedType: 'animationend',
+  prefixedType: 'webkitAnimationEnd',
+  animationCssStyle: '1ms',
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/webkit-animation-iteration-event.html b/testing/web-platform/tests/dom/events/webkit-animation-iteration-event.html
new file mode 100644
index 0000000000..fb251972a3
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/webkit-animation-iteration-event.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Prefixed CSS Animation iteration events</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-listener-invoke">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="resources/prefixed-animation-event-tests.js"></script>
+<script>
+'use strict';
+
+runAnimationEventTests({
+  unprefixedType: 'animationiteration',
+  prefixedType: 'webkitAnimationIteration',
+  // Use a long duration to avoid missing the animation due to slow machines,
+  // but set a negative delay so that the iteration boundary happens shortly
+  // after the animation starts.
+  animationCssStyle: '100s -99.9s 2',
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/webkit-animation-start-event.html b/testing/web-platform/tests/dom/events/webkit-animation-start-event.html
new file mode 100644
index 0000000000..ad1036644a
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/webkit-animation-start-event.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Prefixed CSS Animation start events</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-listener-invoke">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="resources/prefixed-animation-event-tests.js"></script>
+<script>
+'use strict';
+
+runAnimationEventTests({
+  unprefixedType: 'animationstart',
+  prefixedType: 'webkitAnimationStart',
+  animationCssStyle: '1ms',
+});
+</script>
diff --git a/testing/web-platform/tests/dom/events/webkit-transition-end-event.html b/testing/web-platform/tests/dom/events/webkit-transition-end-event.html
new file mode 100644
index 0000000000..2741824e30
--- /dev/null
+++ b/testing/web-platform/tests/dom/events/webkit-transition-end-event.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Prefixed CSS Transition End event</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-listener-invoke">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="resources/prefixed-animation-event-tests.js"></script>
+<script>
+'use strict';
+
+runAnimationEventTests({
+  isTransition: true,
+  unprefixedType: 'transitionend',
+  prefixedType: 'webkitTransitionEnd',
+  animationCssStyle: '1ms',
+});
+</script>
diff --git a/testing/web-platform/tests/dom/historical.html b/testing/web-platform/tests/dom/historical.html
new file mode 100644
index 0000000000..1bc209ec0e
--- /dev/null
+++ b/testing/web-platform/tests/dom/historical.html
@@ -0,0 +1,222 @@
+<!DOCTYPE html>
+<title>Historical DOM features must be removed</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+function isInterfaceRemoved(name) {
+  test(function() {
+    assert_false(name in window)
+    assert_equals(window[name], undefined)
+  }, "Historical DOM features must be removed: " + name)
+}
+var removedInterfaces = [
+  "DOMConfiguration",
+  "DOMCursor",
+  "DOMError",
+  "DOMErrorHandler",
+  "DOMImplementationList",
+  "DOMImplementationSource",
+  "DOMLocator",
+  "DOMObject",
+  "DOMRequest",
+  "DOMSettableTokenList",
+  "DOMUserData",
+  "Entity",
+  "EntityReference",
+  "EventException", // DOM Events
+  "NameList",
+  "Notation",
+  "TypeInfo",
+  "UserDataHandler",
+  "RangeException", // DOM Range
+  "SVGPathSegList"
+]
+removedInterfaces.forEach(isInterfaceRemoved)
+
+function isRemovedFromDocument(name) {
+  test(function() {
+    var doc = document.implementation.createDocument(null,null,null)
+    assert_false(name in document)
+    assert_equals(document[name], undefined)
+    assert_false(name in doc)
+    assert_equals(doc[name], undefined)
+  }, "Historical DOM features must be removed: " + name)
+}
+var documentRemoved = [
+  "createEntityReference",
+  "xmlEncoding",
+  "xmlStandalone",
+  "xmlVersion",
+  "strictErrorChecking",
+  "domConfig",
+  "normalizeDocument",
+  "renameNode",
+  "defaultCharset",
+  "height",
+  "width",
+  // https://github.com/whatwg/html/commit/a64aea7fdb221bba027d95dc3cabda09e0b3e5dc
+  "commands",
+  // https://github.com/whatwg/html/commit/797b4d273955a0fe3cc2e2d0ca5d578f37c0f126
+  "cssElementMap",
+  // https://github.com/whatwg/html/commit/e236f46820b93d6fe2e2caae0363331075c6c4fb
+  "async",
+  // https://github.com/whatwg/dom/pull/815
+  "origin",
+]
+documentRemoved.forEach(isRemovedFromDocument)
+
+test(function() {
+  // https://github.com/whatwg/html/commit/e236f46820b93d6fe2e2caae0363331075c6c4fb
+  assert_false("load" in document);
+  assert_equals(document["load"], undefined)
+}, "document.load");
+
+test(function() {
+  // https://github.com/whatwg/html/commit/523f7a8773d2ab8a1eb0da6510651e8c5d2a7531
+  var doc = document.implementation.createDocument(null, null, null);
+  assert_false("load" in doc);
+  assert_equals(doc["load"], undefined)
+}, "XMLDocument.load");
+
+test(function() {
+  assert_false("getFeature" in document.implementation)
+  assert_equals(document.implementation["getFeature"], undefined)
+}, "DOMImplementation.getFeature() must be removed.")
+
+function isRemovedFromElement(name) {
+  test(function() {
+    var ele = document.createElementNS("test", "test")
+    assert_false(name in document.body)
+    assert_equals(document.body[name], undefined)
+    assert_false(name in ele)
+    assert_equals(ele[name], undefined)
+  }, "Historical DOM features must be removed: " + name)
+}
+var elementRemoved = [
+  "schemaTypeInfo",
+  "setIdAttribute",
+  "setIdAttributeNS",
+  "setIdAttributeNode"
+]
+elementRemoved.forEach(isRemovedFromElement)
+
+function isRemovedFromAttr(name) {
+  test(function() {
+    var attr = document.createAttribute("test")
+    assert_false(name in attr)
+    assert_equals(attr[name], undefined)
+  }, "Attr member must be removed: " + name)
+}
+var attrRemoved = [
+  "schemaTypeInfo",
+  "isId"
+]
+attrRemoved.forEach(isRemovedFromAttr)
+
+function isRemovedFromDoctype(name) {
+  test(function() {
+    var doctype = document.implementation.createDocumentType("test", "", "")
+    assert_false(name in doctype)
+    assert_equals(doctype[name], undefined)
+  }, "DocumentType member must be removed: " + name)
+}
+var doctypeRemoved = [
+  "entities",
+  "notations",
+  "internalSubset"
+]
+doctypeRemoved.forEach(isRemovedFromDoctype)
+
+function isRemovedFromText(name) {
+  test(function() {
+    var text = document.createTextNode("test")
+    assert_false(name in text)
+    assert_equals(text[name], undefined)
+  }, "Text member must be removed: " + name)
+}
+var textRemoved = [
+  "isElementContentWhitespace",
+  "replaceWholeText"
+]
+textRemoved.forEach(isRemovedFromText)
+
+function isRemovedFromNode(name) {
+  test(function() {
+    var doc = document.implementation.createDocument(null,null,null)
+    var doctype = document.implementation.createDocumentType("test", "", "")
+    var text = document.createTextNode("test")
+    assert_false(name in doc)
+    assert_equals(doc[name], undefined)
+    assert_false(name in doctype)
+    assert_equals(doctype[name], undefined)
+    assert_false(name in text)
+    assert_equals(text[name], undefined)
+  }, "Node member must be removed: " + name)
+}
+var nodeRemoved = [
+  "hasAttributes",
+  "attributes",
+  "namespaceURI",
+  "prefix",
+  "localName",
+  "isSupported",
+  "getFeature",
+  "getUserData",
+  "setUserData",
+  "rootNode",
+]
+nodeRemoved.forEach(isRemovedFromNode)
+
+function isRemovedFromWindow(name) {
+  test(function() {
+    assert_false(name in window)
+    assert_equals(window[name], undefined)
+  }, "Window member must be removed: " + name)
+}
+var windowRemoved = [
+  "attachEvent",
+  "content",
+  "sidebar",
+]
+windowRemoved.forEach(isRemovedFromWindow)
+
+function isRemovedFromEvent(name) {
+  test(() => {
+    assert_false(name in Event)
+    assert_equals(Event[name], undefined)
+  }, "Event should not have this constant: " + name)
+}
+var EventRemoved = [
+  "MOUSEDOWN",
+  "MOUSEUP",
+  "MOUSEOVER",
+  "MOUSEOUT",
+  "MOUSEMOVE",
+  "MOUSEDRAG",
+  "CLICK",
+  "DBLCLICK",
+  "KEYDOWN",
+  "KEYUP",
+  "KEYPRESS",
+  "DRAGDROP",
+  "FOCUS",
+  "BLUR",
+  "SELECT",
+  "CHANGE"
+]
+EventRemoved.forEach(isRemovedFromEvent)
+
+var EventPrototypeRemoved = [
+  "getPreventDefault",
+  "path"
+]
+EventPrototypeRemoved.forEach(name => {
+  test(() => {
+    assert_false(name in Event.prototype)
+    assert_equals(Event.prototype[name], undefined)
+    assert_false(name in new Event("test"))
+    assert_equals((new Event("test"))[name], undefined)
+  }, "Event.prototype should not have this property: " + name)
+})
+</script>
diff --git a/testing/web-platform/tests/dom/idlharness-shadowrealm.window.js b/testing/web-platform/tests/dom/idlharness-shadowrealm.window.js
new file mode 100644
index 0000000000..cb03c07c9b
--- /dev/null
+++ b/testing/web-platform/tests/dom/idlharness-shadowrealm.window.js
@@ -0,0 +1,2 @@
+// META: script=/resources/idlharness-shadowrealm.js
+idl_test_shadowrealm(["dom"], ["html"]);
diff --git a/testing/web-platform/tests/dom/idlharness.any.js b/testing/web-platform/tests/dom/idlharness.any.js
new file mode 100644
index 0000000000..26da3ab3bf
--- /dev/null
+++ b/testing/web-platform/tests/dom/idlharness.any.js
@@ -0,0 +1,25 @@
+// META: global=worker
+// META: script=/resources/WebIDLParser.js
+// META: script=/resources/idlharness.js
+// META: timeout=long
+
+// Note: This test doesn't cover the Window context, see idlharness.window.js
+// for that coverage and why it can't be merged into this test.
+
+'use strict';
+
+idl_test(
+  ['dom'],
+  ['html'],
+  idl_array => {
+    idl_array.add_objects({
+      EventTarget: ['new EventTarget()'],
+      Event: ['new Event("foo")'],
+      CustomEvent: ['new CustomEvent("foo")'],
+      AbortController: ['new AbortController()'],
+      AbortSignal: ['new AbortController().signal'],
+    });
+  }
+);
+
+done();
diff --git a/testing/web-platform/tests/dom/idlharness.window.js b/testing/web-platform/tests/dom/idlharness.window.js
new file mode 100644
index 0000000000..2c7bfd727e
--- /dev/null
+++ b/testing/web-platform/tests/dom/idlharness.window.js
@@ -0,0 +1,52 @@
+// META: script=/resources/WebIDLParser.js
+// META: script=/resources/idlharness.js
+// META: script=/common/subset-tests-by-key.js
+// META: variant=?include=Node
+// META: variant=?exclude=Node
+// META: timeout=long
+
+// Note: This isn't merged into idlharness.any.js because of the use of variants,
+// i.e., include=Node wouldn't make sense for workers.
+
+'use strict';
+
+idl_test(
+  ['dom', 'fullscreen'],
+  ['html'],
+  idl_array => {
+    self.xmlDoc = document.implementation.createDocument(null, '', null);
+    self.detachedRange = document.createRange();
+    detachedRange.detach();
+    self.element = xmlDoc.createElementNS(null, 'test');
+    element.setAttribute('bar', 'baz');
+
+    idl_array.add_objects({
+      EventTarget: ['new EventTarget()'],
+      Event: ['document.createEvent("Event")', 'new Event("foo")'],
+      CustomEvent: ['new CustomEvent("foo")'],
+      AbortController: ['new AbortController()'],
+      AbortSignal: ['new AbortController().signal'],
+      Document: ['new Document()'],
+      XMLDocument: ['xmlDoc'],
+      DOMImplementation: ['document.implementation'],
+      DocumentFragment: ['document.createDocumentFragment()'],
+      DocumentType: ['document.doctype'],
+      Element: ['element'],
+      Attr: ['document.querySelector("[id]").attributes[0]'],
+      Text: ['document.createTextNode("abc")'],
+      ProcessingInstruction: ['xmlDoc.createProcessingInstruction("abc", "def")'],
+      Comment: ['document.createComment("abc")'],
+      Range: ['document.createRange()', 'detachedRange'],
+      NodeIterator: ['document.createNodeIterator(document.body, NodeFilter.SHOW_ALL, null, false)'],
+      TreeWalker: ['document.createTreeWalker(document.body, NodeFilter.SHOW_ALL, null, false)'],
+      NodeList: ['document.querySelectorAll("script")'],
+      HTMLCollection: ['document.body.children'],
+      DOMTokenList: ['document.body.classList'],
+      XPathEvaluator: ['new XPathEvaluator()'],
+      XPathExpression: ['document.createExpression("//*")'],
+      XPathNSResolver: ['document.createNSResolver(document.body)'],
+      XPathResult: ['document.evaluate("//*", document.body)'],
+      XSLTProcessor: ['new XSLTProcessor()'],
+    });
+  }
+);
diff --git a/testing/web-platform/tests/dom/interface-objects.html b/testing/web-platform/tests/dom/interface-objects.html
new file mode 100644
index 0000000000..936d63517e
--- /dev/null
+++ b/testing/web-platform/tests/dom/interface-objects.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<title>Interfaces</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function testInterfaceDeletable(iface) {
+  test(function() {
+    assert_true(!!window[iface], "Interface should exist.")
+    assert_true(delete window[iface], "The delete operator should return true.")
+    assert_equals(window[iface], undefined, "Interface should be gone.")
+  }, "Should be able to delete " + iface + ".")
+}
+var interfaces = [
+  "Event",
+  "CustomEvent",
+  "EventTarget",
+  "AbortController",
+  "AbortSignal",
+  "Node",
+  "Document",
+  "DOMImplementation",
+  "DocumentFragment",
+  "ProcessingInstruction",
+  "DocumentType",
+  "Element",
+  "Attr",
+  "CharacterData",
+  "Text",
+  "Comment",
+  "NodeIterator",
+  "TreeWalker",
+  "NodeFilter",
+  "NodeList",
+  "HTMLCollection",
+  "DOMTokenList"
+];
+test(function() {
+  for (var p in window) {
+    interfaces.forEach(function(i) {
+      assert_not_equals(p, i)
+    })
+  }
+}, "Interface objects properties should not be Enumerable")
+interfaces.forEach(testInterfaceDeletable);
+</script>
diff --git a/testing/web-platform/tests/dom/lists/DOMTokenList-Iterable.html b/testing/web-platform/tests/dom/lists/DOMTokenList-Iterable.html
new file mode 100644
index 0000000000..4cf84b12a2
--- /dev/null
+++ b/testing/web-platform/tests/dom/lists/DOMTokenList-Iterable.html
@@ -0,0 +1,34 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>DOMTokenList Iterable Test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<span class="foo   Foo foo   "></span>
+<script>
+    var elementClasses;
+    setup(function() {
+        elementClasses = document.querySelector("span").classList;
+    })
+    test(function() {
+        assert_true('length' in elementClasses);
+    }, 'DOMTokenList has length method.');
+    test(function() {
+        assert_true('values' in elementClasses);
+    }, 'DOMTokenList has values method.');
+    test(function() {
+        assert_true('entries' in elementClasses);
+    }, 'DOMTokenList has entries method.');
+    test(function() {
+        assert_true('forEach' in elementClasses);
+    }, 'DOMTokenList has forEach method.');
+    test(function() {
+        assert_true(Symbol.iterator in elementClasses);
+    }, 'DOMTokenList has Symbol.iterator.');
+    test(function() {
+        var classList = [];
+        for (var className of elementClasses){
+            classList.push(className);
+        }
+        assert_array_equals(classList, ['foo', 'Foo']);
+    }, 'DOMTokenList is iterable via for-of loop.');
+</script>
diff --git a/testing/web-platform/tests/dom/lists/DOMTokenList-coverage-for-attributes.html b/testing/web-platform/tests/dom/lists/DOMTokenList-coverage-for-attributes.html
new file mode 100644
index 0000000000..e5f060b8ac
--- /dev/null
+++ b/testing/web-platform/tests/dom/lists/DOMTokenList-coverage-for-attributes.html
@@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>DOMTokenList coverage for attributes</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+"use strict";
+
+var pairs = [
+  // Defined in DOM
+  {attr: "classList", sup: ["anyElement"]},
+  // Defined in HTML except for a which is also SVG
+  {attr: "relList", sup: ["a", "area", "link"]},
+  // Defined in HTML
+  {attr: "htmlFor", sup: ["output"]},
+  {attr: "sandbox", sup: ["iframe"]},
+  {attr: "sizes", sup: ["link"]}
+];
+var namespaces = [
+  "http://www.w3.org/1999/xhtml",
+  "http://www.w3.org/2000/svg",
+  "http://www.w3.org/1998/Math/MathML",
+  "http://example.com/",
+  ""
+];
+
+var elements = ["a", "area", "link", "iframe", "output", "td", "th"];
+function testAttr(pair, new_el){
+  return (pair.attr === "classList" ||
+          (pair.attr === "relList" && new_el.localName === "a" &&
+           new_el.namespaceURI === "http://www.w3.org/2000/svg") ||
+          (new_el.namespaceURI === "http://www.w3.org/1999/xhtml" &&
+           pair.sup.indexOf(new_el.localName) != -1));
+}
+
+pairs.forEach(function(pair) {
+  namespaces.forEach(function(ns) {
+    elements.forEach(function(el) {
+      var new_el = document.createElementNS(ns, el);
+      if (testAttr(pair, new_el)) {
+        test(function() {
+          assert_class_string(new_el[pair.attr], "DOMTokenList");
+        }, new_el.localName + "." + pair.attr + " in " + new_el.namespaceURI + " namespace should be DOMTokenList.");
+      }
+      else {
+        test(function() {
+          assert_equals(new_el[pair.attr], undefined);
+       }, new_el.localName + "." + pair.attr + " in " + new_el.namespaceURI + " namespace should be undefined.");
+      }
+    });
+  });
+});
+
+</script>
diff --git a/testing/web-platform/tests/dom/lists/DOMTokenList-iteration.html b/testing/web-platform/tests/dom/lists/DOMTokenList-iteration.html
new file mode 100644
index 0000000000..f713ad4aa0
--- /dev/null
+++ b/testing/web-platform/tests/dom/lists/DOMTokenList-iteration.html
@@ -0,0 +1,71 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>DOMTokenList iteration: keys, values, etc.</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<span class="   a  a b "></span>
+<script>
+  test(() => {
+    var list = document.querySelector("span").classList;
+    assert_array_equals([...list], ["a", "b"]);
+  }, "classList");
+
+  test(() => {
+    var keys = document.querySelector("span").classList.keys();
+    assert_false(keys instanceof Array, "must not be Array");
+    keys = [...keys];
+    assert_array_equals(keys, [0, 1]);
+  }, "classList.keys");
+
+  test(() => {
+    var values = document.querySelector("span").classList.values();
+    assert_false(values instanceof Array, "must not be Array");
+    values = [...values];
+    assert_array_equals(values, ["a", "b"]);
+  }, "classList.values");
+
+  test(() => {
+    var entries = document.querySelector("span").classList.entries();
+    assert_false(entries instanceof Array, "must not be Array");
+    entries = [...entries];
+    var keys = [...document.querySelector("span").classList.keys()];
+    var values = [...document.querySelector("span").classList.values()];
+    assert_equals(entries.length, keys.length, "entries.length == keys.length");
+    assert_equals(entries.length, values.length,
+                  "entries.length == values.length");
+    for (var i = 0; i < entries.length; ++i) {
+      assert_array_equals(entries[i], [keys[i], values[i]],
+                          "entries[" + i + "]");
+    }
+  }, "classList.entries");
+
+  test(() => {
+    var list = document.querySelector("span").classList;
+    var values = [...list.values()];
+    var keys = [...list.keys()];
+    var entries = [...list.entries()];
+
+    var cur = 0;
+    var thisObj = {};
+    list.forEach(function(value, key, listObj) {
+      assert_equals(listObj, list, "Entry " + cur + " listObj");
+      assert_equals(this, thisObj, "Entry " + cur + " this");
+      assert_equals(value, values[cur], "Entry " + cur + " value");
+      assert_equals(key, keys[cur], "Entry " + cur + " key");
+      cur++;
+    }, thisObj);
+    assert_equals(cur, entries.length, "length");
+  }, "classList.forEach");
+
+  test(() => {
+    var list = document.querySelector("span").classList;
+    assert_equals(list[Symbol.iterator], Array.prototype[Symbol.iterator],
+                  "[Symbol.iterator]");
+    assert_equals(list.keys, Array.prototype.keys, ".keys");
+    if (Array.prototype.values) {
+      assert_equals(list.values, Array.prototype.values, ".values");
+    }
+    assert_equals(list.entries, Array.prototype.entries, ".entries");
+    assert_equals(list.forEach, Array.prototype.forEach, ".forEach");
+  }, "classList inheritance from Array.prototype");
+</script>
diff --git a/testing/web-platform/tests/dom/lists/DOMTokenList-stringifier.html b/testing/web-platform/tests/dom/lists/DOMTokenList-stringifier.html
new file mode 100644
index 0000000000..b125388e02
--- /dev/null
+++ b/testing/web-platform/tests/dom/lists/DOMTokenList-stringifier.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>DOMTokenList stringifier</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domtokenlist-stringifier">
+<link rel=author title=Ms2ger href="mailto:Ms2ger@gmail.com">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<span class="   a  a b "></span>
+<script>
+test(function() {
+  assert_equals(String(document.createElement("span").classList), "",
+                "String(classList) should return the empty list for an undefined class attribute");
+  var span = document.querySelector("span");
+  assert_equals(span.getAttribute("class"), "   a  a b ",
+                "getAttribute should return the literal value");
+  assert_equals(span.className, "   a  a b ",
+                "className should return the literal value");
+  assert_equals(String(span.classList), "   a  a b ",
+                "String(classList) should return the literal value");
+  assert_equals(span.classList.toString(), "   a  a b ",
+                "classList.toString() should return the literal value");
+  assert_class_string(span.classList, "DOMTokenList");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/lists/DOMTokenList-value.html b/testing/web-platform/tests/dom/lists/DOMTokenList-value.html
new file mode 100644
index 0000000000..b0e39111d9
--- /dev/null
+++ b/testing/web-platform/tests/dom/lists/DOMTokenList-value.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>DOMTokenList value</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domtokenlist-value">
+<link rel=author title=Tangresh href="mailto:dmenzi@tangresh.ch">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<span class="   a  a b "></span>
+<script>
+test(function() {
+  assert_equals(String(document.createElement("span").classList.value), "",
+                "classList.value should return the empty list for an undefined class attribute");
+  var span = document.querySelector("span");
+  assert_equals(span.classList.value, "   a  a b ",
+                "value should return the literal value");
+  span.classList.value = " foo bar foo ";
+  assert_equals(span.classList.value, " foo bar foo ",
+                "assigning value should set the literal value");
+  assert_equals(span.classList.length, 2,
+                "length should be the number of tokens");
+  assert_class_string(span.classList, "DOMTokenList");
+  assert_class_string(span.classList.value, "String");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/lists/README.md b/testing/web-platform/tests/dom/lists/README.md
new file mode 100644
index 0000000000..59c821a7da
--- /dev/null
+++ b/testing/web-platform/tests/dom/lists/README.md
@@ -0,0 +1 @@
+See `../nodes/Element-classlist.html` for more DOMTokenList tests.
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-appendChild.html b/testing/web-platform/tests/dom/nodes/CharacterData-appendChild.html
new file mode 100644
index 0000000000..eb4f36c681
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-appendChild.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Node.appendChild applied to CharacterData</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-appendchild">
+<link rel=help href="https://dom.spec.whatwg.org/#introduction-to-the-dom">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function create(type) {
+  switch (type) {
+    case "Text": return document.createTextNode("test"); break;
+    case "Comment": return document.createComment("test"); break;
+    case "ProcessingInstruction": return document.createProcessingInstruction("target", "test"); break;
+  }
+}
+
+function testNode(type1, type2) {
+  test(function() {
+    var node1 = create(type1);
+    var node2 = create(type2);
+    assert_throws_dom("HierarchyRequestError", function () {
+      node1.appendChild(node2);
+    }, "CharacterData type " + type1 + " must not have children");
+  }, type1 + ".appendChild(" + type2 + ")");
+}
+
+var types = ["Text", "Comment", "ProcessingInstruction"];
+types.forEach(function(type1) {
+  types.forEach(function(type2) {
+    testNode(type1, type2);
+  });
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-appendData.html b/testing/web-platform/tests/dom/nodes/CharacterData-appendData.html
new file mode 100644
index 0000000000..a5d4072244
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-appendData.html
@@ -0,0 +1,70 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>CharacterData.appendData</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-appenddata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function testNode(create, type) {
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.appendData("bar")
+    assert_equals(node.data, "testbar")
+  }, type + ".appendData('bar')")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.appendData("")
+    assert_equals(node.data, "test")
+  }, type + ".appendData('')")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+    node.appendData(", append more 資料，測試資料");
+    assert_equals(node.data, "test, append more 資料，測試資料");
+    assert_equals(node.length, 25);
+  }, type + ".appendData(non-ASCII)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.appendData(null)
+    assert_equals(node.data, "testnull")
+  }, type + ".appendData(null)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.appendData(undefined)
+    assert_equals(node.data, "testundefined")
+  }, type + ".appendData(undefined)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.appendData("", "bar")
+    assert_equals(node.data, "test")
+  }, type + ".appendData('', 'bar')")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_throws_js(TypeError, function() { node.appendData() });
+    assert_equals(node.data, "test")
+  }, type + ".appendData()")
+}
+
+testNode(function() { return document.createTextNode("test") }, "Text")
+testNode(function() { return document.createComment("test") }, "Comment")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-data.html b/testing/web-platform/tests/dom/nodes/CharacterData-data.html
new file mode 100644
index 0000000000..b3b29ea4d7
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-data.html
@@ -0,0 +1,82 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>CharacterData.data</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function testNode(create, type) {
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+    assert_equals(node.length, 4)
+  }, type + ".data initial value")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = null;
+    assert_equals(node.data, "")
+    assert_equals(node.length, 0)
+  }, type + ".data = null")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = undefined;
+    assert_equals(node.data, "undefined")
+    assert_equals(node.length, 9)
+  }, type + ".data = undefined")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = 0;
+    assert_equals(node.data, "0")
+    assert_equals(node.length, 1)
+  }, type + ".data = 0")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "";
+    assert_equals(node.data, "")
+    assert_equals(node.length, 0)
+  }, type + ".data = ''")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "--";
+    assert_equals(node.data, "--")
+    assert_equals(node.length, 2)
+  }, type + ".data = '--'")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "資料";
+    assert_equals(node.data, "資料")
+    assert_equals(node.length, 2)
+  }, type + ".data = '資料'")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST";
+    assert_equals(node.data, "🌠 test 🌠 TEST")
+    assert_equals(node.length, 15)  // Counting UTF-16 code units
+  }, type + ".data = '🌠 test 🌠 TEST'")
+}
+
+testNode(function() { return document.createTextNode("test") }, "Text")
+testNode(function() { return document.createComment("test") }, "Comment")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-deleteData.html b/testing/web-platform/tests/dom/nodes/CharacterData-deleteData.html
new file mode 100644
index 0000000000..84f4d5b415
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-deleteData.html
@@ -0,0 +1,95 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>CharacterData.deleteData</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-deletedata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function testNode(create, type) {
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_throws_dom("INDEX_SIZE_ERR", function() { node.deleteData(5, 10) })
+    assert_throws_dom("INDEX_SIZE_ERR", function() { node.deleteData(5, 0) })
+    assert_throws_dom("INDEX_SIZE_ERR", function() { node.deleteData(-1, 10) })
+    assert_throws_dom("INDEX_SIZE_ERR", function() { node.deleteData(-1, 0) })
+  }, type + ".deleteData() out of bounds")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.deleteData(0, 2)
+    assert_equals(node.data, "st")
+  }, type + ".deleteData() at the start")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.deleteData(2, 10)
+    assert_equals(node.data, "te")
+  }, type + ".deleteData() at the end")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.deleteData(1, 1)
+    assert_equals(node.data, "tst")
+  }, type + ".deleteData() in the middle")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.deleteData(2, 0)
+    assert_equals(node.data, "test")
+
+    node.deleteData(0, 0)
+    assert_equals(node.data, "test")
+  }, type + ".deleteData() with zero count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.deleteData(2, -1)
+    assert_equals(node.data, "te")
+  }, type + ".deleteData() with small negative count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.deleteData(1, -0x100000000 + 2)
+    assert_equals(node.data, "tt")
+  }, type + ".deleteData() with large negative count")
+
+  test(function() {
+    var node = create()
+    node.data = "This is the character data test, append more 資料，更多測試資料";
+
+    node.deleteData(40, 5);
+    assert_equals(node.data, "This is the character data test, append 資料，更多測試資料");
+    node.deleteData(45, 2);
+    assert_equals(node.data, "This is the character data test, append 資料，更多資料");
+  }, type + ".deleteData() with non-ascii data")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST"
+
+    node.deleteData(5, 8);  // Counting UTF-16 code units
+    assert_equals(node.data, "🌠 teST");
+  }, type + ".deleteData() with non-BMP data")
+}
+
+testNode(function() { return document.createTextNode("test") }, "Text")
+testNode(function() { return document.createComment("test") }, "Comment")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-insertData.html b/testing/web-platform/tests/dom/nodes/CharacterData-insertData.html
new file mode 100644
index 0000000000..62c0ca1018
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-insertData.html
@@ -0,0 +1,90 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>CharacterData.insertData</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-insertdata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function testNode(create, type) {
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_throws_dom("INDEX_SIZE_ERR", function() { node.insertData(5, "x") })
+    assert_throws_dom("INDEX_SIZE_ERR", function() { node.insertData(5, "") })
+  }, type + ".insertData() out of bounds")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_throws_dom("INDEX_SIZE_ERR", function() { node.insertData(-1, "x") })
+    assert_throws_dom("INDEX_SIZE_ERR", function() { node.insertData(-0x100000000 + 5, "x") })
+  }, type + ".insertData() negative out of bounds")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.insertData(-0x100000000 + 2, "X")
+    assert_equals(node.data, "teXst")
+  }, type + ".insertData() negative in bounds")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.insertData(0, "")
+    assert_equals(node.data, "test")
+  }, type + ".insertData('')")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.insertData(0, "X")
+    assert_equals(node.data, "Xtest")
+  }, type + ".insertData() at the start")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.insertData(2, "X")
+    assert_equals(node.data, "teXst")
+  }, type + ".insertData() in the middle")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.insertData(4, "ing")
+    assert_equals(node.data, "testing")
+  }, type + ".insertData() at the end")
+
+  test(function() {
+    var node = create()
+    node.data = "This is the character data, append more 資料，測試資料";
+
+    node.insertData(26, " test");
+    assert_equals(node.data, "This is the character data test, append more 資料，測試資料");
+    node.insertData(48, "更多");
+    assert_equals(node.data, "This is the character data test, append more 資料，更多測試資料");
+  }, type + ".insertData() with non-ascii data")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST"
+
+    node.insertData(5, "--");  // Counting UTF-16 code units
+    assert_equals(node.data, "🌠 te--st 🌠 TEST");
+  }, type + ".insertData() with non-BMP data")
+}
+
+testNode(function() { return document.createTextNode("test") }, "Text")
+testNode(function() { return document.createComment("test") }, "Comment")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-remove.html b/testing/web-platform/tests/dom/nodes/CharacterData-remove.html
new file mode 100644
index 0000000000..aef9d56bfa
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-remove.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>CharacterData.remove</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-childnode-remove">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="ChildNode-remove.js"></script>
+<div id=log></div>
+<script>
+var text, text_parent,
+    comment, comment_parent,
+    pi, pi_parent;
+setup(function() {
+  text = document.createTextNode("text");
+  text_parent = document.createElement("div");
+  comment = document.createComment("comment");
+  comment_parent = document.createElement("div");
+  pi = document.createProcessingInstruction("foo", "bar");
+  pi_parent = document.createElement("div");
+});
+testRemove(text, text_parent, "text");
+testRemove(comment, comment_parent, "comment");
+testRemove(pi, pi_parent, "PI");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-replaceData.html b/testing/web-platform/tests/dom/nodes/CharacterData-replaceData.html
new file mode 100644
index 0000000000..537751d832
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-replaceData.html
@@ -0,0 +1,163 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>CharacterData.replaceData</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-replacedata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function testNode(create, type) {
+  // Step 2.
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_throws_dom("IndexSizeError", function() { node.replaceData(5, 1, "x") })
+    assert_throws_dom("IndexSizeError", function() { node.replaceData(5, 0, "") })
+    assert_throws_dom("IndexSizeError", function() { node.replaceData(-1, 1, "x") })
+    assert_throws_dom("IndexSizeError", function() { node.replaceData(-1, 0, "") })
+    assert_equals(node.data, "test")
+  }, type + ".replaceData() with invalid offset")
+
+  // Step 3.
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(2, 10, "yo")
+    assert_equals(node.data, "teyo")
+  }, type + ".replaceData() with clamped count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(2, -1, "yo")
+    assert_equals(node.data, "teyo")
+  }, type + ".replaceData() with negative clamped count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(0, 0, "yo")
+    assert_equals(node.data, "yotest")
+  }, type + ".replaceData() before the start")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(0, 2, "y")
+    assert_equals(node.data, "yst")
+  }, type + ".replaceData() at the start (shorter)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(0, 2, "yo")
+    assert_equals(node.data, "yost")
+  }, type + ".replaceData() at the start (equal length)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(0, 2, "yoa")
+    assert_equals(node.data, "yoast")
+  }, type + ".replaceData() at the start (longer)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(1, 2, "o")
+    assert_equals(node.data, "tot")
+  }, type + ".replaceData() in the middle (shorter)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(1, 2, "yo")
+    assert_equals(node.data, "tyot")
+  }, type + ".replaceData() in the middle (equal length)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(1, 1, "waddup")
+    assert_equals(node.data, "twaddupst")
+    node.replaceData(1, 1, "yup")
+    assert_equals(node.data, "tyupaddupst")
+  }, type + ".replaceData() in the middle (longer)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(1, 20, "yo")
+    assert_equals(node.data, "tyo")
+  }, type + ".replaceData() at the end (shorter)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(2, 20, "yo")
+    assert_equals(node.data, "teyo")
+  }, type + ".replaceData() at the end (same length)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(4, 20, "yo")
+    assert_equals(node.data, "testyo")
+  }, type + ".replaceData() at the end (longer)")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(0, 4, "quux")
+    assert_equals(node.data, "quux")
+  }, type + ".replaceData() the whole string")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.replaceData(0, 4, "")
+    assert_equals(node.data, "")
+  }, type + ".replaceData() with the empty string")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "This is the character data test, append 資料，更多資料";
+
+    node.replaceData(33, 6, "other");
+    assert_equals(node.data, "This is the character data test, other 資料，更多資料");
+    node.replaceData(44, 2, "文字");
+    assert_equals(node.data, "This is the character data test, other 資料，更多文字");
+  }, type + ".replaceData() with non-ASCII data")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST"
+
+    node.replaceData(5, 8, "--");  // Counting UTF-16 code units
+    assert_equals(node.data, "🌠 te--ST");
+  }, type + ".replaceData() with non-BMP data")
+}
+
+testNode(function() { return document.createTextNode("test") }, "Text")
+testNode(function() { return document.createComment("test") }, "Comment")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-substringData.html b/testing/web-platform/tests/dom/nodes/CharacterData-substringData.html
new file mode 100644
index 0000000000..b353526480
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-substringData.html
@@ -0,0 +1,137 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>CharacterData.substringData</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-substringdata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function testNode(create, type) {
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_throws_js(TypeError, function() { node.substringData() })
+    assert_throws_js(TypeError, function() { node.substringData(0) })
+  }, type + ".substringData() with too few arguments")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(0, 1, "test"), "t")
+  }, type + ".substringData() with too many arguments")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_throws_dom("IndexSizeError", function() { node.substringData(5, 0) })
+    assert_throws_dom("IndexSizeError", function() { node.substringData(6, 0) })
+    assert_throws_dom("IndexSizeError", function() { node.substringData(-1, 0) })
+  }, type + ".substringData() with invalid offset")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(0, 1), "t")
+    assert_equals(node.substringData(1, 1), "e")
+    assert_equals(node.substringData(2, 1), "s")
+    assert_equals(node.substringData(3, 1), "t")
+    assert_equals(node.substringData(4, 1), "")
+  }, type + ".substringData() with in-bounds offset")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(0, 0), "")
+    assert_equals(node.substringData(1, 0), "")
+    assert_equals(node.substringData(2, 0), "")
+    assert_equals(node.substringData(3, 0), "")
+    assert_equals(node.substringData(4, 0), "")
+  }, type + ".substringData() with zero count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(0x100000000 + 0, 1), "t")
+    assert_equals(node.substringData(0x100000000 + 1, 1), "e")
+    assert_equals(node.substringData(0x100000000 + 2, 1), "s")
+    assert_equals(node.substringData(0x100000000 + 3, 1), "t")
+    assert_equals(node.substringData(0x100000000 + 4, 1), "")
+  }, type + ".substringData() with very large offset")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(-0x100000000 + 2, 1), "s")
+  }, type + ".substringData() with negative offset")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData("test", 3), "tes")
+  }, type + ".substringData() with string offset")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(0, 1), "t")
+    assert_equals(node.substringData(0, 2), "te")
+    assert_equals(node.substringData(0, 3), "tes")
+    assert_equals(node.substringData(0, 4), "test")
+  }, type + ".substringData() with in-bounds count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(0, 5), "test")
+    assert_equals(node.substringData(2, 20), "st")
+  }, type + ".substringData() with large count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(2, 0x100000000 + 1), "s")
+  }, type + ".substringData() with very large count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    assert_equals(node.substringData(0, -1), "test")
+    assert_equals(node.substringData(0, -0x100000000 + 2), "te")
+  }, type + ".substringData() with negative count")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "This is the character data test, other 資料，更多文字"
+
+    assert_equals(node.substringData(12, 4), "char")
+    assert_equals(node.substringData(39, 2), "資料")
+  }, type + ".substringData() with non-ASCII data")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST"
+
+    assert_equals(node.substringData(5, 8), "st 🌠 TE")  // Counting UTF-16 code units
+  }, type + ".substringData() with non-BMP data")
+}
+
+testNode(function() { return document.createTextNode("test") }, "Text")
+testNode(function() { return document.createComment("test") }, "Comment")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/CharacterData-surrogates.html b/testing/web-platform/tests/dom/nodes/CharacterData-surrogates.html
new file mode 100644
index 0000000000..ff1014c5fd
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/CharacterData-surrogates.html
@@ -0,0 +1,74 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Splitting and joining surrogate pairs in CharacterData methods</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-substringdata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-replacedata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-insertdata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-deletedata">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+function testNode(create, type) {
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST"
+
+    assert_equals(node.substringData(1, 8), "\uDF20 test \uD83C")
+  }, type + ".substringData() splitting surrogate pairs")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST"
+
+    node.replaceData(1, 4, "--");
+    assert_equals(node.data, "\uD83C--st 🌠 TEST");
+
+    node.replaceData(1, 2, "\uDF1F ");
+    assert_equals(node.data, "🌟 st 🌠 TEST");
+
+    node.replaceData(5, 2, "---");
+    assert_equals(node.data, "🌟 st---\uDF20 TEST");
+
+    node.replaceData(6, 2, " \uD83D");
+    assert_equals(node.data, "🌟 st- 🜠 TEST");
+  }, type + ".replaceData() splitting and creating surrogate pairs")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST"
+
+    node.deleteData(1, 4);
+    assert_equals(node.data, "\uD83Cst 🌠 TEST");
+
+    node.deleteData(1, 4);
+    assert_equals(node.data, "🌠 TEST");
+  }, type + ".deleteData() splitting and creating surrogate pairs")
+
+  test(function() {
+    var node = create()
+    assert_equals(node.data, "test")
+
+    node.data = "🌠 test 🌠 TEST"
+
+    node.insertData(1, "--");
+    assert_equals(node.data, "\uD83C--\uDF20 test 🌠 TEST");
+
+    node.insertData(1, "\uDF1F ");
+    assert_equals(node.data, "🌟 --\uDF20 test 🌠 TEST");
+
+    node.insertData(5, " \uD83D");
+    assert_equals(node.data, "🌟 -- 🜠 test 🌠 TEST");
+  }, type + ".insertData() splitting and creating surrogate pairs")
+}
+
+testNode(function() { return document.createTextNode("test") }, "Text")
+testNode(function() { return document.createComment("test") }, "Comment")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ChildNode-after.html b/testing/web-platform/tests/dom/nodes/ChildNode-after.html
new file mode 100644
index 0000000000..b5bf7ab5c2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ChildNode-after.html
@@ -0,0 +1,166 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>ChildNode.after</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-childnode-after">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+function test_after(child, nodeName, innerHTML) {
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.after();
+        assert_equals(parent.innerHTML, innerHTML);
+    }, nodeName + '.after() without any argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.after(null);
+        var expected = innerHTML + 'null';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with null as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.after(undefined);
+        var expected = innerHTML + 'undefined';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with undefined as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.after('');
+        assert_equals(parent.lastChild.data, '');
+    }, nodeName + '.after() with the empty string as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.after('text');
+        var expected = innerHTML + 'text';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with only text as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        child.after(x);
+        var expected = innerHTML + '<x></x>';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with only one element as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        child.after(x, 'text');
+        var expected = innerHTML + '<x></x>text';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with one element and text as arguments.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.after('text', child);
+        var expected = 'text' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with context object itself as the argument.');
+
+    test(function() {
+        var parent = document.createElement('div')
+        var x = document.createElement('x');
+        parent.appendChild(x);
+        parent.appendChild(child);
+        child.after(child, x);
+        var expected = innerHTML + '<x></x>';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with context object itself and node as the arguments, switching positions.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        var z = document.createElement('z');
+        parent.appendChild(y);
+        parent.appendChild(child);
+        parent.appendChild(x);
+        child.after(x, y, z);
+        var expected = innerHTML + '<x></x><y></y><z></z>';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with all siblings of child as arguments.');
+
+    test(function() {
+        var parent = document.createElement('div')
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        var z = document.createElement('z');
+        parent.appendChild(child);
+        parent.appendChild(x);
+        parent.appendChild(y);
+        parent.appendChild(z);
+        child.after(x, y);
+        var expected = innerHTML + '<x></x><y></y><z></z>';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with some siblings of child as arguments; no changes in tree; viable sibling is first child.');
+
+    test(function() {
+        var parent = document.createElement('div')
+        var v = document.createElement('v');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        var z = document.createElement('z');
+        parent.appendChild(child);
+        parent.appendChild(v);
+        parent.appendChild(x);
+        parent.appendChild(y);
+        parent.appendChild(z);
+        child.after(v, x);
+        var expected = innerHTML + '<v></v><x></x><y></y><z></z>';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with some siblings of child as arguments; no changes in tree.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        parent.appendChild(child);
+        parent.appendChild(x);
+        parent.appendChild(y);
+        child.after(y, x);
+        var expected = innerHTML + '<y></y><x></x>';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() when pre-insert behaves like append.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        parent.appendChild(child);
+        parent.appendChild(x);
+        parent.appendChild(document.createTextNode('1'));
+        parent.appendChild(y);
+        child.after(x, '2');
+        var expected = innerHTML + '<x></x>21<y></y>';
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.after() with one sibling of child and text as arguments.');
+
+    test(function() {
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        x.after(y);
+        assert_equals(x.nextSibling, null);
+    }, nodeName + '.after() on a child without any parent.');
+}
+
+test_after(document.createComment('test'), 'Comment', '<!--test-->');
+test_after(document.createElement('test'), 'Element', '<test></test>');
+test_after(document.createTextNode('test'), 'Text', 'test');
+
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ChildNode-before.html b/testing/web-platform/tests/dom/nodes/ChildNode-before.html
new file mode 100644
index 0000000000..8659424465
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ChildNode-before.html
@@ -0,0 +1,166 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>ChildNode.before</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-childnode-before">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+function test_before(child, nodeName, innerHTML) {
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.before();
+        assert_equals(parent.innerHTML, innerHTML);
+    }, nodeName + '.before() without any argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.before(null);
+        var expected = 'null' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with null as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.before(undefined);
+        var expected = 'undefined' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with undefined as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.before('');
+        assert_equals(parent.firstChild.data, '');
+    }, nodeName + '.before() with the empty string as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.before('text');
+        var expected = 'text' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with only text as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        child.before(x);
+        var expected = '<x></x>' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with only one element as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        child.before(x, 'text');
+        var expected = '<x></x>text' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with one element and text as arguments.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.before('text', child);
+        var expected = 'text' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with context object itself as the argument.');
+
+    test(function() {
+        var parent = document.createElement('div')
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        parent.appendChild(x);
+        child.before(x, child);
+        var expected = '<x></x>' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with context object itself and node as the arguments, switching positions.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        var z = document.createElement('z');
+        parent.appendChild(y);
+        parent.appendChild(child);
+        parent.appendChild(x);
+        child.before(x, y, z);
+        var expected = '<x></x><y></y><z></z>' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with all siblings of child as arguments.');
+
+    test(function() {
+        var parent = document.createElement('div')
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        var z = document.createElement('z');
+        parent.appendChild(x);
+        parent.appendChild(y);
+        parent.appendChild(z);
+        parent.appendChild(child);
+        child.before(y, z);
+        var expected = '<x></x><y></y><z></z>' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with some siblings of child as arguments; no changes in tree; viable sibling is first child.');
+
+    test(function() {
+        var parent = document.createElement('div')
+        var v = document.createElement('v');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        var z = document.createElement('z');
+        parent.appendChild(v);
+        parent.appendChild(x);
+        parent.appendChild(y);
+        parent.appendChild(z);
+        parent.appendChild(child);
+        child.before(y, z);
+        var expected = '<v></v><x></x><y></y><z></z>' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with some siblings of child as arguments; no changes in tree.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        parent.appendChild(x);
+        parent.appendChild(y);
+        parent.appendChild(child);
+        child.before(y, x);
+        var expected = '<y></y><x></x>' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() when pre-insert behaves like prepend.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(x);
+        parent.appendChild(document.createTextNode('1'));
+        var y = document.createElement('y');
+        parent.appendChild(y);
+        parent.appendChild(child);
+        child.before(x, '2');
+        var expected = '1<y></y><x></x>2' + innerHTML;
+        assert_equals(parent.innerHTML, expected);
+    }, nodeName + '.before() with one sibling of child and text as arguments.');
+
+    test(function() {
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        x.before(y);
+        assert_equals(x.previousSibling, null);
+    }, nodeName + '.before() on a child without any parent.');
+}
+
+test_before(document.createComment('test'), 'Comment', '<!--test-->');
+test_before(document.createElement('test'), 'Element', '<test></test>');
+test_before(document.createTextNode('test'), 'Text', 'test');
+
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ChildNode-remove.js b/testing/web-platform/tests/dom/nodes/ChildNode-remove.js
new file mode 100644
index 0000000000..c36ba0d117
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ChildNode-remove.js
@@ -0,0 +1,30 @@
+function testRemove(node, parent, type) {
+  test(function() {
+    assert_true("remove" in node);
+    assert_equals(typeof node.remove, "function");
+    assert_equals(node.remove.length, 0);
+  }, type + " should support remove()");
+  test(function() {
+    assert_equals(node.parentNode, null, "Node should not have a parent");
+    assert_equals(node.remove(), undefined);
+    assert_equals(node.parentNode, null, "Removed new node should not have a parent");
+  }, "remove() should work if " + type + " doesn't have a parent");
+  test(function() {
+    assert_equals(node.parentNode, null, "Node should not have a parent");
+    parent.appendChild(node);
+    assert_equals(node.parentNode, parent, "Appended node should have a parent");
+    assert_equals(node.remove(), undefined);
+    assert_equals(node.parentNode, null, "Removed node should not have a parent");
+    assert_array_equals(parent.childNodes, [], "Parent should not have children");
+  }, "remove() should work if " + type + " does have a parent");
+  test(function() {
+    assert_equals(node.parentNode, null, "Node should not have a parent");
+    var before = parent.appendChild(document.createComment("before"));
+    parent.appendChild(node);
+    var after = parent.appendChild(document.createComment("after"));
+    assert_equals(node.parentNode, parent, "Appended node should have a parent");
+    assert_equals(node.remove(), undefined);
+    assert_equals(node.parentNode, null, "Removed node should not have a parent");
+    assert_array_equals(parent.childNodes, [before, after], "Parent should have two children left");
+  }, "remove() should work if " + type + " does have a parent and siblings");
+}
diff --git a/testing/web-platform/tests/dom/nodes/ChildNode-replaceWith.html b/testing/web-platform/tests/dom/nodes/ChildNode-replaceWith.html
new file mode 100644
index 0000000000..aab8b17f2a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ChildNode-replaceWith.html
@@ -0,0 +1,110 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>ChildNode.replaceWith</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-childnode-replaceWith">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+function test_replaceWith(child, nodeName, innerHTML) {
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.replaceWith();
+        assert_equals(parent.innerHTML, '');
+    }, nodeName + '.replaceWith() without any argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.replaceWith(null);
+        assert_equals(parent.innerHTML, 'null');
+    }, nodeName + '.replaceWith() with null as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.replaceWith(undefined);
+        assert_equals(parent.innerHTML, 'undefined');
+    }, nodeName + '.replaceWith() with undefined as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.replaceWith('');
+        assert_equals(parent.innerHTML, '');
+    }, nodeName + '.replaceWith() with empty string as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        parent.appendChild(child);
+        child.replaceWith('text');
+        assert_equals(parent.innerHTML, 'text');
+    }, nodeName + '.replaceWith() with only text as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        child.replaceWith(x);
+        assert_equals(parent.innerHTML, '<x></x>');
+    }, nodeName + '.replaceWith() with only one element as an argument.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        var z = document.createElement('z');
+        parent.appendChild(y);
+        parent.appendChild(child);
+        parent.appendChild(x);
+        child.replaceWith(x, y, z);
+        assert_equals(parent.innerHTML, '<x></x><y></y><z></z>');
+    }, nodeName + '.replaceWith() with sibling of child as arguments.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        parent.appendChild(x);
+        parent.appendChild(document.createTextNode('1'));
+        child.replaceWith(x, '2');
+        assert_equals(parent.innerHTML, '<x></x>21');
+    }, nodeName + '.replaceWith() with one sibling of child and text as arguments.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        parent.appendChild(x);
+        parent.appendChild(document.createTextNode('text'));
+        child.replaceWith(x, child);
+        assert_equals(parent.innerHTML, '<x></x>' + innerHTML + 'text');
+    }, nodeName + '.replaceWith() with one sibling of child and child itself as arguments.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        parent.appendChild(child);
+        child.replaceWith(x, 'text');
+        assert_equals(parent.innerHTML, '<x></x>text');
+    }, nodeName + '.replaceWith() with one element and text as arguments.');
+
+    test(function() {
+        var parent = document.createElement('div');
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        parent.appendChild(x);
+        parent.appendChild(y);
+        child.replaceWith(x, y);
+        assert_equals(parent.innerHTML, '<x></x><y></y>');
+    }, nodeName + '.replaceWith() on a parentless child with two elements as arguments.');
+}
+
+test_replaceWith(document.createComment('test'), 'Comment', '<!--test-->');
+test_replaceWith(document.createElement('test'), 'Element', '<test></test>');
+test_replaceWith(document.createTextNode('test'), 'Text', 'test');
+
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Comment-Text-constructor.js b/testing/web-platform/tests/dom/nodes/Comment-Text-constructor.js
new file mode 100644
index 0000000000..24b4425f4b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Comment-Text-constructor.js
@@ -0,0 +1,77 @@
+function test_constructor(ctor) {
+  test(function() {
+    var object = new window[ctor]();
+    assert_equals(Object.getPrototypeOf(object),
+                  window[ctor].prototype, "Prototype chain: " + ctor);
+    assert_equals(Object.getPrototypeOf(Object.getPrototypeOf(object)),
+                  CharacterData.prototype, "Prototype chain: CharacterData");
+    assert_equals(Object.getPrototypeOf(Object.getPrototypeOf(Object.getPrototypeOf(object))),
+                  Node.prototype, "Prototype chain: Node");
+  }, "new " + ctor + "(): prototype chain");
+
+  test(function() {
+    var object = new window[ctor]();
+    assert_true(object instanceof Node, "Should be a Node");
+    assert_true(object instanceof CharacterData, "Should be a CharacterData");
+    assert_true(object instanceof window[ctor], "Should be a " + ctor);
+  }, "new " + ctor + "(): instanceof");
+
+  test(function() {
+    var object = new window[ctor]();
+    assert_equals(object.data, "");
+    assert_equals(object.nodeValue, "");
+    assert_equals(object.ownerDocument, document);
+  }, "new " + ctor + "(): no arguments");
+
+  var testArgs = [
+    [undefined, ""],
+    [null, "null"],
+    [42, "42"],
+    ["", ""],
+    ["-", "-"],
+    ["--", "--"],
+    ["-->", "-->"],
+    ["<!--", "<!--"],
+    ["\u0000", "\u0000"],
+    ["\u0000test", "\u0000test"],
+    ["&amp;", "&amp;"],
+  ];
+
+  testArgs.forEach(function(a) {
+    var argument = a[0], expected = a[1];
+    test(function() {
+      var object = new window[ctor](argument);
+      assert_equals(object.data, expected);
+      assert_equals(object.nodeValue, expected);
+      assert_equals(object.ownerDocument, document);
+    }, "new " + ctor + "(): " + format_value(argument));
+  });
+
+  test(function() {
+    var called = [];
+    var object = new window[ctor]({
+      toString: function() {
+        called.push("first");
+        return "text";
+      }
+    }, {
+      toString: function() {
+        called.push("second");
+        assert_unreached("Should not look at the second argument.");
+      }
+    });
+    assert_equals(object.data, "text");
+    assert_equals(object.nodeValue, "text");
+    assert_equals(object.ownerDocument, document);
+    assert_array_equals(called, ["first"]);
+  }, "new " + ctor + "(): two arguments")
+
+  async_test("new " + ctor + "() should get the correct ownerDocument across globals").step(function() {
+    var iframe = document.createElement("iframe");
+    iframe.onload = this.step_func_done(function() {
+      var object = new iframe.contentWindow[ctor]();
+      assert_equals(object.ownerDocument, iframe.contentDocument);
+    });
+    document.body.appendChild(iframe);
+  });
+}
diff --git a/testing/web-platform/tests/dom/nodes/Comment-constructor.html b/testing/web-platform/tests/dom/nodes/Comment-constructor.html
new file mode 100644
index 0000000000..5091316bd3
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Comment-constructor.html
@@ -0,0 +1,11 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Comment constructor</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-comment">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Comment-Text-constructor.js"></script>
+<div id="log"></div>
+<script>
+test_constructor("Comment");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Comment-in-doctype.xhtml b/testing/web-platform/tests/dom/nodes/Comment-in-doctype.xhtml
new file mode 100644
index 0000000000..c0817d353d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Comment-in-doctype.xhtml
@@ -0,0 +1,15 @@
+<!DOCTYPE html [<!--x-->]><html xmlns="http://www.w3.org/1999/xhtml">
+  <head>
+    <title>XML: Comment in doctype internal subset</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+  </head>
+  <body>
+    <script>
+      test(() => {
+        assert_equals(document.documentElement.previousSibling, document.firstChild);
+        assert_equals(document.firstChild.nodeType, Node.DOCUMENT_TYPE_NODE);
+      });
+    </script>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocument-with-null-browsing-context-crash.html b/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocument-with-null-browsing-context-crash.html
new file mode 100644
index 0000000000..c9393d0a09
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocument-with-null-browsing-context-crash.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>DOMImplementation.createDocument()</title>
+<link rel="author" title="Nate Chapin" href="mailto:japhet@chromium.org">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domimplementation-createdocument">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1086801">
+<meta name="assert" content="Calling on createDocument() on a DOMImplementation from a document with a null browsing context should not crash"/>
+<iframe id="i"></iframe>
+<script>
+var doc = i.contentDocument;
+i.remove();
+doc.implementation.createDocument("", "");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocument.html b/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocument.html
new file mode 100644
index 0000000000..835002b470
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocument.html
@@ -0,0 +1,170 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>DOMImplementation.createDocument(namespace, qualifiedName, doctype)</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domimplementation-createdocument">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createelementns">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-nodetype">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-documentelement">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-doctype">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-createElementNS.js"></script>
+<div id="log"></div>
+<script>
+var htmlNamespace = "http://www.w3.org/1999/xhtml"
+var svgNamespace = "http://www.w3.org/2000/svg"
+var mathMLNamespace = "http://www.w3.org/1998/Math/MathML"
+
+// Make DocumentTypes distinct
+function my_format_value(val) {
+  if (val instanceof DocumentType) {
+    return "DocumentType node <!DOCTYPE " + val.name
+      + (val.publicId ? " " + val.publicId : "")
+      + (val.systemId ? " " + val.systemId : "")
+      + ">";
+  }
+  return format_value(val);
+}
+
+test(function() {
+  var tests = createElementNS_tests.map(function(t) {
+    return [t[0], t[1], null, t[2]]
+  }).concat([
+    /* Arrays with four elements:
+     *   the namespace argument
+     *   the qualifiedName argument
+     *   the doctype argument
+     *   the expected exception, or null if none
+     */
+    [null, null, false, TypeError],
+    [null, "", null, null],
+    [undefined, null, undefined, null],
+    [undefined, undefined, undefined, null],
+    [undefined, "", undefined, null],
+    ["http://example.com/", null, null, null],
+    ["http://example.com/", "", null, null],
+    ["/", null, null, null],
+    ["/", "", null, null],
+    ["http://www.w3.org/XML/1998/namespace", null, null, null],
+    ["http://www.w3.org/XML/1998/namespace", "", null, null],
+    ["http://www.w3.org/2000/xmlns/", null, null, null],
+    ["http://www.w3.org/2000/xmlns/", "", null, null],
+    ["foo:", null, null, null],
+    ["foo:", "", null, null],
+    [null, null, document.implementation.createDocumentType("foo", "", ""), null],
+    [null, null, document.doctype, null], // This causes a horrible WebKit bug (now fixed in trunk).
+    [null, null, function() {
+        var foo = document.implementation.createDocumentType("bar", "", "");
+        document.implementation.createDocument(null, null, foo);
+        return foo;
+     }(), null], // DOCTYPE already associated with a document.
+    [null, null, function() {
+        var bar = document.implementation.createDocument(null, null, null);
+        return bar.implementation.createDocumentType("baz", "", "");
+     }(), null], // DOCTYPE created by a different implementation.
+    [null, null, function() {
+        var bar = document.implementation.createDocument(null, null, null);
+        var magic = bar.implementation.createDocumentType("quz", "", "");
+        bar.implementation.createDocument(null, null, magic);
+        return magic;
+     }(), null], // DOCTYPE created by a different implementation and already associated with a document.
+    [null, "foo", document.implementation.createDocumentType("foo", "", ""), null],
+    ["foo", null, document.implementation.createDocumentType("foo", "", ""), null],
+    ["foo", "bar", document.implementation.createDocumentType("foo", "", ""), null],
+    [htmlNamespace, "", null, null],
+    [svgNamespace, "", null, null],
+    [mathMLNamespace, "", null, null],
+    [null, "html", null, null],
+    [null, "svg", null, null],
+    [null, "math", null, null],
+    [null, "", document.implementation.createDocumentType("html",
+        "-//W3C//DTD XHTML 1.0 Transitional//EN",
+        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd")],
+    [null, "", document.implementation.createDocumentType("svg",
+        "-//W3C//DTD SVG 1.1//EN",
+        "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd")],
+    [null, "", document.implementation.createDocumentType("math",
+        "-//W3C//DTD MathML 2.0//EN",
+        "http://www.w3.org/Math/DTD/mathml2/mathml2.dtd")],
+  ])
+
+  tests.forEach(function(t, i) {
+    var namespace = t[0], qualifiedName = t[1], doctype = t[2], expected = t[3]
+    test(function() {
+      if (expected != null) {
+        if (typeof expected == "string") {
+          assert_throws_dom(expected, function() { document.implementation.createDocument(namespace, qualifiedName, doctype) });
+        } else {
+          assert_throws_js(expected, function() { document.implementation.createDocument(namespace, qualifiedName, doctype) });
+        }
+      } else {
+        var doc = document.implementation.createDocument(namespace, qualifiedName, doctype)
+        assert_equals(doc.nodeType, Node.DOCUMENT_NODE)
+        assert_equals(doc.nodeType, doc.DOCUMENT_NODE)
+        assert_equals(doc.nodeName, "#document")
+        assert_equals(doc.nodeValue, null)
+        assert_equals(Object.getPrototypeOf(doc), XMLDocument.prototype)
+        var omitRootElement = qualifiedName === null || String(qualifiedName) === ""
+        if (omitRootElement) {
+          assert_equals(doc.documentElement, null)
+        } else {
+          var element = doc.documentElement
+          assert_not_equals(element, null)
+          assert_equals(element.nodeType, Node.ELEMENT_NODE)
+          assert_equals(element.ownerDocument, doc)
+          var qualified = String(qualifiedName), names = []
+          if (qualified.indexOf(":") >= 0) {
+            names = qualified.split(":", 2)
+          } else {
+            names = [null, qualified]
+          }
+          assert_equals(element.prefix, names[0])
+          assert_equals(element.localName, names[1])
+          assert_equals(element.namespaceURI, namespace === undefined ? null : namespace)
+        }
+        if (!doctype) {
+          assert_equals(doc.doctype, null)
+        } else {
+          assert_equals(doc.doctype, doctype)
+          assert_equals(doc.doctype.ownerDocument, doc)
+        }
+        assert_equals(doc.childNodes.length, !omitRootElement + !!doctype)
+      }
+    }, "createDocument test: " + t.map(my_format_value))
+
+    if (expected === null) {
+      test(function() {
+        var doc = document.implementation.createDocument(namespace, qualifiedName, doctype)
+        assert_equals(doc.location, null)
+        assert_equals(doc.compatMode, "CSS1Compat")
+        assert_equals(doc.characterSet, "UTF-8")
+        assert_equals(doc.contentType, namespace == htmlNamespace ? "application/xhtml+xml"
+                                 : namespace == svgNamespace ?  "image/svg+xml"
+                                 : "application/xml")
+        assert_equals(doc.URL, "about:blank")
+        assert_equals(doc.documentURI, "about:blank")
+        assert_equals(doc.createElement("DIV").localName, "DIV");
+      }, "createDocument test: metadata for " +
+      [namespace, qualifiedName, doctype].map(my_format_value))
+
+      test(function() {
+        var doc = document.implementation.createDocument(namespace, qualifiedName, doctype)
+        assert_equals(doc.characterSet, "UTF-8", "characterSet");
+        assert_equals(doc.charset, "UTF-8", "charset");
+        assert_equals(doc.inputEncoding, "UTF-8", "inputEncoding");
+      }, "createDocument test: characterSet aliases for " +
+      [namespace, qualifiedName, doctype].map(my_format_value))
+    }
+  })
+})
+
+test(function() {
+  assert_throws_js(TypeError, function() {
+    document.implementation.createDocument()
+  }, "createDocument() should throw")
+
+  assert_throws_js(TypeError, function() {
+    document.implementation.createDocument('')
+  }, "createDocument('') should throw")
+}, "createDocument with missing arguments");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocumentType.html b/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocumentType.html
new file mode 100644
index 0000000000..8d23e66a2b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DOMImplementation-createDocumentType.html
@@ -0,0 +1,123 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>DOMImplementation.createDocumentType(qualifiedName, publicId, systemId)</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domimplementation-createdocumenttype">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-documenttype-name">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-documenttype-publicid">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-documenttype-systemid">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-ownerdocument">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var tests = [
+    ["", "", "", "INVALID_CHARACTER_ERR"],
+    ["test:root", "1234", "", null],
+    ["test:root", "1234", "test", null],
+    ["test:root", "test", "", null],
+    ["test:root", "test", "test", null],
+    ["_:_", "", "", null],
+    ["_:h0", "", "", null],
+    ["_:test", "", "", null],
+    ["_:_.", "", "", null],
+    ["_:a-", "", "", null],
+    ["l_:_", "", "", null],
+    ["ns:_0", "", "", null],
+    ["ns:a0", "", "", null],
+    ["ns0:test", "", "", null],
+    ["ns:EEE.", "", "", null],
+    ["ns:_-", "", "", null],
+    ["a.b:c", "", "", null],
+    ["a-b:c.j", "", "", null],
+    ["a-b:c", "", "", null],
+    ["foo", "", "", null],
+    ["1foo", "", "", "INVALID_CHARACTER_ERR"],
+    ["foo1", "", "", null],
+    ["f1oo", "", "", null],
+    ["@foo", "", "", "INVALID_CHARACTER_ERR"],
+    ["foo@", "", "", "INVALID_CHARACTER_ERR"],
+    ["f@oo", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:{", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:}", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:~", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:'", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:!", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:@", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:#", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:$", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:%", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:^", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:&", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:*", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:(", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:)", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:+", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:=", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:[", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:]", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:\\", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:/", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:;", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:`", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:<", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:>", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:,", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:a ", "", "", "INVALID_CHARACTER_ERR"],
+    ["edi:\"", "", "", "INVALID_CHARACTER_ERR"],
+    ["{", "", "", "INVALID_CHARACTER_ERR"],
+    ["}", "", "", "INVALID_CHARACTER_ERR"],
+    ["'", "", "", "INVALID_CHARACTER_ERR"],
+    ["~", "", "", "INVALID_CHARACTER_ERR"],
+    ["`", "", "", "INVALID_CHARACTER_ERR"],
+    ["@", "", "", "INVALID_CHARACTER_ERR"],
+    ["#", "", "", "INVALID_CHARACTER_ERR"],
+    ["$", "", "", "INVALID_CHARACTER_ERR"],
+    ["%", "", "", "INVALID_CHARACTER_ERR"],
+    ["^", "", "", "INVALID_CHARACTER_ERR"],
+    ["&", "", "", "INVALID_CHARACTER_ERR"],
+    ["*", "", "", "INVALID_CHARACTER_ERR"],
+    ["(", "", "", "INVALID_CHARACTER_ERR"],
+    [")", "", "", "INVALID_CHARACTER_ERR"],
+    ["f:oo", "", "", null],
+    [":foo", "", "", "INVALID_CHARACTER_ERR"],
+    ["foo:", "", "", "INVALID_CHARACTER_ERR"],
+    ["prefix::local", "", "", "INVALID_CHARACTER_ERR"],
+    ["foo", "foo", "", null],
+    ["foo", "", "foo", null],
+    ["foo", "f'oo", "", null],
+    ["foo", "", "f'oo", null],
+    ["foo", 'f"oo', "", null],
+    ["foo", "", 'f"oo', null],
+    ["foo", "f'o\"o", "", null],
+    ["foo", "", "f'o\"o", null],
+    ["foo", "foo>", "", null],
+    ["foo", "", "foo>", null]
+  ]
+
+  var doc = document.implementation.createHTMLDocument("title");
+  var doTest = function(aDocument, aQualifiedName, aPublicId, aSystemId) {
+    var doctype = aDocument.implementation.createDocumentType(aQualifiedName, aPublicId, aSystemId);
+    assert_equals(doctype.name, aQualifiedName, "name")
+    assert_equals(doctype.nodeName, aQualifiedName, "nodeName")
+    assert_equals(doctype.publicId, aPublicId, "publicId")
+    assert_equals(doctype.systemId, aSystemId, "systemId")
+    assert_equals(doctype.ownerDocument, aDocument, "ownerDocument")
+    assert_equals(doctype.nodeValue, null, "nodeValue")
+  }
+  tests.forEach(function(t) {
+    var qualifiedName = t[0], publicId = t[1], systemId = t[2], expected = t[3]
+    test(function() {
+      if (expected) {
+        assert_throws_dom(expected, function() {
+          document.implementation.createDocumentType(qualifiedName, publicId, systemId)
+        })
+      } else {
+        doTest(document, qualifiedName, publicId, systemId);
+        doTest(doc, qualifiedName, publicId, systemId);
+      }
+    }, "createDocumentType(" + format_value(qualifiedName) + ", " + format_value(publicId) + ", " + format_value(systemId) + ") should " +
+       (expected ? "throw " + expected : "work"));
+  });
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument-with-null-browsing-context-crash.html b/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument-with-null-browsing-context-crash.html
new file mode 100644
index 0000000000..d0cd6f1f74
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument-with-null-browsing-context-crash.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>DOMImplementation.createHTMLDocument()</title>
+<link rel="author" title="Nate Chapin" href="mailto:japhet@chromium.org">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domimplementation-createhtmldocument">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1086800">
+<meta name="assert" content="Calling on createHTMLDocument() on a DOMImplementation from a document with a null browsing context should not crash"/>
+<iframe id="i"></iframe>
+<script>
+var doc = i.contentDocument;
+i.remove();
+doc.implementation.createHTMLDocument();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument-with-saved-implementation.html b/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument-with-saved-implementation.html
new file mode 100644
index 0000000000..bae22660bf
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument-with-saved-implementation.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>DOMImplementation.createHTMLDocument</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domimplementation-createhtmldocument">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+// Test the document location getter is null outside of browser context
+test(function() {
+  var iframe = document.createElement("iframe");
+  document.body.appendChild(iframe);
+  var implementation = iframe.contentDocument.implementation;
+  iframe.remove();
+  assert_not_equals(implementation.createHTMLDocument(), null);
+}, "createHTMLDocument(): from a saved and detached implementation does not return null")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument.html b/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument.html
new file mode 100644
index 0000000000..c6e0beaf75
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument.html
@@ -0,0 +1,96 @@
+<!DOCTYPE html>
+<meta charset=windows-1252>
+<!-- Using windows-1252 to ensure that DOMImplementation.createHTMLDocument()
+     doesn't inherit utf-8 from the parent document. -->
+<title>DOMImplementation.createHTMLDocument</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domimplementation-createhtmldocument">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-documenttype-name">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-documenttype-publicid">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-documenttype-systemid">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-documentelement">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="DOMImplementation-createHTMLDocument.js"></script>
+<div id="log"></div>
+<script>
+createHTMLDocuments(function(doc, expectedtitle, normalizedtitle) {
+  assert_true(doc instanceof Document, "Should be a Document")
+  assert_true(doc instanceof Node, "Should be a Node")
+  assert_equals(doc.childNodes.length, 2,
+                "Document should have two child nodes")
+
+  var doctype = doc.doctype
+  assert_true(doctype instanceof DocumentType,
+              "Doctype should be a DocumentType")
+  assert_true(doctype instanceof Node, "Doctype should be a Node")
+  assert_equals(doctype.name, "html")
+  assert_equals(doctype.publicId, "")
+  assert_equals(doctype.systemId, "")
+
+  var documentElement = doc.documentElement
+  assert_true(documentElement instanceof HTMLHtmlElement,
+              "Document element should be a HTMLHtmlElement")
+  assert_equals(documentElement.childNodes.length, 2,
+                "Document element should have two child nodes")
+  assert_equals(documentElement.localName, "html")
+  assert_equals(documentElement.tagName, "HTML")
+
+  var head = documentElement.firstChild
+  assert_true(head instanceof HTMLHeadElement,
+              "Head should be a HTMLHeadElement")
+  assert_equals(head.localName, "head")
+  assert_equals(head.tagName, "HEAD")
+
+  if (expectedtitle !== undefined) {
+    assert_equals(head.childNodes.length, 1)
+
+    var title = head.firstChild
+    assert_true(title instanceof HTMLTitleElement,
+                "Title should be a HTMLTitleElement")
+    assert_equals(title.localName, "title")
+    assert_equals(title.tagName, "TITLE")
+    assert_equals(title.childNodes.length, 1)
+    assert_equals(title.firstChild.data, expectedtitle)
+  } else {
+    assert_equals(head.childNodes.length, 0)
+  }
+
+  var body = documentElement.lastChild
+  assert_true(body instanceof HTMLBodyElement,
+              "Body should be a HTMLBodyElement")
+  assert_equals(body.localName, "body")
+  assert_equals(body.tagName, "BODY")
+  assert_equals(body.childNodes.length, 0)
+})
+
+test(function() {
+  var doc = document.implementation.createHTMLDocument("test");
+  assert_equals(doc.URL, "about:blank");
+  assert_equals(doc.documentURI, "about:blank");
+  assert_equals(doc.compatMode, "CSS1Compat");
+  assert_equals(doc.characterSet, "UTF-8");
+  assert_equals(doc.contentType, "text/html");
+  assert_equals(doc.createElement("DIV").localName, "div");
+}, "createHTMLDocument(): metadata")
+
+test(function() {
+  var doc = document.implementation.createHTMLDocument("test");
+  assert_equals(doc.characterSet, "UTF-8", "characterSet");
+  assert_equals(doc.charset, "UTF-8", "charset");
+  assert_equals(doc.inputEncoding, "UTF-8", "inputEncoding");
+}, "createHTMLDocument(): characterSet aliases")
+
+test(function() {
+  var doc = document.implementation.createHTMLDocument("test");
+  var a = doc.createElement("a");
+  // In UTF-8: 0xC3 0xA4
+  a.href = "http://example.org/?\u00E4";
+  assert_equals(a.href, "http://example.org/?%C3%A4");
+}, "createHTMLDocument(): URL parsing")
+
+// Test the document location getter is null outside of browser context
+test(function() {
+  var doc = document.implementation.createHTMLDocument();
+  assert_equals(doc.location, null);
+}, "createHTMLDocument(): document location getter is null")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument.js b/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument.js
new file mode 100644
index 0000000000..3e7e9aa9b7
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DOMImplementation-createHTMLDocument.js
@@ -0,0 +1,25 @@
+function createHTMLDocuments(checkDoc) {
+  var tests = [
+    ["", "", ""],
+    [null, "null", "null"],
+    [undefined, undefined, ""],
+    ["foo  bar baz", "foo  bar baz", "foo bar baz"],
+    ["foo\t\tbar baz", "foo\t\tbar baz", "foo bar baz"],
+    ["foo\n\nbar baz", "foo\n\nbar baz", "foo bar baz"],
+    ["foo\f\fbar baz", "foo\f\fbar baz", "foo bar baz"],
+    ["foo\r\rbar baz", "foo\r\rbar baz", "foo bar baz"],
+  ]
+
+  tests.forEach(function(t, i) {
+    var title = t[0], expectedtitle = t[1], normalizedtitle = t[2]
+    test(function() {
+      var doc = document.implementation.createHTMLDocument(title);
+      checkDoc(doc, expectedtitle, normalizedtitle)
+    }, "createHTMLDocument test " + i + ": " + t.map(function(el) { return format_value(el) }))
+  })
+
+  test(function() {
+    var doc = document.implementation.createHTMLDocument();
+    checkDoc(doc, undefined, "")
+  }, "Missing title argument");
+}
diff --git a/testing/web-platform/tests/dom/nodes/DOMImplementation-hasFeature.html b/testing/web-platform/tests/dom/nodes/DOMImplementation-hasFeature.html
new file mode 100644
index 0000000000..637565a60f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DOMImplementation-hasFeature.html
@@ -0,0 +1,155 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>DOMImplementation.hasFeature(feature, version)</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domimplementation-hasfeature">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var tests = [
+        [],
+        ["Core"],
+        ["XML"],
+        ["org.w3c.svg"],
+        ["org.w3c.dom.svg"],
+        ["http://www.w3.org/TR/SVG11/feature#Script"],
+        ["Core", "1.0"],
+        ["Core", "2.0"],
+        ["Core", "3.0"],
+        ["Core", "100.0"],
+        ["XML", "1.0"],
+        ["XML", "2.0"],
+        ["XML", "3.0"],
+        ["XML", "100.0"],
+        ["Core", "1"],
+        ["Core", "2"],
+        ["Core", "3"],
+        ["Core", "100"],
+        ["XML", "1"],
+        ["XML", "2"],
+        ["XML", "3"],
+        ["XML", "100"],
+        ["Core", "1.1"],
+        ["Core", "2.1"],
+        ["Core", "3.1"],
+        ["Core", "100.1"],
+        ["XML", "1.1"],
+        ["XML", "2.1"],
+        ["XML", "3.1"],
+        ["XML", "100.1"],
+        ["Core", ""],
+        ["XML", ""],
+        ["core", ""],
+        ["xml", ""],
+        ["CoRe", ""],
+        ["XmL", ""],
+        [" Core", ""],
+        [" XML", ""],
+        ["Core ", ""],
+        ["XML ", ""],
+        ["Co re", ""],
+        ["XM L", ""],
+        ["aCore", ""],
+        ["aXML", ""],
+        ["Corea", ""],
+        ["XMLa", ""],
+        ["Coare", ""],
+        ["XMaL", ""],
+        ["Core", " "],
+        ["XML", " "],
+        ["Core", " 1.0"],
+        ["Core", " 2.0"],
+        ["Core", " 3.0"],
+        ["Core", " 100.0"],
+        ["XML", " 1.0"],
+        ["XML", " 2.0"],
+        ["XML", " 3.0"],
+        ["XML", " 100.0"],
+        ["Core", "1.0 "],
+        ["Core", "2.0 "],
+        ["Core", "3.0 "],
+        ["Core", "100.0 "],
+        ["XML", "1.0 "],
+        ["XML", "2.0 "],
+        ["XML", "3.0 "],
+        ["XML", "100.0 "],
+        ["Core", "1. 0"],
+        ["Core", "2. 0"],
+        ["Core", "3. 0"],
+        ["Core", "100. 0"],
+        ["XML", "1. 0"],
+        ["XML", "2. 0"],
+        ["XML", "3. 0"],
+        ["XML", "100. 0"],
+        ["Core", "a1.0"],
+        ["Core", "a2.0"],
+        ["Core", "a3.0"],
+        ["Core", "a100.0"],
+        ["XML", "a1.0"],
+        ["XML", "a2.0"],
+        ["XML", "a3.0"],
+        ["XML", "a100.0"],
+        ["Core", "1.0a"],
+        ["Core", "2.0a"],
+        ["Core", "3.0a"],
+        ["Core", "100.0a"],
+        ["XML", "1.0a"],
+        ["XML", "2.0a"],
+        ["XML", "3.0a"],
+        ["XML", "100.0a"],
+        ["Core", "1.a0"],
+        ["Core", "2.a0"],
+        ["Core", "3.a0"],
+        ["Core", "100.a0"],
+        ["XML", "1.a0"],
+        ["XML", "2.a0"],
+        ["XML", "3.a0"],
+        ["XML", "100.a0"],
+        ["Core", 1],
+        ["Core", 2],
+        ["Core", 3],
+        ["Core", 100],
+        ["XML", 1],
+        ["XML", 2],
+        ["XML", 3],
+        ["XML", 100],
+        ["Core", null],
+        ["XML", null],
+        ["core", null],
+        ["xml", null],
+        ["CoRe", null],
+        ["XmL", null],
+        [" Core", null],
+        [" XML", null],
+        ["Core ", null],
+        ["XML ", null],
+        ["Co re", null],
+        ["XM L", null],
+        ["aCore", null],
+        ["aXML", null],
+        ["Corea", null],
+        ["XMLa", null],
+        ["Coare", null],
+        ["XMaL", null],
+        ["Core", undefined],
+        ["XML", undefined],
+        ["This is filler text.", ""],
+        [null, ""],
+        [undefined, ""],
+        ["org.w3c.svg", ""],
+        ["org.w3c.svg", "1.0"],
+        ["org.w3c.svg", "1.1"],
+        ["org.w3c.dom.svg", ""],
+        ["org.w3c.dom.svg", "1.0"],
+        ["org.w3c.dom.svg", "1.1"],
+        ["http://www.w3.org/TR/SVG11/feature#Script", "7.5"],
+      ];
+  tests.forEach(function(data) {
+    test(function() {
+      assert_equals(document.implementation.hasFeature
+                    .apply(document.implementation, data), true)
+    }, "hasFeature(" + data.map(format_value).join(", ") + ")")
+  })
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-Element-getElementsByTagName.js b/testing/web-platform/tests/dom/nodes/Document-Element-getElementsByTagName.js
new file mode 100644
index 0000000000..dbbe667ff5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-Element-getElementsByTagName.js
@@ -0,0 +1,208 @@
+function test_getElementsByTagName(context, element) {
+  // TODO: getElementsByTagName("*")
+  test(function() {
+    assert_false(context.getElementsByTagName("html") instanceof NodeList,
+                 "Should not return a NodeList")
+    assert_true(context.getElementsByTagName("html") instanceof HTMLCollection,
+                "Should return an HTMLCollection")
+  }, "Interfaces")
+
+  test(function() {
+    var firstCollection = context.getElementsByTagName("html"),
+        secondCollection = context.getElementsByTagName("html")
+    assert_true(firstCollection !== secondCollection ||
+                firstCollection === secondCollection)
+  }, "Caching is allowed")
+
+  test(function() {
+    var l = context.getElementsByTagName("nosuchtag")
+    l[5] = "foopy"
+    assert_equals(l[5], undefined)
+    assert_equals(l.item(5), null)
+  }, "Shouldn't be able to set unsigned properties on a HTMLCollection (non-strict mode)")
+
+  test(function() {
+    var l = context.getElementsByTagName("nosuchtag")
+    assert_throws_js(TypeError, function() {
+      "use strict";
+      l[5] = "foopy"
+    })
+    assert_equals(l[5], undefined)
+    assert_equals(l.item(5), null)
+  }, "Shouldn't be able to set unsigned properties on a HTMLCollection (strict mode)")
+
+  test(function() {
+    var l = context.getElementsByTagName("nosuchtag")
+    var fn = l.item;
+    assert_equals(fn, HTMLCollection.prototype.item);
+    l.item = "pass"
+    assert_equals(l.item, "pass")
+    assert_equals(HTMLCollection.prototype.item, fn);
+  }, "Should be able to set expando shadowing a proto prop (item)")
+
+  test(function() {
+    var l = context.getElementsByTagName("nosuchtag")
+    var fn = l.namedItem;
+    assert_equals(fn, HTMLCollection.prototype.namedItem);
+    l.namedItem = "pass"
+    assert_equals(l.namedItem, "pass")
+    assert_equals(HTMLCollection.prototype.namedItem, fn);
+  }, "Should be able to set expando shadowing a proto prop (namedItem)")
+
+  test(function() {
+    var t1 = element.appendChild(document.createElement("pre"));
+    t1.id = "x";
+    var t2 = element.appendChild(document.createElement("pre"));
+    t2.setAttribute("name", "y");
+    var t3 = element.appendChild(document.createElementNS("", "pre"));
+    t3.setAttribute("id", "z");
+    var t4 = element.appendChild(document.createElementNS("", "pre"));
+    t4.setAttribute("name", "w");
+    this.add_cleanup(function() {
+      element.removeChild(t1)
+      element.removeChild(t2)
+      element.removeChild(t3)
+      element.removeChild(t4)
+    });
+
+    var list = context.getElementsByTagName('pre');
+    var pre = list[0];
+    assert_equals(pre.id, "x");
+
+    var exposedNames = { 'x': 0, 'y': 1, 'z': 2 };
+    for (var exposedName in exposedNames) {
+      assert_equals(list[exposedName], list[exposedNames[exposedName]]);
+      assert_equals(list[exposedName], list.namedItem(exposedName));
+      assert_true(exposedName in list, "'" + exposedName + "' in list");
+      assert_true(list.hasOwnProperty(exposedName),
+                  "list.hasOwnProperty('" + exposedName + "')");
+    }
+
+    var unexposedNames = ["w"];
+    for (var unexposedName of unexposedNames) {
+      assert_false(unexposedName in list);
+      assert_false(list.hasOwnProperty(unexposedName));
+      assert_equals(list[unexposedName], undefined);
+      assert_equals(list.namedItem(unexposedName), null);
+    }
+
+    assert_array_equals(Object.getOwnPropertyNames(list).sort(),
+                        ["0", "1", "2", "3", "x", "y", "z"]);
+
+    var desc = Object.getOwnPropertyDescriptor(list, '0');
+    assert_equals(typeof desc, "object", "descriptor should be an object");
+    assert_true(desc.enumerable, "desc.enumerable");
+    assert_true(desc.configurable, "desc.configurable");
+
+    desc = Object.getOwnPropertyDescriptor(list, 'x');
+    assert_equals(typeof desc, "object", "descriptor should be an object");
+    assert_false(desc.enumerable, "desc.enumerable");
+    assert_true(desc.configurable, "desc.configurable");
+  }, "hasOwnProperty, getOwnPropertyDescriptor, getOwnPropertyNames")
+
+  test(function() {
+    assert_equals(document.createElementNS("http://www.w3.org/1999/xhtml", "i").localName, "i") // Sanity
+    var t = element.appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "I"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_equals(t.localName, "I")
+    assert_equals(t.tagName, "I")
+    assert_equals(context.getElementsByTagName("I").length, 0)
+    assert_equals(context.getElementsByTagName("i").length, 0)
+  }, "HTML element with uppercase tagName never matches in HTML Documents")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "st"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagName("st"), [t])
+    assert_array_equals(context.getElementsByTagName("ST"), [])
+  }, "Element in non-HTML namespace, no prefix, lowercase name")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "ST"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagName("ST"), [t])
+    assert_array_equals(context.getElementsByTagName("st"), [])
+  }, "Element in non-HTML namespace, no prefix, uppercase name")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "te:st"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagName("st"), [])
+    assert_array_equals(context.getElementsByTagName("ST"), [])
+    assert_array_equals(context.getElementsByTagName("te:st"), [t])
+    assert_array_equals(context.getElementsByTagName("te:ST"), [])
+  }, "Element in non-HTML namespace, prefix, lowercase name")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "te:ST"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagName("st"), [])
+    assert_array_equals(context.getElementsByTagName("ST"), [])
+    assert_array_equals(context.getElementsByTagName("te:st"), [])
+    assert_array_equals(context.getElementsByTagName("te:ST"), [t])
+  }, "Element in non-HTML namespace, prefix, uppercase name")
+
+  test(function() {
+    var t = element.appendChild(document.createElement("aÇ"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_equals(t.localName, "aÇ")
+    assert_array_equals(context.getElementsByTagName("AÇ"), [t], "All uppercase input")
+    assert_array_equals(context.getElementsByTagName("aÇ"), [t], "Ascii lowercase input")
+    assert_array_equals(context.getElementsByTagName("aç"), [], "All lowercase input")
+  }, "Element in HTML namespace, no prefix, non-ascii characters in name")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "AÇ"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagName("AÇ"), [t])
+    assert_array_equals(context.getElementsByTagName("aÇ"), [])
+    assert_array_equals(context.getElementsByTagName("aç"), [])
+  }, "Element in non-HTML namespace, non-ascii characters in name")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "test:aÇ"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagName("TEST:AÇ"), [t], "All uppercase input")
+    assert_array_equals(context.getElementsByTagName("test:aÇ"), [t], "Ascii lowercase input")
+    assert_array_equals(context.getElementsByTagName("test:aç"), [], "All lowercase input")
+  }, "Element in HTML namespace, prefix, non-ascii characters in name")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "TEST:AÇ"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagName("TEST:AÇ"), [t], "All uppercase input")
+    assert_array_equals(context.getElementsByTagName("test:aÇ"), [], "Ascii lowercase input")
+    assert_array_equals(context.getElementsByTagName("test:aç"), [], "All lowercase input")
+  }, "Element in non-HTML namespace, prefix, non-ascii characters in name")
+
+  test(function() {
+    var actual = context.getElementsByTagName("*");
+    var expected = [];
+    var get_elements = function(node) {
+      for (var i = 0; i < node.childNodes.length; i++) {
+        var child = node.childNodes[i];
+        if (child.nodeType === child.ELEMENT_NODE) {
+          expected.push(child);
+          get_elements(child);
+        }
+      }
+    }
+    get_elements(context);
+    assert_array_equals(actual, expected);
+  }, "getElementsByTagName('*')")
+
+  test(function() {
+    var t1 = element.appendChild(document.createElement("abc"));
+    this.add_cleanup(function() {element.removeChild(t1)});
+
+    var l = context.getElementsByTagName("abc");
+    assert_true(l instanceof HTMLCollection);
+    assert_equals(l.length, 1);
+
+    var t2 = element.appendChild(document.createElement("abc"));
+    assert_equals(l.length, 2);
+
+    element.removeChild(t2);
+    assert_equals(l.length, 1);
+  }, "getElementsByTagName() should be a live collection");
+}
diff --git a/testing/web-platform/tests/dom/nodes/Document-Element-getElementsByTagNameNS.js b/testing/web-platform/tests/dom/nodes/Document-Element-getElementsByTagNameNS.js
new file mode 100644
index 0000000000..b610c49d86
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-Element-getElementsByTagNameNS.js
@@ -0,0 +1,143 @@
+function test_getElementsByTagNameNS(context, element) {
+  test(function() {
+    assert_false(context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "html") instanceof NodeList, "NodeList")
+    assert_true(context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "html") instanceof HTMLCollection, "HTMLCollection")
+    var firstCollection = context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "html"),
+        secondCollection = context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "html")
+    assert_true(firstCollection !== secondCollection || firstCollection === secondCollection,
+                "Caching is allowed.")
+  })
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "body"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    var actual = context.getElementsByTagNameNS("*", "body");
+    var expected = [];
+    var get_elements = function(node) {
+      for (var i = 0; i < node.childNodes.length; i++) {
+        var child = node.childNodes[i];
+        if (child.nodeType === child.ELEMENT_NODE) {
+          if (child.localName == "body") {
+            expected.push(child);
+          }
+          get_elements(child);
+        }
+      }
+    }
+    get_elements(context);
+    assert_array_equals(actual, expected);
+  }, "getElementsByTagNameNS('*', 'body')")
+
+  test(function() {
+    assert_array_equals(context.getElementsByTagNameNS("", "*"), []);
+    var t = element.appendChild(document.createElementNS("", "body"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagNameNS("", "*"), [t]);
+  }, "Empty string namespace")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "body"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagNameNS("test", "body"), [t]);
+  }, "body element in test namespace, no prefix")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "test:body"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagNameNS("test", "body"), [t]);
+  }, "body element in test namespace, prefix")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "BODY"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagNameNS("test", "BODY"), [t]);
+    assert_array_equals(context.getElementsByTagNameNS("test", "body"), []);
+  }, "BODY element in test namespace, no prefix")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "abc"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "abc"), [t]);
+    assert_array_equals(context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "ABC"), []);
+    assert_array_equals(context.getElementsByTagNameNS("test", "ABC"), []);
+  }, "abc element in html namespace")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "ABC"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "abc"), []);
+    assert_array_equals(context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "ABC"), [t]);
+  }, "ABC element in html namespace")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "AÇ"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "AÇ"), [t]);
+    assert_array_equals(context.getElementsByTagNameNS("test", "aÇ"), []);
+    assert_array_equals(context.getElementsByTagNameNS("test", "aç"), []);
+  }, "AÇ, case sensitivity")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "test:BODY"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    assert_array_equals(context.getElementsByTagNameNS("test", "BODY"), [t]);
+    assert_array_equals(context.getElementsByTagNameNS("test", "body"), []);
+  }, "BODY element in test namespace, prefix")
+
+  test(function() {
+    var t = element.appendChild(document.createElementNS("test", "test:test"))
+    this.add_cleanup(function() {element.removeChild(t)})
+    var actual = context.getElementsByTagNameNS("http://www.w3.org/1999/xhtml", "*");
+    var expected = [];
+    var get_elements = function(node) {
+      for (var i = 0; i < node.childNodes.length; i++) {
+        var child = node.childNodes[i];
+        if (child.nodeType === child.ELEMENT_NODE) {
+          if (child !== t) {
+            expected.push(child);
+          }
+          get_elements(child);
+        }
+      }
+    }
+    get_elements(context);
+    assert_array_equals(actual, expected);
+  }, "getElementsByTagNameNS('http://www.w3.org/1999/xhtml', '*')")
+
+  test(function() {
+    var actual = context.getElementsByTagNameNS("*", "*");
+    var expected = [];
+    var get_elements = function(node) {
+      for (var i = 0; i < node.childNodes.length; i++) {
+        var child = node.childNodes[i];
+        if (child.nodeType === child.ELEMENT_NODE) {
+          expected.push(child);
+          get_elements(child);
+        }
+      }
+    }
+    get_elements(context);
+    assert_array_equals(actual, expected);
+  }, "getElementsByTagNameNS('*', '*')")
+
+  test(function() {
+    assert_array_equals(context.getElementsByTagNameNS("**", "*"), []);
+    assert_array_equals(context.getElementsByTagNameNS(null, "0"), []);
+    assert_array_equals(context.getElementsByTagNameNS(null, "div"), []);
+  }, "Empty lists")
+
+  test(function() {
+    var t1 = element.appendChild(document.createElementNS("test", "abc"));
+    this.add_cleanup(function() {element.removeChild(t1)});
+
+    var l = context.getElementsByTagNameNS("test", "abc");
+    assert_true(l instanceof HTMLCollection);
+    assert_equals(l.length, 1);
+
+    var t2 = element.appendChild(document.createElementNS("test", "abc"));
+    assert_equals(l.length, 2);
+
+    element.removeChild(t2);
+    assert_equals(l.length, 1);
+  }, "getElementsByTagNameNS() should be a live collection");
+}
diff --git a/testing/web-platform/tests/dom/nodes/Document-URL.html b/testing/web-platform/tests/dom/nodes/Document-URL.html
new file mode 100644
index 0000000000..242def1fb3
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-URL.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Document.URL with redirect</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement("iframe");
+  iframe.src = "/common/redirect.py?location=/common/blank.html";
+  document.body.appendChild(iframe);
+  this.add_cleanup(function() { document.body.removeChild(iframe); });
+  iframe.onload = this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.URL,
+                  location.origin + "/common/blank.html");
+  });
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-adoptNode.html b/testing/web-platform/tests/dom/nodes/Document-adoptNode.html
new file mode 100644
index 0000000000..60a4e6772a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-adoptNode.html
@@ -0,0 +1,50 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Document.adoptNode</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-adoptnode">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<!--creates an element with local name "x<": --><x<>x</x<>
+<script>
+test(function() {
+  var y = document.getElementsByTagName("x<")[0]
+  var child = y.firstChild
+  assert_equals(y.parentNode, document.body)
+  assert_equals(y.ownerDocument, document)
+  assert_equals(document.adoptNode(y), y)
+  assert_equals(y.parentNode, null)
+  assert_equals(y.firstChild, child)
+  assert_equals(y.ownerDocument, document)
+  assert_equals(child.ownerDocument, document)
+  var doc = document.implementation.createDocument(null, null, null)
+  assert_equals(doc.adoptNode(y), y)
+  assert_equals(y.parentNode, null)
+  assert_equals(y.firstChild, child)
+  assert_equals(y.ownerDocument, doc)
+  assert_equals(child.ownerDocument, doc)
+}, "Adopting an Element called 'x<' should work.")
+
+test(function() {
+  var x = document.createElement(":good:times:")
+  assert_equals(document.adoptNode(x), x);
+  var doc = document.implementation.createDocument(null, null, null)
+  assert_equals(doc.adoptNode(x), x)
+  assert_equals(x.parentNode, null)
+  assert_equals(x.ownerDocument, doc)
+}, "Adopting an Element called ':good:times:' should work.")
+
+test(function() {
+  var doctype = document.doctype;
+  assert_equals(doctype.parentNode, document)
+  assert_equals(doctype.ownerDocument, document)
+  assert_equals(document.adoptNode(doctype), doctype)
+  assert_equals(doctype.parentNode, null)
+  assert_equals(doctype.ownerDocument, document)
+}, "Explicitly adopting a DocumentType should work.")
+
+test(function() {
+  var doc = document.implementation.createDocument(null, null, null)
+  assert_throws_dom("NOT_SUPPORTED_ERR", function() { document.adoptNode(doc) })
+}, "Adopting a Document should throw.")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-characterSet-normalization-1.html b/testing/web-platform/tests/dom/nodes/Document-characterSet-normalization-1.html
new file mode 100644
index 0000000000..0facd50e49
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-characterSet-normalization-1.html
@@ -0,0 +1,157 @@
+<!doctype html>
+<title>document.characterSet (inputEncoding and charset as aliases) normalization tests</title>
+<link rel=author title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src="./characterset-helper.js"></script>
+<style>iframe { display: none }</style>
+<script>
+"use strict";
+
+// Taken straight from https://encoding.spec.whatwg.org/
+var encodingMap = {
+  "UTF-8": [
+    "unicode-1-1-utf-8",
+    "utf-8",
+    "utf8",
+    // As we use <meta>, utf-16 will map to utf-8 per
+    // https://html.spec.whatwg.org/multipage/#documentEncoding
+    "utf-16",
+    "utf-16le",
+    "utf-16be",
+  ],
+  "IBM866": [
+    "866",
+    "cp866",
+    "csibm866",
+    "ibm866",
+  ],
+  "ISO-8859-2": [
+    "csisolatin2",
+    "iso-8859-2",
+    "iso-ir-101",
+    "iso8859-2",
+    "iso88592",
+    "iso_8859-2",
+    "iso_8859-2:1987",
+    "l2",
+    "latin2",
+  ],
+  "ISO-8859-3": [
+    "csisolatin3",
+    "iso-8859-3",
+    "iso-ir-109",
+    "iso8859-3",
+    "iso88593",
+    "iso_8859-3",
+    "iso_8859-3:1988",
+    "l3",
+    "latin3",
+  ],
+  "ISO-8859-4": [
+    "csisolatin4",
+    "iso-8859-4",
+    "iso-ir-110",
+    "iso8859-4",
+    "iso88594",
+    "iso_8859-4",
+    "iso_8859-4:1988",
+    "l4",
+    "latin4",
+  ],
+  "ISO-8859-5": [
+    "csisolatincyrillic",
+    "cyrillic",
+    "iso-8859-5",
+    "iso-ir-144",
+    "iso8859-5",
+    "iso88595",
+    "iso_8859-5",
+    "iso_8859-5:1988",
+  ],
+  "ISO-8859-6": [
+    "arabic",
+    "asmo-708",
+    "csiso88596e",
+    "csiso88596i",
+    "csisolatinarabic",
+    "ecma-114",
+    "iso-8859-6",
+    "iso-8859-6-e",
+    "iso-8859-6-i",
+    "iso-ir-127",
+    "iso8859-6",
+    "iso88596",
+    "iso_8859-6",
+    "iso_8859-6:1987",
+  ],
+  "ISO-8859-7": [
+    "csisolatingreek",
+    "ecma-118",
+    "elot_928",
+    "greek",
+    "greek8",
+    "iso-8859-7",
+    "iso-ir-126",
+    "iso8859-7",
+    "iso88597",
+    "iso_8859-7",
+    "iso_8859-7:1987",
+    "sun_eu_greek",
+  ],
+  "ISO-8859-8": [
+    "csiso88598e",
+    "csisolatinhebrew",
+    "hebrew",
+    "iso-8859-8",
+    "iso-8859-8-e",
+    "iso-ir-138",
+    "iso8859-8",
+    "iso88598",
+    "iso_8859-8",
+    "iso_8859-8:1988",
+    "visual",
+  ],
+  "ISO-8859-8-I": [
+    "csiso88598i",
+    "iso-8859-8-i",
+    "logical",
+  ],
+  "ISO-8859-10": [
+    "csisolatin6",
+    "iso-8859-10",
+    "iso-ir-157",
+    "iso8859-10",
+    "iso885910",
+    "l6",
+    "latin6",
+  ],
+  "ISO-8859-13": [
+    "iso-8859-13",
+    "iso8859-13",
+    "iso885913",
+  ],
+  "ISO-8859-14": [
+    "iso-8859-14",
+    "iso8859-14",
+    "iso885914",
+  ],
+  "ISO-8859-15": [
+    "csisolatin9",
+    "iso-8859-15",
+    "iso8859-15",
+    "iso885915",
+    "iso_8859-15",
+    "l9",
+  ],
+  "ISO-8859-16": [
+    "iso-8859-16",
+  ],
+};
+
+runCharacterSetTests(encodingMap);
+
+</script>
+<!-- vim: set expandtab tabstop=2 shiftwidth=2: -->
diff --git a/testing/web-platform/tests/dom/nodes/Document-characterSet-normalization-2.html b/testing/web-platform/tests/dom/nodes/Document-characterSet-normalization-2.html
new file mode 100644
index 0000000000..7c7691bdc1
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-characterSet-normalization-2.html
@@ -0,0 +1,179 @@
+<!doctype html>
+<title>document.characterSet (inputEncoding and charset as aliases) normalization tests</title>
+<link rel=author title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src="./characterset-helper.js"></script>
+<style>iframe { display: none }</style>
+<script>
+"use strict";
+
+// Taken straight from https://encoding.spec.whatwg.org/
+var encodingMap = {
+  "KOI8-R": [
+    "cskoi8r",
+    "koi",
+    "koi8",
+    "koi8-r",
+    "koi8_r",
+  ],
+  "KOI8-U": [
+    "koi8-ru",
+    "koi8-u",
+  ],
+  "macintosh": [
+    "csmacintosh",
+    "mac",
+    "macintosh",
+    "x-mac-roman",
+  ],
+  "windows-874": [
+    "dos-874",
+    "iso-8859-11",
+    "iso8859-11",
+    "iso885911",
+    "tis-620",
+    "windows-874",
+  ],
+  "windows-1250": [
+    "cp1250",
+    "windows-1250",
+    "x-cp1250",
+  ],
+  "windows-1251": [
+    "cp1251",
+    "windows-1251",
+    "x-cp1251",
+  ],
+  "windows-1252": [
+    "ansi_x3.4-1968",
+    "ascii",
+    "cp1252",
+    "cp819",
+    "csisolatin1",
+    "ibm819",
+    "iso-8859-1",
+    "iso-ir-100",
+    "iso8859-1",
+    "iso88591",
+    "iso_8859-1",
+    "iso_8859-1:1987",
+    "l1",
+    "latin1",
+    "us-ascii",
+    "windows-1252",
+    "x-cp1252",
+    // As we use <meta>, x-user-defined will map to windows-1252 per
+    // https://html.spec.whatwg.org/multipage/#documentEncoding
+    "x-user-defined"
+  ],
+  "windows-1253": [
+    "cp1253",
+    "windows-1253",
+    "x-cp1253",
+  ],
+  "windows-1254": [
+    "cp1254",
+    "csisolatin5",
+    "iso-8859-9",
+    "iso-ir-148",
+    "iso8859-9",
+    "iso88599",
+    "iso_8859-9",
+    "iso_8859-9:1989",
+    "l5",
+    "latin5",
+    "windows-1254",
+    "x-cp1254",
+  ],
+  "windows-1255": [
+    "cp1255",
+    "windows-1255",
+    "x-cp1255",
+  ],
+  "windows-1256": [
+    "cp1256",
+    "windows-1256",
+    "x-cp1256",
+  ],
+  "windows-1257": [
+    "cp1257",
+    "windows-1257",
+    "x-cp1257",
+  ],
+  "windows-1258": [
+    "cp1258",
+    "windows-1258",
+    "x-cp1258",
+  ],
+  "x-mac-cyrillic": [
+    "x-mac-cyrillic",
+    "x-mac-ukrainian",
+  ],
+  "GBK": [
+    "chinese",
+    "csgb2312",
+    "csiso58gb231280",
+    "gb2312",
+    "gb_2312",
+    "gb_2312-80",
+    "gbk",
+    "iso-ir-58",
+    "x-gbk",
+  ],
+  "gb18030": [
+    "gb18030",
+  ],
+  "Big5": [
+    "big5",
+    "big5-hkscs",
+    "cn-big5",
+    "csbig5",
+    "x-x-big5",
+  ],
+  "EUC-JP": [
+    "cseucpkdfmtjapanese",
+    "euc-jp",
+    "x-euc-jp",
+  ],
+  "ISO-2022-JP": [
+    "csiso2022jp",
+    "iso-2022-jp",
+  ],
+  "Shift_JIS": [
+    "csshiftjis",
+    "ms932",
+    "ms_kanji",
+    "shift-jis",
+    "shift_jis",
+    "sjis",
+    "windows-31j",
+    "x-sjis",
+  ],
+  "EUC-KR": [
+    "cseuckr",
+    "csksc56011987",
+    "euc-kr",
+    "iso-ir-149",
+    "korean",
+    "ks_c_5601-1987",
+    "ks_c_5601-1989",
+    "ksc5601",
+    "ksc_5601",
+    "windows-949",
+  ],
+  "replacement": [
+    "csiso2022kr",
+    "hz-gb-2312",
+    "iso-2022-cn",
+    "iso-2022-cn-ext",
+    "iso-2022-kr",
+  ],
+};
+
+runCharacterSetTests(encodingMap);
+
+</script>
+<!-- vim: set expandtab tabstop=2 shiftwidth=2: -->
diff --git a/testing/web-platform/tests/dom/nodes/Document-constructor-svg.svg b/testing/web-platform/tests/dom/nodes/Document-constructor-svg.svg
new file mode 100644
index 0000000000..77e3d8996e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-constructor-svg.svg
@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="windows-1252"?>
+<!-- Using windows-1252 to ensure that new Document() doesn't inherit utf-8
+     from the parent document. -->
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:html="http://www.w3.org/1999/xhtml"
+  width="100%" height="100%" viewBox="0 0 800 600">
+<title>Document constructor</title>
+<html:script src="/resources/testharness.js"></html:script>
+<html:script src="/resources/testharnessreport.js"></html:script>
+<html:script><![CDATA[
+test(function() {
+  var doc = new Document();
+  assert_true(doc instanceof Node, "Should be a Node");
+  assert_true(doc instanceof Document, "Should be a Document");
+  assert_false(doc instanceof XMLDocument, "Should not be an XMLDocument");
+  assert_equals(Object.getPrototypeOf(doc), Document.prototype,
+                "Document should be the primary interface");
+}, "new Document(): interfaces")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.firstChild, null, "firstChild");
+  assert_equals(doc.lastChild, null, "lastChild");
+  assert_equals(doc.doctype, null, "doctype");
+  assert_equals(doc.documentElement, null, "documentElement");
+  assert_array_equals(doc.childNodes, [], "childNodes");
+}, "new Document(): children")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.URL, "about:blank");
+  assert_equals(doc.documentURI, "about:blank");
+  assert_equals(doc.compatMode, "CSS1Compat");
+  assert_equals(doc.characterSet, "UTF-8");
+  assert_equals(doc.contentType, "application/xml");
+  assert_equals(doc.createElement("DIV").localName, "DIV");
+}, "new Document(): metadata")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.characterSet, "UTF-8", "characterSet");
+  assert_equals(doc.charset, "UTF-8", "charset");
+  assert_equals(doc.inputEncoding, "UTF-8", "inputEncoding");
+}, "new Document(): characterSet aliases")
+]]></html:script>
+</svg>
+
diff --git a/testing/web-platform/tests/dom/nodes/Document-constructor-xml.xml b/testing/web-platform/tests/dom/nodes/Document-constructor-xml.xml
new file mode 100644
index 0000000000..c9fc775806
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-constructor-xml.xml
@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="windows-1252"?>
+<!-- Using windows-1252 to ensure that new Document() doesn't inherit utf-8
+     from the parent document. -->
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Document constructor</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-document" />
+</head>
+<body>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script><![CDATA[
+test(function() {
+  var doc = new Document();
+  assert_true(doc instanceof Node, "Should be a Node");
+  assert_true(doc instanceof Document, "Should be a Document");
+  assert_false(doc instanceof XMLDocument, "Should not be an XMLDocument");
+  assert_equals(Object.getPrototypeOf(doc), Document.prototype,
+                "Document should be the primary interface");
+}, "new Document(): interfaces")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.firstChild, null, "firstChild");
+  assert_equals(doc.lastChild, null, "lastChild");
+  assert_equals(doc.doctype, null, "doctype");
+  assert_equals(doc.documentElement, null, "documentElement");
+  assert_array_equals(doc.childNodes, [], "childNodes");
+}, "new Document(): children")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.URL, "about:blank");
+  assert_equals(doc.documentURI, "about:blank");
+  assert_equals(doc.compatMode, "CSS1Compat");
+  assert_equals(doc.characterSet, "UTF-8");
+  assert_equals(doc.contentType, "application/xml");
+  assert_equals(doc.createElement("DIV").localName, "DIV");
+}, "new Document(): metadata")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.characterSet, "UTF-8", "characterSet");
+  assert_equals(doc.charset, "UTF-8", "charset");
+  assert_equals(doc.inputEncoding, "UTF-8", "inputEncoding");
+}, "new Document(): characterSet aliases")
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-constructor.html b/testing/web-platform/tests/dom/nodes/Document-constructor.html
new file mode 100644
index 0000000000..e17de28471
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-constructor.html
@@ -0,0 +1,56 @@
+<!doctype html>
+<meta charset=windows-1252>
+<!-- Using windows-1252 to ensure that new Document() doesn't inherit utf-8
+     from the parent document. -->
+<title>Document constructor</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var doc = new Document();
+  assert_true(doc instanceof Node, "Should be a Node");
+  assert_true(doc instanceof Document, "Should be a Document");
+  assert_false(doc instanceof XMLDocument, "Should not be an XMLDocument");
+  assert_equals(Object.getPrototypeOf(doc), Document.prototype,
+                "Document should be the primary interface");
+}, "new Document(): interfaces")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.firstChild, null, "firstChild");
+  assert_equals(doc.lastChild, null, "lastChild");
+  assert_equals(doc.doctype, null, "doctype");
+  assert_equals(doc.documentElement, null, "documentElement");
+  assert_array_equals(doc.childNodes, [], "childNodes");
+}, "new Document(): children")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.location, null);
+  assert_equals(doc.URL, "about:blank");
+  assert_equals(doc.documentURI, "about:blank");
+  assert_equals(doc.compatMode, "CSS1Compat");
+  assert_equals(doc.characterSet, "UTF-8");
+  assert_equals(doc.contentType, "application/xml");
+  assert_equals(doc.createElement("DIV").localName, "DIV");
+  assert_equals(doc.createElement("a").constructor, Element);
+}, "new Document(): metadata")
+
+test(function() {
+  var doc = new Document();
+  assert_equals(doc.characterSet, "UTF-8", "characterSet");
+  assert_equals(doc.charset, "UTF-8", "charset");
+  assert_equals(doc.inputEncoding, "UTF-8", "inputEncoding");
+}, "new Document(): characterSet aliases")
+
+test(function() {
+  var doc = new Document();
+  var a = doc.createElementNS("http://www.w3.org/1999/xhtml", "a");
+  assert_equals(a.constructor, HTMLAnchorElement);
+  // In UTF-8: 0xC3 0xA4
+  a.href = "http://example.org/?\u00E4";
+  assert_equals(a.href, "http://example.org/?%C3%A4");
+}, "new Document(): URL parsing")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_bmp.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_bmp.html
new file mode 100644
index 0000000000..8286437416
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_bmp.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>BMP document.contentType === 'image/bmp'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "image/bmp");
+  }), false);
+  iframe.src = "../resources/t.bmp";
+  document.body.appendChild(iframe);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_css.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_css.html
new file mode 100644
index 0000000000..0eb35edd5e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_css.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>CSS document.contentType === 'text/css'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "text/css");
+  }), false);
+  iframe.src = "../resources/style.css";
+  document.body.appendChild(iframe);
+});
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_datauri_02.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_datauri_02.html
new file mode 100644
index 0000000000..c124cb3979
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_datauri_02.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>Data URI document.contentType === 'text/html' when data URI MIME type is set</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  self.onmessage = this.step_func_done(e => {
+    assert_equals(e.data, "text/html");
+  });
+  iframe.src = "data:text/html;charset=utf-8,<!DOCTYPE html><script>parent.postMessage(document.contentType,'*')<\/script>";
+  document.body.appendChild(iframe);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_gif.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_gif.html
new file mode 100644
index 0000000000..8dd66dae59
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_gif.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>GIF document.contentType === 'image/gif'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "image/gif");
+  }), false);
+  iframe.src = "../resources/t.gif";
+  document.body.appendChild(iframe);
+});
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_html.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_html.html
new file mode 100644
index 0000000000..2b2d7263eb
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_html.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>HTM document.contentType === 'text/html'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "text/html");
+  }), false);
+  iframe.src = "../resources/blob.htm";
+  document.body.appendChild(iframe);
+});
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_javascripturi.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_javascripturi.html
new file mode 100644
index 0000000000..956589615a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_javascripturi.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<title>Javascript URI document.contentType === 'text/html'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "text/html");
+    assert_equals(iframe.contentDocument.documentElement.textContent, "text/html");
+  }), false);
+  iframe.src = "javascript:document.contentType";
+  document.body.appendChild(iframe);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_jpg.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_jpg.html
new file mode 100644
index 0000000000..13f57ec8b9
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_jpg.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>JPG document.contentType === 'image/jpeg'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "image/jpeg");
+  }), false);
+  iframe.src = "../resources/t.jpg";
+  document.body.appendChild(iframe);
+});
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_mimeheader_01.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_mimeheader_01.html
new file mode 100644
index 0000000000..87885efba6
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_mimeheader_01.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>Custom document.contentType === 'text/xml' when explicitly set to this value</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "text/xml");
+  }), false);
+  iframe.src = "../support/contenttype_setter.py?type=text&subtype=xml";
+  document.body.appendChild(iframe);
+});
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_mimeheader_02.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_mimeheader_02.html
new file mode 100644
index 0000000000..33870147fc
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_mimeheader_02.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>Custom document.contentType === 'text/html' when explicitly set to this value and an attempt is made to override this value in an HTML meta header</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "text/html");
+  }), false);
+  iframe.src = "../support/contenttype_setter.py?type=text&subtype=html&mimeHead=text%2Fxml";
+  document.body.appendChild(iframe);
+});
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_png.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_png.html
new file mode 100644
index 0000000000..a214ad3e98
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_png.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>PNG document.contentType === 'image/png'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "image/png");
+  }), false);
+  iframe.src = "../resources/t.png";
+  document.body.appendChild(iframe);
+});
+</script>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_txt.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_txt.html
new file mode 100644
index 0000000000..f40f641fb0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_txt.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>TXT document.contentType === 'text/plain'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "text/plain");
+  }), false);
+  iframe.src = "../resources/blob.txt";
+  document.body.appendChild(iframe);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_xml.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_xml.html
new file mode 100644
index 0000000000..c382de8490
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/contenttype_xml.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<title>XML document.contentType === 'application/xml'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var iframe = document.createElement('iframe');
+  iframe.addEventListener('load', this.step_func_done(function() {
+    assert_equals(iframe.contentDocument.contentType, "application/xml");
+  }), false);
+  iframe.src = "../resources/blob.xml";
+  document.body.appendChild(iframe);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/createDocument.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/createDocument.html
new file mode 100644
index 0000000000..78a952de4a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/createDocument.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<title>document.implementation.createDocument: document.contentType === 'application/xhtml+xml'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+test(function() {
+  var doc = document.implementation.createDocument("http://www.w3.org/1999/xhtml", "html", null);
+  assert_equals(doc.contentType, "application/xhtml+xml");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/createHTMLDocument.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/createHTMLDocument.html
new file mode 100644
index 0000000000..185e3c8c92
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/createHTMLDocument.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<title>document.implementation.createHTMLDocument: document.contentType === 'text/html'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+test(function() {
+  var doc = document.implementation.createHTMLDocument("test");
+  assert_equals(doc.contentType, "text/html");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/xhr_responseType_document.html b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/xhr_responseType_document.html
new file mode 100644
index 0000000000..c2fb6c19fd
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/contentType/xhr_responseType_document.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>XHR - retrieve HTML document: document.contentType === 'application/xml'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+async_test(function() {
+  var xhr = new XMLHttpRequest();
+  xhr.open("GET", "../resources/blob.xml");
+  xhr.responseType = "document";
+  xhr.onload = this.step_func_done(function(response) {
+    assert_equals(xhr.readyState, 4);
+    assert_equals(xhr.status, 200);
+    assert_equals(xhr.responseXML.contentType, "application/xml");
+  });
+  xhr.send(null);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.htm b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.htm
new file mode 100644
index 0000000000..9d235ed07c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.htm
@@ -0,0 +1 @@
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.txt b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.txt
new file mode 100644
index 0000000000..9d235ed07c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.txt
@@ -0,0 +1 @@
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.xml b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.xml
new file mode 100644
index 0000000000..0922ed14b8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/blob.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<blob>aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</blob>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/lib.js b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/lib.js
new file mode 100644
index 0000000000..c41d336c08
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/lib.js
@@ -0,0 +1 @@
+var t;
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/style.css b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/style.css
new file mode 100644
index 0000000000..bb4ff575b7
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/style.css
@@ -0,0 +1,12 @@
+.unknown
+{
+  background-color:lightblue;
+}
+.pass
+{
+  background-color:lime;
+}
+.fail
+{
+  background-color:red;
+}
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.bmp b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.bmp
new file mode 100644
index 0000000000..5697c0aef4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.bmp
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.gif b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.gif
new file mode 100644
index 0000000000..91f269207a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.gif
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.jpg b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.jpg
new file mode 100644
index 0000000000..72b51899e4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.jpg
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.png b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.png
new file mode 100644
index 0000000000..447d9e3012
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/resources/t.png
diff --git a/testing/web-platform/tests/dom/nodes/Document-contentType/support/contenttype_setter.py b/testing/web-platform/tests/dom/nodes/Document-contentType/support/contenttype_setter.py
new file mode 100644
index 0000000000..c4b1f8df27
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-contentType/support/contenttype_setter.py
@@ -0,0 +1,20 @@
+def main(request, response):
+    type = request.GET.first(b"type", None)
+    subtype = request.GET.first(b"subtype", None)
+    if type and subtype:
+        response.headers[b"Content-Type"] = type + b"/" + subtype
+
+    removeContentType = request.GET.first(b"removeContentType", None)
+    if removeContentType:
+        try:
+            del response.headers[b"Content-Type"]
+        except KeyError:
+            pass
+
+    content = b'<head>'
+    mimeHead = request.GET.first(b"mime", None);
+    if mimeHead:
+        content += b'<meta http-equiv="Content-Type" content="%s; charset=utf-8"/>' % mimeHead
+    content += b"</head>"
+
+    return content
diff --git a/testing/web-platform/tests/dom/nodes/Document-createAttribute.html b/testing/web-platform/tests/dom/nodes/Document-createAttribute.html
new file mode 100644
index 0000000000..b3dc8b60b9
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createAttribute.html
@@ -0,0 +1,55 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Document.createAttribute</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=attributes.js></script>
+<script src=productions.js></script>
+<div id=log>
+<script>
+var xml_document;
+setup(function() {
+  xml_document = document.implementation.createDocument(null, null, null);
+});
+
+invalid_names.forEach(function(name) {
+  test(function() {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
+      document.createAttribute(name, "test");
+    });
+  }, "HTML document.createAttribute(" + format_value(name) + ") should throw");
+
+  test(function() {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
+      xml_document.createAttribute(name, "test");
+    });
+  }, "XML document.createAttribute(" + format_value(name) + ") should throw");
+});
+
+valid_names.forEach(name => {
+  test(() => {
+    let attr = document.createAttribute(name);
+    attr_is(attr, "", name.toLowerCase(), null, null, name.toLowerCase());
+  }, `HTML document.createAttribute(${format_value(name)})`);
+
+  test(() => {
+    let attr = xml_document.createAttribute(name);
+    attr_is(attr, "", name, null, null, name);
+  }, `XML document.createAttribute(${format_value(name)})`);
+});
+
+var tests = ["title", "TITLE", null, undefined];
+tests.forEach(function(name) {
+  test(function() {
+    var attribute = document.createAttribute(name);
+    attr_is(attribute, "", String(name).toLowerCase(), null, null, String(name).toLowerCase());
+    assert_equals(attribute.ownerElement, null);
+  }, "HTML document.createAttribute(" + format_value(name) + ")");
+
+  test(function() {
+    var attribute = xml_document.createAttribute(name);
+    attr_is(attribute, "", String(name), null, null, String(name));
+    assert_equals(attribute.ownerElement, null);
+  }, "XML document.createAttribute(" + format_value(name) + ")");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createCDATASection-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Document-createCDATASection-xhtml.xhtml
new file mode 100644
index 0000000000..b0a5a7f284
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createCDATASection-xhtml.xhtml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+  <meta charset="utf-8"/>
+  <title>document.createCDATASection</title>
+  <link rel="help" href="https://dom.spec.whatwg.org/#dom-document-createcdatasection"/>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="Document-createComment-createTextNode.js"></script>
+</head>
+
+<body>
+  <script>
+  "use strict";
+  test_create("createCDATASection", CDATASection, 4, "#cdata-section");
+
+  test(() => {
+    assert_throws_dom("InvalidCharacterError", () => document.createCDATASection(" ]" + "]>  "));
+  }, "Creating a CDATA section containing the string \"]" + "]>\" must throw");
+  </script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createCDATASection.html b/testing/web-platform/tests/dom/nodes/Document-createCDATASection.html
new file mode 100644
index 0000000000..72b3684c75
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createCDATASection.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>document.createCDATASection must throw in HTML documents</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-document-createcdatasection">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+setup({ single_test: true });
+
+assert_throws_dom("NotSupportedError", () => document.createCDATASection("foo"));
+
+done();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createComment-createTextNode.js b/testing/web-platform/tests/dom/nodes/Document-createComment-createTextNode.js
new file mode 100644
index 0000000000..62a38d380d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createComment-createTextNode.js
@@ -0,0 +1,22 @@
+function test_create(method, iface, nodeType, nodeName) {
+  ["\u000b", "a -- b", "a-", "-b", null, undefined].forEach(function(value) {
+    test(function() {
+      var c = document[method](value);
+      var expected = String(value);
+      assert_true(c instanceof iface);
+      assert_true(c instanceof CharacterData);
+      assert_true(c instanceof Node);
+      assert_equals(c.ownerDocument, document);
+      assert_equals(c.data, expected, "data");
+      assert_equals(c.nodeValue, expected, "nodeValue");
+      assert_equals(c.textContent, expected, "textContent");
+      assert_equals(c.length, expected.length);
+      assert_equals(c.nodeType, nodeType);
+      assert_equals(c.nodeName, nodeName);
+      assert_equals(c.hasChildNodes(), false);
+      assert_equals(c.childNodes.length, 0);
+      assert_equals(c.firstChild, null);
+      assert_equals(c.lastChild, null);
+    }, method + "(" + format_value(value) + ")");
+  });
+}
diff --git a/testing/web-platform/tests/dom/nodes/Document-createComment.html b/testing/web-platform/tests/dom/nodes/Document-createComment.html
new file mode 100644
index 0000000000..a175c3a2f8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createComment.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.createComment</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createcomment">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-ownerdocument">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-nodevalue">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-textcontent">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-length">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-nodetype">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-haschildnodes">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-childnodes">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-firstchild">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-lastchild">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-createComment-createTextNode.js"></script>
+<div id="log"></div>
+<script>
+test_create("createComment", Comment, 8, "#comment");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.html
new file mode 100644
index 0000000000..b80a99a784
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.html
@@ -0,0 +1 @@
+<math></math>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.svg
new file mode 100644
index 0000000000..b80a99a784
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.svg
@@ -0,0 +1 @@
+<math></math>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.xhtml
new file mode 100644
index 0000000000..b80a99a784
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.xhtml
@@ -0,0 +1 @@
+<math></math>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.xml
new file mode 100644
index 0000000000..b80a99a784
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_mathml.xml
@@ -0,0 +1 @@
+<math></math>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.html
new file mode 100644
index 0000000000..dc1ced5b6b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.html
@@ -0,0 +1 @@
+<svg></svg>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.svg
new file mode 100644
index 0000000000..dc1ced5b6b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.svg
@@ -0,0 +1 @@
+<svg></svg>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.xhtml
new file mode 100644
index 0000000000..dc1ced5b6b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.xhtml
@@ -0,0 +1 @@
+<svg></svg>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.xml
new file mode 100644
index 0000000000..dc1ced5b6b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_svg.xml
@@ -0,0 +1 @@
+<svg></svg>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.html
new file mode 100644
index 0000000000..6c70bcfe4d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.html
@@ -0,0 +1 @@
+<html></html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.svg
new file mode 100644
index 0000000000..6c70bcfe4d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.svg
@@ -0,0 +1 @@
+<html></html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.xhtml
new file mode 100644
index 0000000000..6c70bcfe4d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.xhtml
@@ -0,0 +1 @@
+<html></html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.xml
new file mode 100644
index 0000000000..6c70bcfe4d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/bare_xhtml.xml
@@ -0,0 +1 @@
+<html></html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.html
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.html
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.svg
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.svg
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.xhtml
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.xhtml
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.xml
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/empty.xml
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/generate.py b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/generate.py
new file mode 100755
index 0000000000..20c866bee8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/generate.py
@@ -0,0 +1,78 @@
+#!/usr/bin/python
+
+import os
+import sys
+
+THIS_NAME = u"generate.py"
+
+# Note: these lists must be kept in sync with the lists in
+# Document-createElement-namespace.html, and this script must be run whenever
+# the lists are updated.  (We could keep the lists in a shared JSON file, but
+# seems like too much effort.)
+FILES = (
+    (u"empty", u""),
+    (u"minimal_html", u"<!doctype html><title></title>"),
+
+    (u"xhtml", u'<html xmlns="http://www.w3.org/1999/xhtml"></html>'),
+    (u"svg", u'<svg xmlns="http://www.w3.org/2000/svg"></svg>'),
+    (u"mathml", u'<mathml xmlns="http://www.w3.org/1998/Math/MathML"></mathml>'),
+
+    (u"bare_xhtml", u"<html></html>"),
+    (u"bare_svg", u"<svg></svg>"),
+    (u"bare_mathml", u"<math></math>"),
+
+    (u"xhtml_ns_removed", u"""\
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS(null, "html");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
+"""),
+    (u"xhtml_ns_changed", u"""\
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS("http://www.w3.org/2000/svg", "abc");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
+"""),
+)
+
+EXTENSIONS = (
+    u"html",
+    u"xhtml",
+    u"xml",
+    u"svg",
+    # Was not able to get server MIME type working properly :(
+    #"mml",
+)
+
+def __main__():
+    if len(sys.argv) > 1:
+        print(u"No arguments expected, aborting")
+        return
+
+    if not os.access(THIS_NAME, os.F_OK):
+        print(u"Must be run from the directory of " + THIS_NAME + u", aborting")
+        return
+
+    for name in os.listdir(u"."):
+        if name == THIS_NAME:
+            continue
+        os.remove(name)
+
+    manifest = open(u"MANIFEST", u"w")
+
+    for name, contents in FILES:
+        for extension in EXTENSIONS:
+            f = open(name + u"." + extension, u"w")
+            f.write(contents)
+            f.close()
+            manifest.write(u"support " + name + u"." + extension + u"\n")
+
+    manifest.close()
+
+__main__()
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.html
new file mode 100644
index 0000000000..0bec8e99e4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.html
@@ -0,0 +1 @@
+<mathml xmlns="http://www.w3.org/1998/Math/MathML"></mathml>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.svg
new file mode 100644
index 0000000000..0bec8e99e4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.svg
@@ -0,0 +1 @@
+<mathml xmlns="http://www.w3.org/1998/Math/MathML"></mathml>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.xhtml
new file mode 100644
index 0000000000..0bec8e99e4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.xhtml
@@ -0,0 +1 @@
+<mathml xmlns="http://www.w3.org/1998/Math/MathML"></mathml>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.xml
new file mode 100644
index 0000000000..0bec8e99e4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/mathml.xml
@@ -0,0 +1 @@
+<mathml xmlns="http://www.w3.org/1998/Math/MathML"></mathml>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.html
new file mode 100644
index 0000000000..a33d9859af
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.html
@@ -0,0 +1 @@
+<!doctype html><title></title>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.svg
new file mode 100644
index 0000000000..a33d9859af
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.svg
@@ -0,0 +1 @@
+<!doctype html><title></title>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.xhtml
new file mode 100644
index 0000000000..a33d9859af
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.xhtml
@@ -0,0 +1 @@
+<!doctype html><title></title>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.xml
new file mode 100644
index 0000000000..a33d9859af
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/minimal_html.xml
@@ -0,0 +1 @@
+<!doctype html><title></title>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.html
new file mode 100644
index 0000000000..64def4af7f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.html
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg"></svg>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.svg
new file mode 100644
index 0000000000..64def4af7f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg"></svg>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.xhtml
new file mode 100644
index 0000000000..64def4af7f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.xhtml
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg"></svg>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.xml
new file mode 100644
index 0000000000..64def4af7f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/svg.xml
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg"></svg>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.html
new file mode 100644
index 0000000000..1cba998241
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.html
@@ -0,0 +1 @@
+<html xmlns="http://www.w3.org/1999/xhtml"></html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.svg
new file mode 100644
index 0000000000..1cba998241
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.svg
@@ -0,0 +1 @@
+<html xmlns="http://www.w3.org/1999/xhtml"></html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.xhtml
new file mode 100644
index 0000000000..1cba998241
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.xhtml
@@ -0,0 +1 @@
+<html xmlns="http://www.w3.org/1999/xhtml"></html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.xml
new file mode 100644
index 0000000000..1cba998241
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml.xml
@@ -0,0 +1 @@
+<html xmlns="http://www.w3.org/1999/xhtml"></html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.html
new file mode 100644
index 0000000000..b228c7f740
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.html
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS("http://www.w3.org/2000/svg", "abc");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.svg
new file mode 100644
index 0000000000..b228c7f740
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.svg
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS("http://www.w3.org/2000/svg", "abc");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.xhtml
new file mode 100644
index 0000000000..b228c7f740
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.xhtml
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS("http://www.w3.org/2000/svg", "abc");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.xml
new file mode 100644
index 0000000000..b228c7f740
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_changed.xml
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS("http://www.w3.org/2000/svg", "abc");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.html
new file mode 100644
index 0000000000..dba395fed0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.html
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS(null, "html");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.svg b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.svg
new file mode 100644
index 0000000000..dba395fed0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.svg
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS(null, "html");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.xhtml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.xhtml
new file mode 100644
index 0000000000..dba395fed0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.xhtml
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS(null, "html");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.xml b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.xml
new file mode 100644
index 0000000000..dba395fed0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace-tests/xhtml_ns_removed.xml
@@ -0,0 +1,7 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head><script>
+    var newRoot = document.createElementNS(null, "html");
+    document.removeChild(document.documentElement);
+    document.appendChild(newRoot);
+  </script></head>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement-namespace.html b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace.html
new file mode 100644
index 0000000000..cea61f1aec
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement-namespace.html
@@ -0,0 +1,117 @@
+<!doctype html>
+<title>document.createElement() namespace tests</title>
+<link rel=author title="Aryeh Gregor" href=ayg@aryeh.name>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+"use strict";
+/**
+ * This tests the namespace of elements created by the Document interface's
+ * createElement() method.  See bug:
+ * https://www.w3.org/Bugs/Public/show_bug.cgi?id=19431
+ */
+
+/**
+ * Test that an element created using the Document object doc has the namespace
+ * that would be expected for the given contentType.
+ */
+function testDoc(doc, contentType) {
+  if (doc.contentType !== undefined) {
+    // Sanity check
+    assert_equals(doc.contentType, contentType,
+                  "Wrong MIME type returned from doc.contentType");
+  }
+
+  var expectedNamespace = contentType == "text/html" ||
+                          contentType == "application/xhtml+xml"
+                          ? "http://www.w3.org/1999/xhtml" : null;
+
+  assert_equals(doc.createElement("x").namespaceURI, expectedNamespace);
+}
+
+// First test various objects we create in JS
+test(function() {
+  testDoc(document, "text/html")
+}, "Created element's namespace in current document");
+test(function() {
+  testDoc(document.implementation.createHTMLDocument(""), "text/html");
+}, "Created element's namespace in created HTML document");
+test(function() {
+  testDoc(document.implementation.createDocument(null, "", null),
+          "application/xml");
+}, "Created element's namespace in created XML document");
+test(function() {
+  testDoc(document.implementation.createDocument("http://www.w3.org/1999/xhtml", "html", null),
+          "application/xhtml+xml");
+}, "Created element's namespace in created XHTML document");
+test(function() {
+  testDoc(document.implementation.createDocument("http://www.w3.org/2000/svg", "svg", null),
+          "image/svg+xml");
+}, "Created element's namespace in created SVG document");
+test(function() {
+  testDoc(document.implementation.createDocument("http://www.w3.org/1998/Math/MathML", "math", null),
+          "application/xml");
+}, "Created element's namespace in created MathML document");
+
+// Second also test document created by DOMParser
+test(function() {
+  testDoc(new DOMParser().parseFromString("", "text/html"), "text/html");
+}, "Created element's namespace in created HTML document by DOMParser ('text/html')");
+test(function() {
+  testDoc(new DOMParser().parseFromString("<root/>", "text/xml"), "text/xml");
+}, "Created element's namespace in created XML document by DOMParser ('text/xml')");
+test(function() {
+  testDoc(new DOMParser().parseFromString("<root/>", "application/xml"), "application/xml");
+}, "Created element's namespace in created XML document by DOMParser ('application/xml')");
+test(function() {
+  testDoc(new DOMParser().parseFromString("<html/>", "application/xhtml+xml"), "application/xhtml+xml");
+}, "Created element's namespace in created XHTML document by DOMParser ('application/xhtml+xml')");
+test(function() {
+  testDoc(new DOMParser().parseFromString("<math/>", "image/svg+xml"), "image/svg+xml");
+}, "Created element's namespace in created SVG document by DOMParser ('image/svg+xml')");
+
+// Now for various externally-loaded files.  Note: these lists must be kept
+// synced with the lists in generate.py in the subdirectory, and that script
+// must be run whenever the lists are updated.  (We could keep the lists in a
+// shared JSON file, but it seems like too much effort.)
+var testExtensions = {
+  html: "text/html",
+  xhtml: "application/xhtml+xml",
+  xml: "application/xml",
+  svg: "image/svg+xml",
+  // Was not able to get server MIME type working properly :(
+  //mml: "application/mathml+xml",
+};
+
+var tests = [
+  "empty",
+  "minimal_html",
+
+  "xhtml",
+  "svg",
+  "mathml",
+
+  "bare_xhtml",
+  "bare_svg",
+  "bare_mathml",
+
+  "xhtml_ns_removed",
+  "xhtml_ns_changed",
+];
+
+tests.forEach(function(testName) {
+  Object.keys(testExtensions).forEach(function(ext) {
+    async_test(function(t) {
+      var iframe = document.createElement("iframe");
+      iframe.src = "Document-createElement-namespace-tests/" +
+                  testName + "." + ext;
+      iframe.onload = t.step_func_done(function() {
+        testDoc(iframe.contentDocument, testExtensions[ext]);
+        document.body.removeChild(iframe);
+      });
+      document.body.appendChild(iframe);
+    }, "Created element's namespace in " + testName + "." + ext);
+  });
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement.html b/testing/web-platform/tests/dom/nodes/Document-createElement.html
new file mode 100644
index 0000000000..93435ac82d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement.html
@@ -0,0 +1,158 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.createElement</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createelement">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-localname">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-tagname">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-prefix">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-namespaceuri">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<iframe src="/common/dummy.xml"></iframe>
+<iframe src="/common/dummy.xhtml"></iframe>
+<script>
+function toASCIIUppercase(str) {
+  var diff = "a".charCodeAt(0) - "A".charCodeAt(0);
+  var res = "";
+  for (var i = 0; i < str.length; ++i) {
+    if ("a" <= str[i] && str[i] <= "z") {
+      res += String.fromCharCode(str.charCodeAt(i) - diff);
+    } else {
+      res += str[i];
+    }
+  }
+  return res;
+}
+function toASCIILowercase(str) {
+  var diff = "a".charCodeAt(0) - "A".charCodeAt(0);
+  var res = "";
+  for (var i = 0; i < str.length; ++i) {
+    if ("A" <= str[i] && str[i] <= "Z") {
+      res += String.fromCharCode(str.charCodeAt(i) + diff);
+    } else {
+      res += str[i];
+    }
+  }
+  return res;
+}
+var HTMLNS = "http://www.w3.org/1999/xhtml",
+    valid = [
+      undefined,
+      null,
+      "foo",
+      "f1oo",
+      "foo1",
+      "f\u0BC6",
+      "foo\u0BC6",
+      ":",
+      ":foo",
+      "f:oo",
+      "foo:",
+      "f:o:o",
+      "f::oo",
+      "f::oo:",
+      "foo:0",
+      "foo:_",
+      // combining char after :, invalid QName but valid Name
+      "foo:\u0BC6",
+      "foo:foo\u0BC6",
+      "foo\u0BC6:foo",
+      "xml",
+      "xmlns",
+      "xmlfoo",
+      "xml:foo",
+      "xmlns:foo",
+      "xmlfoo:bar",
+      "svg",
+      "math",
+      "FOO",
+      // Test that non-ASCII chars don't get uppercased/lowercased
+      "mar\u212a",
+      "\u0130nput",
+      "\u0131nput",
+    ],
+    invalid = [
+      "",
+      "1foo",
+      "1:foo",
+      "fo o",
+      "\u0300foo",
+      "}foo",
+      "f}oo",
+      "foo}",
+      "\ufffffoo",
+      "f\uffffoo",
+      "foo\uffff",
+      "<foo",
+      "foo>",
+      "<foo>",
+      "f<oo",
+      "-foo",
+      ".foo",
+      "\u0300",
+    ]
+
+var xmlIframe = document.querySelector('[src="/common/dummy.xml"]');
+var xhtmlIframe = document.querySelector('[src="/common/dummy.xhtml"]');
+
+function getWin(desc) {
+  if (desc == "HTML document") {
+    return window;
+  }
+  if (desc == "XML document") {
+    assert_equals(xmlIframe.contentDocument.documentElement.textContent,
+                  "Dummy XML document", "XML document didn't load");
+    return xmlIframe.contentWindow;
+  }
+  if (desc == "XHTML document") {
+    assert_equals(xhtmlIframe.contentDocument.documentElement.textContent,
+                  "Dummy XHTML document", "XHTML document didn't load");
+    return xhtmlIframe.contentWindow;
+  }
+}
+
+
+valid.forEach(function(t) {
+  ["HTML document", "XML document", "XHTML document"].forEach(function(desc) {
+    async_test(function(testObj) {
+      window.addEventListener("load", function() {
+        testObj.step(function() {
+          var win = getWin(desc);
+          var doc = win.document;
+          var elt = doc.createElement(t)
+          assert_true(elt instanceof win.Element, "instanceof Element")
+          assert_true(elt instanceof win.Node, "instanceof Node")
+          assert_equals(elt.localName,
+                        desc == "HTML document" ? toASCIILowercase(String(t))
+                                                : String(t),
+                        "localName")
+          assert_equals(elt.tagName,
+                        desc == "HTML document" ? toASCIIUppercase(String(t))
+                                                : String(t),
+                        "tagName")
+          assert_equals(elt.prefix, null, "prefix")
+          assert_equals(elt.namespaceURI,
+                        desc == "XML document" ? null : HTMLNS, "namespaceURI")
+        });
+        testObj.done();
+      });
+    }, "createElement(" + format_value(t) + ") in " + desc);
+  });
+});
+invalid.forEach(function(arg) {
+  ["HTML document", "XML document", "XHTML document"].forEach(function(desc) {
+    async_test(function(testObj) {
+      window.addEventListener("load", function() {
+        testObj.step(function() {
+          let win = getWin(desc);
+          let doc = win.document;
+          assert_throws_dom("InvalidCharacterError", win.DOMException,
+                            function() { doc.createElement(arg) })
+        });
+        testObj.done();
+      });
+    }, "createElement(" + format_value(arg) + ") in " + desc);
+  });
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElementNS.html b/testing/web-platform/tests/dom/nodes/Document-createElementNS.html
new file mode 100644
index 0000000000..5ad81043de
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElementNS.html
@@ -0,0 +1,224 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.createElementNS</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createelementns">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-createElementNS.js"></script>
+<div id="log"></div>
+<iframe src="/common/dummy.xml"></iframe>
+<iframe src="/common/dummy.xhtml"></iframe>
+<script>
+var tests = createElementNS_tests.concat([
+  /* Arrays with three elements:
+   *   the namespace argument
+   *   the qualifiedName argument
+   *   the expected exception, or null if none
+   */
+  ["", "", "INVALID_CHARACTER_ERR"],
+  [null, "", "INVALID_CHARACTER_ERR"],
+  [undefined, "", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", null, null],
+  ["http://example.com/", "", "INVALID_CHARACTER_ERR"],
+  ["/", null, null],
+  ["/", "", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/XML/1998/namespace", null, null],
+  ["http://www.w3.org/XML/1998/namespace", "", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/2000/xmlns/", null, "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "", "INVALID_CHARACTER_ERR"],
+  ["foo:", null, null],
+  ["foo:", "", "INVALID_CHARACTER_ERR"],
+])
+
+var xmlIframe = document.querySelector('[src="/common/dummy.xml"]');
+var xhtmlIframe = document.querySelector('[src="/common/dummy.xhtml"]');
+
+function runTest(t, i, desc) {
+  async_test(function(testObj) {
+    window.addEventListener("load", function() {
+      testObj.step(function() {
+        var doc;
+        if (desc == "HTML document") {
+          doc = document;
+        } else if (desc == "XML document") {
+          doc = xmlIframe.contentDocument;
+          // Make sure we're testing the right document
+          assert_equals(doc.documentElement.textContent, "Dummy XML document");
+        } else if (desc == "XHTML document") {
+          doc = xhtmlIframe.contentDocument;
+          assert_equals(doc.documentElement.textContent, "Dummy XHTML document");
+        }
+        var namespace = t[0], qualifiedName = t[1], expected = t[2]
+        if (expected != null) {
+          assert_throws_dom(expected, doc.defaultView.DOMException, function() {doc.createElementNS(namespace, qualifiedName) });
+        } else {
+          var element = doc.createElementNS(namespace, qualifiedName)
+          assert_not_equals(element, null)
+          assert_equals(element.nodeType, Node.ELEMENT_NODE)
+          assert_equals(element.nodeType, element.ELEMENT_NODE)
+          assert_equals(element.nodeValue, null)
+          assert_equals(element.ownerDocument, doc)
+          var qualified = String(qualifiedName), names = []
+          if (qualified.indexOf(":") >= 0) {
+            names = qualified.split(":", 2)
+          } else {
+            names = [null, qualified]
+          }
+          assert_equals(element.prefix, names[0])
+          assert_equals(element.localName, names[1])
+          assert_equals(element.tagName, qualified)
+          assert_equals(element.nodeName, qualified)
+          assert_equals(element.namespaceURI,
+                        namespace === undefined || namespace === "" ? null
+                                                                    : namespace)
+        }
+      });
+      testObj.done();
+    });
+  }, "createElementNS test in " + desc + ": " + t.map(format_value))
+}
+
+tests.forEach(function(t, i) {
+  runTest(t, i, "HTML document")
+  runTest(t, i, "XML document")
+  runTest(t, i, "XHTML document")
+})
+
+
+test(function() {
+  var HTMLNS = "http://www.w3.org/1999/xhtml";
+  var element = document.createElementNS(HTMLNS, "span");
+  assert_equals(element.namespaceURI, HTMLNS);
+  assert_equals(element.prefix, null);
+  assert_equals(element.localName, "span");
+  assert_equals(element.tagName, "SPAN");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_true(element instanceof HTMLElement, "Should be an HTMLElement");
+  assert_true(element instanceof HTMLSpanElement, "Should be an HTMLSpanElement");
+}, "Lower-case HTML element without a prefix");
+
+test(function() {
+  var HTMLNS = "http://www.w3.org/1999/xhtml";
+  var element = document.createElementNS(HTMLNS, "html:span");
+  assert_equals(element.namespaceURI, HTMLNS);
+  assert_equals(element.prefix, "html");
+  assert_equals(element.localName, "span");
+  assert_equals(element.tagName, "HTML:SPAN");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_true(element instanceof HTMLElement, "Should be an HTMLElement");
+  assert_true(element instanceof HTMLSpanElement, "Should be an HTMLSpanElement");
+}, "Lower-case HTML element with a prefix");
+
+test(function() {
+  var element = document.createElementNS("test", "span");
+  assert_equals(element.namespaceURI, "test");
+  assert_equals(element.prefix, null);
+  assert_equals(element.localName, "span");
+  assert_equals(element.tagName, "span");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_false(element instanceof HTMLElement, "Should not be an HTMLElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "Lower-case non-HTML element without a prefix");
+
+test(function() {
+  var element = document.createElementNS("test", "html:span");
+  assert_equals(element.namespaceURI, "test");
+  assert_equals(element.prefix, "html");
+  assert_equals(element.localName, "span");
+  assert_equals(element.tagName, "html:span");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_false(element instanceof HTMLElement, "Should not be an HTMLElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "Lower-case non-HTML element with a prefix");
+
+test(function() {
+  var HTMLNS = "http://www.w3.org/1999/xhtml";
+  var element = document.createElementNS(HTMLNS, "SPAN");
+  assert_equals(element.namespaceURI, HTMLNS);
+  assert_equals(element.prefix, null);
+  assert_equals(element.localName, "SPAN");
+  assert_equals(element.tagName, "SPAN");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_true(element instanceof HTMLElement, "Should be an HTMLElement");
+  assert_true(element instanceof HTMLUnknownElement, "Should be an HTMLUnknownElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "Upper-case HTML element without a prefix");
+
+test(function() {
+  var HTMLNS = "http://www.w3.org/1999/xhtml";
+  var element = document.createElementNS(HTMLNS, "html:SPAN");
+  assert_equals(element.namespaceURI, HTMLNS);
+  assert_equals(element.prefix, "html");
+  assert_equals(element.localName, "SPAN");
+  assert_equals(element.tagName, "HTML:SPAN");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_true(element instanceof HTMLElement, "Should be an HTMLElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "Upper-case HTML element with a prefix");
+
+test(function() {
+  var element = document.createElementNS("test", "SPAN");
+  assert_equals(element.namespaceURI, "test");
+  assert_equals(element.prefix, null);
+  assert_equals(element.localName, "SPAN");
+  assert_equals(element.tagName, "SPAN");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_false(element instanceof HTMLElement, "Should not be an HTMLElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "Upper-case non-HTML element without a prefix");
+
+test(function() {
+  var element = document.createElementNS("test", "html:SPAN");
+  assert_equals(element.namespaceURI, "test");
+  assert_equals(element.prefix, "html");
+  assert_equals(element.localName, "SPAN");
+  assert_equals(element.tagName, "html:SPAN");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_false(element instanceof HTMLElement, "Should not be an HTMLElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "Upper-case non-HTML element with a prefix");
+
+test(function() {
+  var element = document.createElementNS(null, "span");
+  assert_equals(element.namespaceURI, null);
+  assert_equals(element.prefix, null);
+  assert_equals(element.localName, "span");
+  assert_equals(element.tagName, "span");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_false(element instanceof HTMLElement, "Should not be an HTMLElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "null namespace");
+
+test(function() {
+  var element = document.createElementNS(undefined, "span");
+  assert_equals(element.namespaceURI, null);
+  assert_equals(element.prefix, null);
+  assert_equals(element.localName, "span");
+  assert_equals(element.tagName, "span");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_false(element instanceof HTMLElement, "Should not be an HTMLElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "undefined namespace");
+
+test(function() {
+  var element = document.createElementNS("", "span");
+  assert_equals(element.namespaceURI, null);
+  assert_equals(element.prefix, null);
+  assert_equals(element.localName, "span");
+  assert_equals(element.tagName, "span");
+  assert_true(element instanceof Node, "Should be a Node");
+  assert_true(element instanceof Element, "Should be an Element");
+  assert_false(element instanceof HTMLElement, "Should not be an HTMLElement");
+  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
+}, "empty string namespace");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElementNS.js b/testing/web-platform/tests/dom/nodes/Document-createElementNS.js
new file mode 100644
index 0000000000..2cf2948563
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createElementNS.js
@@ -0,0 +1,189 @@
+var createElementNS_tests = [
+  /* Arrays with three elements:
+   *   the namespace argument
+   *   the qualifiedName argument
+   *   the expected exception, or null if none
+   */
+  [null, null, null],
+  [null, undefined, null],
+  [null, "foo", null],
+  [null, "1foo", "INVALID_CHARACTER_ERR"],
+  [null, "f1oo", null],
+  [null, "foo1", null],
+  [null, "\u0BC6foo", null],
+  [null, "\u037Efoo", "INVALID_CHARACTER_ERR"],
+  [null, "}foo", "INVALID_CHARACTER_ERR"],
+  [null, "f}oo", "INVALID_CHARACTER_ERR"],
+  [null, "foo}", "INVALID_CHARACTER_ERR"],
+  [null, "\uFFFFfoo", "INVALID_CHARACTER_ERR"],
+  [null, "f\uFFFFoo", "INVALID_CHARACTER_ERR"],
+  [null, "foo\uFFFF", "INVALID_CHARACTER_ERR"],
+  [null, "<foo", "INVALID_CHARACTER_ERR"],
+  [null, "foo>", "INVALID_CHARACTER_ERR"],
+  [null, "<foo>", "INVALID_CHARACTER_ERR"],
+  [null, "f<oo", "INVALID_CHARACTER_ERR"],
+  [null, "^^", "INVALID_CHARACTER_ERR"],
+  [null, "fo o", "INVALID_CHARACTER_ERR"],
+  [null, "-foo", "INVALID_CHARACTER_ERR"],
+  [null, ".foo", "INVALID_CHARACTER_ERR"],
+  [null, ":foo", "INVALID_CHARACTER_ERR"],
+  [null, "f:oo", "NAMESPACE_ERR"],
+  [null, "foo:", "INVALID_CHARACTER_ERR"],
+  [null, "f:o:o", "INVALID_CHARACTER_ERR"],
+  [null, ":", "INVALID_CHARACTER_ERR"],
+  [null, "xml", null],
+  [null, "xmlns", "NAMESPACE_ERR"],
+  [null, "xmlfoo", null],
+  [null, "xml:foo", "NAMESPACE_ERR"],
+  [null, "xmlns:foo", "NAMESPACE_ERR"],
+  [null, "xmlfoo:bar", "NAMESPACE_ERR"],
+  [null, "null:xml", "NAMESPACE_ERR"],
+  ["", null, null],
+  ["", ":foo", "INVALID_CHARACTER_ERR"],
+  ["", "f:oo", "NAMESPACE_ERR"],
+  ["", "foo:", "INVALID_CHARACTER_ERR"],
+  [undefined, null, null],
+  [undefined, undefined, null],
+  [undefined, "foo", null],
+  [undefined, "1foo", "INVALID_CHARACTER_ERR"],
+  [undefined, "f1oo", null],
+  [undefined, "foo1", null],
+  [undefined, ":foo", "INVALID_CHARACTER_ERR"],
+  [undefined, "f:oo", "NAMESPACE_ERR"],
+  [undefined, "foo:", "INVALID_CHARACTER_ERR"],
+  [undefined, "f::oo", "INVALID_CHARACTER_ERR"],
+  [undefined, "xml", null],
+  [undefined, "xmlns", "NAMESPACE_ERR"],
+  [undefined, "xmlfoo", null],
+  [undefined, "xml:foo", "NAMESPACE_ERR"],
+  [undefined, "xmlns:foo", "NAMESPACE_ERR"],
+  [undefined, "xmlfoo:bar", "NAMESPACE_ERR"],
+  ["http://example.com/", "foo", null],
+  ["http://example.com/", "1foo", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "<foo>", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "fo<o", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "-foo", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", ".foo", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "f1oo", null],
+  ["http://example.com/", "foo1", null],
+  ["http://example.com/", ":foo", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "f:oo", null],
+  ["http://example.com/", "f:o:o", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "foo:", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "f::oo", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "a:0", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "0:a", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "a:_", null],
+  ["http://example.com/", "a:\u0BC6", null],
+  ["http://example.com/", "a:\u037E", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "a:\u0300", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "\u0BC6:a", null],
+  ["http://example.com/", "\u0300:a", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "\u037E:a", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "a:a\u0BC6", null],
+  ["http://example.com/", "a\u0BC6:a", null],
+  ["http://example.com/", "xml:test", "NAMESPACE_ERR"],
+  ["http://example.com/", "xmlns:test", "NAMESPACE_ERR"],
+  ["http://example.com/", "test:xmlns", null],
+  ["http://example.com/", "xmlns", "NAMESPACE_ERR"],
+  ["http://example.com/", "_:_", null],
+  ["http://example.com/", "_:h0", null],
+  ["http://example.com/", "_:test", null],
+  ["http://example.com/", "l_:_", null],
+  ["http://example.com/", "ns:_0", null],
+  ["http://example.com/", "ns:a0", null],
+  ["http://example.com/", "ns0:test", null],
+  ["http://example.com/", "a.b:c", null],
+  ["http://example.com/", "a-b:c", null],
+  ["http://example.com/", "xml", null],
+  ["http://example.com/", "XMLNS", null],
+  ["http://example.com/", "xmlfoo", null],
+  ["http://example.com/", "xml:foo", "NAMESPACE_ERR"],
+  ["http://example.com/", "XML:foo", null],
+  ["http://example.com/", "xmlns:foo", "NAMESPACE_ERR"],
+  ["http://example.com/", "XMLNS:foo", null],
+  ["http://example.com/", "xmlfoo:bar", null],
+  ["http://example.com/", "prefix::local", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:{", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:}", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:~", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:'", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:!", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:@", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:#", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:$", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:%", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:^", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:&", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:*", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:(", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:)", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:+", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:=", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:[", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:]", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:\\", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:/", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:;", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:`", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:<", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:>", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:,", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:a ", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "namespaceURI:\"", "INVALID_CHARACTER_ERR"],
+  ["/", "foo", null],
+  ["/", "1foo", "INVALID_CHARACTER_ERR"],
+  ["/", "f1oo", null],
+  ["/", "foo1", null],
+  ["/", ":foo", "INVALID_CHARACTER_ERR"],
+  ["/", "f:oo", null],
+  ["/", "foo:", "INVALID_CHARACTER_ERR"],
+  ["/", "xml", null],
+  ["/", "xmlns", "NAMESPACE_ERR"],
+  ["/", "xmlfoo", null],
+  ["/", "xml:foo", "NAMESPACE_ERR"],
+  ["/", "xmlns:foo", "NAMESPACE_ERR"],
+  ["/", "xmlfoo:bar", null],
+  ["http://www.w3.org/XML/1998/namespace", "foo", null],
+  ["http://www.w3.org/XML/1998/namespace", "1foo", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/XML/1998/namespace", "f1oo", null],
+  ["http://www.w3.org/XML/1998/namespace", "foo1", null],
+  ["http://www.w3.org/XML/1998/namespace", ":foo", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/XML/1998/namespace", "f:oo", null],
+  ["http://www.w3.org/XML/1998/namespace", "foo:", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/XML/1998/namespace", "xml", null],
+  ["http://www.w3.org/XML/1998/namespace", "xmlns", "NAMESPACE_ERR"],
+  ["http://www.w3.org/XML/1998/namespace", "xmlfoo", null],
+  ["http://www.w3.org/XML/1998/namespace", "xml:foo", null],
+  ["http://www.w3.org/XML/1998/namespace", "xmlns:foo", "NAMESPACE_ERR"],
+  ["http://www.w3.org/XML/1998/namespace", "xmlfoo:bar", null],
+  ["http://www.w3.org/XML/1998/namespaces", "xml:foo", "NAMESPACE_ERR"],
+  ["http://www.w3.org/xml/1998/namespace", "xml:foo", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "foo", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "1foo", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "f1oo", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "foo1", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", ":foo", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "f:oo", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "foo:", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "xml", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "xmlns", null],
+  ["http://www.w3.org/2000/xmlns/", "xmlfoo", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "xml:foo", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "xmlns:foo", null],
+  ["http://www.w3.org/2000/xmlns/", "xmlfoo:bar", "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "foo:xmlns", "NAMESPACE_ERR"],
+  ["foo:", "foo", null],
+  ["foo:", "1foo", "INVALID_CHARACTER_ERR"],
+  ["foo:", "f1oo", null],
+  ["foo:", "foo1", null],
+  ["foo:", ":foo", "INVALID_CHARACTER_ERR"],
+  ["foo:", "f:oo", null],
+  ["foo:", "foo:", "INVALID_CHARACTER_ERR"],
+  ["foo:", "xml", null],
+  ["foo:", "xmlns", "NAMESPACE_ERR"],
+  ["foo:", "xmlfoo", null],
+  ["foo:", "xml:foo", "NAMESPACE_ERR"],
+  ["foo:", "xmlns:foo", "NAMESPACE_ERR"],
+  ["foo:", "xmlfoo:bar", null],
+]
diff --git a/testing/web-platform/tests/dom/nodes/Document-createEvent-touchevent.window.js b/testing/web-platform/tests/dom/nodes/Document-createEvent-touchevent.window.js
new file mode 100644
index 0000000000..6523ac5a02
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createEvent-touchevent.window.js
@@ -0,0 +1,12 @@
+for (const variant of ['TouchEvent', 'touchevent', 'TOUCHEVENT']) {
+  test(() => {
+    if (!('ontouchstart' in document)) {
+      assert_throws_dom("NOT_SUPPORTED_ERR", () => {
+        document.createEvent(variant);
+      });
+    } else {
+      document.createEvent(variant);
+      // The interface and other details of the event is tested in Document-createEvent.https.html
+    }
+  }, `document.createEvent('${variant}') should throw if 'expose legacy touch event APIs' is false`);
+}
diff --git a/testing/web-platform/tests/dom/nodes/Document-createEvent.https.html b/testing/web-platform/tests/dom/nodes/Document-createEvent.https.html
new file mode 100644
index 0000000000..4781d54e8e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createEvent.https.html
@@ -0,0 +1,170 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.createEvent</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createevent">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-createEvent.js"></script>
+<div id="log"></div>
+<script>
+function supportsTouchEvents(isTouchEvent) {
+  if (isTouchEvent) {
+    assert_implements_optional('ontouchstart' in document, "'expose legacy touch event APIs'");
+  }
+}
+function testAlias(arg, iface, isTouchEvent) {
+  var ev;
+  test(function() {
+    supportsTouchEvents(isTouchEvent);
+    ev = document.createEvent(arg);
+    assert_equals(Object.getPrototypeOf(ev), window[iface].prototype);
+  }, arg + " should be an alias for " + iface + ".");
+  test(function() {
+    supportsTouchEvents(isTouchEvent);
+    assert_equals(ev.type, "",
+                  "type should be initialized to the empty string");
+    assert_equals(ev.target, null,
+                  "target should be initialized to null");
+    assert_equals(ev.currentTarget, null,
+                  "currentTarget should be initialized to null");
+    assert_equals(ev.eventPhase, 0,
+                  "eventPhase should be initialized to NONE (0)");
+    assert_equals(ev.bubbles, false,
+                  "bubbles should be initialized to false");
+    assert_equals(ev.cancelable, false,
+                  "cancelable should be initialized to false");
+    assert_equals(ev.defaultPrevented, false,
+                  "defaultPrevented should be initialized to false");
+    assert_equals(ev.isTrusted, false,
+                  "isTrusted should be initialized to false");
+  }, "createEvent('" + arg + "') should be initialized correctly.");
+}
+aliases.TouchEvent = 'TouchEvent';
+for (var alias in aliases) {
+  var isTouchEvent = alias === 'TouchEvent';
+  var iface = aliases[alias];
+  testAlias(alias, iface, isTouchEvent);
+  testAlias(alias.toLowerCase(), iface, isTouchEvent);
+  testAlias(alias.toUpperCase(), iface, isTouchEvent);
+
+  if (alias[alias.length - 1] != "s") {
+    var plural = alias + "s";
+    if (!(plural in aliases)) {
+      test(function () {
+        assert_throws_dom("NOT_SUPPORTED_ERR", function () {
+          var evt = document.createEvent(plural);
+        });
+      }, 'Should throw NOT_SUPPORTED_ERR for pluralized legacy event interface "' + plural + '"');
+    }
+  }
+}
+
+test(function() {
+  assert_throws_dom("NOT_SUPPORTED_ERR", function() {
+    var evt = document.createEvent("foo");
+  });
+  assert_throws_dom("NOT_SUPPORTED_ERR", function() {
+    // 'LATIN CAPITAL LETTER I WITH DOT ABOVE' (U+0130)
+    var evt = document.createEvent("U\u0130Event");
+  });
+  assert_throws_dom("NOT_SUPPORTED_ERR", function() {
+    // 'LATIN SMALL LETTER DOTLESS I' (U+0131)
+    var evt = document.createEvent("U\u0131Event");
+  });
+}, "Should throw NOT_SUPPORTED_ERR for unrecognized arguments");
+
+/*
+ * The following are event interfaces which do actually exist, but must still
+ * throw since they're absent from the table in the spec for
+ * document.createEvent().  This list is not exhaustive, but includes all
+ * interfaces that it is known some UA does or did not throw for.
+ */
+var someNonCreateableEvents = [
+  "AnimationEvent",
+  "AnimationPlaybackEvent",
+  "AnimationPlayerEvent",
+  "ApplicationCacheErrorEvent",
+  "AudioProcessingEvent",
+  "AutocompleteErrorEvent",
+  "BeforeInstallPromptEvent",
+  "BlobEvent",
+  "ClipboardEvent",
+  "CloseEvent",
+  "CommandEvent",
+  "DataContainerEvent",
+  "ErrorEvent",
+  "ExtendableEvent",
+  "ExtendableMessageEvent",
+  "FetchEvent",
+  "FontFaceSetLoadEvent",
+  "GamepadEvent",
+  "GeofencingEvent",
+  "IDBVersionChangeEvent",
+  "InstallEvent",
+  "KeyEvent",
+  "MIDIConnectionEvent",
+  "MIDIMessageEvent",
+  "MediaEncryptedEvent",
+  "MediaKeyEvent",
+  "MediaKeyMessageEvent",
+  "MediaQueryListEvent",
+  "MediaStreamEvent",
+  "MediaStreamTrackEvent",
+  "MouseScrollEvent",
+  "MutationEvent",
+  "NotificationEvent",
+  "NotifyPaintEvent",
+  "OfflineAudioCompletionEvent",
+  "OrientationEvent",
+  "PageTransition", // Yes, with no "Event"
+  "PageTransitionEvent",
+  "PointerEvent",
+  "PopStateEvent",
+  "PopUpEvent",
+  "PresentationConnectionAvailableEvent",
+  "PresentationConnectionCloseEvent",
+  "ProgressEvent",
+  "PromiseRejectionEvent",
+  "PushEvent",
+  "RTCDTMFToneChangeEvent",
+  "RTCDataChannelEvent",
+  "RTCIceCandidateEvent",
+  "RelatedEvent",
+  "ResourceProgressEvent",
+  "SVGEvent",
+  "SVGZoomEvent",
+  "ScrollAreaEvent",
+  "SecurityPolicyViolationEvent",
+  "ServicePortConnectEvent",
+  "ServiceWorkerMessageEvent",
+  "SimpleGestureEvent",
+  "SpeechRecognitionError",
+  "SpeechRecognitionEvent",
+  "SpeechSynthesisEvent",
+  "SyncEvent",
+  "TimeEvent",
+  "TrackEvent",
+  "TransitionEvent",
+  "WebGLContextEvent",
+  "WebKitAnimationEvent",
+  "WebKitTransitionEvent",
+  "WheelEvent",
+  "XULCommandEvent",
+];
+someNonCreateableEvents.forEach(function (eventInterface) {
+  test(function () {
+    assert_throws_dom("NOT_SUPPORTED_ERR", function () {
+      var evt = document.createEvent(eventInterface);
+    });
+  }, 'Should throw NOT_SUPPORTED_ERR for non-legacy event interface "' + eventInterface + '"');
+
+  // SVGEvents is allowed, other plurals are not
+  if (eventInterface !== "SVGEvent") {
+    test(function () {
+      assert_throws_dom("NOT_SUPPORTED_ERR", function () {
+        var evt = document.createEvent(eventInterface + "s");
+      });
+    }, 'Should throw NOT_SUPPORTED_ERR for pluralized non-legacy event interface "' + eventInterface + 's"');
+  }
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createEvent.js b/testing/web-platform/tests/dom/nodes/Document-createEvent.js
new file mode 100644
index 0000000000..57e8e966f8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createEvent.js
@@ -0,0 +1,22 @@
+var aliases = {
+  "BeforeUnloadEvent": "BeforeUnloadEvent",
+  "CompositionEvent": "CompositionEvent",
+  "CustomEvent": "CustomEvent",
+  "DeviceMotionEvent": "DeviceMotionEvent",
+  "DeviceOrientationEvent": "DeviceOrientationEvent",
+  "DragEvent": "DragEvent",
+  "Event": "Event",
+  "Events": "Event",
+  "FocusEvent": "FocusEvent",
+  "HashChangeEvent": "HashChangeEvent",
+  "HTMLEvents": "Event",
+  "KeyboardEvent": "KeyboardEvent",
+  "MessageEvent": "MessageEvent",
+  "MouseEvent": "MouseEvent",
+  "MouseEvents": "MouseEvent",
+  "StorageEvent": "StorageEvent",
+  "SVGEvents": "Event",
+  "TextEvent": "CompositionEvent",
+  "UIEvent": "UIEvent",
+  "UIEvents": "UIEvent",
+};
diff --git a/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction-xhtml.xhtml
new file mode 100644
index 0000000000..d06f70fdcb
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction-xhtml.xhtml
@@ -0,0 +1,15 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Document.createProcessingInstruction in XML documents</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-document-createprocessinginstruction"/>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-processinginstruction-target"/>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-characterdata-data"/>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-node-ownerdocument"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"/>
+<script src="Document-createProcessingInstruction.js"/>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction.html b/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction.html
new file mode 100644
index 0000000000..c57a792fac
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.createProcessingInstruction in HTML documents</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createprocessinginstruction">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-processinginstruction-target">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-ownerdocument">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script src="Document-createProcessingInstruction.js"></script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction.js b/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction.js
new file mode 100644
index 0000000000..d6cc3725f0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createProcessingInstruction.js
@@ -0,0 +1,39 @@
+test(function() {
+  var invalid = [
+        ["A", "?>"],
+        ["\u00B7A", "x"],
+        ["\u00D7A", "x"],
+        ["A\u00D7", "x"],
+        ["\\A", "x"],
+        ["\f", "x"],
+        [0, "x"],
+        ["0", "x"]
+      ],
+      valid = [
+        ["xml:fail", "x"],
+        ["A\u00B7A", "x"],
+        ["a0", "x"]
+      ]
+
+  for (var i = 0, il = invalid.length; i < il; i++) {
+    test(function() {
+      assert_throws_dom("INVALID_CHARACTER_ERR", function() {
+        document.createProcessingInstruction(invalid[i][0], invalid[i][1])
+      })
+    }, "Should throw an INVALID_CHARACTER_ERR for target " +
+       format_value(invalid[i][0]) + " and data " +
+       format_value(invalid[i][1]) + ".")
+  }
+  for (var i = 0, il = valid.length; i < il; ++i) {
+    test(function() {
+      var pi = document.createProcessingInstruction(valid[i][0], valid[i][1]);
+      assert_equals(pi.target, valid[i][0]);
+      assert_equals(pi.data, valid[i][1]);
+      assert_equals(pi.ownerDocument, document);
+      assert_true(pi instanceof ProcessingInstruction);
+      assert_true(pi instanceof Node);
+    }, "Should get a ProcessingInstruction for target " +
+      format_value(valid[i][0]) + " and data " +
+      format_value(valid[i][1]) + ".")
+  }
+})
diff --git a/testing/web-platform/tests/dom/nodes/Document-createTextNode.html b/testing/web-platform/tests/dom/nodes/Document-createTextNode.html
new file mode 100644
index 0000000000..ccc1b1b77f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createTextNode.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.createTextNode</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createtextnode">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-ownerdocument">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-data">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-nodevalue">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-textcontent">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-characterdata-length">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-nodetype">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-haschildnodes">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-childnodes">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-firstchild">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-lastchild">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-createComment-createTextNode.js"></script>
+<div id="log"></div>
+<script>
+test_create("createTextNode", Text, 3, "#text");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createTreeWalker.html b/testing/web-platform/tests/dom/nodes/Document-createTreeWalker.html
new file mode 100644
index 0000000000..1e8420d841
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-createTreeWalker.html
@@ -0,0 +1,42 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Document.createTreeWalker</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+test(function() {
+  assert_throws_js(TypeError, function() {
+    document.createTreeWalker();
+  });
+}, "Required arguments to createTreeWalker should be required.");
+test(function() {
+  var tw = document.createTreeWalker(document.body);
+  assert_equals(tw.root, document.body);
+  assert_equals(tw.currentNode, document.body);
+  assert_equals(tw.whatToShow, 0xFFFFFFFF);
+  assert_equals(tw.filter, null);
+}, "Optional arguments to createTreeWalker should be optional (1 passed).");
+test(function() {
+  var tw = document.createTreeWalker(document.body, 42);
+  assert_equals(tw.root, document.body);
+  assert_equals(tw.currentNode, document.body);
+  assert_equals(tw.whatToShow, 42);
+  assert_equals(tw.filter, null);
+}, "Optional arguments to createTreeWalker should be optional (2 passed).");
+test(function() {
+  var tw = document.createTreeWalker(document.body, 42, null);
+  assert_equals(tw.root, document.body);
+  assert_equals(tw.currentNode, document.body);
+  assert_equals(tw.whatToShow, 42);
+  assert_equals(tw.filter, null);
+}, "Optional arguments to createTreeWalker should be optional (3 passed, null).");
+test(function() {
+  var fn = function() {};
+  var tw = document.createTreeWalker(document.body, 42, fn);
+  assert_equals(tw.root, document.body);
+  assert_equals(tw.currentNode, document.body);
+  assert_equals(tw.whatToShow, 42);
+  assert_equals(tw.filter, fn);
+}, "Optional arguments to createTreeWalker should be optional (3 passed, function).");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-doctype.html b/testing/web-platform/tests/dom/nodes/Document-doctype.html
new file mode 100644
index 0000000000..75bfd8506d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-doctype.html
@@ -0,0 +1,21 @@
+<!-- comment -->
+<!doctype html>
+<meta charset=utf-8>
+<title>Document.doctype</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-doctype">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  assert_true(document.doctype instanceof DocumentType,
+              "Doctype should be a DocumentType");
+  assert_equals(document.doctype, document.childNodes[1]);
+}, "Window document with doctype");
+
+test(function() {
+  var newdoc = new Document();
+  newdoc.appendChild(newdoc.createElement("html"));
+  assert_equals(newdoc.doctype, null);
+}, "new Document()");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-getElementById.html b/testing/web-platform/tests/dom/nodes/Document-getElementById.html
new file mode 100644
index 0000000000..1dec4c085b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-getElementById.html
@@ -0,0 +1,350 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.getElementById</title>
+<link rel="author" title="Tetsuharu OHZEKI" href="mailto:saneyuki.snyk@gmail.com">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementbyid">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+  <div id="log"></div>
+
+  <!-- test 0 -->
+  <div id=""></div>
+
+  <!-- test 1 -->
+  <div id="test1"></div>
+
+  <!-- test 5 -->
+  <div id="test5" data-name="1st">
+    <p id="test5" data-name="2nd">P</p>
+    <input id="test5" type="submit" value="Submit" data-name="3rd">
+  </div>
+
+  <!-- test 15 -->
+  <div id="outer">
+    <div id="middle">
+      <div id="inner"></div>
+    </div>
+  </div>
+
+<script>
+  var gBody = document.getElementsByTagName("body")[0];
+
+  test(function() {
+    assert_equals(document.getElementById(""), null);
+  }, "Calling document.getElementById with an empty string argument.");
+
+  test(function() {
+    var element = document.createElement("div");
+    element.setAttribute("id", "null");
+    document.body.appendChild(element);
+    this.add_cleanup(function() { document.body.removeChild(element) });
+    assert_equals(document.getElementById(null), element);
+  }, "Calling document.getElementById with a null argument.");
+
+  test(function() {
+    var element = document.createElement("div");
+    element.setAttribute("id", "undefined");
+    document.body.appendChild(element);
+    this.add_cleanup(function() { document.body.removeChild(element) });
+    assert_equals(document.getElementById(undefined), element);
+  }, "Calling document.getElementById with an undefined argument.");
+
+
+  test(function() {
+    var bar = document.getElementById("test1");
+    assert_not_equals(bar, null, "should not be null");
+    assert_equals(bar.tagName, "DIV", "should have expected tag name.");
+    assert_true(bar instanceof HTMLDivElement, "should be a valid Element instance");
+  }, "on static page");
+
+
+  test(function() {
+    var TEST_ID = "test2";
+
+    var test = document.createElement("div");
+    test.setAttribute("id", TEST_ID);
+    gBody.appendChild(test);
+
+    // test: appended element
+    var result = document.getElementById(TEST_ID);
+    assert_not_equals(result, null, "should not be null.");
+    assert_equals(result.tagName, "DIV", "should have appended element's tag name");
+    assert_true(result instanceof HTMLDivElement, "should be a valid Element instance");
+
+    // test: removed element
+    gBody.removeChild(test);
+    var removed = document.getElementById(TEST_ID);
+    // `document.getElementById()` returns `null` if there is none.
+    // https://dom.spec.whatwg.org/#dom-nonelementparentnode-getelementbyid
+    assert_equals(removed, null, "should not get removed element.");
+  }, "Document.getElementById with a script-inserted element");
+
+
+  test(function() {
+    // setup fixtures.
+    var TEST_ID = "test3";
+    var test = document.createElement("div");
+    test.setAttribute("id", TEST_ID);
+    gBody.appendChild(test);
+
+    // update id
+    var UPDATED_ID = "test3-updated";
+    test.setAttribute("id", UPDATED_ID);
+    var e = document.getElementById(UPDATED_ID);
+    assert_equals(e, test, "should get the element with id.");
+
+    var old = document.getElementById(TEST_ID);
+    assert_equals(old, null, "shouldn't get the element by the old id.");
+
+    // remove id.
+    test.removeAttribute("id");
+    var e2 = document.getElementById(UPDATED_ID);
+    assert_equals(e2, null, "should return null when the passed id is none in document.");
+  }, "update `id` attribute via setAttribute/removeAttribute");
+
+
+  test(function() {
+    var TEST_ID = "test4-should-not-exist";
+
+    var e = document.createElement('div');
+    e.setAttribute("id", TEST_ID);
+
+    assert_equals(document.getElementById(TEST_ID), null, "should be null");
+    document.body.appendChild(e);
+    assert_equals(document.getElementById(TEST_ID), e, "should be the appended element");
+  }, "Ensure that the id attribute only affects elements present in a document");
+
+
+  test(function() {
+    // the method should return the 1st element.
+    var TEST_ID = "test5";
+    var target = document.getElementById(TEST_ID);
+    assert_not_equals(target, null, "should not be null");
+    assert_equals(target.getAttribute("data-name"), "1st", "should return the 1st");
+
+    // even if after the new element was appended.
+    var element4 = document.createElement("div");
+    element4.setAttribute("id", TEST_ID);
+    element4.setAttribute("data-name", "4th");
+    gBody.appendChild(element4);
+    var target2 = document.getElementById(TEST_ID);
+    assert_not_equals(target2, null, "should not be null");
+    assert_equals(target2.getAttribute("data-name"), "1st", "should be the 1st");
+
+    // should return the next element after removed the subtree including the 1st element.
+    target2.parentNode.removeChild(target2);
+    var target3 = document.getElementById(TEST_ID);
+    assert_not_equals(target3, null, "should not be null");
+    assert_equals(target3.getAttribute("data-name"), "4th", "should be the 4th");
+  }, "in tree order, within the context object's tree");
+
+
+  test(function() {
+    var TEST_ID = "test6";
+    var s = document.createElement("div");
+    s.setAttribute("id", TEST_ID);
+    // append to Element, not Document.
+    document.createElement("div").appendChild(s);
+
+    assert_equals(document.getElementById(TEST_ID), null, "should be null");
+  }, "Modern browsers optimize this method with using internal id cache. " +
+     "This test checks that their optimization should effect only append to `Document`, not append to `Node`.");
+
+
+  test(function() {
+    var TEST_ID = "test7"
+    var element = document.createElement("div");
+    element.setAttribute("id", TEST_ID);
+    gBody.appendChild(element);
+
+    var target = document.getElementById(TEST_ID);
+    assert_equals(target, element, "should return the element before changing the value");
+
+    element.attributes[0].value = TEST_ID + "-updated";
+    var target2 = document.getElementById(TEST_ID);
+    assert_equals(target2, null, "should return null after updated id via Attr.value");
+    var target3 = document.getElementById(TEST_ID + "-updated");
+    assert_equals(target3, element, "should be equal to the updated element.");
+  }, "changing attribute's value via `Attr` gotten from `Element.attribute`.");
+
+
+  test(function() {
+    var TEST_ID = "test8";
+
+    // setup fixture
+    var element = document.createElement("div");
+    element.setAttribute("id", TEST_ID + "-fixture");
+    gBody.appendChild(element);
+
+    // add id-ed element with using innerHTML
+    element.innerHTML = "<div id='"+ TEST_ID +"'></div>";
+    var test = document.getElementById(TEST_ID);
+    assert_equals(test, element.firstChild, "should not be null");
+    assert_equals(test.tagName, "DIV", "should have expected tag name.");
+    assert_true(test instanceof HTMLDivElement, "should be a valid Element instance");
+  }, "add id attribute via innerHTML");
+
+
+  test(function() {
+    var TEST_ID = "test9";
+
+    // add fixture
+    var fixture = document.createElement("div");
+    fixture.setAttribute("id", TEST_ID + "-fixture");
+    gBody.appendChild(fixture);
+
+    var element = document.createElement("div");
+    element.setAttribute("id", TEST_ID);
+    fixture.appendChild(element);
+
+    // check 'getElementById' should get the 'element'
+    assert_equals(document.getElementById(TEST_ID), element, "should not be null");
+
+    // remove id-ed element with using innerHTML (clear 'element')
+    fixture.innerHTML = "";
+    var test = document.getElementById(TEST_ID);
+    assert_equals(test, null, "should be null.");
+  }, "remove id attribute via innerHTML");
+
+
+  test(function() {
+    var TEST_ID = "test10";
+
+    // setup fixture
+    var element = document.createElement("div");
+    element.setAttribute("id", TEST_ID + "-fixture");
+    gBody.appendChild(element);
+
+    // add id-ed element with using outerHTML
+    element.outerHTML = "<div id='"+ TEST_ID +"'></div>";
+    var test = document.getElementById(TEST_ID);
+    assert_not_equals(test, null, "should not be null");
+    assert_equals(test.tagName, "DIV", "should have expected tag name.");
+    assert_true(test instanceof HTMLDivElement,"should be a valid Element instance");
+  }, "add id attribute via outerHTML");
+
+
+  test(function() {
+    var TEST_ID = "test11";
+
+    var element = document.createElement("div");
+    element.setAttribute("id", TEST_ID);
+    gBody.appendChild(element);
+
+    var test = document.getElementById(TEST_ID);
+    assert_equals(test, element, "should be equal to the appended element.");
+
+    // remove id-ed element with using outerHTML
+    element.outerHTML = "<div></div>";
+    var test = document.getElementById(TEST_ID);
+    assert_equals(test, null, "should be null.");
+  }, "remove id attribute via outerHTML");
+
+
+  test(function() {
+    // setup fixtures.
+    var TEST_ID = "test12";
+    var test = document.createElement("div");
+    test.id = TEST_ID;
+    gBody.appendChild(test);
+
+    // update id
+    var UPDATED_ID = TEST_ID + "-updated";
+    test.id =  UPDATED_ID;
+    var e = document.getElementById(UPDATED_ID);
+    assert_equals(e, test, "should get the element with id.");
+
+    var old = document.getElementById(TEST_ID);
+    assert_equals(old, null, "shouldn't get the element by the old id.");
+
+    // remove id.
+    test.id = "";
+    var e2 = document.getElementById(UPDATED_ID);
+    assert_equals(e2, null, "should return null when the passed id is none in document.");
+  }, "update `id` attribute via element.id");
+
+
+  test(function() {
+    var TEST_ID = "test13";
+
+    var create_same_id_element = function (order) {
+      var element = document.createElement("div");
+      element.setAttribute("id", TEST_ID);
+      element.setAttribute("data-order", order);// for debug
+      return element;
+    };
+
+    // create fixture
+    var container = document.createElement("div");
+    container.setAttribute("id", TEST_ID + "-fixture");
+    gBody.appendChild(container);
+
+    var element1 = create_same_id_element("1");
+    var element2 = create_same_id_element("2");
+    var element3 = create_same_id_element("3");
+    var element4 = create_same_id_element("4");
+
+    // append element: 2 -> 4 -> 3 -> 1
+    container.appendChild(element2);
+    container.appendChild(element4);
+    container.insertBefore(element3, element4);
+    container.insertBefore(element1, element2);
+
+
+    var test = document.getElementById(TEST_ID);
+    assert_equals(test, element1, "should return 1st element");
+    container.removeChild(element1);
+
+    test = document.getElementById(TEST_ID);
+    assert_equals(test, element2, "should return 2nd element");
+    container.removeChild(element2);
+
+    test = document.getElementById(TEST_ID);
+    assert_equals(test, element3, "should return 3rd element");
+    container.removeChild(element3);
+
+    test = document.getElementById(TEST_ID);
+    assert_equals(test, element4, "should return 4th element");
+    container.removeChild(element4);
+
+
+  }, "where insertion order and tree order don't match");
+
+  test(function() {
+    var TEST_ID = "test14";
+    var a = document.createElement("a");
+    var b = document.createElement("b");
+    a.appendChild(b);
+    b.id = TEST_ID;
+    assert_equals(document.getElementById(TEST_ID), null);
+
+    gBody.appendChild(a);
+    assert_equals(document.getElementById(TEST_ID), b);
+  }, "Inserting an id by inserting its parent node");
+
+  test(function () {
+    var TEST_ID = "test15"
+    var outer = document.getElementById("outer");
+    var middle = document.getElementById("middle");
+    var inner = document.getElementById("inner");
+    outer.removeChild(middle);
+
+    var new_el = document.createElement("h1");
+    new_el.id = "heading";
+    inner.appendChild(new_el);
+    // the new element is not part of the document since
+    // "middle" element was removed previously
+    assert_equals(document.getElementById("heading"), null);
+  }, "Document.getElementById must not return nodes not present in document");
+
+  // TODO:
+  // id attribute in a namespace
+
+
+  // TODO:
+  // SVG + MathML elements with id attributes
+
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-getElementsByClassName.html b/testing/web-platform/tests/dom/nodes/Document-getElementsByClassName.html
new file mode 100644
index 0000000000..db8fac212d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-getElementsByClassName.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<title>Document.getElementsByClassName</title>
+<link rel="author" title="Intel" href="http://www.intel.com">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var a = document.createElement("a"),
+      b = document.createElement("b");
+  a.className = "foo";
+  this.add_cleanup(function() {document.body.removeChild(a);});
+  document.body.appendChild(a);
+
+  var l = document.getElementsByClassName("foo");
+  assert_true(l instanceof HTMLCollection);
+  assert_equals(l.length, 1);
+
+  b.className = "foo";
+  document.body.appendChild(b);
+  assert_equals(l.length, 2);
+
+  document.body.removeChild(b);
+  assert_equals(l.length, 1);
+}, "getElementsByClassName() should be a live collection");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-getElementsByTagName-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Document-getElementsByTagName-xhtml.xhtml
new file mode 100644
index 0000000000..309a29ae77
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-getElementsByTagName-xhtml.xhtml
@@ -0,0 +1,104 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Document.getElementsByTagName</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"></div>
+<pre id="x"></pre>
+<script>
+test(function() {
+  var t = document.body.appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "I"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_equals(t.localName, "I")
+  assert_equals(t.tagName, "I")
+  assert_array_equals(document.getElementsByTagName("I"), [t])
+  assert_array_equals(document.getElementsByTagName("i"), [])
+  assert_array_equals(document.body.getElementsByTagName("I"), [t])
+  assert_array_equals(document.body.getElementsByTagName("i"), [])
+}, "HTML element with uppercase tag name matches in XHTML documents")
+
+test(function() {
+  var t = document.body.appendChild(document.createElementNS("test", "st"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_array_equals(document.getElementsByTagName("st"), [t])
+  assert_array_equals(document.getElementsByTagName("ST"), [])
+}, "Element in non-HTML namespace, no prefix, lowercase name")
+
+test(function() {
+  var t = document.body.appendChild(document.createElementNS("test", "ST"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_array_equals(document.getElementsByTagName("ST"), [t])
+  assert_array_equals(document.getElementsByTagName("st"), [])
+}, "Element in non-HTML namespace, no prefix, uppercase name")
+
+test(function() {
+  var t = document.body.appendChild(document.createElementNS("test", "te:st"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_array_equals(document.getElementsByTagName("st"), [])
+  assert_array_equals(document.getElementsByTagName("ST"), [])
+  assert_array_equals(document.getElementsByTagName("te:st"), [t])
+  assert_array_equals(document.getElementsByTagName("te:ST"), [])
+}, "Element in non-HTML namespace, prefix, lowercase name")
+
+test(function() {
+  var t = document.body.appendChild(document.createElementNS("test", "te:ST"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_array_equals(document.getElementsByTagName("ST"), [])
+  assert_array_equals(document.getElementsByTagName("st"), [])
+  assert_array_equals(document.getElementsByTagName("te:st"), [])
+  assert_array_equals(document.getElementsByTagName("te:ST"), [t])
+}, "Element in non-HTML namespace, prefix, uppercase name")
+
+test(function() {
+  var t = document.body.appendChild(document.createElement("AÇ"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_array_equals(document.getElementsByTagName("AÇ"), [t], "All uppercase input")
+  assert_array_equals(document.getElementsByTagName("aÇ"), [], "Ascii lowercase input")
+  assert_array_equals(document.getElementsByTagName("aç"), [], "All lowercase input")
+}, "Element in HTML namespace, no prefix, non-ascii characters in name")
+
+test(function() {
+  var t = document.body.appendChild(document.createElementNS("test", "AÇ"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_array_equals(document.getElementsByTagName("AÇ"), [t], "All uppercase input")
+  assert_array_equals(document.getElementsByTagName("aÇ"), [], "Ascii lowercase input")
+  assert_array_equals(document.getElementsByTagName("aç"), [], "All lowercase input")
+}, "Element in non-HTML namespace, non-ascii characters in name")
+
+test(function() {
+  var t = document.body.appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "test:aÇ"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_array_equals(document.getElementsByTagName("TEST:AÇ"), [], "All uppercase input")
+  assert_array_equals(document.getElementsByTagName("test:aÇ"), [t], "Ascii lowercase input")
+  assert_array_equals(document.getElementsByTagName("test:aç"), [], "All lowercase input")
+}, "Element in HTML namespace, prefix, non-ascii characters in name")
+
+test(function() {
+  var t = document.body.appendChild(document.createElementNS("test", "TEST:AÇ"))
+  this.add_cleanup(function() {document.body.removeChild(t)})
+  assert_array_equals(document.getElementsByTagName("TEST:AÇ"), [t], "All uppercase input")
+  assert_array_equals(document.getElementsByTagName("test:aÇ"), [], "Ascii lowercase input")
+  assert_array_equals(document.getElementsByTagName("test:aç"), [], "All lowercase input")
+}, "Element in non-HTML namespace, prefix, non-ascii characters in name")
+
+test(function() {
+  var actual = document.getElementsByTagName("*");
+  var expected = [];
+  var get_elements = function(node) {
+    for (var i = 0; i &lt; node.childNodes.length; i++) {
+      var child = node.childNodes[i];
+      if (child.nodeType === child.ELEMENT_NODE) {
+        expected.push(child);
+        get_elements(child);
+      }
+    }
+  }
+  get_elements(document);
+  assert_array_equals(actual, expected);
+}, "getElementsByTagName('*')")
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Document-getElementsByTagName.html b/testing/web-platform/tests/dom/nodes/Document-getElementsByTagName.html
new file mode 100644
index 0000000000..00e3435c4c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-getElementsByTagName.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.getElementsByTagName</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementsbytagname">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-Element-getElementsByTagName.js"></script>
+<div id="log"></div>
+<script>
+test_getElementsByTagName(document, document.body);
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-getElementsByTagNameNS.html b/testing/web-platform/tests/dom/nodes/Document-getElementsByTagNameNS.html
new file mode 100644
index 0000000000..063dc98215
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-getElementsByTagNameNS.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.getElementsByTagNameNS</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementsbytagnamens">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-Element-getElementsByTagNameNS.js"></script>
+<div id="log"></div>
+<script>
+test_getElementsByTagNameNS(document, document.body);
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-implementation.html b/testing/web-platform/tests/dom/nodes/Document-implementation.html
new file mode 100644
index 0000000000..aed5259659
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-implementation.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.implementation</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-implementation">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var implementation = document.implementation;
+  assert_true(implementation instanceof DOMImplementation,
+              "implementation should implement DOMImplementation");
+  assert_equals(document.implementation, implementation);
+}, "Getting implementation off the same document");
+
+test(function() {
+  var doc = document.implementation.createHTMLDocument();
+  assert_not_equals(document.implementation, doc.implementation);
+}, "Getting implementation off different documents");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-importNode.html b/testing/web-platform/tests/dom/nodes/Document-importNode.html
new file mode 100644
index 0000000000..d27cce6c56
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Document-importNode.html
@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Document.importNode</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-importnode">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var doc = document.implementation.createHTMLDocument("Title");
+  var div = doc.body.appendChild(doc.createElement("div"));
+  div.appendChild(doc.createElement("span"));
+  assert_equals(div.ownerDocument, doc);
+  assert_equals(div.firstChild.ownerDocument, doc);
+  var newDiv = document.importNode(div);
+  assert_equals(div.ownerDocument, doc);
+  assert_equals(div.firstChild.ownerDocument, doc);
+  assert_equals(newDiv.ownerDocument, document);
+  assert_equals(newDiv.firstChild, null);
+}, "No 'deep' argument.")
+test(function() {
+  var doc = document.implementation.createHTMLDocument("Title");
+  var div = doc.body.appendChild(doc.createElement("div"));
+  div.appendChild(doc.createElement("span"));
+  assert_equals(div.ownerDocument, doc);
+  assert_equals(div.firstChild.ownerDocument, doc);
+  var newDiv = document.importNode(div, undefined);
+  assert_equals(div.ownerDocument, doc);
+  assert_equals(div.firstChild.ownerDocument, doc);
+  assert_equals(newDiv.ownerDocument, document);
+  assert_equals(newDiv.firstChild, null);
+}, "Undefined 'deep' argument.")
+test(function() {
+  var doc = document.implementation.createHTMLDocument("Title");
+  var div = doc.body.appendChild(doc.createElement("div"));
+  div.appendChild(doc.createElement("span"));
+  assert_equals(div.ownerDocument, doc);
+  assert_equals(div.firstChild.ownerDocument, doc);
+  var newDiv = document.importNode(div, true);
+  assert_equals(div.ownerDocument, doc);
+  assert_equals(div.firstChild.ownerDocument, doc);
+  assert_equals(newDiv.ownerDocument, document);
+  assert_equals(newDiv.firstChild.ownerDocument, document);
+}, "True 'deep' argument.")
+test(function() {
+  var doc = document.implementation.createHTMLDocument("Title");
+  var div = doc.body.appendChild(doc.createElement("div"));
+  div.appendChild(doc.createElement("span"));
+  assert_equals(div.ownerDocument, doc);
+  assert_equals(div.firstChild.ownerDocument, doc);
+  var newDiv = document.importNode(div, false);
+  assert_equals(div.ownerDocument, doc);
+  assert_equals(div.firstChild.ownerDocument, doc);
+  assert_equals(newDiv.ownerDocument, document);
+  assert_equals(newDiv.firstChild, null);
+}, "False 'deep' argument.")
+
+test(function() {
+  let doc = document.implementation.createHTMLDocument("Title");
+  doc.body.setAttributeNS("http://example.com/", "p:name", "value");
+  let originalAttr = doc.body.getAttributeNodeNS("http://example.com/", "name");
+  let imported = document.importNode(originalAttr, true);
+  assert_equals(imported.prefix, originalAttr.prefix);
+  assert_equals(imported.namespaceURI, originalAttr.namespaceURI);
+  assert_equals(imported.localName, originalAttr.localName);
+}, "Import an Attr node with namespace/prefix correctly.");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DocumentFragment-constructor.html b/testing/web-platform/tests/dom/nodes/DocumentFragment-constructor.html
new file mode 100644
index 0000000000..e97a7c4836
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DocumentFragment-constructor.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>DocumentFragment constructor</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-documentfragment-documentfragment">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+  const fragment = new DocumentFragment();
+  assert_equals(fragment.ownerDocument, document);
+}, "Sets the owner document to the current global object associated document");
+
+test(() => {
+  const fragment = new DocumentFragment();
+  const text = document.createTextNode("");
+  fragment.appendChild(text);
+  assert_equals(fragment.firstChild, text);
+}, "Create a valid document DocumentFragment");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DocumentFragment-getElementById.html b/testing/web-platform/tests/dom/nodes/DocumentFragment-getElementById.html
new file mode 100644
index 0000000000..ce0d302c12
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DocumentFragment-getElementById.html
@@ -0,0 +1,62 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>DocumentFragment.prototype.getElementById</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-nonelementparentnode-getelementbyid">
+<link rel="author" title="Domenic Denicola" href="mailto:d@domenic.me">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<template>
+  <div id="bar">
+    <span id="foo" data-yes></span>
+  </div>
+  <div id="foo">
+    <span id="foo"></span>
+    <ul id="bar">
+      <li id="foo"></li>
+    </ul>
+  </div>
+</template>
+
+<script>
+"use strict";
+
+test(() => {
+  assert_equals(typeof DocumentFragment.prototype.getElementById, "function", "It must exist on the prototype");
+  assert_equals(typeof document.createDocumentFragment().getElementById, "function", "It must exist on an instance");
+}, "The method must exist");
+
+test(() => {
+  assert_equals(document.createDocumentFragment().getElementById("foo"), null);
+  assert_equals(document.createDocumentFragment().getElementById(""), null);
+}, "It must return null when there are no matches");
+
+test(() => {
+  const frag = document.createDocumentFragment();
+  frag.appendChild(document.createElement("div"));
+  frag.appendChild(document.createElement("span"));
+  frag.childNodes[0].id = "foo";
+  frag.childNodes[1].id = "foo";
+
+  assert_equals(frag.getElementById("foo"), frag.childNodes[0]);
+}, "It must return the first element when there are matches");
+
+test(() => {
+  const frag = document.createDocumentFragment();
+  frag.appendChild(document.createElement("div"));
+  frag.childNodes[0].setAttribute("id", "");
+
+  assert_equals(
+    frag.getElementById(""),
+    null,
+    "Even if there is an element with an empty-string ID attribute, it must not be returned"
+  );
+}, "Empty string ID values");
+
+test(() => {
+  const frag = document.querySelector("template").content;
+
+  assert_true(frag.getElementById("foo").hasAttribute("data-yes"));
+}, "It must return the first element when there are matches, using a template");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DocumentFragment-querySelectorAll-after-modification.html b/testing/web-platform/tests/dom/nodes/DocumentFragment-querySelectorAll-after-modification.html
new file mode 100644
index 0000000000..8049363885
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DocumentFragment-querySelectorAll-after-modification.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>querySelectorAll should still work on DocumentFragments after they are modified</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!-- Regression test for https://github.com/jsdom/jsdom/issues/2290 -->
+
+<script>
+"use strict";
+
+setup({ single_test: true });
+
+const frag = document.createDocumentFragment();
+frag.appendChild(document.createElement("div"));
+
+assert_array_equals(frag.querySelectorAll("img"), [], "before modification");
+
+frag.appendChild(document.createElement("div"));
+
+// If the bug is present, this will throw.
+assert_array_equals(frag.querySelectorAll("img"), [], "after modification");
+
+done();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DocumentType-literal-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/DocumentType-literal-xhtml.xhtml
new file mode 100644
index 0000000000..2b6965c14b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DocumentType-literal-xhtml.xhtml
@@ -0,0 +1,23 @@
+<!DOCTYPE html PUBLIC "STAFF" "staffNS.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>DocumentType literals</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-documenttype-name"/>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-documenttype-publicid"/>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-documenttype-systemid"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"/>
+<script>
+test(function() {
+  var doctype = document.firstChild;
+  assert_true(doctype instanceof DocumentType)
+  assert_equals(doctype.name, "html")
+  assert_equals(doctype.publicId, 'STAFF')
+  assert_equals(doctype.systemId, 'staffNS.dtd')
+})
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/DocumentType-literal.html b/testing/web-platform/tests/dom/nodes/DocumentType-literal.html
new file mode 100644
index 0000000000..a755c397b0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DocumentType-literal.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html PUBLIC "STAFF" "staffNS.dtd">
+<title>DocumentType literals</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-documenttype-name">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-documenttype-publicid">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-documenttype-systemid">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var doctype = document.firstChild;
+  assert_true(doctype instanceof DocumentType)
+  assert_equals(doctype.name, "html")
+  assert_equals(doctype.publicId, 'STAFF')
+  assert_equals(doctype.systemId, 'staffNS.dtd')
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/DocumentType-remove.html b/testing/web-platform/tests/dom/nodes/DocumentType-remove.html
new file mode 100644
index 0000000000..9e18d3511a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/DocumentType-remove.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>DocumentType.remove</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-childnode-remove">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="ChildNode-remove.js"></script>
+<div id=log></div>
+<script>
+var node, parentNode;
+setup(function() {
+  node = document.implementation.createDocumentType("html", "", "");
+  parentNode = document.implementation.createDocument(null, "", null);
+});
+testRemove(node, parentNode, "doctype");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElement-null-svg.svg b/testing/web-platform/tests/dom/nodes/Element-childElement-null-svg.svg
new file mode 100644
index 0000000000..388482874b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElement-null-svg.svg
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>Null test</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of firstElementChild and lastChildElement returning null</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle" font-weight="bold">Test</text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_equals(parentEl.firstElementChild, null)
+  assert_equals(parentEl.lastElementChild, null)
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElement-null-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-childElement-null-xhtml.xhtml
new file mode 100644
index 0000000000..daedab6d97
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElement-null-xhtml.xhtml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Null Test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of firstElementChild and lastChildElement returning null</h1>
+<div id="log"></div>
+<p id="parentEl" style="font-weight:bold;">Test.</p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_equals(parentEl.firstElementChild, null)
+  assert_equals(parentEl.lastElementChild, null)
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElement-null.html b/testing/web-platform/tests/dom/nodes/Element-childElement-null.html
new file mode 100644
index 0000000000..1863a41da5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElement-null.html
@@ -0,0 +1,15 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Null test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of firstElementChild and lastChildElement returning null</h1>
+<div id="log"></div>
+<p id="parentEl" style="font-weight:bold;">Test.</p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_equals(parentEl.firstElementChild, null)
+  assert_equals(parentEl.lastElementChild, null)
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add-svg.svg b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add-svg.svg
new file mode 100644
index 0000000000..d149f1ea3f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add-svg.svg
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>Dynamic Adding of Elements</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of Dynamic Adding of Elements</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of this test is
+<tspan id="first_element_child" font-weight="bold">unknown.</tspan></text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var newChild = document.createElementNS("http://www.w3.org/2000/svg", "tspan");
+  parentEl.appendChild(newChild);
+  assert_equals(parentEl.childElementCount, 2)
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add-xhtml.xhtml
new file mode 100644
index 0000000000..c97ed1965b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add-xhtml.xhtml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Dynamic Adding of Elements</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of Dynamic Adding of Elements</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is
+<span id="first_element_child" style="font-weight:bold;">logged above.</span></p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var newChild = document.createElement("span");
+  parentEl.appendChild(newChild);
+  assert_equals(parentEl.childElementCount, 2)
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add.html b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add.html
new file mode 100644
index 0000000000..3e7490b21d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-add.html
@@ -0,0 +1,17 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Dynamic Adding of Elements</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of Dynamic Adding of Elements</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is
+<span id="first_element_child" style="font-weight:bold;">logged above.</span></p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var newChild = document.createElement("span");
+  parentEl.appendChild(newChild);
+  assert_equals(parentEl.childElementCount, 2)
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove-svg.svg b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove-svg.svg
new file mode 100644
index 0000000000..bf99de65aa
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove-svg.svg
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>Dynamic Removal of Elements</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of Dynamic Removal of Elements</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of this test is
+<tspan id="first_element_child" font-weight="bold">unknown.</tspan><tspan id="last_element_child"> </tspan></text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = parentEl.lastElementChild;
+  parentEl.removeChild(lec);
+  assert_equals(parentEl.childElementCount, 1)
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove-xhtml.xhtml
new file mode 100644
index 0000000000..f0009b0a77
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove-xhtml.xhtml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Dynamic Removal of Elements</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of Removal Adding of Elements</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is
+<span id="first_element_child" style="font-weight:bold;">logged above.</span><span id="last_element_child"> </span></p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = parentEl.lastElementChild;
+  parentEl.removeChild(lec);
+  assert_equals(parentEl.childElementCount, 1)
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove.html b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove.html
new file mode 100644
index 0000000000..3f7e7c7ead
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-dynamic-remove.html
@@ -0,0 +1,17 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Dynamic Removal of Elements</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of Dynamic Removal of Elements</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is
+<span id="first_element_child" style="font-weight:bold;">unknown.</span><span id="last_element_child"> </span></p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = parentEl.lastElementChild;
+  parentEl.removeChild(lec);
+  assert_equals(parentEl.childElementCount, 1)
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild-svg.svg b/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild-svg.svg
new file mode 100644
index 0000000000..8ba5743607
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild-svg.svg
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>childElementCount</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of childElementCount with No Child Element Nodes</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle" font-weight="bold">Test</text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_equals(parentEl.childElementCount, 0)
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild-xhtml.xhtml
new file mode 100644
index 0000000000..f567a20c23
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild-xhtml.xhtml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>childElementCount without Child Element Nodes</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of childElementCount with No Child Element Nodes</h1>
+<div id="log"></div>
+<p id="parentEl" style="font-weight:bold;">Test.</p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_equals(parentEl.childElementCount, 0)
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild.html b/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild.html
new file mode 100644
index 0000000000..fb52fb205c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-nochild.html
@@ -0,0 +1,14 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>childElementCount without Child Element Nodes</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of childElementCount with No Child Element Nodes</h1>
+<div id="log"></div>
+<p id="parentEl" style="font-weight:bold;">Test.</p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_equals(parentEl.childElementCount, 0)
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-svg.svg b/testing/web-platform/tests/dom/nodes/Element-childElementCount-svg.svg
new file mode 100644
index 0000000000..ff93eff625
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-svg.svg
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>childElementCount</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of childElementCount</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of <tspan id="first_element_child"><tspan>this</tspan> <tspan>test</tspan></tspan> is
+<tspan id="middle_element_child" font-weight="bold">unknown.</tspan>
+
+
+
+<tspan id="last_element_child" style="display:none;">fnord</tspan> </text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_true("childElementCount" in parentEl)
+  assert_equals(parentEl.childElementCount, 3)
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-childElementCount-xhtml.xhtml
new file mode 100644
index 0000000000..6b719ff7a8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount-xhtml.xhtml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>childElementCount</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of childElementCount</h1>
+<div id="log"></div>
+<p id="parentEl">The result of <span id="first_element_child"><span>this</span> <span>test</span></span> is
+<span id="middle_element_child" style="font-weight:bold;">unknown.</span>
+
+
+
+<span id="last_element_child" style="display:none;">fnord</span> </p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_true("childElementCount" in parentEl)
+  assert_equals(parentEl.childElementCount, 3)
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-childElementCount.html b/testing/web-platform/tests/dom/nodes/Element-childElementCount.html
new file mode 100644
index 0000000000..8cfe567f91
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-childElementCount.html
@@ -0,0 +1,20 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>childElementCount</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of childElementCount</h1>
+<div id="log"></div>
+<p id="parentEl">The result of <span id="first_element_child"><span>this</span> <span>test</span></span> is
+<span id="middle_element_child" style="font-weight:bold;">given above.</span>
+
+
+
+<span id="last_element_child" style="display:none;">fnord</span> </p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  assert_true("childElementCount" in parentEl)
+  assert_equals(parentEl.childElementCount, 3)
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-children.html b/testing/web-platform/tests/dom/nodes/Element-children.html
new file mode 100644
index 0000000000..c0210f9667
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-children.html
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<title>HTMLCollection edge cases</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="test"><img><img id=foo><img id=foo><img name="bar"></div>
+<script>
+setup(function() {
+  // Add some non-HTML elements in there to test what happens with those.
+  var container = document.getElementById("test");
+  var child = document.createElementNS("", "img");
+  child.setAttribute("id", "baz");
+  container.appendChild(child);
+
+  child = document.createElementNS("", "img");
+  child.setAttribute("name", "qux");
+  container.appendChild(child);
+});
+
+test(function() {
+  var container = document.getElementById("test");
+  var result = container.children.item("foo");
+  assert_true(result instanceof Element, "Expected an Element.");
+  assert_false(result.hasAttribute("id"), "Expected the IDless Element.")
+})
+
+test(function() {
+  var container = document.getElementById("test");
+  var list = container.children;
+  var result = [];
+  for (var p in list) {
+    if (list.hasOwnProperty(p)) {
+      result.push(p);
+    }
+  }
+  assert_array_equals(result, ['0', '1', '2', '3', '4', '5']);
+  result = Object.getOwnPropertyNames(list);
+  assert_array_equals(result, ['0', '1', '2', '3', '4', '5', 'foo', 'bar', 'baz']);
+
+  // Mapping of exposed names to their indices in the list.
+  var exposedNames = { 'foo': 1, 'bar': 3, 'baz': 4 };
+  for (var exposedName in exposedNames) {
+    assert_true(exposedName in list);
+    assert_true(list.hasOwnProperty(exposedName));
+    assert_equals(list[exposedName], list.namedItem(exposedName));
+    assert_equals(list[exposedName], list.item(exposedNames[exposedName]));
+    assert_true(list[exposedName] instanceof Element);
+  }
+
+  var unexposedNames = ['qux'];
+  for (var unexposedName of unexposedNames) {
+    assert_false(unexposedName in list);
+    assert_false(list.hasOwnProperty(unexposedName));
+    assert_equals(list[unexposedName], undefined);
+    assert_equals(list.namedItem(unexposedName), null);
+  }
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-classlist.html b/testing/web-platform/tests/dom/nodes/Element-classlist.html
new file mode 100644
index 0000000000..2b5a271ba4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-classlist.html
@@ -0,0 +1,478 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Test for the classList element attribute</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id="content"></div>
+<script>
+const SVG_NS = "http://www.w3.org/2000/svg";
+const XHTML_NS = "http://www.w3.org/1999/xhtml"
+const MATHML_NS = "http://www.w3.org/1998/Math/MathML";
+
+function setClass(e, newVal) {
+  if (newVal === null) {
+    e.removeAttribute("class");
+  } else {
+    e.setAttribute("class", newVal);
+  }
+}
+
+function checkModification(e, funcName, args, expectedRes, before, after,
+                           expectedException, desc) {
+  if (!Array.isArray(args)) {
+    args = [args];
+  }
+
+  test(function() {
+    var shouldThrow = typeof(expectedException) === "string";
+    if (shouldThrow) {
+      // If an exception is thrown, the class attribute shouldn't change.
+      after = before;
+    }
+    setClass(e, before);
+
+    var obs;
+    // If we have MutationObservers available,  do some checks to make
+    // sure attribute sets are happening at sane times.
+    if (self.MutationObserver) {
+      obs = new MutationObserver(() => {});
+      obs.observe(e, { attributes: true });
+    }
+    if (shouldThrow) {
+      assert_throws_dom(expectedException, function() {
+        var list = e.classList;
+        var res = list[funcName].apply(list, args);
+      });
+    } else {
+      var list = e.classList;
+      var res = list[funcName].apply(list, args);
+    }
+    if (obs) {
+      var mutationRecords = obs.takeRecords();
+      obs.disconnect();
+      if (shouldThrow) {
+        assert_equals(mutationRecords.length, 0,
+                      "There should have been no mutation");
+      } else if (funcName == "replace") {
+        assert_equals(mutationRecords.length == 1,
+                      expectedRes,
+                      "Should have a mutation exactly when replace() returns true");
+      } else {
+        // For other functions, would need to check when exactly
+        // mutations are supposed to happen.
+      }
+    }
+    if (!shouldThrow) {
+      assert_equals(res, expectedRes, "wrong return value");
+    }
+
+    var expectedAfter = after;
+
+    assert_equals(e.getAttribute("class"), expectedAfter,
+                  "wrong class after modification");
+  }, "classList." + funcName + "(" + args.map(format_value).join(", ") +
+  ") with attribute value " + format_value(before) + desc);
+}
+
+function assignToClassListStrict(e) {
+  "use strict";
+  e.classList = "foo";
+  e.removeAttribute("class");
+}
+
+function assignToClassList(e) {
+  var expect = e.classList;
+  e.classList = "foo";
+  assert_equals(e.classList, expect,
+                "classList should be unchanged after assignment");
+  e.removeAttribute("class");
+}
+
+function testClassList(e, desc) {
+
+  // assignment
+
+  test(function() {
+    assignToClassListStrict(e);
+    assignToClassList(e);
+  }, "Assigning to classList" + desc);
+
+  // supports
+  test(function() {
+    assert_throws_js(TypeError, function() {
+      e.classList.supports("a");
+    })
+  }, ".supports() must throw TypeError" + desc);
+
+  // length attribute
+
+  function checkLength(value, length) {
+    test(function() {
+      setClass(e, value);
+      assert_equals(e.classList.length, length);
+    }, "classList.length when " +
+    (value === null ? "removed" : "set to " + format_value(value)) + desc);
+  }
+
+  checkLength(null, 0);
+  checkLength("", 0);
+  checkLength("   \t  \f", 0);
+  checkLength("a", 1);
+  checkLength("a A", 2);
+  checkLength("\r\na\t\f", 1);
+  checkLength("a a", 1);
+  checkLength("a a a a a a", 1);
+  checkLength("a a b b", 2);
+  checkLength("a A B b", 4);
+  checkLength("a b c c b a a b c c", 3);
+  checkLength("   a  a b", 2);
+  checkLength("a\tb\nc\fd\re f", 6);
+
+  // [Stringifies]
+
+  function checkStringifier(value, expected) {
+    test(function() {
+      setClass(e, value);
+      assert_equals(e.classList.toString(), expected);
+    }, "classList.toString() when " +
+    (value === null ? "removed" : "set to " + format_value(value)) + desc);
+  }
+
+  checkStringifier(null, "");
+  checkStringifier("foo", "foo");
+  checkStringifier("   a  a b", "   a  a b");
+
+  // item() method
+
+  function checkItems(attributeValue, expectedValues) {
+    function checkItemFunction(index, expected) {
+      assert_equals(e.classList.item(index), expected,
+                    "classList.item(" + index + ")");
+    }
+
+    function checkItemArray(index, expected) {
+      assert_equals(e.classList[index], expected, "classList[" + index + "]");
+    }
+
+    test(function() {
+      setClass(e, attributeValue);
+
+      checkItemFunction(-1, null);
+      checkItemArray(-1, undefined);
+
+      var i = 0;
+      while (i < expectedValues.length) {
+        checkItemFunction(i, expectedValues[i]);
+        checkItemArray(i, expectedValues[i]);
+        i++;
+      }
+
+      checkItemFunction(i, null);
+      checkItemArray(i, undefined);
+
+      checkItemFunction(0xffffffff, null);
+      checkItemArray(0xffffffff, undefined);
+
+      checkItemFunction(0xfffffffe, null);
+      checkItemArray(0xfffffffe, undefined);
+    }, "classList.item() when set to " + format_value(attributeValue) + desc);
+  }
+
+  checkItems(null, []);
+  checkItems("a", ["a"]);
+  checkItems("aa AA aa", ["aa", "AA"]);
+  checkItems("a b", ["a", "b"]);
+  checkItems("   a  a b", ["a", "b"]);
+  checkItems("\t\n\f\r a\t\n\f\r b\t\n\f\r ", ["a", "b"]);
+
+  // contains() method
+
+  function checkContains(attributeValue, args, expectedRes) {
+    if (!Array.isArray(expectedRes)) {
+      expectedRes = Array(args.length).fill(expectedRes);
+    }
+    setClass(e, attributeValue);
+    for (var i = 0; i < args.length; i++) {
+      test(function() {
+        assert_equals(e.classList.contains(args[i]), expectedRes[i],
+                      "classList.contains(\"" + args[i] + "\")");
+      }, "classList.contains(" + format_value(args[i]) + ") when set to " +
+      format_value(attributeValue) + desc);
+    }
+  }
+
+  checkContains(null, ["a", "", "  "], false);
+  checkContains("", ["a"], false);
+
+  checkContains("a", ["a"], true);
+  checkContains("a", ["aa", "b", "A", "a.", "a)",, "a'", 'a"', "a$", "a~",
+                      "a?", "a\\"], false);
+
+  // All "ASCII whitespace" per spec, before and after
+  checkContains("a", ["a\t", "\ta", "a\n", "\na", "a\f", "\fa", "a\r", "\ra",
+                      "a ", " a"], false);
+
+  checkContains("aa AA", ["aa", "AA", "aA"], [true, true, false]);
+  checkContains("a a a", ["a", "aa", "b"], [true, false, false]);
+  checkContains("a b c", ["a", "b"], true);
+
+  checkContains("null undefined", [null, undefined], true);
+  checkContains("\t\n\f\r a\t\n\f\r b\t\n\f\r ", ["a", "b"], true);
+
+  // add() method
+
+  function checkAdd(before, argument, after, param) {
+    var expectedException = undefined;
+    var noop = false;
+    if (param == "noop") {
+      noop = true;
+    } else {
+      expectedException = param;
+    }
+    checkModification(e, "add", argument, undefined, before, after,
+                      expectedException, desc);
+    // Also check force toggle.  The only difference is that it doesn't run the
+    // update steps for a no-op.
+    if (!Array.isArray(argument)) {
+      checkModification(e, "toggle", [argument, true], true, before,
+                        noop ? before : after, expectedException, desc);
+    }
+  }
+
+  checkAdd(null, "", null, "SyntaxError");
+  checkAdd(null, ["a", ""], null, "SyntaxError");
+  checkAdd(null, " ", null, "InvalidCharacterError");
+  checkAdd(null, "\ta", null, "InvalidCharacterError");
+  checkAdd(null, "a\t", null, "InvalidCharacterError");
+  checkAdd(null, "\na", null, "InvalidCharacterError");
+  checkAdd(null, "a\n", null, "InvalidCharacterError");
+  checkAdd(null, "\fa", null, "InvalidCharacterError");
+  checkAdd(null, "a\f", null, "InvalidCharacterError");
+  checkAdd(null, "\ra", null, "InvalidCharacterError");
+  checkAdd(null, "a\r", null, "InvalidCharacterError");
+  checkAdd(null, " a", null, "InvalidCharacterError");
+  checkAdd(null, "a ", null, "InvalidCharacterError");
+  checkAdd(null, ["a", " "], null, "InvalidCharacterError");
+  checkAdd(null, ["a", "aa "], null, "InvalidCharacterError");
+
+  checkAdd("a", "a", "a");
+  checkAdd("aa", "AA", "aa AA");
+  checkAdd("a b c", "a", "a b c");
+  checkAdd("a a a  b", "a", "a b", "noop");
+  checkAdd(null, "a", "a");
+  checkAdd("", "a", "a");
+  checkAdd(" ", "a", "a");
+  checkAdd("   \f", "a", "a");
+  checkAdd("a", "b", "a b");
+  checkAdd("a b c", "d", "a b c d");
+  checkAdd("a b c ", "d", "a b c d");
+  checkAdd("   a  a b", "c", "a b c");
+  checkAdd("   a  a b", "a", "a b", "noop");
+  checkAdd("\t\n\f\r a\t\n\f\r b\t\n\f\r ", "c", "a b c");
+
+  // multiple add
+  checkAdd("a b c ", ["d", "e"], "a b c d e");
+  checkAdd("a b c ", ["a", "a"], "a b c");
+  checkAdd("a b c ", ["d", "d"], "a b c d");
+  checkAdd("a b c a ", [], "a b c");
+  checkAdd(null, ["a", "b"], "a b");
+  checkAdd("", ["a", "b"], "a b");
+
+  checkAdd(null, null, "null");
+  checkAdd(null, undefined, "undefined");
+
+  // remove() method
+
+  function checkRemove(before, argument, after, param) {
+    var expectedException = undefined;
+    var noop = false;
+    if (param == "noop") {
+      noop = true;
+    } else {
+      expectedException = param;
+    }
+    checkModification(e, "remove", argument, undefined, before, after,
+                      expectedException, desc);
+    // Also check force toggle.  The only difference is that it doesn't run the
+    // update steps for a no-op.
+    if (!Array.isArray(argument)) {
+      checkModification(e, "toggle", [argument, false], false, before,
+                        noop ? before : after, expectedException, desc);
+    }
+  }
+
+  checkRemove(null, "", null, "SyntaxError");
+  checkRemove(null, " ", null, "InvalidCharacterError");
+  checkRemove("\ta", "\ta", "\ta", "InvalidCharacterError");
+  checkRemove("a\t", "a\t", "a\t", "InvalidCharacterError");
+  checkRemove("\na", "\na", "\na", "InvalidCharacterError");
+  checkRemove("a\n", "a\n", "a\n", "InvalidCharacterError");
+  checkRemove("\fa", "\fa", "\fa", "InvalidCharacterError");
+  checkRemove("a\f", "a\f", "a\f", "InvalidCharacterError");
+  checkRemove("\ra", "\ra", "\ra", "InvalidCharacterError");
+  checkRemove("a\r", "a\r", "a\r", "InvalidCharacterError");
+  checkRemove(" a", " a", " a", "InvalidCharacterError");
+  checkRemove("a ", "a ", "a ", "InvalidCharacterError");
+  checkRemove("aa ", "aa ", null, "InvalidCharacterError");
+
+  checkRemove(null, "a", null);
+  checkRemove("", "a", "");
+  checkRemove("a b  c", "d", "a b c", "noop");
+  checkRemove("a b  c", "A", "a b c", "noop");
+  checkRemove(" a a a ", "a", "");
+  checkRemove("a  b", "a", "b");
+  checkRemove("a  b  ", "a", "b");
+  checkRemove("a a b", "a", "b");
+  checkRemove("aa aa bb", "aa", "bb");
+  checkRemove("a a b a a c a a", "a", "b c");
+
+  checkRemove("a  b  c", "b", "a c");
+  checkRemove("aaa  bbb  ccc", "bbb", "aaa ccc");
+  checkRemove(" a  b  c ", "b", "a c");
+  checkRemove("a b b b c", "b", "a c");
+
+  checkRemove("a  b  c", "c", "a b");
+  checkRemove(" a  b  c ", "c", "a b");
+  checkRemove("a b c c c", "c", "a b");
+
+  checkRemove("a b a c a d a", "a", "b c d");
+  checkRemove("AA BB aa CC AA dd aa", "AA", "BB aa CC dd");
+
+  checkRemove("\ra\na\ta\f", "a", "");
+  checkRemove("\t\n\f\r a\t\n\f\r b\t\n\f\r ", "a", "b");
+
+  // multiple remove
+  checkRemove("a b c ", ["d", "e"], "a b c");
+  checkRemove("a b c ", ["a", "b"], "c");
+  checkRemove("a b c ", ["a", "c"], "b");
+  checkRemove("a b c ", ["a", "a"], "b c");
+  checkRemove("a b c ", ["d", "d"], "a b c");
+  checkRemove("a b c ", [], "a b c");
+  checkRemove(null, ["a", "b"], null);
+  checkRemove("", ["a", "b"], "");
+  checkRemove("a a", [], "a");
+
+  checkRemove("null", null, "");
+  checkRemove("undefined", undefined, "");
+
+  // toggle() method
+
+  function checkToggle(before, argument, expectedRes, after, expectedException) {
+    checkModification(e, "toggle", argument, expectedRes, before, after,
+                      expectedException, desc);
+  }
+
+  checkToggle(null, "", null, null, "SyntaxError");
+  checkToggle(null, "aa ", null, null, "InvalidCharacterError");
+
+  checkToggle(null, "a", true, "a");
+  checkToggle("", "a", true, "a");
+  checkToggle(" ", "a", true, "a");
+  checkToggle("   \f", "a", true, "a");
+  checkToggle("a", "b", true, "a b");
+  checkToggle("a", "A", true, "a A");
+  checkToggle("a b c", "d", true, "a b c d");
+  checkToggle("   a  a b", "d", true, "a b d");
+
+  checkToggle("a", "a", false, "");
+  checkToggle(" a a a ", "a", false, "");
+  checkToggle(" A A A ", "a", true, "A a");
+  checkToggle(" a b c ", "b", false, "a c");
+  checkToggle(" a b c b b", "b", false, "a c");
+  checkToggle(" a b  c  ", "c", false, "a b");
+  checkToggle(" a b c ", "a", false, "b c");
+  checkToggle("   a  a b", "b", false, "a");
+  checkToggle("\t\n\f\r a\t\n\f\r b\t\n\f\r ", "a", false, "b");
+  checkToggle("\t\n\f\r a\t\n\f\r b\t\n\f\r ", "c", true, "a b c");
+
+  checkToggle("null", null, false, "");
+  checkToggle("", null, true, "null");
+  checkToggle("undefined", undefined, false, "");
+  checkToggle("", undefined, true, "undefined");
+
+
+  // replace() method
+  function checkReplace(before, token, newToken, expectedRes, after, expectedException) {
+    checkModification(e, "replace", [token, newToken], expectedRes, before,
+                      after, expectedException, desc);
+  }
+
+  checkReplace(null, "", "a", null, null, "SyntaxError");
+  checkReplace(null, "", " ", null, null, "SyntaxError");
+  checkReplace(null, " ", "a", null, null, "InvalidCharacterError");
+  checkReplace(null, "\ta", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, "a\t", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, "\na", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, "a\n", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, "\fa", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, "a\f", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, "\ra", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, "a\r", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, " a", "b", null, null, "InvalidCharacterError");
+  checkReplace(null, "a ", "b", null, null, "InvalidCharacterError");
+
+  checkReplace(null, "a", "", null, null, "SyntaxError");
+  checkReplace(null, " ", "", null, null, "SyntaxError");
+  checkReplace(null, "a", " ", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "\ta", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "a\t", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "\na", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "a\n", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "\fa", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "a\f", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "\ra", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "a\r", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", " a", null, null, "InvalidCharacterError");
+  checkReplace(null, "b", "a ", null, null, "InvalidCharacterError");
+
+  checkReplace("a", "a", "a", true, "a");
+  checkReplace("a", "a", "b", true, "b");
+  checkReplace("a", "A", "b", false, "a");
+  checkReplace("a b", "b", "A", true, "a A");
+  checkReplace("a b", "c", "a", false, "a b");
+  checkReplace("a b c", "d", "e", false, "a b c");
+  // https://github.com/whatwg/dom/issues/443
+  checkReplace("a a a  b", "a", "a", true, "a b");
+  checkReplace("a a a  b", "c", "d", false, "a a a  b");
+  checkReplace(null, "a", "b", false, null);
+  checkReplace("", "a", "b", false, "");
+  checkReplace(" ", "a", "b", false, " ");
+  checkReplace(" a  \f", "a", "b", true, "b");
+  checkReplace("a b c", "b", "d", true, "a d c");
+  checkReplace("a b c", "c", "a", true, "a b");
+  checkReplace("c b a", "c", "a", true, "a b");
+  checkReplace("a b a", "a", "c", true, "c b");
+  checkReplace("a b a", "b", "c", true, "a c");
+  checkReplace("   a  a b", "a", "c", true, "c b");
+  checkReplace("   a  a b", "b", "c", true, "a c");
+  checkReplace("\t\n\f\r a\t\n\f\r b\t\n\f\r ", "a", "c", true, "c b");
+  checkReplace("\t\n\f\r a\t\n\f\r b\t\n\f\r ", "b", "c", true, "a c");
+
+  checkReplace("a null", null, "b", true, "a b");
+  checkReplace("a b", "a", null, true, "null b");
+  checkReplace("a undefined", undefined, "b", true, "a b");
+  checkReplace("a b", "a", undefined, true, "undefined b");
+}
+
+var content = document.getElementById("content");
+
+var htmlNode = document.createElement("div");
+content.appendChild(htmlNode);
+testClassList(htmlNode, " (HTML node)");
+
+var xhtmlNode = document.createElementNS(XHTML_NS, "div");
+content.appendChild(xhtmlNode);
+testClassList(xhtmlNode, " (XHTML node)");
+
+var mathMLNode = document.createElementNS(MATHML_NS, "math");
+content.appendChild(mathMLNode);
+testClassList(mathMLNode, " (MathML node)");
+
+var xmlNode = document.createElementNS(null, "foo");
+content.appendChild(xmlNode);
+testClassList(xmlNode, " (XML node with null namespace)");
+
+var fooNode = document.createElementNS("http://example.org/foo", "foo");
+content.appendChild(fooNode);
+testClassList(fooNode, " (foo node)");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-closest.html b/testing/web-platform/tests/dom/nodes/Element-closest.html
new file mode 100644
index 0000000000..386e3bd251
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-closest.html
@@ -0,0 +1,73 @@
+<!DOCTYPE HTML>
+<meta charset=utf8>
+<title>Test for Element.closest</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body id="body">
+  <div id="test8" class="div3" style="display:none">
+    <div id="test7" class="div2">
+      <div id="test6" class="div1">
+        <form id="test10" class="form2"></form>
+        <form id="test5" class="form1" name="form-a">
+          <input id="test1" class="input1" required>
+          <fieldset class="fieldset2" id="test2">
+            <select id="test3" class="select1" required>
+              <option default id="test4" value="">Test4</option>
+              <option selected id="test11">Test11</option>
+              <option id="test12">Test12</option>
+              <option id="test13">Test13</option>
+            </select>
+            <input id="test9" type="text" required>
+          </fieldset>
+        </form>
+      </div>
+    </div>
+  </div>
+  <div id=log></div>
+<script>
+  do_test("select"                     , "test12", "test3");
+  do_test("fieldset"                   , "test13", "test2");
+  do_test("div"                        , "test13", "test6");
+  do_test("body"                       , "test3" , "body");
+
+  do_test("[default]"                  , "test4" , "test4");
+  do_test("[selected]"                 , "test4" , "");
+  do_test("[selected]"                 , "test11", "test11");
+  do_test('[name="form-a"]'            , "test12", "test5");
+  do_test('form[name="form-a"]'        , "test13", "test5");
+  do_test("input[required]"            , "test9" , "test9");
+  do_test("select[required]"           , "test9" , "");
+
+  do_test("div:not(.div1)"             , "test13", "test7");
+  do_test("div.div3"                   , "test6" , "test8");
+  do_test("div#test7"                  , "test1" , "test7");
+
+  do_test(".div3 > .div2"              , "test12", "test7");
+  do_test(".div3 > .div1"              , "test12", "");
+  do_test("form > input[required]"     , "test9" , "");
+  do_test("fieldset > select[required]", "test12", "test3");
+
+  do_test("input + fieldset"           , "test6" , "");
+  do_test("form + form"                , "test3" , "test5");
+  do_test("form + form"                , "test5" , "test5");
+
+  do_test(":empty"                     , "test10", "test10");
+  do_test(":last-child"                , "test11", "test2");
+  do_test(":first-child"               , "test12", "test3");
+  do_test(":invalid"                   , "test11", "test2");
+
+  do_test(":scope"                     , "test4",  "test4");
+  do_test("select > :scope"            , "test4",  "test4");
+  do_test("div > :scope"               , "test4",  "");
+  do_test(":has(> :scope)"             , "test4",  "test3");
+function do_test(aSelector, aElementId, aTargetId) {
+  test(function() {
+    var el = document.getElementById(aElementId).closest(aSelector);
+    if (el === null) {
+      assert_equals("", aTargetId, aSelector);
+    } else {
+      assert_equals(el.id, aTargetId, aSelector);
+    }
+  }, "Element.closest with context node '" + aElementId + "' and selector '" + aSelector + "'");
+}
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-firstElementChild-entity-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-entity-xhtml.xhtml
new file mode 100644
index 0000000000..f28005e9c8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-entity-xhtml.xhtml
@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
+        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
+[
+<!ENTITY tree "<span id='first_element_child' style='font-weight:bold;'>unknown.</span>">
+]>
+<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
+<head>
+<title>Entity References</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of Entity References</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is &tree;</p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  var fec = parentEl.firstElementChild;
+  assert_true(!!fec)
+  assert_equals(fec.nodeType, 1)
+  assert_equals(fec.getAttribute("id"), "first_element_child")
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-firstElementChild-entity.svg b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-entity.svg
new file mode 100644
index 0000000000..3a20ea79ab
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-entity.svg
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"
+[
+<!ENTITY tree "<tspan id='first_element_child' font-weight='bold'>unknown.</tspan>">
+]>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>Entity References</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of Entity References</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of this test is &tree;</text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  var fec = parentEl.firstElementChild;
+  assert_true(!!fec)
+  assert_equals(fec.nodeType, 1)
+  assert_equals(fec.getAttribute("id"), "first_element_child")
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace-svg.svg b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace-svg.svg
new file mode 100644
index 0000000000..d42c08777c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace-svg.svg
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     xmlns:pickle="http://ns.example.org/pickle"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>firstElementChild with namespaces</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of firstElementChild with namespaces</text>
+<g id="parentEl">
+  <pickle:dill id="first_element_child"/>
+</g>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var fec = parentEl.firstElementChild;
+  assert_true(!!fec)
+  assert_equals(fec.nodeType, 1)
+  assert_equals(fec.getAttribute("id"), "first_element_child")
+  assert_equals(fec.localName, "dill")
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace-xhtml.xhtml
new file mode 100644
index 0000000000..29441d2786
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace-xhtml.xhtml
@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml"
+      xmlns:pickle="http://ns.example.org/pickle">
+<head>
+<title>firstElementChild with namespaces</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of firstElementChild with namespaces</h1>
+<div id="parentEl">
+  <pickle:dill id="first_element_child"/>
+</div>
+<div id="log"></div>
+<p id="parentEl">The result of this test is
+<span id="first_element_child" style="font-weight:bold;">logged above.</span></p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var fec = parentEl.firstElementChild;
+  assert_true(!!fec)
+  assert_equals(fec.nodeType, 1)
+  assert_equals(fec.getAttribute("id"), "first_element_child")
+  assert_equals(fec.localName, "dill")
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace.html b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace.html
new file mode 100644
index 0000000000..629deab3ae
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-namespace.html
@@ -0,0 +1,21 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>firstElementChild with namespaces</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of firstElementChild with namespaces</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is a unknown.</p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl")
+  var el = document.createElementNS("http://ns.example.org/pickle", "pickle:dill")
+  el.setAttribute("id", "first_element_child")
+  parentEl.appendChild(el)
+  var fec = parentEl.firstElementChild
+  assert_true(!!fec)
+  assert_equals(fec.nodeType, 1)
+  assert_equals(fec.getAttribute("id"), "first_element_child")
+  assert_equals(fec.localName, "dill")
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-firstElementChild-svg.svg b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-svg.svg
new file mode 100644
index 0000000000..359c5b82ca
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-svg.svg
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>firstElementChild</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of firstElementChild</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of this test is
+<tspan id="first_element_child" font-weight="bold">unknown.</tspan></text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var fec = parentEl.firstElementChild;
+  assert_true(!!fec)
+  assert_equals(fec.nodeType, 1)
+  assert_equals(fec.getAttribute("id"), "first_element_child")
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-firstElementChild-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-xhtml.xhtml
new file mode 100644
index 0000000000..302052b0fc
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-firstElementChild-xhtml.xhtml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>firstElementChild</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of firstElementChild</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is
+<span id="first_element_child" style="font-weight:bold;">logged above.</span></p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var fec = parentEl.firstElementChild;
+  assert_true(!!fec)
+  assert_equals(fec.nodeType, 1)
+  assert_equals(fec.getAttribute("id"), "first_element_child")
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-firstElementChild.html b/testing/web-platform/tests/dom/nodes/Element-firstElementChild.html
new file mode 100644
index 0000000000..12a0c5946e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-firstElementChild.html
@@ -0,0 +1,18 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>firstElementChild</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of firstElementChild</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is
+<span id="first_element_child" style="font-weight:bold;">logged above.</span></p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var fec = parentEl.firstElementChild;
+  assert_true(!!fec)
+  assert_equals(fec.nodeType, 1)
+  assert_equals(fec.getAttribute("id"), "first_element_child")
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-getElementsByClassName.html b/testing/web-platform/tests/dom/nodes/Element-getElementsByClassName.html
new file mode 100644
index 0000000000..bc87b05d25
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-getElementsByClassName.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<title>Element.getElementsByClassName</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var a = document.createElement("a"), b = document.createElement("b")
+  b.className = "foo"
+  a.appendChild(b)
+  var list = a.getElementsByClassName("foo")
+  assert_array_equals(list, [b])
+  var secondList = a.getElementsByClassName("foo")
+  assert_true(list === secondList || list !== secondList, "Caching is allowed.")
+}, "getElementsByClassName should work on disconnected subtrees.")
+
+test(function() {
+  var list = document.getElementsByClassName("foo")
+  assert_false(list instanceof NodeList, "NodeList")
+  assert_true(list instanceof HTMLCollection, "HTMLCollection")
+}, "Interface should be correct.")
+
+test(function() {
+  var a = document.createElement("a");
+  var b = document.createElement("b");
+  var c = document.createElement("c");
+  b.className = "foo";
+  document.body.appendChild(a);
+  this.add_cleanup(function() {document.body.removeChild(a)});
+  a.appendChild(b);
+
+  var l = a.getElementsByClassName("foo");
+  assert_true(l instanceof HTMLCollection);
+  assert_equals(l.length, 1);
+
+  c.className = "foo";
+  a.appendChild(c);
+  assert_equals(l.length, 2);
+
+  a.removeChild(c);
+  assert_equals(l.length, 1);
+}, "getElementsByClassName() should be a live collection");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess-iframe.xml b/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess-iframe.xml
new file mode 100644
index 0000000000..f3f286eafc
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess-iframe.xml
@@ -0,0 +1 @@
+<root/>
diff --git a/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess.html b/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess.html
new file mode 100644
index 0000000000..c41ee2e877
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName-change-document-HTMLNess.html
@@ -0,0 +1,51 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<iframe src="Element-getElementsByTagName-change-document-HTMLNess-iframe.xml"></iframe>
+<script>
+  setup({ single_test: true });
+  onload = function() {
+    var parent = document.createElement("div");
+    var child1 = document.createElementNS("http://www.w3.org/1999/xhtml", "a");
+    child1.textContent = "xhtml:a";
+    var child2 = document.createElementNS("http://www.w3.org/1999/xhtml", "A");
+    child2.textContent = "xhtml:A";
+    var child3 = document.createElementNS("", "a");
+    child3.textContent = "a";
+    var child4 = document.createElementNS("", "A");
+    child4.textContent = "A";
+
+    parent.appendChild(child1);
+    parent.appendChild(child2);
+    parent.appendChild(child3);
+    parent.appendChild(child4);
+
+    var list = parent.getElementsByTagName("A");
+    assert_array_equals(list, [child1, child4],
+      "In an HTML document, should lowercase the tagname passed in for HTML " +
+      "elements only");
+
+    frames[0].document.documentElement.appendChild(parent);
+    assert_array_equals(list, [child1, child4],
+      "After changing document, should still be lowercasing for HTML");
+
+    assert_array_equals(parent.getElementsByTagName("A"),
+                        [child2, child4],
+      "New list with same root and argument should not be lowercasing now");
+
+    // Now reinsert all those nodes into the parent, to blow away caches.
+    parent.appendChild(child1);
+    parent.appendChild(child2);
+    parent.appendChild(child3);
+    parent.appendChild(child4);
+    assert_array_equals(list, [child1, child4],
+      "After blowing away caches, should still have the same list");
+
+    assert_array_equals(parent.getElementsByTagName("A"),
+                        [child2, child4],
+      "New list with same root and argument should still not be lowercasing");
+    done();
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName.html b/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName.html
new file mode 100644
index 0000000000..87c4fe934a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-getElementsByTagName.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Element.getElementsByTagName</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-getelementsbytagname">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-Element-getElementsByTagName.js"></script>
+<div id="log"></div>
+<script>
+var element;
+setup(function() {
+  element = document.createElement("div");
+  element.appendChild(document.createTextNode("text"));
+  var p = element.appendChild(document.createElement("p"));
+  p.appendChild(document.createElement("a"))
+   .appendChild(document.createTextNode("link"));
+  p.appendChild(document.createElement("b"))
+   .appendChild(document.createTextNode("bold"));
+  p.appendChild(document.createElement("em"))
+   .appendChild(document.createElement("u"))
+   .appendChild(document.createTextNode("emphasized"));
+  element.appendChild(document.createComment("comment"));
+});
+
+test_getElementsByTagName(element, element);
+
+test(function() {
+  assert_array_equals(element.getElementsByTagName(element.localName), []);
+}, "Matching the context object");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-getElementsByTagNameNS.html b/testing/web-platform/tests/dom/nodes/Element-getElementsByTagNameNS.html
new file mode 100644
index 0000000000..f826afc391
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-getElementsByTagNameNS.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Element.getElementsByTagNameNS</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-getelementsbytagnamens">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Document-Element-getElementsByTagNameNS.js"></script>
+<div id="log"></div>
+<script>
+var element;
+setup(function() {
+  element = document.createElement("div");
+  element.appendChild(document.createTextNode("text"));
+  var p = element.appendChild(document.createElement("p"));
+  p.appendChild(document.createElement("a"))
+   .appendChild(document.createTextNode("link"));
+  p.appendChild(document.createElement("b"))
+   .appendChild(document.createTextNode("bold"));
+  p.appendChild(document.createElement("em"))
+   .appendChild(document.createElement("u"))
+   .appendChild(document.createTextNode("emphasized"));
+  element.appendChild(document.createComment("comment"));
+});
+
+test_getElementsByTagNameNS(element, element);
+
+test(function() {
+  assert_array_equals(element.getElementsByTagNameNS("*", element.localName), []);
+}, "Matching the context object (wildcard namespace)");
+
+test(function() {
+  assert_array_equals(
+    element.getElementsByTagNameNS("http://www.w3.org/1999/xhtml",
+                                   element.localName),
+    []);
+}, "Matching the context object (specific namespace)");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-hasAttribute.html b/testing/web-platform/tests/dom/nodes/Element-hasAttribute.html
new file mode 100644
index 0000000000..26528d7569
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-hasAttribute.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Element.prototype.hasAttribute</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-hasattribute">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<span data-e2="2" data-F2="3" id="t"></span>
+
+<script>
+"use strict";
+
+test(() => {
+
+  const el = document.createElement("p");
+  el.setAttributeNS("foo", "x", "first");
+
+  assert_true(el.hasAttribute("x"));
+
+}, "hasAttribute should check for attribute presence, irrespective of namespace");
+
+test(() => {
+
+  const el = document.getElementById("t");
+
+  assert_true(el.hasAttribute("data-e2"));
+  assert_true(el.hasAttribute("data-E2"));
+  assert_true(el.hasAttribute("data-f2"));
+  assert_true(el.hasAttribute("data-F2"));
+
+}, "hasAttribute should work with all attribute casings");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-hasAttributes.html b/testing/web-platform/tests/dom/nodes/Element-hasAttributes.html
new file mode 100644
index 0000000000..fbb9c233b7
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-hasAttributes.html
@@ -0,0 +1,40 @@
+<!doctype html>
+<meta charset="utf-8">
+<title></title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<button></button>
+<div id="foo"></div>
+<p data-foo=""></p>
+
+<script>
+test(function() {
+    var buttonElement = document.getElementsByTagName('button')[0];
+    assert_equals(buttonElement.hasAttributes(), false, 'hasAttributes() on empty element must return false.');
+
+    var emptyDiv = document.createElement('div');
+    assert_equals(emptyDiv.hasAttributes(), false, 'hasAttributes() on dynamically created empty element must return false.');
+
+}, 'element.hasAttributes() must return false when the element does not have attribute.');
+
+test(function() {
+    var divWithId = document.getElementById('foo');
+    assert_equals(divWithId.hasAttributes(), true, 'hasAttributes() on element with id attribute must return true.');
+
+    var divWithClass = document.createElement('div');
+    divWithClass.setAttribute('class', 'foo');
+    assert_equals(divWithClass.hasAttributes(), true, 'hasAttributes() on dynamically created element with class attribute must return true.');
+
+    var pWithCustomAttr = document.getElementsByTagName('p')[0];
+    assert_equals(pWithCustomAttr.hasAttributes(), true, 'hasAttributes() on element with custom attribute must return true.');
+
+    var divWithCustomAttr = document.createElement('div');
+    divWithCustomAttr.setAttribute('data-custom', 'foo');
+    assert_equals(divWithCustomAttr.hasAttributes(), true, 'hasAttributes() on dynamically created element with custom attribute must return true.');
+
+}, 'element.hasAttributes() must return true when the element has attribute.');
+
+</script>
+</body>
diff --git a/testing/web-platform/tests/dom/nodes/Element-insertAdjacentElement.html b/testing/web-platform/tests/dom/nodes/Element-insertAdjacentElement.html
new file mode 100644
index 0000000000..9eafee6a76
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-insertAdjacentElement.html
@@ -0,0 +1,91 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+
+<div id="target"></div>
+<div id="parent"><span id=target2></span></div>
+<div id="log" style="visibility:visible"></div>
+<span id="test1"></span>
+<span id="test2"></span>
+<span id="test3"></span>
+<span id="test4"></span>
+<script>
+var target = document.getElementById("target");
+var target2 = document.getElementById("target2");
+
+test(function() {
+  assert_throws_dom("SyntaxError", function() {
+    target.insertAdjacentElement("test", document.getElementById("test1"))
+  });
+
+  assert_throws_dom("SyntaxError", function() {
+    target2.insertAdjacentElement("test", document.getElementById("test1"))
+  });
+}, "Inserting to an invalid location should cause a Syntax Error exception")
+
+test(function() {
+  var el = target.insertAdjacentElement("beforebegin", document.getElementById("test1"));
+  assert_equals(target.previousSibling.id, "test1");
+  assert_equals(el.id, "test1");
+
+  el = target2.insertAdjacentElement("beforebegin", document.getElementById("test1"));
+  assert_equals(target2.previousSibling.id, "test1");
+  assert_equals(el.id, "test1");
+}, "Inserted element should be target element's previous sibling for 'beforebegin' case")
+
+test(function() {
+  var el = target.insertAdjacentElement("afterbegin", document.getElementById("test2"));
+  assert_equals(target.firstChild.id, "test2");
+  assert_equals(el.id, "test2");
+
+  el = target2.insertAdjacentElement("afterbegin", document.getElementById("test2"));
+  assert_equals(target2.firstChild.id, "test2");
+  assert_equals(el.id, "test2");
+}, "Inserted element should be target element's first child for 'afterbegin' case")
+
+test(function() {
+  var el = target.insertAdjacentElement("beforeend", document.getElementById("test3"));
+  assert_equals(target.lastChild.id, "test3");
+  assert_equals(el.id, "test3");
+
+  el = target2.insertAdjacentElement("beforeend", document.getElementById("test3"));
+  assert_equals(target2.lastChild.id, "test3");
+  assert_equals(el.id, "test3");
+}, "Inserted element should be target element's last child for 'beforeend' case")
+
+test(function() {
+  var el = target.insertAdjacentElement("afterend", document.getElementById("test4"));
+  assert_equals(target.nextSibling.id, "test4");
+  assert_equals(el.id, "test4");
+
+  el = target2.insertAdjacentElement("afterend", document.getElementById("test4"));
+  assert_equals(target2.nextSibling.id, "test4");
+  assert_equals(el.id, "test4");
+}, "Inserted element should be target element's next sibling for 'afterend' case")
+
+test(function() {
+  var docElement = document.documentElement;
+  docElement.style.visibility="hidden";
+
+  assert_throws_dom("HierarchyRequestError", function() {
+    var el = docElement.insertAdjacentElement("beforebegin", document.getElementById("test1"));
+    assert_equals(el, null);
+  });
+
+  var el = docElement.insertAdjacentElement("afterbegin", document.getElementById("test2"));
+  assert_equals(docElement.firstChild.id, "test2");
+  assert_equals(el.id, "test2");
+
+  el = docElement.insertAdjacentElement("beforeend", document.getElementById("test3"));
+  assert_equals(docElement.lastChild.id, "test3");
+  assert_equals(el.id, "test3");
+
+  assert_throws_dom("HierarchyRequestError", function() {
+    var el = docElement.insertAdjacentElement("afterend", document.getElementById("test4"));
+    assert_equals(el, null);
+  });
+}, "Adding more than one child to document should cause a HierarchyRequestError exception")
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-insertAdjacentText.html b/testing/web-platform/tests/dom/nodes/Element-insertAdjacentText.html
new file mode 100644
index 0000000000..be744fd49e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-insertAdjacentText.html
@@ -0,0 +1,76 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<body style="visibility:hidden">
+<div id="target"></div>
+<div id="parent"><span id=target2></span></div>
+<div id="log" style="visibility:visible"></div>
+</body>
+<script>
+var target = document.getElementById("target");
+var target2 = document.getElementById("target2");
+
+test(function() {
+  assert_throws_dom("SyntaxError", function() {
+    target.insertAdjacentText("test", "text")
+  });
+
+  assert_throws_dom("SyntaxError", function() {
+    target2.insertAdjacentText("test", "test")
+  });
+}, "Inserting to an invalid location should cause a Syntax Error exception")
+
+test(function() {
+  target.insertAdjacentText("beforebegin", "test1");
+  assert_equals(target.previousSibling.nodeValue, "test1");
+
+  target2.insertAdjacentText("beforebegin", "test1");
+  assert_equals(target2.previousSibling.nodeValue, "test1");
+}, "Inserted text node should be target element's previous sibling for 'beforebegin' case")
+
+test(function() {
+  target.insertAdjacentText("afterbegin", "test2");
+  assert_equals(target.firstChild.nodeValue, "test2");
+
+  target2.insertAdjacentText("afterbegin", "test2");
+  assert_equals(target2.firstChild.nodeValue, "test2");
+}, "Inserted text node should be target element's first child for 'afterbegin' case")
+
+test(function() {
+  target.insertAdjacentText("beforeend", "test3");
+  assert_equals(target.lastChild.nodeValue, "test3");
+
+  target2.insertAdjacentText("beforeend", "test3");
+  assert_equals(target2.lastChild.nodeValue, "test3");
+}, "Inserted text node should be target element's last child for 'beforeend' case")
+
+test(function() {
+  target.insertAdjacentText("afterend", "test4");
+  assert_equals(target.nextSibling.nodeValue, "test4");
+
+  target2.insertAdjacentText("afterend", "test4");
+  assert_equals(target.nextSibling.nodeValue, "test4");
+}, "Inserted text node should be target element's next sibling for 'afterend' case")
+
+test(function() {
+  var docElement = document.documentElement;
+  docElement.style.visibility="hidden";
+
+  assert_throws_dom("HierarchyRequestError", function() {
+    docElement.insertAdjacentText("beforebegin", "text1")
+  });
+
+  docElement.insertAdjacentText("afterbegin", "test2");
+  assert_equals(docElement.firstChild.nodeValue, "test2");
+
+  docElement.insertAdjacentText("beforeend", "test3");
+  assert_equals(docElement.lastChild.nodeValue, "test3");
+
+  assert_throws_dom("HierarchyRequestError", function() {
+    docElement.insertAdjacentText("afterend", "test4")
+  });
+}, "Adding more than one child to document should cause a HierarchyRequestError exception")
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-lastElementChild-svg.svg b/testing/web-platform/tests/dom/nodes/Element-lastElementChild-svg.svg
new file mode 100644
index 0000000000..1cec4a1308
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-lastElementChild-svg.svg
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>lastElementChild</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of lastElementChild</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of <tspan id="first_element_child">this test</tspan> is <tspan id="last_element_child" font-weight="bold">not</tspan> known.</text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = parentEl.lastElementChild;
+  assert_true(!!lec)
+  assert_equals(lec.nodeType, 1)
+  assert_equals(lec.getAttribute("id"), "last_element_child")
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-lastElementChild-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-lastElementChild-xhtml.xhtml
new file mode 100644
index 0000000000..3150b92a42
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-lastElementChild-xhtml.xhtml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>firstElementChild</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of firstElementChild</h1>
+<div id="log"></div>
+<p id="parentEl">The result of <span id="first_element_child">this test</span> is <span id="last_element_child" style="font-weight:bold;">logged</span> above.</p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = parentEl.lastElementChild;
+  assert_true(!!lec)
+  assert_equals(lec.nodeType, 1)
+  assert_equals(lec.getAttribute("id"), "last_element_child")
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-lastElementChild.html b/testing/web-platform/tests/dom/nodes/Element-lastElementChild.html
new file mode 100644
index 0000000000..de7aebdf24
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-lastElementChild.html
@@ -0,0 +1,17 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>lastElementChild</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of lastElementChild</h1>
+<div id="log"></div>
+<p id="parentEl">The result of <span id="first_element_child">this test</span> is <span id="last_element_child" style="font-weight:bold;">logged</span> above.</p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = parentEl.lastElementChild;
+  assert_true(!!lec)
+  assert_equals(lec.nodeType, 1)
+  assert_equals(lec.getAttribute("id"), "last_element_child")
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-matches-init.js b/testing/web-platform/tests/dom/nodes/Element-matches-init.js
new file mode 100644
index 0000000000..254af61565
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-matches-init.js
@@ -0,0 +1,65 @@
+function init(e, method) {
+  /*
+   * This test suite tests Selectors API methods in 4 different contexts:
+   * 1. Document node
+   * 2. In-document Element node
+   * 3. Detached Element node (an element with no parent, not in the document)
+   * 4. Document Fragment node
+   *
+   * For each context, the following tests are run:
+   *
+   * The interface check tests ensure that each type of node exposes the Selectors API methods.
+   *
+   * The matches() tests are run
+   * All the selectors tested for both the valid and invalid selector tests are found in selectors.js.
+   * See comments in that file for documentation of the format used.
+   *
+   * The level2-lib.js file contains all the common test functions for running each of the aforementioned tests
+   */
+
+  var docType  = "html"; // Only run tests suitable for HTML
+
+  // Prepare the nodes for testing
+  var doc = e.target.contentDocument;                 // Document Node tests
+
+  var element = doc.getElementById("root");   // In-document Element Node tests
+
+  //Setup the namespace tests
+  setupSpecialElements(doc, element);
+
+  var outOfScope = element.cloneNode(true);   // Append this to the body before running the in-document
+                                               // Element tests, but after running the Document tests. This
+                                               // tests that no elements that are not descendants of element
+                                               // are selected.
+
+  traverse(outOfScope, function(elem) {        // Annotate each element as being a clone; used for verifying
+    elem.setAttribute("data-clone", "");     // that none of these elements ever match.
+  });
+
+
+  var detached = element.cloneNode(true);     // Detached Element Node tests
+
+  var fragment = doc.createDocumentFragment(); // Fragment Node tests
+  fragment.appendChild(element.cloneNode(true));
+
+  // Setup Tests
+  interfaceCheckMatches(method, "Document", doc);
+  interfaceCheckMatches(method, "Detached Element", detached);
+  interfaceCheckMatches(method, "Fragment", fragment);
+  interfaceCheckMatches(method, "In-document Element", element);
+
+  runSpecialMatchesTests(method, "DIV Element", element);
+  runSpecialMatchesTests(method, "NULL Element", document.createElement("null"));
+  runSpecialMatchesTests(method, "UNDEFINED Element", document.createElement("undefined"));
+
+  runInvalidSelectorTestMatches(method, "Document", doc, invalidSelectors);
+  runInvalidSelectorTestMatches(method, "Detached Element", detached, invalidSelectors);
+  runInvalidSelectorTestMatches(method, "Fragment", fragment, invalidSelectors);
+  runInvalidSelectorTestMatches(method, "In-document Element", element, invalidSelectors);
+
+  runMatchesTest(method, "In-document", doc, validSelectors, "html");
+  runMatchesTest(method, "Detached", detached, validSelectors, "html");
+  runMatchesTest(method, "Fragment", fragment, validSelectors, "html");
+
+  runMatchesTest(method, "In-document", doc, scopedSelectors, "html");
+}
diff --git a/testing/web-platform/tests/dom/nodes/Element-matches-namespaced-elements.html b/testing/web-platform/tests/dom/nodes/Element-matches-namespaced-elements.html
new file mode 100644
index 0000000000..e61b11ca61
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-matches-namespaced-elements.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>matches/webkitMatchesSelector must work when an element has a namespace</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!-- Regression tests for https://github.com/jsdom/jsdom/issues/1846, https://github.com/jsdom/jsdom/issues/2247 -->
+
+<script>
+"use strict";
+
+for (const method of ["matches", "webkitMatchesSelector"]) {
+  test(() => {
+    assert_true(document.createElementNS("", "element")[method]("element"));
+  }, `empty string namespace, ${method}`);
+
+  test(() => {
+    assert_true(document.createElementNS("urn:ns", "h")[method]("h"));
+  }, `has a namespace, ${method}`);
+
+  test(() => {
+    assert_true(document.createElementNS("urn:ns", "h")[method]("*|h"));
+  }, `has a namespace, *|, ${method}`);
+}
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-matches.html b/testing/web-platform/tests/dom/nodes/Element-matches.html
new file mode 100644
index 0000000000..de234b6639
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-matches.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>Selectors-API Level 2 Test Suite: HTML with Selectors Level 3</title>
+<!-- Selectors API Test Suite Version 3 -->
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/dom/nodes/selectors.js"></script>
+<script src="/dom/nodes/ParentNode-querySelector-All.js"></script>
+<script src="Element-matches.js"></script>
+<script src="Element-matches-init.js"></script>
+<style>iframe { visibility: hidden; position: absolute; }</style>
+
+<div id="log">This test requires JavaScript.</div>
+
+<script>
+  async_test(function() {
+    var frame = document.createElement("iframe");
+    frame.onload = this.step_func_done(e => init(e, "matches" ));
+    frame.src = "/dom/nodes/ParentNode-querySelector-All-content.html#target";
+    document.body.appendChild(frame);
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-matches.js b/testing/web-platform/tests/dom/nodes/Element-matches.js
new file mode 100644
index 0000000000..a1455c671f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-matches.js
@@ -0,0 +1,135 @@
+/*
+ * Check that the matches() method exists on the given Node
+ */
+function interfaceCheckMatches(method, type, obj) {
+  if (obj.nodeType === obj.ELEMENT_NODE) {
+    test(function() {
+      assert_idl_attribute(obj, method, type + " supports " + method);
+    }, type + " supports " + method)
+  } else {
+    test(function() {
+      assert_false(method in obj, type + " supports " + method);
+    }, type + " should not support " + method)
+  }
+}
+
+function runSpecialMatchesTests(method, type, element) {
+  test(function() { // 1
+    if (element.tagName.toLowerCase() === "null") {
+      assert_true(element[method](null), "An element with the tag name '" + element.tagName.toLowerCase() + "' should match.");
+    } else {
+      assert_false(element[method](null), "An element with the tag name '" + element.tagName.toLowerCase() + "' should not match.");
+    }
+  }, type + "." + method + "(null)")
+
+  test(function() { // 2
+    if (element.tagName.toLowerCase() === "undefined") {
+      assert_true(element[method](undefined), "An element with the tag name '" + element.tagName.toLowerCase() + "' should match.");
+    } else {
+      assert_false(element[method](undefined), "An element with the tag name '" + element.tagName.toLowerCase() + "' should not match.");
+    }
+  }, type + "." + method + "(undefined)")
+
+  test(function() { // 3
+    assert_throws_js(element.ownerDocument.defaultView.TypeError, function() {
+      element[method]();
+    }, "This should throw a TypeError.")
+  }, type + "." + method + " no parameter")
+}
+
+/*
+ * Execute queries with the specified invalid selectors for matches()
+ * Only run these tests when errors are expected. Don't run for valid selector tests.
+ */
+function runInvalidSelectorTestMatches(method, type, root, selectors) {
+  if (root.nodeType === root.ELEMENT_NODE) {
+    for (var i = 0; i < selectors.length; i++) {
+      var s = selectors[i];
+      var n = s["name"];
+      var q = s["selector"];
+
+      test(function() {
+        assert_throws_dom(
+          "SyntaxError",
+          root.ownerDocument.defaultView.DOMException,
+          function() {
+            root[method](q)
+          }
+        );
+      }, type + "." + method + ": " + n + ": " + q);
+    }
+  }
+}
+
+function runMatchesTest(method, type, root, selectors, docType) {
+  var nodeType = getNodeType(root);
+
+  for (var i = 0; i < selectors.length; i++) {
+    var s = selectors[i];
+    var n = s["name"];
+    var q = s["selector"];
+    var e = s["expect"];
+    var u = s["unexpected"];
+
+    var ctx = s["ctx"];
+    var ref = s["ref"];
+
+    if ((!s["exclude"] || (s["exclude"].indexOf(nodeType) === -1 && s["exclude"].indexOf(docType) === -1))
+     && (s["testType"] & TEST_MATCH) ) {
+
+      if (ctx && !ref) {
+        test(function() {
+          var j, element, refNode;
+          for (j = 0; j < e.length; j++) {
+            element = root.querySelector("#" + e[j]);
+            refNode = root.querySelector(ctx);
+            assert_true(element[method](q, refNode), "The element #" + e[j] + " should match the selector.")
+          }
+
+          if (u) {
+            for (j = 0; j < u.length; j++) {
+              element = root.querySelector("#" + u[j]);
+              refNode = root.querySelector(ctx);
+              assert_false(element[method](q, refNode), "The element #" + u[j] + " should not match the selector.")
+            }
+          }
+        }, type + " Element." + method + ": " + n + " (with refNode Element): " + q);
+      }
+
+      if (ref) {
+        test(function() {
+          var j, element, refNodes;
+          for (j = 0; j < e.length; j++) {
+            element = root.querySelector("#" + e[j]);
+            refNodes = root.querySelectorAll(ref);
+            assert_true(element[method](q, refNodes), "The element #" + e[j] + " should match the selector.")
+          }
+
+          if (u) {
+            for (j = 0; j < u.length; j++) {
+              element = root.querySelector("#" + u[j]);
+              refNodes = root.querySelectorAll(ref);
+              assert_false(element[method](q, refNodes), "The element #" + u[j] + " should not match the selector.")
+            }
+          }
+        }, type + " Element." + method + ": " + n + " (with refNodes NodeList): " + q);
+      }
+
+      if (!ctx && !ref) {
+        test(function() {
+          for (var j = 0; j < e.length; j++) {
+            var element = root.querySelector("#" + e[j]);
+            assert_true(element[method](q), "The element #" + e[j] + " should match the selector.")
+          }
+
+          if (u) {
+            for (j = 0; j < u.length; j++) {
+              element = root.querySelector("#" + u[j]);
+              assert_false(element[method](q), "The element #" + u[j] + " should not match the selector.")
+            }
+          }
+        }, type + " Element." + method + ": " + n + " (with no refNodes): " + q);
+      }
+    }
+  }
+}
diff --git a/testing/web-platform/tests/dom/nodes/Element-nextElementSibling-svg.svg b/testing/web-platform/tests/dom/nodes/Element-nextElementSibling-svg.svg
new file mode 100644
index 0000000000..3e17cad20c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-nextElementSibling-svg.svg
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>nextElementSibling</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of nextElementSibling</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of <tspan id="first_element_child">this test</tspan> is <tspan id="last_element_child" font-weight="bold">unknown.</tspan></text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var fec = document.getElementById("first_element_child");
+  var nes = fec.nextElementSibling;
+  assert_true(!!nes)
+  assert_equals(nes.nodeType, 1)
+  assert_equals(nes.getAttribute("id"), "last_element_child")
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-nextElementSibling-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-nextElementSibling-xhtml.xhtml
new file mode 100644
index 0000000000..915209bda2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-nextElementSibling-xhtml.xhtml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>nextElementSibling</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of nextElementSibling</h1>
+<div id="log"></div>
+<p id="parentEl">The result of <span id="first_element_child">this test</span> is <span id="last_element_child" style="font-weight:bold;">unknown.</span></p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var fec = document.getElementById("first_element_child");
+  var nes = fec.nextElementSibling;
+  assert_true(!!nes)
+  assert_equals(nes.nodeType, 1)
+  assert_equals(nes.getAttribute("id"), "last_element_child")
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-nextElementSibling.html b/testing/web-platform/tests/dom/nodes/Element-nextElementSibling.html
new file mode 100644
index 0000000000..985c602f41
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-nextElementSibling.html
@@ -0,0 +1,18 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>nextElementSibling</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of nextElementSibling</h1>
+<div id="log"></div>
+<p id="parentEl">The result of <span id="first_element_child">this test</span> is <span id="last_element_child" style="font-weight:bold;">unknown.</span></p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var fec = document.getElementById("first_element_child");
+  var nes = fec.nextElementSibling;
+  assert_true(!!nes)
+  assert_equals(nes.nodeType, 1)
+  assert_equals(nes.getAttribute("id"), "last_element_child")
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-previousElementSibling-svg.svg b/testing/web-platform/tests/dom/nodes/Element-previousElementSibling-svg.svg
new file mode 100644
index 0000000000..671d2c87f2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-previousElementSibling-svg.svg
@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>previousElementSibling</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of previousElementSibling</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of <tspan id="first_element_child">this test</tspan> is
+<tspan id="middle_element_child" font-weight="bold">unknown.</tspan>
+
+
+
+<tspan id="last_element_child" display="none">fnord</tspan> </text>
+
+<h:script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = document.getElementById("last_element_child");
+  var pes = lec.previousElementSibling;
+  assert_true(!!pes)
+  assert_equals(pes.nodeType, 1)
+  assert_equals(pes.getAttribute("id"), "middle_element_child")
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-previousElementSibling-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-previousElementSibling-xhtml.xhtml
new file mode 100644
index 0000000000..7fbbc6d384
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-previousElementSibling-xhtml.xhtml
@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>previousElementSibling</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of previousElementSibling</h1>
+<div id="log"></div>
+<p id="parentEl">The result of <span id="first_element_child">this test</span> is
+<span id="middle_element_child" style="font-weight:bold;">unknown.</span>
+
+
+
+<span id="last_element_child" style="display:none;">fnord</span> </p>
+<script><![CDATA[
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = document.getElementById("last_element_child");
+  var pes = lec.previousElementSibling;
+  assert_true(!!pes)
+  assert_equals(pes.nodeType, 1)
+  assert_equals(pes.getAttribute("id"), "middle_element_child")
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-previousElementSibling.html b/testing/web-platform/tests/dom/nodes/Element-previousElementSibling.html
new file mode 100644
index 0000000000..02c7b16df5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-previousElementSibling.html
@@ -0,0 +1,23 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>previousElementSibling</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of previousElementSibling</h1>
+<div id="log"></div>
+<p id="parentEl">The result of <span id="first_element_child">this test</span> is
+<span id="middle_element_child" style="font-weight:bold;">unknown.</span>
+
+
+
+<span id="last_element_child" style="display:none;">fnord</span> </p>
+<script>
+test(function() {
+  var parentEl = document.getElementById("parentEl");
+  var lec = document.getElementById("last_element_child");
+  var pes = lec.previousElementSibling;
+  assert_true(!!pes)
+  assert_equals(pes.nodeType, 1)
+  assert_equals(pes.getAttribute("id"), "middle_element_child")
+})
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-remove.html b/testing/web-platform/tests/dom/nodes/Element-remove.html
new file mode 100644
index 0000000000..ab642d660b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-remove.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Element.remove</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-childnode-remove">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="ChildNode-remove.js"></script>
+<div id=log></div>
+<script>
+var node, parentNode;
+setup(function() {
+  node = document.createElement("div");
+  parentNode = document.createElement("div");
+});
+testRemove(node, parentNode, "element");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-removeAttribute.html b/testing/web-platform/tests/dom/nodes/Element-removeAttribute.html
new file mode 100644
index 0000000000..df79e62cf4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-removeAttribute.html
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Element.prototype.removeAttribute</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-removeattribute">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+
+  const el = document.createElement("p");
+  el.setAttribute("x", "first");
+  el.setAttributeNS("foo", "x", "second");
+
+  assert_equals(el.attributes.length, 2);
+  assert_equals(el.getAttribute("x"), "first");
+  assert_equals(el.getAttributeNS(null, "x"), "first");
+  assert_equals(el.getAttributeNS("foo", "x"), "second");
+
+  // removeAttribute removes the first attribute with name "x" that
+  // we set on the element, irrespective of namespace.
+  el.removeAttribute("x");
+
+  // The only attribute remaining should be the second one.
+  assert_equals(el.getAttribute("x"), "second");
+  assert_equals(el.getAttributeNS(null, "x"), null);
+  assert_equals(el.getAttributeNS("foo", "x"), "second");
+  assert_equals(el.attributes.length, 1, "one attribute");
+
+}, "removeAttribute should remove the first attribute, irrespective of namespace, when the first attribute is " +
+   "not in a namespace");
+
+test(() => {
+
+  const el = document.createElement("p");
+  el.setAttributeNS("foo", "x", "first");
+  el.setAttributeNS("foo2", "x", "second");
+
+  assert_equals(el.attributes.length, 2);
+  assert_equals(el.getAttribute("x"), "first");
+  assert_equals(el.getAttributeNS("foo", "x"), "first");
+  assert_equals(el.getAttributeNS("foo2", "x"), "second");
+
+  // removeAttribute removes the first attribute with name "x" that
+  // we set on the element, irrespective of namespace.
+  el.removeAttribute("x");
+
+  // The only attribute remaining should be the second one.
+  assert_equals(el.getAttribute("x"), "second");
+  assert_equals(el.getAttributeNS("foo", "x"), null);
+  assert_equals(el.getAttributeNS("foo2", "x"), "second");
+  assert_equals(el.attributes.length, 1, "one attribute");
+
+}, "removeAttribute should remove the first attribute, irrespective of namespace, when the first attribute is " +
+   "in a namespace");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-removeAttributeNS.html b/testing/web-platform/tests/dom/nodes/Element-removeAttributeNS.html
new file mode 100644
index 0000000000..a2773e6f1e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-removeAttributeNS.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>Element.removeAttributeNS</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="attributes.js"></script>
+<div id="log"></div>
+<script>
+var XML = "http://www.w3.org/XML/1998/namespace"
+
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttributeNS(XML, "a:bb", "pass")
+  attr_is(el.attributes[0], "pass", "bb", XML, "a", "a:bb")
+  el.removeAttributeNS(XML, "a:bb")
+  assert_equals(el.attributes.length, 1)
+  attr_is(el.attributes[0], "pass", "bb", XML, "a", "a:bb")
+}, "removeAttributeNS should take a local name.")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-setAttribute-crbug-1138487.html b/testing/web-platform/tests/dom/nodes/Element-setAttribute-crbug-1138487.html
new file mode 100644
index 0000000000..9aa9ed8139
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-setAttribute-crbug-1138487.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+// Regression test for crbug.com/1138487.
+//
+// It was possible for a non-ASCII-lowercase string to be used when inserting
+// into the attribute collection if a hashtable encountered it during probing
+// while looking for the ASCII-lowercase equivalent.
+//
+// This caused such a string to be illegally used as an attribute name, thus
+// causing inconsistent behavior in future attribute lookup.
+test(() => {
+  const el = document.createElement('div');
+  el.setAttribute('labelXQL', 'abc');
+  el.setAttribute('_valueXQL', 'def');
+  assert_equals(el.getAttribute('labelXQL'), 'abc');
+  assert_equals(el.getAttribute('labelxql'), 'abc');
+  assert_equals(el.getAttribute('_valueXQL'), 'def');
+  assert_equals(el.getAttribute('_valuexql'), 'def');
+}, "Attributes first seen in mixed ASCII case should not be corrupted.");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-setAttribute.html b/testing/web-platform/tests/dom/nodes/Element-setAttribute.html
new file mode 100644
index 0000000000..7609406815
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-setAttribute.html
@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Element.prototype.setAttribute</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-setattribute">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+
+  const el = document.createElement("p");
+  el.setAttributeNS("foo", "x", "first");
+  el.setAttributeNS("foo2", "x", "second");
+
+  el.setAttribute("x", "changed");
+
+  assert_equals(el.attributes.length, 2);
+  assert_equals(el.getAttribute("x"), "changed");
+  assert_equals(el.getAttributeNS("foo", "x"), "changed");
+  assert_equals(el.getAttributeNS("foo2", "x"), "second");
+
+}, "setAttribute should change the first attribute, irrespective of namespace");
+
+test(() => {
+  // https://github.com/whatwg/dom/issues/31
+
+  const el = document.createElement("p");
+  el.setAttribute("FOO", "bar");
+
+  assert_equals(el.getAttribute("foo"), "bar");
+  assert_equals(el.getAttribute("FOO"), "bar");
+  assert_equals(el.getAttributeNS("", "foo"), "bar");
+  assert_equals(el.getAttributeNS("", "FOO"), null);
+
+}, "setAttribute should lowercase before setting");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-siblingElement-null-svg.svg b/testing/web-platform/tests/dom/nodes/Element-siblingElement-null-svg.svg
new file mode 100644
index 0000000000..48c981b8c8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-siblingElement-null-svg.svg
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:h="http://www.w3.org/1999/xhtml"
+     version="1.1"
+     width="100%" height="100%" viewBox="0 0 400 400">
+<title>Null test</title>
+<h:script src="/resources/testharness.js"/>
+<h:script src="/resources/testharnessreport.js"/>
+
+<text x="200" y="40" font-size="25" fill="black" text-anchor="middle">Test of previousElementSibling and nextElementSibling returning null</text>
+<text id="parentEl" x="200" y="70" font-size="20" fill="black" text-anchor="middle">The result of this test is <tspan id="first_element_child" font-weight="bold">unknown.</tspan></text>
+
+<h:script><![CDATA[
+test(function() {
+  var fec = document.getElementById("first_element_child");
+  assert_equals(fec.previousElementSibling, null)
+  assert_equals(fec.nextElementSibling, null)
+})
+]]></h:script>
+</svg>
diff --git a/testing/web-platform/tests/dom/nodes/Element-siblingElement-null-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Element-siblingElement-null-xhtml.xhtml
new file mode 100644
index 0000000000..fcf4d54ff9
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-siblingElement-null-xhtml.xhtml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Null Test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<h1>Test of previousElementSibling and nextElementSibling returning null</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is <span id="first_element_child" style="font-weight:bold;">unknown.</span></p>
+<script><![CDATA[
+test(function() {
+  var fec = document.getElementById("first_element_child");
+  assert_equals(fec.previousElementSibling, null)
+  assert_equals(fec.nextElementSibling, null)
+})
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Element-siblingElement-null.html b/testing/web-platform/tests/dom/nodes/Element-siblingElement-null.html
new file mode 100644
index 0000000000..a7920b4fb8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-siblingElement-null.html
@@ -0,0 +1,16 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Null test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>Test of previousElementSibling and nextElementSibling returning null</h1>
+<div id="log"></div>
+<p id="parentEl">The result of this test is <span id="first_element_child" style="font-weight:bold;">unknown.</span></p>
+<script>
+test(function() {
+  var fec = document.getElementById("first_element_child");
+  assert_equals(fec.previousElementSibling, null)
+  assert_equals(fec.nextElementSibling, null)
+})
+</script>
+
diff --git a/testing/web-platform/tests/dom/nodes/Element-tagName.html b/testing/web-platform/tests/dom/nodes/Element-tagName.html
new file mode 100644
index 0000000000..43e7a2d2bf
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-tagName.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<title>Element.tagName</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var HTMLNS = "http://www.w3.org/1999/xhtml"
+  assert_equals(document.createElementNS(HTMLNS, "I").tagName, "I")
+  assert_equals(document.createElementNS(HTMLNS, "i").tagName, "I")
+  assert_equals(document.createElementNS(HTMLNS, "x:b").tagName, "X:B")
+}, "tagName should upper-case for HTML elements in HTML documents.")
+
+test(function() {
+  var SVGNS = "http://www.w3.org/2000/svg"
+  assert_equals(document.createElementNS(SVGNS, "svg").tagName, "svg")
+  assert_equals(document.createElementNS(SVGNS, "SVG").tagName, "SVG")
+  assert_equals(document.createElementNS(SVGNS, "s:svg").tagName, "s:svg")
+  assert_equals(document.createElementNS(SVGNS, "s:SVG").tagName, "s:SVG")
+
+  assert_equals(document.createElementNS(SVGNS, "textPath").tagName, "textPath");
+}, "tagName should not upper-case for SVG elements in HTML documents.")
+
+test(() => {
+  const el2 = document.createElementNS("http://example.com/", "mixedCase");
+  assert_equals(el2.tagName, "mixedCase");
+}, "tagName should not upper-case for other non-HTML namespaces");
+
+test(function() {
+  if ("DOMParser" in window) {
+    var xmlel = new DOMParser()
+      .parseFromString('<div xmlns="http://www.w3.org/1999/xhtml">Test</div>', 'text/xml')
+      .documentElement;
+    assert_equals(xmlel.tagName, "div", "tagName should be lowercase in XML")
+    var htmlel = document.importNode(xmlel, true)
+    assert_equals(htmlel.tagName, "DIV", "tagName should be uppercase in HTML")
+  }
+}, "tagName should be updated when changing ownerDocument")
+
+test(function() {
+  var xmlel = document.implementation
+    .createDocument("http://www.w3.org/1999/xhtml", "div", null)
+    .documentElement;
+  assert_equals(xmlel.tagName, "div", "tagName should be lowercase in XML")
+  var htmlel = document.importNode(xmlel, true)
+  assert_equals(htmlel.tagName, "DIV", "tagName should be uppercase in HTML")
+}, "tagName should be updated when changing ownerDocument (createDocument without prefix)")
+
+test(function() {
+  var xmlel = document.implementation
+    .createDocument("http://www.w3.org/1999/xhtml", "foo:div", null)
+    .documentElement;
+  assert_equals(xmlel.tagName, "foo:div", "tagName should be lowercase in XML")
+  var htmlel = document.importNode(xmlel, true)
+  assert_equals(htmlel.tagName, "FOO:DIV", "tagName should be uppercase in HTML")
+}, "tagName should be updated when changing ownerDocument (createDocument with prefix)")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Element-webkitMatchesSelector.html b/testing/web-platform/tests/dom/nodes/Element-webkitMatchesSelector.html
new file mode 100644
index 0000000000..107f810203
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Element-webkitMatchesSelector.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>Selectors-API Level 2 Test Suite: HTML with Selectors Level 3</title>
+<!-- Selectors API Test Suite Version 3 -->
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/dom/nodes/selectors.js"></script>
+<script src="/dom/nodes/ParentNode-querySelector-All.js"></script>
+<script src="Element-matches.js"></script>
+<script src="Element-matches-init.js"></script>
+<style>iframe { visibility: hidden; position: absolute; }</style>
+
+<div id="log">This test requires JavaScript.</div>
+
+<script>
+  async_test(function() {
+    var frame = document.createElement("iframe");
+    frame.onload = this.step_func_done(e => init(e, "webkitMatchesSelector" ));
+    frame.src = "/dom/nodes/ParentNode-querySelector-All-content.html#target";
+    document.body.appendChild(frame);
+  });
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-attributes.html b/testing/web-platform/tests/dom/nodes/MutationObserver-attributes.html
new file mode 100644
index 0000000000..6721b7eecd
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-attributes.html
@@ -0,0 +1,406 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObservers: attributes mutations</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="mutationobservers.js"></script>
+<h1>MutationObservers: attributes mutations</h1>
+<div id="log"></div>
+
+<section style="display: none">
+<p id='n'></p>
+
+<p id='n00'></p>
+<p id='n01'></p>
+<p id='n02'></p>
+<p id='n03'></p>
+<input id="n04" type="text">
+
+<p id='n10'></p>
+<p id='n11'></p>
+<p id='n12' class='c01'></p>
+<p id='n13' class='c01 c02'></p>
+
+<p id='n20'></p>
+<p id='n21'></p>
+<p id='n22'></p>
+<p id='n23'></p>
+<p id='n24' class="c01 c02"></p>
+
+<p id='n30' class="c01 c02"></p>
+<p id='n31' class="c01 c02"></p>
+<p id='n32' class="c01 c02"></p>
+
+<p id='n40' class="c01 c02"></p>
+<p id='n41' class="c01 c02"></p>
+<p id='n42' class="c01 c02"></p>
+<p id='n43' class="c01 c02"></p>
+<p id='n44' class="c01 c02"></p>
+<p id='n45' class="c01 c02"></p>
+
+<p id='n50' class="c01 c02"></p>
+<p id='n51'></p>
+
+<p id='n60'></p>
+<p id='n61' class="c01"></p>
+<p id='n62'></p>
+
+<p id='n70' class="c01"></p>
+<p id='n71'></p>
+<input id="n72" type="text">
+
+<p id='n80'></p>
+<p id='n81'></p>
+
+<p id='n90'></p>
+<p id='n91'></p>
+<p id='n92'></p>
+
+<p id='n1000'></p>
+<p id='n1001' class='c01'></p>
+
+<p id='n2000'></p>
+<p id='n2001' class='c01'></p>
+
+<p id='n3000'></p>
+
+</section>
+
+<script>
+
+var n = document.getElementById('n');
+
+runMutationTest(n,
+                  {"attributes":true},
+                  [{type: "attributes", attributeName: "id"}],
+                  function() { n.id = "n000";},
+                  "attributes Element.id: update, no oldValue, mutation");
+
+var n00 = document.getElementById('n00');
+runMutationTest(n00,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n00", attributeName: "id"}],
+                  function() { n00.id = "n000";},
+                  "attributes Element.id: update mutation");
+
+var n01 = document.getElementById('n01');
+runMutationTest(n01,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n01", attributeName: "id"}],
+                  function() { n01.id = "";},
+                  "attributes Element.id: empty string update mutation");
+
+var n02 = document.getElementById('n02');
+runMutationTest(n02,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n02", attributeName: "id"}, {type: "attributes", attributeName: "class"}],
+                  function() { n02.id = "n02"; n02.setAttribute("class", "c01");},
+                  "attributes Element.id: same value mutation");
+
+var n03 = document.getElementById('n03');
+runMutationTest(n03,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n03", attributeName: "id"}],
+                  function() { n03.unknown = "c02"; n03.id = "n030";},
+                  "attributes Element.unknown: IDL attribute no mutation");
+
+var n04 = document.getElementById('n04');
+runMutationTest(n04,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "text", attributeName: "type"}, {type: "attributes", oldValue: "n04", attributeName: "id"}],
+                  function() { n04.type = "unknown"; n04.id = "n040";},
+                  "attributes HTMLInputElement.type: type update mutation");
+
+  var n10 = document.getElementById('n10');
+runMutationTest(n10,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", attributeName: "class"}],
+                  function() { n10.className = "c01";},
+                  "attributes Element.className: new value mutation");
+
+  var n11 = document.getElementById('n11');
+runMutationTest(n11,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", attributeName: "class"}],
+                  function() { n11.className = "";},
+                  "attributes Element.className: empty string update mutation");
+
+  var n12 = document.getElementById('n12');
+runMutationTest(n12,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01", attributeName: "class"}],
+                  function() { n12.className = "c01";},
+                  "attributes Element.className: same value mutation");
+
+  var n13 = document.getElementById('n13');
+runMutationTest(n13,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}],
+                  function() { n13.className = "c01 c02";},
+                  "attributes Element.className: same multiple values mutation");
+
+  var n20 = document.getElementById('n20');
+runMutationTest(n20,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", attributeName: "class"}],
+                  function() { n20.classList.add("c01");},
+                  "attributes Element.classList.add: single token addition mutation");
+
+  var n21 = document.getElementById('n21');
+runMutationTest(n21,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", attributeName: "class"}],
+                  function() { n21.classList.add("c01", "c02", "c03");},
+                  "attributes Element.classList.add: multiple tokens addition mutation");
+
+  var n22 = document.getElementById('n22');
+runMutationTest(n22,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n22", attributeName: "id"}],
+                  function() { try { n22.classList.add("c01", "", "c03"); } catch (e) { };
+                               n22.id = "n220"; },
+                  "attributes Element.classList.add: syntax err/no mutation");
+
+  var n23 = document.getElementById('n23');
+runMutationTest(n23,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n23", attributeName: "id"}],
+                  function() { try { n23.classList.add("c01", "c 02", "c03"); } catch (e) { };
+                               n23.id = "n230"; },
+                  "attributes Element.classList.add: invalid character/no mutation");
+
+  var n24 = document.getElementById('n24');
+runMutationTest(n24,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}, {type: "attributes", oldValue: "n24", attributeName: "id"}],
+                  function() { n24.classList.add("c02"); n24.id = "n240";},
+                  "attributes Element.classList.add: same value mutation");
+
+  var n30 = document.getElementById('n30');
+runMutationTest(n30,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}],
+                  function() { n30.classList.remove("c01");},
+                  "attributes Element.classList.remove: single token removal mutation");
+
+  var n31 = document.getElementById('n31');
+runMutationTest(n31,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}],
+                  function() { n31.classList.remove("c01", "c02");},
+                  "attributes Element.classList.remove: multiple tokens removal mutation");
+
+  var n32 = document.getElementById('n32');
+runMutationTest(n32,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}, {type: "attributes", oldValue: "n32", attributeName: "id"}],
+                  function() { n32.classList.remove("c03"); n32.id = "n320";},
+                  "attributes Element.classList.remove: missing token removal mutation");
+
+  var n40 = document.getElementById('n40');
+runMutationTest(n40,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}],
+                  function() { n40.classList.toggle("c01");},
+                  "attributes Element.classList.toggle: token removal mutation");
+
+  var n41 = document.getElementById('n41');
+runMutationTest(n41,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}],
+                  function() { n41.classList.toggle("c03");},
+                  "attributes Element.classList.toggle: token addition mutation");
+
+  var n42 = document.getElementById('n42');
+runMutationTest(n42,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}],
+                  function() { n42.classList.toggle("c01", false);},
+                  "attributes Element.classList.toggle: forced token removal mutation");
+
+  var n43 = document.getElementById('n43');
+runMutationTest(n43,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n43", attributeName: "id"}],
+                  function() { n43.classList.toggle("c03", false); n43.id = "n430"; },
+                  "attributes Element.classList.toggle: forced missing token removal no mutation");
+
+  var n44 = document.getElementById('n44');
+runMutationTest(n44,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n44", attributeName: "id"}],
+                  function() { n44.classList.toggle("c01", true); n44.id = "n440"; },
+                  "attributes Element.classList.toggle: forced existing token addition no mutation");
+
+  var n45 = document.getElementById('n45');
+runMutationTest(n45,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}],
+                  function() { n45.classList.toggle("c03", true);},
+                  "attributes Element.classList.toggle: forced token addition mutation");
+
+  var n50 = document.getElementById('n50');
+runMutationTest(n50,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01 c02", attributeName: "class"}],
+                  function() {
+                    for (var i = 0; i < n50.attributes.length; i++) {
+                      var attr = n50.attributes[i];
+                      if (attr.localName === "class") {
+                        attr.value = "c03";
+                      }
+                    };
+                  },
+                  "attributes Element.attributes.value: update mutation");
+
+  var n51 = document.getElementById('n51');
+runMutationTest(n51,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n51", attributeName: "id"}],
+                  function() {
+                    n51.attributes[0].value = "n51";
+                  },
+                  "attributes Element.attributes.value: same id mutation");
+
+  var n60 = document.getElementById('n60');
+runMutationTest(n60,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n60", attributeName: "id"}],
+                  function() {
+                    n60.setAttribute("id", "n601");
+                  },
+                  "attributes Element.setAttribute: id mutation");
+
+  var n61 = document.getElementById('n61');
+runMutationTest(n61,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01", attributeName: "class"}],
+                  function() {
+                    n61.setAttribute("class", "c01");
+                  },
+                  "attributes Element.setAttribute: same class mutation");
+
+  var n62 = document.getElementById('n62');
+runMutationTest(n62,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", attributeName: "classname"}],
+                  function() {
+                    n62.setAttribute("classname", "c01");
+                  },
+                  "attributes Element.setAttribute: classname mutation");
+
+  var n70 = document.getElementById('n70');
+runMutationTest(n70,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "c01", attributeName: "class"}],
+                  function() {
+                    n70.removeAttribute("class");
+                  },
+                  "attributes Element.removeAttribute: removal mutation");
+
+  var n71 = document.getElementById('n71');
+runMutationTest(n71,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n71", attributeName: "id"}],
+                  function() {
+                    n71.removeAttribute("class");
+                    n71.id = "n710";
+                  },
+                  "attributes Element.removeAttribute: removal no mutation");
+
+  var n72 = document.getElementById('n72');
+runMutationTest(n72,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "text", attributeName: "type"}, {type: "attributes", oldValue: "n72", attributeName: "id"}],
+                  function() {
+                    n72.removeAttribute("type");
+                    n72.id = "n720";
+                  },
+                  "childList HTMLInputElement.removeAttribute: type removal mutation");
+
+  var n80 = document.getElementById('n80');
+runMutationTest(n80,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", attributeName: "private", attributeNamespace: "http://example.org/"}],
+                  function() {
+                    n80.setAttributeNS("http://example.org/", "private", "42");
+                  },
+                  "attributes Element.setAttributeNS: creation mutation");
+
+  var n81 = document.getElementById('n81');
+runMutationTest(n81,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", attributeName: "lang", attributeNamespace: "http://www.w3.org/XML/1998/namespace"}],
+                  function() {
+                    n81.setAttributeNS("http://www.w3.org/XML/1998/namespace", "xml:lang", "42");
+                  },
+                  "attributes Element.setAttributeNS: prefixed attribute creation mutation");
+
+  var n90 = document.getElementById('n90');
+  n90.setAttributeNS("http://example.org/", "private", "42");
+runMutationTest(n90,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "42", attributeName: "private", attributeNamespace: "http://example.org/"}],
+                  function() {
+                    n90.removeAttributeNS("http://example.org/", "private");
+                  },
+                  "attributes Element.removeAttributeNS: removal mutation");
+
+  var n91 = document.getElementById('n91');
+runMutationTest(n91,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n91", attributeName: "id"}],
+                  function() {
+                    n91.removeAttributeNS("http://example.org/", "private");
+                    n91.id = "n910";
+                  },
+                  "attributes Element.removeAttributeNS: removal no mutation");
+
+  var n92 = document.getElementById('n92');
+runMutationTest(n92,
+                  {"attributes":true, "attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n92", attributeName: "id"}],
+                  function() {
+                    n92.removeAttributeNS("http://www.w3.org/XML/1998/namespace", "xml:lang");
+                    n92.id = "n920";
+                  },
+                  "attributes Element.removeAttributeNS: prefixed attribute removal no mutation");
+
+  var n1000 = document.getElementById('n1000');
+runMutationTest(n1000,
+                  {"attributes":true, "attributeOldValue": true,"attributeFilter": ["id"]},
+                  [{type: "attributes", oldValue: "n1000", attributeName: "id"}],
+                  function() { n1000.id = "abc"; n1000.className = "c01"},
+                  "attributes/attributeFilter Element.id/Element.className: update mutation");
+
+  var n1001 = document.getElementById('n1001');
+runMutationTest(n1001,
+                  {"attributes":true, "attributeOldValue": true,"attributeFilter": ["id", "class"]},
+                  [{type: "attributes", oldValue: "n1001", attributeName: "id"},
+                   {type: "attributes", oldValue: "c01", attributeName: "class"}],
+                  function() { n1001.id = "abc"; n1001.className = "c02"; n1001.setAttribute("lang", "fr");},
+                  "attributes/attributeFilter Element.id/Element.className: multiple filter update mutation");
+
+  var n2000 = document.getElementById('n2000');
+runMutationTest(n2000,
+                  {"attributeOldValue": true},
+                  [{type: "attributes", oldValue: "n2000", attributeName: "id"}],
+                  function() { n2000.id = "abc";},
+                  "attributeOldValue alone Element.id: update mutation");
+
+  var n2001 = document.getElementById('n2001');
+runMutationTest(n2001,
+                  {"attributeFilter": ["id", "class"]},
+                  [{type: "attributes", attributeName: "id"},
+                   {type: "attributes", attributeName: "class"}],
+                  function() { n2001.id = "abcd"; n2001.className = "c02"; n2001.setAttribute("lang", "fr");},
+                  "attributeFilter alone Element.id/Element.className: multiple filter update mutation");
+
+  var n3000 = document.getElementById('n3000');
+runMutationTest(n3000,
+                  {"subtree": true, "childList":false, "attributes" : true},
+                  [{type: "attributes", attributeName: "id" }],
+                  function() { n3000.textContent = "CHANGED"; n3000.id = "abc";},
+                  "childList false: no childList mutation");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-callback-arguments.html b/testing/web-platform/tests/dom/nodes/MutationObserver-callback-arguments.html
new file mode 100644
index 0000000000..d64758cb4f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-callback-arguments.html
@@ -0,0 +1,31 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObserver: callback arguments</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#notify-mutation-observers">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="mo-target"></div>
+<div id="log"></div>
+<script>
+"use strict";
+
+async_test(t => {
+  const moTarget = document.querySelector("#mo-target");
+  const mo = new MutationObserver(function(records, observer) {
+    t.step(() => {
+      assert_equals(this, mo);
+      assert_equals(arguments.length, 2);
+      assert_true(Array.isArray(records));
+      assert_equals(records.length, 1);
+      assert_true(records[0] instanceof MutationRecord);
+      assert_equals(observer, mo);
+
+      mo.disconnect();
+      t.done();
+    });
+  });
+
+  mo.observe(moTarget, {attributes: true});
+  moTarget.className = "trigger-mutation";
+}, "Callback is invoked with |this| value of MutationObserver and two arguments");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-characterData.html b/testing/web-platform/tests/dom/nodes/MutationObserver-characterData.html
new file mode 100644
index 0000000000..addaef03da
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-characterData.html
@@ -0,0 +1,215 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObservers: characterData mutations</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="mutationobservers.js"></script>
+<h1>MutationObservers: characterData mutations</h1>
+<div id="log"></div>
+
+<section style="display: none">
+
+<p id='n'>text content</p>
+
+<p id='n00'>text content</p>
+
+<p id='n10'>CHAN</p>
+<p id='n11'>CHANGED</p>
+<p id='n12'>CHANGED</p>
+
+<p id='n20'>CHGED</p>
+<p id='n21'>CHANGED</p>
+<p id='n22'>CHANGED</p>
+
+<p id='n30'>CCCHANGED</p>
+<p id='n31'>CHANGED</p>
+
+<p id='n40'>CCCHANGED</p>
+<p id='n41'>CHANGED</p>
+
+<p id="n50"><?processing data?></p>
+
+<p id="n60"><!-- data --></p>
+
+<p id='n70'>CHANN</p>
+<p id='n71'>CHANN</p>
+
+<p id='n80'>CHANN</p>
+<p id='n81'>CHANN</p>
+
+<p id='n90'>CHANN</p>
+
+</section>
+
+<script>
+  var n = document.getElementById('n').firstChild;
+runMutationTest(n,
+                  {"characterData":true},
+                  [{type: "characterData"}],
+                  function() { n.data = "NEW VALUE"; },
+                  "characterData Text.data: simple mutation without oldValue");
+
+  var n00 = document.getElementById('n00').firstChild;
+runMutationTest(n00,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "text content" }],
+                  function() { n00.data = "CHANGED"; },
+                  "characterData Text.data: simple mutation");
+
+  var n10 = document.getElementById('n10').firstChild;
+runMutationTest(n10,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHAN" }],
+                  function() { n10.appendData("GED"); },
+                  "characterData Text.appendData: simple mutation");
+
+  var n11 = document.getElementById('n11').firstChild;
+runMutationTest(n11,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANGED" }],
+                  function() { n11.appendData(""); },
+                  "characterData Text.appendData: empty string mutation");
+
+  var n12 = document.getElementById('n12').firstChild;
+runMutationTest(n12,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANGED" }],
+                  function() { n12.appendData(null); },
+                  "characterData Text.appendData: null string mutation");
+
+  var n20 = document.getElementById('n20').firstChild;
+runMutationTest(n20,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHGED" }],
+                  function() { n20.insertData(2, "AN"); },
+                  "characterData Text.insertData: simple mutation");
+
+  var n21 = document.getElementById('n21').firstChild;
+runMutationTest(n21,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANGED" }],
+                  function() { n21.insertData(2, ""); },
+                  "characterData Text.insertData: empty string mutation");
+
+  var n22 = document.getElementById('n22').firstChild;
+runMutationTest(n22,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANGED" }],
+                  function() { n22.insertData(2, null); },
+                  "characterData Text.insertData: null string mutation");
+
+  var n30 = document.getElementById('n30').firstChild;
+runMutationTest(n30,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CCCHANGED" }],
+                  function() { n30.deleteData(0, 2); },
+                  "characterData Text.deleteData: simple mutation");
+
+  var n31 = document.getElementById('n31').firstChild;
+runMutationTest(n31,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANGED" }, {type: "characterData", oldValue: "CHANGED" }],
+                  function() { n31.deleteData(0, 0); n31.data = "n31"; },
+                  "characterData Text.deleteData: empty mutation");
+
+  var n40 = document.getElementById('n40').firstChild;
+runMutationTest(n40,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CCCHANGED" }],
+                  function() { n40.replaceData(0, 2, "CH"); },
+                  "characterData Text.replaceData: simple mutation");
+
+  var n41 = document.getElementById('n41').firstChild;
+runMutationTest(n41,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANGED" }],
+                  function() { n41.replaceData(0, 0, "CH"); },
+                  "characterData Text.replaceData: empty mutation");
+
+  var n50 = document.getElementById('n50').firstChild;
+runMutationTest(n50,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "?processing data?" },{type: "characterData", oldValue: "CHANGED" },{type: "characterData", oldValue: "CHANGED" }],
+                  function() {
+                    n50.data = "CHANGED";
+                    n50.deleteData(0, 0);
+                    n50.replaceData(0, 2, "CH"); },
+                  "characterData ProcessingInstruction: data mutations");
+
+  var n60 = document.getElementById('n60').firstChild;
+runMutationTest(n60,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: " data " },{type: "characterData", oldValue: "CHANGED" },{type: "characterData", oldValue: "CHANGED" }],
+                  function() {
+                    n60.data = "CHANGED";
+                    n60.deleteData(0, 0);
+                    n60.replaceData(0, 2, "CH"); },
+                  "characterData Comment: data mutations");
+
+  var n70 = document.getElementById('n70');
+  var r70 = null;
+  test(function () {
+    n70.appendChild(document.createTextNode("NNN"));
+    n70.appendChild(document.createTextNode("NGED"));
+    r70 = document.createRange();
+    r70.setStart(n70.firstChild, 4);
+    r70.setEnd(n70.lastChild, 1);
+   }, "Range (r70) is created");
+runMutationTest(n70.firstChild,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANN" }],
+                  function() { r70.deleteContents(); },
+                  "characterData Range.deleteContents: child and data removal mutation");
+
+  var n71 = document.getElementById('n71');
+  var r71 = null;
+  test(function () {
+    n71.appendChild(document.createTextNode("NNN"));
+    n71.appendChild(document.createTextNode("NGED"));
+    r71 = document.createRange();
+    r71.setStart(n71.firstChild, 4);
+    r71.setEnd(n71.lastChild, 1);
+   }, "Range (r71) is created");
+runMutationTest(n71.lastChild,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "NGED"}],
+                  function() { r71.deleteContents(); },
+                  "characterData Range.deleteContents: child and data removal mutation (2)");
+
+  var n80 = document.getElementById('n80');
+  var r80 = null;
+  test(function () {
+    n80.appendChild(document.createTextNode("NNN"));
+    n80.appendChild(document.createTextNode("NGED"));
+    r80 = document.createRange();
+    r80.setStart(n80.firstChild, 4);
+    r80.setEnd(n80.lastChild, 1);
+   }, "Range (r80) is created");
+runMutationTest(n80.firstChild,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANN" }],
+                  function() { r80.extractContents(); },
+                  "characterData Range.extractContents: child and data removal mutation");
+
+  var n81 = document.getElementById('n81');
+  var r81 = null;
+  test(function () {
+    n81.appendChild(document.createTextNode("NNN"));
+    n81.appendChild(document.createTextNode("NGED"));
+    r81 = document.createRange();
+    r81.setStart(n81.firstChild, 4);
+    r81.setEnd(n81.lastChild, 1);
+   }, "Range (r81) is created");
+runMutationTest(n81.lastChild,
+                  {"characterData":true,"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "NGED" }],
+                  function() { r81.extractContents(); },
+                  "characterData Range.extractContents: child and data removal mutation (2)");
+
+  var n90 = document.getElementById('n90').firstChild;
+runMutationTest(n90,
+                  {"characterDataOldValue":true},
+                  [{type: "characterData", oldValue: "CHANN" }],
+                  function() { n90.data = "CHANGED"; },
+                  "characterData/characterDataOldValue alone Text.data: simple mutation");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-childList.html b/testing/web-platform/tests/dom/nodes/MutationObserver-childList.html
new file mode 100644
index 0000000000..e4c674e027
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-childList.html
@@ -0,0 +1,434 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObservers: childList mutations</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="mutationobservers.js"></script>
+<h1>MutationObservers: childList mutations</h1>
+<div id="log"></div>
+
+<section style="display: none">
+<p id='dummies'>
+<span id='d30'>text content</span>
+<span id='d35'>text content</span>
+<span id='d40'>text content</span>
+<span id='d45'>text content</span>
+<span id='d50'>text content</span>
+<span id='d51'>text content</span>
+</p>
+
+</section>
+<section style="display: none">
+<p id='n00'><span>text content</span></p>
+
+<p id='n10'><span>text content</span></p>
+<p id='n11'></p>
+<p id='n12'></p>
+<p id='n13'><span>text content</span></p>
+
+<p id='n20'>PAS</p>
+<p id='n21'>CH</p>
+
+<p id='n30'><span>text content</span></p>
+<p id='n31'><span>text content</span></p>
+<p id='n32'><span>AN</span><span>CH</span><span>GED</span></p>
+<p id='n33'><span>text content</span></p>
+<p id='n34'><span>text content</span></p>
+<p id='n35'><span>text content</span></p>
+
+<p id='n40'><span>text content</span></p>
+<p id='n41'><span>text content</span></p>
+<p id='n42'><span>CH</span><span>GED</span><span>AN</span></p>
+<p id='n43'><span>text content</span></p>
+<p id='n44'><span>text content</span></p>
+<p id='n45'><span>text content</span></p>
+
+
+<p id='n50'><span>text content</span></p>
+<p id='n51'><span>text content</span></p>
+<p id='n52'><span>NO </span><span>CHANGED</span></p>
+<p id='n53'><span>text content</span></p>
+
+<p id='n60'><span>text content</span></p>
+
+<p id='n70'><span>NO </span><span>CHANGED</span></p>
+<p id='n71'>CHANN</p>
+
+<p id='n80'><span>NO </span><span>CHANGED</span></p>
+<p id='n81'>CHANN</p>
+
+<p id='n90'><span>CHA</span><span>ED</span></p>
+<p id='n91'>CHAE</p>
+
+<p id='n100'><span id="s1">CHAN</span><span id="s2">GED</span></p>
+
+</section>
+
+<script>
+  var dummies = document.getElementById('dummies');
+
+  function createFragment() {
+    var fragment = document.createDocumentFragment();
+    fragment.appendChild(document.createTextNode("11"));
+    fragment.appendChild(document.createTextNode("22"));
+    return fragment;
+  }
+
+  var n00 = document.getElementById('n00');
+
+  runMutationTest(n00,
+                  {"childList":true, "attributes":true},
+                  [{type: "attributes", attributeName: "class"}],
+                  function() { n00.nodeValue = ""; n00.setAttribute("class", "dummy");},
+                  "childList Node.nodeValue: no mutation");
+
+  var n10 = document.getElementById('n10');
+  runMutationTest(n10,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n10.firstChild],
+                    addedNodes: function() {return [n10.firstChild]}}],
+                  function() { n10.textContent = "new data"; },
+                  "childList Node.textContent: replace content mutation");
+
+  var n11 = document.getElementById('n11');
+  runMutationTest(n11,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: function() {return [n11.firstChild]}}],
+                  function() { n11.textContent = "new data"; },
+                  "childList Node.textContent: no previous content mutation");
+
+  var n12 = document.getElementById('n12');
+  runMutationTest(n12,
+                  {"childList":true, "attributes":true},
+                  [{type: "attributes", attributeName: "class"}],
+                  function() { n12.textContent = ""; n12.setAttribute("class", "dummy");},
+                  "childList Node.textContent: textContent no mutation");
+
+  var n13 = document.getElementById('n13');
+  runMutationTest(n13,
+                  {"childList":true},
+                  [{type: "childList", removedNodes: [n13.firstChild]}],
+                  function() { n13.textContent = ""; },
+                  "childList Node.textContent: empty string mutation");
+
+  var n20 = document.getElementById('n20');
+  n20.appendChild(document.createTextNode("S"));
+  runMutationTest(n20,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n20.lastChild],
+                    previousSibling: n20.firstChild}],
+                  function() { n20.normalize(); },
+                  "childList Node.normalize mutation");
+
+  var n21 = document.getElementById('n21');
+  n21.appendChild(document.createTextNode("AN"));
+  n21.appendChild(document.createTextNode("GED"));
+  runMutationTest(n21,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n21.lastChild.previousSibling],
+                    previousSibling: n21.firstChild,
+                    nextSibling: n21.lastChild},
+                   {type: "childList",
+                    removedNodes: [n21.lastChild],
+                    previousSibling: n21.firstChild}],
+                  function() { n21.normalize(); },
+                  "childList Node.normalize mutations");
+
+  var n30 = document.getElementById('n30');
+  var d30 = document.getElementById('d30');
+  runMutationTest(n30,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: [d30],
+                    nextSibling: n30.firstChild}],
+                  function() { n30.insertBefore(d30, n30.firstChild); },
+                  "childList Node.insertBefore: addition mutation");
+
+  var n31 = document.getElementById('n31');
+  runMutationTest(n31,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n31.firstChild]}],
+                  function() { dummies.insertBefore(n31.firstChild, dummies.firstChild); },
+                  "childList Node.insertBefore: removal mutation");
+
+  var n32 = document.getElementById('n32');
+  runMutationTest(n32,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n32.firstChild.nextSibling],
+                    previousSibling: n32.firstChild, nextSibling: n32.lastChild},
+                    {type: "childList",
+                    addedNodes: [n32.firstChild.nextSibling],
+                    nextSibling: n32.firstChild}],
+                  function() { n32.insertBefore(n32.firstChild.nextSibling, n32.firstChild); },
+                  "childList Node.insertBefore: removal and addition mutations");
+
+  var n33 = document.getElementById('n33');
+  var f33 = createFragment();
+  runMutationTest(n33,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: [f33.firstChild, f33.lastChild],
+                    nextSibling: n33.firstChild}],
+                  function() { n33.insertBefore(f33, n33.firstChild); },
+                  "childList Node.insertBefore: fragment addition mutations");
+
+  var n34 = document.getElementById('n34');
+  var f34 = createFragment();
+  runMutationTest(f34,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [f34.firstChild, f34.lastChild]}],
+                  function() { n34.insertBefore(f34, n34.firstChild); },
+                  "childList Node.insertBefore: fragment removal mutations");
+
+  var n35 = document.getElementById('n35');
+  var d35 = document.getElementById('d35');
+  runMutationTest(n35,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: [d35],
+                    previousSibling: n35.firstChild}],
+                  function() { n35.insertBefore(d35, null); },
+                  "childList Node.insertBefore: last child addition mutation");
+
+  var n40 = document.getElementById('n40');
+  var d40 = document.getElementById('d40');
+  runMutationTest(n40,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: [d40],
+                    previousSibling: n40.firstChild}],
+                  function() { n40.appendChild(d40); },
+                  "childList Node.appendChild: addition mutation");
+
+  var n41 = document.getElementById('n41');
+  runMutationTest(n41,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n41.firstChild]}],
+                  function() { dummies.appendChild(n41.firstChild); },
+                  "childList Node.appendChild: removal mutation");
+
+  var n42 = document.getElementById('n42');
+  runMutationTest(n42,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n42.firstChild.nextSibling],
+                    previousSibling: n42.firstChild, nextSibling: n42.lastChild},
+                    {type: "childList",
+                    addedNodes: [n42.firstChild.nextSibling],
+                    previousSibling: n42.lastChild}],
+                  function() { n42.appendChild(n42.firstChild.nextSibling); },
+                  "childList Node.appendChild: removal and addition mutations");
+
+  var n43 = document.getElementById('n43');
+  var f43 = createFragment();
+  runMutationTest(n43,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: [f43.firstChild, f43.lastChild],
+                    previousSibling: n43.firstChild}],
+                  function() { n43.appendChild(f43); },
+                  "childList Node.appendChild: fragment addition mutations");
+
+  var n44 = document.getElementById('n44');
+  var f44 = createFragment();
+  runMutationTest(f44,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [f44.firstChild, f44.lastChild]}],
+                  function() { n44.appendChild(f44); },
+                  "childList Node.appendChild: fragment removal mutations");
+
+  var n45 = document.createElement('p');
+  var d45 = document.createElement('span');
+  runMutationTest(n45,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: [d45]}],
+                  function() { n45.appendChild(d45); },
+                  "childList Node.appendChild: addition outside document tree mutation");
+
+  var n50 = document.getElementById('n50');
+  var d50 = document.getElementById('d50');
+  runMutationTest(n50,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n50.firstChild],
+                    addedNodes: [d50]}],
+                  function() { n50.replaceChild(d50, n50.firstChild); },
+                  "childList Node.replaceChild: replacement mutation");
+
+  var n51 = document.getElementById('n51');
+  var d51 = document.getElementById('d51');
+  runMutationTest(n51,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n51.firstChild]}],
+                  function() { d51.parentNode.replaceChild(n51.firstChild, d51); },
+                  "childList Node.replaceChild: removal mutation");
+
+  var n52 = document.getElementById('n52');
+  runMutationTest(n52,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n52.lastChild],
+                    previousSibling: n52.firstChild},
+                   {type: "childList",
+                    removedNodes: [n52.firstChild],
+                    addedNodes: [n52.lastChild]}],
+                  function() { n52.replaceChild(n52.lastChild, n52.firstChild); },
+                  "childList Node.replaceChild: internal replacement mutation");
+
+  var n53 = document.getElementById('n53');
+  runMutationTest(n53,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n53.firstChild]},
+                   {type: "childList",
+                    addedNodes: [n53.firstChild]}],
+                  function() { n53.replaceChild(n53.firstChild, n53.firstChild); },
+                  "childList Node.replaceChild: self internal replacement mutation");
+
+  var n60 = document.getElementById('n60');
+  runMutationTest(n60,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n60.firstChild]}],
+                  function() { n60.removeChild(n60.firstChild); },
+                  "childList Node.removeChild: removal mutation");
+
+  var n70 = document.getElementById('n70');
+  var r70 = null;
+  test(function () {
+    r70 = document.createRange();
+    r70.setStartBefore(n70.firstChild);
+    r70.setEndAfter(n70.firstChild);
+   }, "Range (r70) is created");
+  runMutationTest(n70,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n70.firstChild],
+                    nextSibling: n70.lastChild}],
+                  function() { r70.deleteContents(); },
+                  "childList Range.deleteContents: child removal mutation");
+
+  var n71 = document.getElementById('n71');
+  var r71 = null;
+  test(function () {
+    n71.appendChild(document.createTextNode("NNN"));
+    n71.appendChild(document.createTextNode("NGED"));
+    r71 = document.createRange();
+    r71.setStart(n71.firstChild, 4);
+    r71.setEnd(n71.lastChild, 1);
+   }, "Range (r71) is created");
+  runMutationTest(n71,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n71.firstChild.nextSibling],
+                    previousSibling: n71.firstChild,
+                    nextSibling: n71.lastChild}],
+                  function() { r71.deleteContents(); },
+                  "childList Range.deleteContents: child and data removal mutation");
+
+  var n80 = document.getElementById('n80');
+  var r80 = null;
+  test(function () {
+    r80 = document.createRange();
+    r80.setStartBefore(n80.firstChild);
+    r80.setEndAfter(n80.firstChild);
+   }, "Range (r80) is created");
+  runMutationTest(n80,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n80.firstChild],
+                    nextSibling: n80.lastChild}],
+                  function() { r80.extractContents(); },
+                  "childList Range.extractContents: child removal mutation");
+
+  var n81 = document.getElementById('n81');
+  var r81 = null;
+  test(function () {
+    n81.appendChild(document.createTextNode("NNN"));
+    n81.appendChild(document.createTextNode("NGED"));
+    r81 = document.createRange();
+    r81.setStart(n81.firstChild, 4);
+    r81.setEnd(n81.lastChild, 1);
+   }, "Range (r81) is created");
+  runMutationTest(n81,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n81.firstChild.nextSibling],
+                    previousSibling: n81.firstChild,
+                    nextSibling: n81.lastChild}],
+                  function() { r81.extractContents(); },
+                  "childList Range.extractContents: child and data removal mutation");
+
+  var n90 = document.getElementById('n90');
+  var f90 = document.createTextNode("NG");
+  var r90 = null;
+  test(function () {
+    r90 = document.createRange();
+    r90.setStartAfter(n90.firstChild);
+    r90.setEndBefore(n90.lastChild);
+   }, "Range (r90) is created");
+  runMutationTest(n90,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: [f90],
+                    previousSibling: n90.firstChild,
+                    nextSibling: n90.lastChild}],
+                  function() { r90.insertNode(f90); },
+                  "childList Range.insertNode: child insertion mutation");
+
+  var n91 = document.getElementById('n91');
+  var f91 = document.createTextNode("NG");
+  var r91 = null;
+  test(function () {
+    n91.appendChild(document.createTextNode("D"));
+    r91 = document.createRange();
+    r91.setStart(n91.firstChild, 3);
+    r91.setEnd(n91.lastChild, 0);
+   }, "Range (r91) is created");
+  runMutationTest(n91,
+                  {"childList":true},
+                  [{type: "childList",
+                    addedNodes: function() { return [n91.lastChild.previousSibling]; },
+                    previousSibling: n91.firstChild,
+                    nextSibling: n91.lastChild},
+                   {type: "childList",
+                    addedNodes: [f91],
+                    previousSibling: n91.firstChild,
+                    nextSibling: function () { return n91.lastChild.previousSibling; } }],
+                  function() { r91.insertNode(f91); },
+                  "childList Range.insertNode: children insertion mutation");
+
+  var n100 = document.getElementById('n100');
+  var f100 = document.createElement("span");
+  var r100 = null;
+  test(function () {
+    r100 = document.createRange();
+    r100.setStartBefore(n100.firstChild);
+    r100.setEndAfter(n100.lastChild);
+   }, "Range (r100) is created");
+  runMutationTest(n100,
+                  {"childList":true},
+                  [{type: "childList",
+                    removedNodes: [n100.firstChild],
+                    nextSibling: n100.lastChild},
+                   {type: "childList",
+                    removedNodes: [n100.lastChild]},
+                   {type: "childList",
+                    addedNodes: [f100] }],
+                  function() { r100.surroundContents(f100); },
+                  "childList Range.surroundContents: children removal and addition mutation");
+
+</script>
+
+
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-cross-realm-callback-report-exception.html b/testing/web-platform/tests/dom/nodes/MutationObserver-cross-realm-callback-report-exception.html
new file mode 100644
index 0000000000..7d05c045b3
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-cross-realm-callback-report-exception.html
@@ -0,0 +1,32 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>MutationObserver reports the exception from its callback in the callback's global object</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<iframe></iframe>
+<iframe></iframe>
+<iframe></iframe>
+<script>
+setup({ allow_uncaught_exception: true });
+
+const onerrorCalls = [];
+window.onerror = () => { onerrorCalls.push("top"); };
+frames[0].onerror = () => { onerrorCalls.push("frame0"); };
+frames[1].onerror = () => { onerrorCalls.push("frame1"); };
+frames[2].onerror = () => { onerrorCalls.push("frame2"); };
+
+async_test(t => {
+  window.onload = t.step_func(() => {
+    const target = frames[0].document.body;
+    const mo = new frames[0].MutationObserver(new frames[1].Function(`throw new parent.frames[2].Error("PASS");`));
+
+    mo.observe(target, { childList: true, subtree: true });
+    target.append("foo");
+
+    t.step_timeout(() => {
+      assert_array_equals(onerrorCalls, ["frame1"]);
+      t.done();
+    }, 4);
+  });
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-disconnect.html b/testing/web-platform/tests/dom/nodes/MutationObserver-disconnect.html
new file mode 100644
index 0000000000..883edecf74
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-disconnect.html
@@ -0,0 +1,48 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObservers: disconnect</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<h1>MutationObservers: disconnect</h1>
+<div id="log"></div>
+<section style="display: none">
+<p id='n00'></p>
+</section>
+<script>
+var n00 = document.getElementById('n00');
+var parentTest = async_test("subtree mutations");
+function masterMO(sequence, obs) {
+  parentTest.step(function() {
+    assert_equals(sequence.length, 4, "mutation records must match");
+  });
+  parentTest.done();
+}
+parentTest.step(function() {
+  (new MutationObserver(masterMO)).observe(n00.parentNode, {"subtree": true, "attributes": true});
+});
+
+var disconnectTest = async_test("disconnect discarded some mutations");
+function observerCallback(sequence, obs) {
+  disconnectTest.step(function() {
+    assert_equals(sequence.length, 1);
+    assert_equals(sequence[0].type, "attributes");
+    assert_equals(sequence[0].attributeName, "id");
+    assert_equals(sequence[0].oldValue, "latest");
+    disconnectTest.done();
+  });
+}
+
+var observer;
+disconnectTest.step(function() {
+  observer = new MutationObserver(observerCallback);
+  observer.observe(n00, {"attributes": true});
+  n00.id = "foo";
+  n00.id = "bar";
+  observer.disconnect();
+  observer.observe(n00, {"attributes": true, "attributeOldValue": true});
+  n00.id = "latest";
+  observer.disconnect();
+  observer.observe(n00, {"attributes": true, "attributeOldValue": true});
+  n00.id = "n0000";
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-document.html b/testing/web-platform/tests/dom/nodes/MutationObserver-document.html
new file mode 100644
index 0000000000..4662b23459
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-document.html
@@ -0,0 +1,167 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObservers: takeRecords</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="mutationobservers.js"></script>
+<h1>MutationObservers: document mutations</h1>
+<div id="log"></div>
+
+<script id='s001'>
+  var setupTest = async_test("setup test");
+  var insertionTest = async_test("parser insertion mutations");
+  var insertionTest2 = async_test("parser script insertion mutation");
+  var testCounter = 0;
+
+  function masterMO(sequence, obs) {
+    testCounter++;
+    if (testCounter == 1) {
+      insertionTest.step(
+        function () {
+          checkRecords(document, sequence,
+                       [{type: "childList",
+                         addedNodes: function () {
+                           return [ document.getElementById("n00") ];
+                         },
+                         previousSibling: function () {
+                           return document.getElementById("s001");
+                         },
+                         target: document.body},
+                        {type: "childList",
+                         addedNodes: function () {
+                           return [ document.getElementById("s002") ];
+                         },
+                         previousSibling: function () {
+                           return document.getElementById("n00");
+                         },
+                         target: document.body},
+                        {type: "childList",
+                         addedNodes: function () {
+                           return [ document.getElementById("s002").firstChild ];
+                         },
+                         target: function () {
+                           return document.getElementById("s002");
+                         }}]);
+        });
+    } else if (testCounter == 2) {
+      insertionTest2.step(
+        function () {
+          checkRecords(document, sequence,
+                       [{type: "childList",
+                         addedNodes: function () {
+                           return [ document.getElementById("inserted_script") ];
+                         },
+                         target: function () {
+                          return document.getElementById("n00");
+                         }},
+                        {type: "childList",
+                         addedNodes: function () {
+                           return [ document.getElementById("inserted_element") ];
+                         },
+                         previousSibling: function () {
+                           return document.getElementById("s002");
+                         },
+                         target: document.body}
+                        ]);
+        });
+    }
+  }
+  var document_observer;
+  var newElement;
+  setupTest.step(function() {
+    document_observer = new MutationObserver(masterMO);
+    newElement = document.createElement("span");
+    document_observer.observe(document, {subtree:true,childList:true});
+    newElement.id = "inserted_element";
+    newElement.setAttribute("style", "display: none");
+    newElement.textContent = "my new span for n00";
+  });
+</script><p id='n00'></p><script id='s002'>
+  var newScript = document.createElement("script");
+  setupTest.step(function() {
+    newScript.textContent = "document.body.appendChild(newElement);";
+    newScript.id = "inserted_script";
+    document.getElementById("n00").appendChild(newScript);
+  });
+  if (testCounter < 1) {
+    insertionTest.step(
+      function () {
+        assert_unreached("document observer did not trigger");
+      });
+  }
+</script><script id='s003'>
+  setupTest.step(function() {
+    document_observer.disconnect();
+  });
+  if (testCounter < 2) {
+    insertionTest2.step(
+      function () {
+        assert_unreached("document observer did not trigger");
+      });
+  }
+  insertionTest.done();
+  insertionTest2.done();
+</script>
+
+<p id='n012'></p><div id='d01'>
+<script id='s011'>
+  var removalTest = async_test("removal of parent during parsing");
+  var d01 = document.getElementById("d01");
+  testCounter = 0;
+
+  function removalMO(sequence, obs) {
+    testCounter++;
+    if (testCounter == 1) {
+      removalTest.step(
+        function () {
+          checkRecords(document, sequence,
+                       [{type: "childList",
+                         removedNodes: function () {
+                           return [ d01 ];
+                         },
+                         previousSibling: function () {
+                           return document.getElementById("n012");
+                         },
+                         target: document.body}]);
+        });
+    } else if (testCounter == 2) {
+      removalTest.step(
+        function () {
+          checkRecords(document, sequence,
+                       [{type: "childList",
+                         addedNodes: function () {
+                           return [ document.getElementById("s012") ];
+                         },
+                         previousSibling: function () {
+                           return document.getElementById("n012");
+                         },
+                         target: document.body},
+                        {type: "childList",
+                          addedNodes: function () {
+                            return [ document.getElementById("s012").firstChild ];
+                          },
+                          target: function () {
+                            return document.getElementById("s012");
+                          }}]);
+        });
+    }
+  }
+  var document2_observer;
+  setupTest.step(function() {
+    document2_observer = new MutationObserver(removalMO);
+    document2_observer.observe(document, {subtree:true,childList:true});
+    d01.parentNode.removeChild(d01);
+  });
+</script><p id='n01'></p></div><script id='s012'>
+  setupTest.step(function() {
+    document2_observer.disconnect();
+  });
+  if (testCounter < 2) {
+    removalTest.step(
+      function () {
+        assert_unreached("document observer did not trigger");
+      });
+  }
+  removalTest.done();
+  setupTest.done();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-inner-outer.html b/testing/web-platform/tests/dom/nodes/MutationObserver-inner-outer.html
new file mode 100644
index 0000000000..9f6d871417
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-inner-outer.html
@@ -0,0 +1,65 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObservers: innerHTML, outerHTML mutations</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="mutationobservers.js"></script>
+<h1>MutationObservers: innerHTML, outerHTML mutations</h1>
+<div id="log"></div>
+
+<section style="display: none">
+
+<p id='n00'>old text</p>
+
+<p id='n01'>old text</p>
+
+<div id='n02'><p>old text</p></div>
+</section>
+
+<script>
+  var n00;
+  var n00oldText;
+  var n01;
+  var n01oldText;
+  var n02;
+
+  setup(function() {
+    n00 = document.getElementById('n00');
+    n00oldText = n00.firstChild;
+    n01 = document.getElementById('n01');
+    n01oldText = n01.firstChild;
+    n02 = document.getElementById('n02');
+  })
+
+  runMutationTest(n00,
+                  {childList:true,attributes:true},
+                  [{type: "childList",
+                    removedNodes: [n00oldText],
+                    addedNodes: function() {
+                      return [document.getElementById("n00").firstChild];
+                    }},
+                    {type: "attributes", attributeName: "class"}],
+                  function() { n00.innerHTML = "new text"; n00.className = "c01"},
+                  "innerHTML mutation");
+
+  runMutationTest(n01,
+                  {childList:true},
+                  [{type: "childList",
+                    removedNodes: [n01oldText],
+                    addedNodes: function() {
+                      return [document.getElementById("n01").firstChild,
+                              document.getElementById("n01").lastChild];
+                    }}],
+                  function() { n01.innerHTML = "<span>new</span><span>text</span>"; },
+                  "innerHTML with 2 children mutation");
+
+  runMutationTest(n02,
+                  {childList:true},
+                  [{type: "childList",
+                    removedNodes: [n02.firstChild],
+                    addedNodes: function() {
+                      return [n02.firstChild];
+                    }}],
+                  function() { n02.firstChild.outerHTML = "<p>next text</p>"; },
+                  "outerHTML mutation");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-sanity.html b/testing/web-platform/tests/dom/nodes/MutationObserver-sanity.html
new file mode 100644
index 0000000000..a4f6382b94
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-sanity.html
@@ -0,0 +1,95 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+  test(() => {
+      var m = new MutationObserver(() => {});
+      assert_throws_js(TypeError, () => {
+          m.observe(document, {});
+      });
+  }, "Should throw if none of childList, attributes, characterData are true");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { childList: true });
+      m.disconnect();
+  }, "Should not throw if childList is true");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { attributes: true });
+      m.disconnect();
+  }, "Should not throw if attributes is true");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { characterData: true });
+      m.disconnect();
+  }, "Should not throw if characterData is true");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { attributeOldValue: true });
+      m.disconnect();
+  }, "Should not throw if attributeOldValue is true and attributes is omitted");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { characterDataOldValue: true });
+      m.disconnect();
+  }, "Should not throw if characterDataOldValue is true and characterData is omitted");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { attributes: ["abc"] });
+      m.disconnect();
+  }, "Should not throw if attributeFilter is present and attributes is omitted");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      assert_throws_js(TypeError, () => {
+          m.observe(document, { childList: true, attributeOldValue: true,
+                                attributes: false });
+      });
+  }, "Should throw if attributeOldValue is true and attributes is false");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { childList: true, attributeOldValue: true,
+                            attributes: true });
+      m.disconnect();
+  }, "Should not throw if attributeOldValue and attributes are both true");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      assert_throws_js(TypeError, () => {
+          m.observe(document, { childList: true, attributeFilter: ["abc"],
+                                attributes: false });
+      });
+  }, "Should throw if attributeFilter is present and attributes is false");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { childList: true, attributeFilter: ["abc"],
+                            attributes: true });
+      m.disconnect();
+  }, "Should not throw if attributeFilter is present and attributes is true");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      assert_throws_js(TypeError, () => {
+          m.observe(document, { childList: true, characterDataOldValue: true,
+                                characterData: false });
+      });
+  }, "Should throw if characterDataOldValue is true and characterData is false");
+
+  test(() => {
+      var m = new MutationObserver(() => {});
+      m.observe(document, { childList: true, characterDataOldValue: true,
+                            characterData: true });
+      m.disconnect();
+  }, "Should not throw if characterDataOldValue is true and characterData is true");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/MutationObserver-takeRecords.html b/testing/web-platform/tests/dom/nodes/MutationObserver-takeRecords.html
new file mode 100644
index 0000000000..6a27ef77ec
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/MutationObserver-takeRecords.html
@@ -0,0 +1,53 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObservers: takeRecords</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="mutationobservers.js"></script>
+<h1>MutationObservers: takeRecords</h1>
+<div id="log"></div>
+
+<section style="display: none">
+
+<p id='n00'></p>
+
+</section>
+
+<script>
+
+  var n00 = document.getElementById('n00');
+
+  var unused = async_test("unreachabled test");
+
+  var observer;
+  unused.step(function () {
+    observer = new MutationObserver(unused.unreached_func("the observer callback should not fire"));
+    observer.observe(n00, { "subtree": true,
+                          "childList": true,
+                          "attributes": true,
+                          "characterData": true,
+                          "attributeOldValue": true,
+                          "characterDataOldValue": true});
+    n00.id = "foo";
+    n00.id = "bar";
+    n00.className = "bar";
+    n00.textContent = "old data";
+    n00.firstChild.data = "new data";
+  });
+
+  test(function() {
+    checkRecords(n00, observer.takeRecords(), [{type: "attributes", attributeName: "id", oldValue: "n00"},
+                           {type: "attributes", attributeName: "id", oldValue: "foo"},
+                           {type: "attributes", attributeName: "class"},
+                           {type: "childList", addedNodes: [n00.firstChild]},
+                           {type: "characterData", oldValue: "old data", target: n00.firstChild}]);
+  }, "All records present");
+
+  test(function() {
+    checkRecords(n00, observer.takeRecords(), []);
+  }, "No more records present");
+</script>
+<script>
+  unused.done();
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-appendChild-cereactions-vs-script.window.js b/testing/web-platform/tests/dom/nodes/Node-appendChild-cereactions-vs-script.window.js
new file mode 100644
index 0000000000..bc0b8ad6dc
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-appendChild-cereactions-vs-script.window.js
@@ -0,0 +1,27 @@
+const results = [];
+test(() => {
+  class Script1 extends HTMLScriptElement {
+    constructor() {
+      super();
+    }
+    connectedCallback() {
+      results.push("ce connected s1");
+    }
+  }
+  class Script2 extends HTMLScriptElement {
+    constructor() {
+      super();
+    }
+    connectedCallback() {
+      results.push("ce connected s2");
+    }
+  }
+  customElements.define("script-1", Script1, { extends: "script" });
+  customElements.define("script-2", Script2, { extends: "script" });
+  const s1 = new Script1();
+  s1.textContent = "results.push('s1')";
+  const s2 = new Script2();
+  s2.textContent = "results.push('s2')";
+  document.body.append(s1, s2);
+  assert_array_equals(results, ["s1", "s2", "ce connected s1", "ce connected s2"]);
+}, "Custom element reactions follow script execution");
diff --git a/testing/web-platform/tests/dom/nodes/Node-appendChild.html b/testing/web-platform/tests/dom/nodes/Node-appendChild.html
new file mode 100644
index 0000000000..8264cb11a5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-appendChild.html
@@ -0,0 +1,59 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Node.appendChild</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-appendchild">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<iframe src=about:blank></iframe>
+<script>
+// TODO: Exhaustive tests
+function testLeaf(node, desc) {
+  // WebIDL.
+  test(function() {
+    assert_throws_js(TypeError, function() { node.appendChild(null) })
+  }, "Appending null to a " + desc)
+
+  // Pre-insert step 1.
+  test(function() {
+    assert_throws_dom("HIERARCHY_REQUEST_ERR", function() { node.appendChild(document.createTextNode("fail")) })
+  }, "Appending to a " + desc)
+}
+
+// WebIDL.
+test(function() {
+  assert_throws_js(TypeError, function() { document.body.appendChild(null) })
+  assert_throws_js(TypeError, function() { document.body.appendChild({'a':'b'}) })
+}, "WebIDL tests")
+
+// WebIDL and pre-insert step 1.
+test(function() {
+  testLeaf(document.createTextNode("Foo"), "text node")
+  testLeaf(document.createComment("Foo"), "comment")
+  testLeaf(document.doctype, "doctype")
+}, "Appending to a leaf node.")
+
+// Pre-insert step 5.
+test(function() {
+  var frameDoc = frames[0].document
+  assert_throws_dom("HIERARCHY_REQUEST_ERR", function() { document.body.appendChild(frameDoc) })
+}, "Appending a document")
+
+// Pre-insert step 8.
+test(function() {
+  var frameDoc = frames[0].document
+  var s = frameDoc.createElement("a")
+  assert_equals(s.ownerDocument, frameDoc)
+  document.body.appendChild(s)
+  assert_equals(s.ownerDocument, document)
+}, "Adopting an orphan")
+test(function() {
+  var frameDoc = frames[0].document
+  var s = frameDoc.createElement("b")
+  assert_equals(s.ownerDocument, frameDoc)
+  frameDoc.body.appendChild(s)
+  assert_equals(s.ownerDocument, frameDoc)
+  document.body.appendChild(s)
+  assert_equals(s.ownerDocument, document)
+}, "Adopting a non-orphan")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-baseURI.html b/testing/web-platform/tests/dom/nodes/Node-baseURI.html
new file mode 100644
index 0000000000..e9e9d76a10
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-baseURI.html
@@ -0,0 +1,62 @@
+<!DOCTYPE html>
+<title>Node.baseURI</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+const elementTests = [
+  {
+    name: "elements belonging to document",
+    creator: () => {
+      const element = document.createElement("div");
+      document.body.appendChild(element);
+      return element;
+    }
+  },
+  {
+    name: "elements unassigned to document",
+    creator: () => document.createElement("div")
+  },
+  {
+    name: "elements belonging to document fragments",
+    creator: () => {
+      const fragment = document.createDocumentFragment();
+      const element = document.createElement("div");
+      fragment.appendChild(element);
+      return element;
+    }
+  },
+  {
+    name: "elements belonging to document fragments in document",
+    creator: () => {
+      const fragment = document.createDocumentFragment();
+      const element = document.createElement("div");
+      fragment.appendChild(element);
+      document.body.appendChild(fragment);
+      return element;
+    }
+  },
+];
+
+const attributeTests = [
+  {
+    name: "attributes unassigned to element",
+    creator: () => document.createAttribute("class")
+  },
+  ...elementTests.map(({ name, creator }) => ({
+    name: "attributes in " + name,
+    creator: () => {
+      const element = creator();
+      element.setAttribute("class", "abc");
+      return element.getAttributeNode("class");
+    }
+  }))
+];
+
+for (const { name, creator } of [...elementTests, ...attributeTests]) {
+  test(function() {
+    const node = creator();
+    assert_equals(node.baseURI, document.URL);
+  }, `For ${name}, baseURI should be document URL`)
+}
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-childNodes.html b/testing/web-platform/tests/dom/nodes/Node-childNodes.html
new file mode 100644
index 0000000000..0d38df37b2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-childNodes.html
@@ -0,0 +1,117 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Node.childNodes</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-childnodes">
+<link rel=author title="Tim Taubert" href="mailto:ttaubert@mozilla.com">
+<link rel=author title="Ms2ger" href="mailto:Ms2ger@gmail.com">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div style="display: none">
+  <ul id='test'><li>1</li><li>2</li><li>3</li><li>4</li></ul>
+</div>
+<script>
+test(function() {
+  var element = document.createElement("p");
+  assert_equals(element.childNodes, element.childNodes);
+}, "Caching of Node.childNodes");
+
+var check_parent_node = function(node) {
+  assert_array_equals(node.childNodes, []);
+
+  var children = node.childNodes;
+  var child = document.createElement("p");
+  node.appendChild(child);
+  assert_equals(node.childNodes, children);
+  assert_array_equals(children, [child]);
+  assert_equals(children.item(0), child);
+
+  var child2 = document.createComment("comment");
+  node.appendChild(child2);
+  assert_array_equals(children, [child, child2]);
+  assert_equals(children.item(0), child);
+  assert_equals(children.item(1), child2);
+
+  assert_false(2 in children);
+  assert_equals(children[2], undefined);
+  assert_equals(children.item(2), null);
+};
+
+test(function() {
+  check_parent_node(document.createElement("p"));
+}, "Node.childNodes on an Element.");
+
+test(function() {
+  check_parent_node(document.createDocumentFragment());
+}, "Node.childNodes on a DocumentFragment.");
+
+test(function() {
+  check_parent_node(new Document());
+}, "Node.childNodes on a Document.");
+
+test(function() {
+  var node = document.createElement("div");
+  var kid1 = document.createElement("p");
+  var kid2 = document.createTextNode("hey");
+  var kid3 = document.createElement("span");
+  node.appendChild(kid1);
+  node.appendChild(kid2);
+  node.appendChild(kid3);
+
+  var list = node.childNodes;
+  assert_array_equals([...list], [kid1, kid2, kid3]);
+
+  var keys = list.keys();
+  assert_false(keys instanceof Array);
+  keys = [...keys];
+  assert_array_equals(keys, [0, 1, 2]);
+
+  var values = list.values();
+  assert_false(values instanceof Array);
+  values = [...values];
+  assert_array_equals(values, [kid1, kid2, kid3]);
+
+  var entries = list.entries();
+  assert_false(entries instanceof Array);
+  entries = [...entries];
+  assert_equals(entries.length, keys.length);
+  assert_equals(entries.length, values.length);
+  for (var i = 0; i < entries.length; ++i) {
+    assert_array_equals(entries[i], [keys[i], values[i]]);
+  }
+
+  var cur = 0;
+  var thisObj = {};
+  list.forEach(function(value, key, listObj) {
+    assert_equals(listObj, list);
+    assert_equals(this, thisObj);
+    assert_equals(value, values[cur]);
+    assert_equals(key, keys[cur]);
+    cur++;
+  }, thisObj);
+  assert_equals(cur, entries.length);
+
+  assert_equals(list[Symbol.iterator], Array.prototype[Symbol.iterator]);
+  assert_equals(list.keys, Array.prototype.keys);
+  if (Array.prototype.values) {
+    assert_equals(list.values, Array.prototype.values);
+  }
+  assert_equals(list.entries, Array.prototype.entries);
+  assert_equals(list.forEach, Array.prototype.forEach);
+}, "Iterator behavior of Node.childNodes");
+
+
+test(() => {
+  var node = document.getElementById("test");
+  var children = node.childNodes;
+  assert_true(children instanceof NodeList);
+  var li = document.createElement("li");
+  assert_equals(children.length, 4);
+
+  node.appendChild(li);
+  assert_equals(children.length, 5);
+
+  node.removeChild(li);
+  assert_equals(children.length, 4);
+}, "Node.childNodes should be a live collection");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-cloneNode-XMLDocument.html b/testing/web-platform/tests/dom/nodes/Node-cloneNode-XMLDocument.html
new file mode 100644
index 0000000000..2c63c77530
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-cloneNode-XMLDocument.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Cloning of an XMLDocument</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-node-clonenode">
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-node-clone">
+
+<!-- This is testing in particular "that implements the same interfaces as node" -->
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+  const doc = document.implementation.createDocument("namespace", "");
+
+  assert_equals(
+    doc.constructor, XMLDocument,
+    "Precondition check: document.implementation.createDocument() creates an XMLDocument"
+  );
+
+  const clone = doc.cloneNode(true);
+
+  assert_equals(clone.constructor, XMLDocument);
+}, "Created with createDocument");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-cloneNode-document-with-doctype.html b/testing/web-platform/tests/dom/nodes/Node-cloneNode-document-with-doctype.html
new file mode 100644
index 0000000000..21963084d2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-cloneNode-document-with-doctype.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Cloning of a document with a doctype</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-node-clonenode">
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-node-clone">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+  const doctype = document.implementation.createDocumentType("name", "publicId", "systemId");
+  const doc = document.implementation.createDocument("namespace", "", doctype);
+
+  const clone = doc.cloneNode(true);
+
+  assert_equals(clone.childNodes.length, 1, "Only one child node");
+  assert_equals(clone.childNodes[0].nodeType, Node.DOCUMENT_TYPE_NODE, "Is a document fragment");
+  assert_equals(clone.childNodes[0].name, "name");
+  assert_equals(clone.childNodes[0].publicId, "publicId");
+  assert_equals(clone.childNodes[0].systemId, "systemId");
+}, "Created with the createDocument/createDocumentType");
+
+test(() => {
+  const doc = document.implementation.createHTMLDocument();
+
+  const clone = doc.cloneNode(true);
+
+  assert_equals(clone.childNodes.length, 2, "Two child nodes");
+  assert_equals(clone.childNodes[0].nodeType, Node.DOCUMENT_TYPE_NODE, "Is a document fragment");
+  assert_equals(clone.childNodes[0].name, "html");
+  assert_equals(clone.childNodes[0].publicId, "");
+  assert_equals(clone.childNodes[0].systemId, "");
+}, "Created with the createHTMLDocument");
+
+test(() => {
+  const parser = new window.DOMParser();
+  const doc = parser.parseFromString("<!DOCTYPE html><html></html>", "text/html");
+
+  const clone = doc.cloneNode(true);
+
+  assert_equals(clone.childNodes.length, 2, "Two child nodes");
+  assert_equals(clone.childNodes[0].nodeType, Node.DOCUMENT_TYPE_NODE, "Is a document fragment");
+  assert_equals(clone.childNodes[0].name, "html");
+  assert_equals(clone.childNodes[0].publicId, "");
+  assert_equals(clone.childNodes[0].systemId, "");
+}, "Created with DOMParser");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-cloneNode-external-stylesheet-no-bc.sub.html b/testing/web-platform/tests/dom/nodes/Node-cloneNode-external-stylesheet-no-bc.sub.html
new file mode 100644
index 0000000000..bce6074aad
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-cloneNode-external-stylesheet-no-bc.sub.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>cloneNode on a stylesheet link in a browsing-context-less document</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!-- Regression test for https://github.com/jsdom/jsdom/issues/2497 -->
+
+<script>
+"use strict";
+
+setup({ single_test: true });
+
+const doc = document.implementation.createHTMLDocument();
+
+// Bug was only triggered by absolute URLs, for some reason...
+const absoluteURL = new URL("/common/canvas-frame.css", location.href);
+doc.head.innerHTML = `<link rel="stylesheet" href="${absoluteURL}">`;
+
+// Test passes if this does not throw/crash
+doc.cloneNode(true);
+
+done();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-cloneNode-on-inactive-document-crash.html b/testing/web-platform/tests/dom/nodes/Node-cloneNode-on-inactive-document-crash.html
new file mode 100644
index 0000000000..cbd7a1e6a5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-cloneNode-on-inactive-document-crash.html
@@ -0,0 +1,6 @@
+<iframe id="i"></iframe>
+<script>
+var doc = i.contentDocument;
+i.remove();
+doc.cloneNode();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-cloneNode-svg.html b/testing/web-platform/tests/dom/nodes/Node-cloneNode-svg.html
new file mode 100644
index 0000000000..9d4704b074
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-cloneNode-svg.html
@@ -0,0 +1,63 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Cloning of SVG elements and attributes</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-node-clonenode">
+<link rel="help" href="https://dom.spec.whatwg.org/#concept-node-clone">
+<!-- regression test for https://github.com/jsdom/jsdom/issues/1601 -->
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<svg xmlns:xlink='http://www.w3.org/1999/xlink'><use xlink:href='#test'></use></svg>
+
+<script>
+"use strict";
+
+const svg = document.querySelector("svg");
+const clone = svg.cloneNode(true);
+
+test(() => {
+
+  assert_equals(clone.namespaceURI, "http://www.w3.org/2000/svg");
+  assert_equals(clone.prefix, null);
+  assert_equals(clone.localName, "svg");
+  assert_equals(clone.tagName, "svg");
+
+}, "cloned <svg> should have the right properties");
+
+test(() => {
+
+  const attr = clone.attributes[0];
+
+  assert_equals(attr.namespaceURI, "http://www.w3.org/2000/xmlns/");
+  assert_equals(attr.prefix, "xmlns");
+  assert_equals(attr.localName, "xlink");
+  assert_equals(attr.name, "xmlns:xlink");
+  assert_equals(attr.value, "http://www.w3.org/1999/xlink");
+
+}, "cloned <svg>'s xmlns:xlink attribute should have the right properties");
+
+test(() => {
+
+  const use = clone.firstElementChild;
+  assert_equals(use.namespaceURI, "http://www.w3.org/2000/svg");
+  assert_equals(use.prefix, null);
+  assert_equals(use.localName, "use");
+  assert_equals(use.tagName, "use");
+
+}, "cloned <use> should have the right properties");
+
+test(() => {
+
+  const use = clone.firstElementChild;
+  const attr = use.attributes[0];
+
+  assert_equals(attr.namespaceURI, "http://www.w3.org/1999/xlink");
+  assert_equals(attr.prefix, "xlink");
+  assert_equals(attr.localName, "href");
+  assert_equals(attr.name, "xlink:href");
+  assert_equals(attr.value, "#test");
+
+}, "cloned <use>'s xlink:href attribute should have the right properties");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-cloneNode.html b/testing/web-platform/tests/dom/nodes/Node-cloneNode.html
new file mode 100644
index 0000000000..e97259dace
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-cloneNode.html
@@ -0,0 +1,346 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Node.cloneNode</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-clonenode">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+function assert_equal_node(nodeA, nodeB) {
+  assert_equals(nodeB.nodeType, nodeA.nodeType, "nodeType");
+  assert_equals(nodeB.nodeName, nodeA.nodeName, "nodeName");
+
+  if (nodeA.nodeType === Node.ELEMENT_NODE) {
+    assert_equals(nodeB.prefix, nodeA.prefix, "prefix");
+    assert_equals(nodeB.namespaceURI, nodeA.namespaceURI, "namespaceURI");
+    assert_equals(nodeB.localName, nodeA.localName, "localName");
+    assert_equals(nodeB.tagName, nodeA.tagName, "tagName");
+    assert_not_equals(nodeB.attributes != nodeA.attributes, "attributes");
+    assert_equals(nodeB.attributes.length, nodeA.attributes.length,
+                  "attributes.length");
+    for (var i = 0, il = nodeA.attributes.length; i < il; ++i) {
+      assert_not_equals(nodeB.attributes[i], nodeA.attributes[i],
+                        "attributes[" + i + "]");
+      assert_equals(nodeB.attributes[i].name, nodeA.attributes[i].name,
+                    "attributes[" + i + "].name");
+      assert_equals(nodeB.attributes[i].prefix, nodeA.attributes[i].prefix,
+                    "attributes[" + i + "].prefix");
+      assert_equals(nodeB.attributes[i].namespaceURI, nodeA.attributes[i].namespaceURI,
+                    "attributes[" + i + "].namespaceURI");
+      assert_equals(nodeB.attributes[i].value, nodeA.attributes[i].value,
+                    "attributes[" + i + "].value");
+    }
+  }
+}
+
+function check_copy(orig, copy, type) {
+    assert_not_equals(orig, copy, "Object equality");
+    assert_equal_node(orig, copy, "Node equality");
+    assert_true(orig instanceof type, "original instanceof " + type);
+    assert_true(copy instanceof type, "copy instanceof " + type);
+}
+
+function create_element_and_check(localName, typeName) {
+  test(function() {
+    assert_true(typeName in window, typeName + " is not supported");
+    var element = document.createElement(localName);
+    var copy = element.cloneNode();
+    check_copy(element, copy, window[typeName]);
+  }, "createElement(" + localName + ")");
+}
+
+// test1: createElement
+create_element_and_check("a",         "HTMLAnchorElement");
+create_element_and_check("abbr",      "HTMLElement");
+create_element_and_check("acronym",   "HTMLElement");
+create_element_and_check("address",   "HTMLElement");
+create_element_and_check("area",      "HTMLAreaElement");
+create_element_and_check("article",   "HTMLElement");
+create_element_and_check("aside",     "HTMLElement");
+create_element_and_check("audio",     "HTMLAudioElement");
+create_element_and_check("b",         "HTMLElement");
+create_element_and_check("base",      "HTMLBaseElement");
+create_element_and_check("bdi",       "HTMLElement");
+create_element_and_check("bdo",       "HTMLElement");
+create_element_and_check("bgsound",   "HTMLElement");
+create_element_and_check("big",       "HTMLElement");
+create_element_and_check("blockquote","HTMLElement");
+create_element_and_check("body",      "HTMLBodyElement");
+create_element_and_check("br",        "HTMLBRElement");
+create_element_and_check("button",    "HTMLButtonElement");
+create_element_and_check("canvas",    "HTMLCanvasElement");
+create_element_and_check("caption",   "HTMLTableCaptionElement");
+create_element_and_check("center",    "HTMLElement");
+create_element_and_check("cite",      "HTMLElement");
+create_element_and_check("code",      "HTMLElement");
+create_element_and_check("col",       "HTMLTableColElement");
+create_element_and_check("colgroup",  "HTMLTableColElement");
+create_element_and_check("data",      "HTMLDataElement");
+create_element_and_check("datalist",  "HTMLDataListElement");
+create_element_and_check("dialog",    "HTMLDialogElement");
+create_element_and_check("dd",        "HTMLElement");
+create_element_and_check("del",       "HTMLModElement");
+create_element_and_check("details",   "HTMLElement");
+create_element_and_check("dfn",       "HTMLElement");
+create_element_and_check("dir",       "HTMLDirectoryElement");
+create_element_and_check("div",       "HTMLDivElement");
+create_element_and_check("dl",        "HTMLDListElement");
+create_element_and_check("dt",        "HTMLElement");
+create_element_and_check("embed",     "HTMLEmbedElement");
+create_element_and_check("fieldset",  "HTMLFieldSetElement");
+create_element_and_check("figcaption","HTMLElement");
+create_element_and_check("figure",    "HTMLElement");
+create_element_and_check("font",      "HTMLFontElement");
+create_element_and_check("footer",    "HTMLElement");
+create_element_and_check("form",      "HTMLFormElement");
+create_element_and_check("frame",     "HTMLFrameElement");
+create_element_and_check("frameset",  "HTMLFrameSetElement");
+create_element_and_check("h1",        "HTMLHeadingElement");
+create_element_and_check("h2",        "HTMLHeadingElement");
+create_element_and_check("h3",        "HTMLHeadingElement");
+create_element_and_check("h4",        "HTMLHeadingElement");
+create_element_and_check("h5",        "HTMLHeadingElement");
+create_element_and_check("h6",        "HTMLHeadingElement");
+create_element_and_check("head",      "HTMLHeadElement");
+create_element_and_check("header",    "HTMLElement");
+create_element_and_check("hgroup",    "HTMLElement");
+create_element_and_check("hr",        "HTMLHRElement");
+create_element_and_check("html",      "HTMLHtmlElement");
+create_element_and_check("i",         "HTMLElement");
+create_element_and_check("iframe",    "HTMLIFrameElement");
+create_element_and_check("img",       "HTMLImageElement");
+create_element_and_check("input",     "HTMLInputElement");
+create_element_and_check("ins",       "HTMLModElement");
+create_element_and_check("isindex",   "HTMLElement");
+create_element_and_check("kbd",       "HTMLElement");
+create_element_and_check("label",     "HTMLLabelElement");
+create_element_and_check("legend",    "HTMLLegendElement");
+create_element_and_check("li",        "HTMLLIElement");
+create_element_and_check("link",      "HTMLLinkElement");
+create_element_and_check("main",      "HTMLElement");
+create_element_and_check("map",       "HTMLMapElement");
+create_element_and_check("mark",      "HTMLElement");
+create_element_and_check("marquee",   "HTMLElement");
+create_element_and_check("meta",      "HTMLMetaElement");
+create_element_and_check("meter",     "HTMLMeterElement");
+create_element_and_check("nav",       "HTMLElement");
+create_element_and_check("nobr",      "HTMLElement");
+create_element_and_check("noframes",  "HTMLElement");
+create_element_and_check("noscript",  "HTMLElement");
+create_element_and_check("object",    "HTMLObjectElement");
+create_element_and_check("ol",        "HTMLOListElement");
+create_element_and_check("optgroup",  "HTMLOptGroupElement");
+create_element_and_check("option",    "HTMLOptionElement");
+create_element_and_check("output",    "HTMLOutputElement");
+create_element_and_check("p",         "HTMLParagraphElement");
+create_element_and_check("param",     "HTMLParamElement");
+create_element_and_check("pre",       "HTMLPreElement");
+create_element_and_check("progress",  "HTMLProgressElement");
+create_element_and_check("q",         "HTMLQuoteElement");
+create_element_and_check("rp",        "HTMLElement");
+create_element_and_check("rt",        "HTMLElement");
+create_element_and_check("ruby",      "HTMLElement");
+create_element_and_check("s",         "HTMLElement");
+create_element_and_check("samp",      "HTMLElement");
+create_element_and_check("script",    "HTMLScriptElement");
+create_element_and_check("section",   "HTMLElement");
+create_element_and_check("select",    "HTMLSelectElement");
+create_element_and_check("small",     "HTMLElement");
+create_element_and_check("source",    "HTMLSourceElement");
+create_element_and_check("spacer",    "HTMLElement");
+create_element_and_check("span",      "HTMLSpanElement");
+create_element_and_check("strike",    "HTMLElement");
+create_element_and_check("style",     "HTMLStyleElement");
+create_element_and_check("sub",       "HTMLElement");
+create_element_and_check("summary",   "HTMLElement");
+create_element_and_check("sup",       "HTMLElement");
+create_element_and_check("table",     "HTMLTableElement");
+create_element_and_check("tbody",     "HTMLTableSectionElement");
+create_element_and_check("td",        "HTMLTableCellElement");
+create_element_and_check("template",  "HTMLTemplateElement");
+create_element_and_check("textarea",  "HTMLTextAreaElement");
+create_element_and_check("th",        "HTMLTableCellElement");
+create_element_and_check("time",      "HTMLTimeElement");
+create_element_and_check("title",     "HTMLTitleElement");
+create_element_and_check("tr",        "HTMLTableRowElement");
+create_element_and_check("tt",        "HTMLElement");
+create_element_and_check("track",     "HTMLTrackElement");
+create_element_and_check("u",         "HTMLElement");
+create_element_and_check("ul",        "HTMLUListElement");
+create_element_and_check("var",       "HTMLElement");
+create_element_and_check("video",     "HTMLVideoElement");
+create_element_and_check("unknown",   "HTMLUnknownElement");
+create_element_and_check("wbr",       "HTMLElement");
+
+test(function() {
+    var fragment = document.createDocumentFragment();
+    var copy = fragment.cloneNode();
+    check_copy(fragment, copy, DocumentFragment);
+}, "createDocumentFragment");
+
+test(function() {
+    var text = document.createTextNode("hello world");
+    var copy = text.cloneNode();
+    check_copy(text, copy, Text);
+    assert_equals(text.data, copy.data);
+    assert_equals(text.wholeText, copy.wholeText);
+}, "createTextNode");
+
+test(function() {
+    var comment = document.createComment("a comment");
+    var copy = comment.cloneNode();
+    check_copy(comment, copy, Comment);
+    assert_equals(comment.data, copy.data);
+}, "createComment");
+
+test(function() {
+  var el = document.createElement("foo");
+  el.setAttribute("a", "b");
+  el.setAttribute("c", "d");
+  var c = el.cloneNode();
+  check_copy(el, c, Element);
+}, "createElement with attributes")
+
+test(function() {
+  var el = document.createElementNS("http://www.w3.org/1999/xhtml", "foo:div");
+  var c = el.cloneNode();
+  check_copy(el, c, HTMLDivElement);
+}, "createElementNS HTML")
+
+test(function() {
+  var el = document.createElementNS("http://www.example.com/", "foo:div");
+  var c = el.cloneNode();
+  check_copy(el, c, Element);
+}, "createElementNS non-HTML")
+
+test(function() {
+    var pi = document.createProcessingInstruction("target", "data");
+    var copy = pi.cloneNode();
+    check_copy(pi, copy, ProcessingInstruction);
+    assert_equals(pi.data, copy.data, "data");
+    assert_equals(pi.target, pi.target, "target");
+}, "createProcessingInstruction");
+
+test(function() {
+    var attr = document.createAttribute("class");
+    var copy = attr.cloneNode();
+    check_copy(attr, copy, Attr);
+    assert_equals(attr.namespaceURI, copy.namespaceURI);
+    assert_equals(attr.prefix, copy.prefix);
+    assert_equals(attr.localName, copy.localName);
+    assert_equals(attr.value, copy.value);
+
+    attr.value = "abc";
+    assert_equals(attr.namespaceURI, copy.namespaceURI);
+    assert_equals(attr.prefix, copy.prefix);
+    assert_equals(attr.localName, copy.localName);
+    assert_not_equals(attr.value, copy.value);
+
+    var copy2 = attr.cloneNode();
+    check_copy(attr, copy2, Attr);
+    assert_equals(attr.namespaceURI, copy.namespaceURI);
+    assert_equals(attr.prefix, copy.prefix);
+    assert_equals(attr.localName, copy2.localName);
+    assert_equals(attr.value, copy2.value);
+}, "createAttribute");
+
+test(function() {
+    var attr = document.createAttributeNS("http://www.w3.org/1999/xhtml", "foo:class");
+    var copy = attr.cloneNode();
+    check_copy(attr, copy, Attr);
+    assert_equals(attr.namespaceURI, copy.namespaceURI);
+    assert_equals(attr.prefix, copy.prefix);
+    assert_equals(attr.localName, copy.localName);
+    assert_equals(attr.value, copy.value);
+
+    attr.value = "abc";
+    assert_equals(attr.namespaceURI, copy.namespaceURI);
+    assert_equals(attr.prefix, copy.prefix);
+    assert_equals(attr.localName, copy.localName);
+    assert_not_equals(attr.value, copy.value);
+
+    var copy2 = attr.cloneNode();
+    check_copy(attr, copy2, Attr);
+    assert_equals(attr.namespaceURI, copy.namespaceURI);
+    assert_equals(attr.prefix, copy.prefix);
+    assert_equals(attr.localName, copy2.localName);
+    assert_equals(attr.value, copy2.value);
+}, "createAttributeNS");
+
+test(function() {
+    var doctype = document.implementation.createDocumentType("html", "public", "system");
+    var copy = doctype.cloneNode();
+    check_copy(doctype, copy, DocumentType);
+    assert_equals(doctype.name, copy.name, "name");
+    assert_equals(doctype.publicId, copy.publicId, "publicId");
+    assert_equals(doctype.systemId, copy.systemId, "systemId");
+}, "implementation.createDocumentType");
+
+test(function() {
+    var doc = document.implementation.createDocument(null, null);
+    var copy = doc.cloneNode();
+    check_copy(doc, copy, Document);
+    assert_equals(doc.charset, "UTF-8", "charset value");
+    assert_equals(doc.charset, copy.charset, "charset equality");
+    assert_equals(doc.contentType, "application/xml", "contentType value");
+    assert_equals(doc.contentType, copy.contentType, "contentType equality");
+    assert_equals(doc.URL, "about:blank", "URL value")
+    assert_equals(doc.URL, copy.URL, "URL equality");
+    assert_equals(doc.compatMode, "CSS1Compat", "compatMode value");
+    assert_equals(doc.compatMode, copy.compatMode, "compatMode equality");
+}, "implementation.createDocument");
+
+test(function() {
+    var html = document.implementation.createHTMLDocument("title");
+    var copy = html.cloneNode();
+    check_copy(html, copy, Document);
+    assert_equals(copy.title, "", "title value");
+}, "implementation.createHTMLDocument");
+
+test(function() {
+    var parent = document.createElement("div");
+    var child1 = document.createElement("div");
+    var child2 = document.createElement("div");
+    var grandChild = document.createElement("div");
+
+    child2.appendChild(grandChild);
+    parent.appendChild(child1);
+    parent.appendChild(child2);
+
+    var deep = true;
+    var copy = parent.cloneNode(deep);
+
+    check_copy(parent, copy, HTMLDivElement);
+    assert_equals(copy.childNodes.length, 2,
+                  "copy.childNodes.length with deep copy");
+
+    check_copy(child1, copy.childNodes[0], HTMLDivElement);
+    assert_equals(copy.childNodes[0].childNodes.length, 0,
+                  "copy.childNodes[0].childNodes.length");
+
+    check_copy(child2, copy.childNodes[1], HTMLDivElement);
+    assert_equals(copy.childNodes[1].childNodes.length, 1,
+                  "copy.childNodes[1].childNodes.length");
+    check_copy(grandChild, copy.childNodes[1].childNodes[0], HTMLDivElement);
+
+    deep = false;
+    copy = parent.cloneNode(deep);
+
+    check_copy(parent, copy, HTMLDivElement);
+    assert_equals(copy.childNodes.length, 0,
+                  "copy.childNodes.length with non-deep copy");
+}, "node with children");
+
+test(() => {
+  const proto = Object.create(HTMLElement.prototype),
+        node = document.createElement("hi");
+  Object.setPrototypeOf(node, proto);
+  assert_true(proto.isPrototypeOf(node));
+  const clone = node.cloneNode();
+  assert_false(proto.isPrototypeOf(clone));
+  assert_true(HTMLUnknownElement.prototype.isPrototypeOf(clone));
+  const deepClone = node.cloneNode(true);
+  assert_false(proto.isPrototypeOf(deepClone));
+  assert_true(HTMLUnknownElement.prototype.isPrototypeOf(deepClone));
+}, "Node with custom prototype")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-compareDocumentPosition.html b/testing/web-platform/tests/dom/nodes/Node-compareDocumentPosition.html
new file mode 100644
index 0000000000..afae60aad1
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-compareDocumentPosition.html
@@ -0,0 +1,87 @@
+<!doctype html>
+<title>Node.compareDocumentPosition() tests</title>
+<link rel=author title="Aryeh Gregor" href=ayg@aryeh.name>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+testNodes.forEach(function(referenceName) {
+  var reference = eval(referenceName);
+  testNodes.forEach(function(otherName) {
+    var other = eval(otherName);
+    test(function() {
+      var result = reference.compareDocumentPosition(other);
+
+      // "If other and reference are the same object, return zero and
+      // terminate these steps."
+      if (other === reference) {
+        assert_equals(result, 0);
+        return;
+      }
+
+      // "If other and reference are not in the same tree, return the result of
+      // adding DOCUMENT_POSITION_DISCONNECTED,
+      // DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC, and either
+      // DOCUMENT_POSITION_PRECEDING or DOCUMENT_POSITION_FOLLOWING, with the
+      // constraint that this is to be consistent, together and terminate these
+      // steps."
+      if (furthestAncestor(reference) !== furthestAncestor(other)) {
+        // TODO: Test that it's consistent.
+        assert_in_array(result, [Node.DOCUMENT_POSITION_DISCONNECTED +
+                                 Node.DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC +
+                                 Node.DOCUMENT_POSITION_PRECEDING,
+                                 Node.DOCUMENT_POSITION_DISCONNECTED +
+                                 Node.DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC +
+                                 Node.DOCUMENT_POSITION_FOLLOWING]);
+        return;
+      }
+
+      // "If other is an ancestor of reference, return the result of
+      // adding DOCUMENT_POSITION_CONTAINS to DOCUMENT_POSITION_PRECEDING
+      // and terminate these steps."
+      var ancestor = reference.parentNode;
+      while (ancestor && ancestor !== other) {
+        ancestor = ancestor.parentNode;
+      }
+      if (ancestor === other) {
+        assert_equals(result, Node.DOCUMENT_POSITION_CONTAINS +
+                              Node.DOCUMENT_POSITION_PRECEDING);
+        return;
+      }
+
+      // "If other is a descendant of reference, return the result of adding
+      // DOCUMENT_POSITION_CONTAINED_BY to DOCUMENT_POSITION_FOLLOWING and
+      // terminate these steps."
+      ancestor = other.parentNode;
+      while (ancestor && ancestor !== reference) {
+        ancestor = ancestor.parentNode;
+      }
+      if (ancestor === reference) {
+        assert_equals(result, Node.DOCUMENT_POSITION_CONTAINED_BY +
+                              Node.DOCUMENT_POSITION_FOLLOWING);
+        return;
+      }
+
+      // "If other is preceding reference return DOCUMENT_POSITION_PRECEDING
+      // and terminate these steps."
+      var prev = previousNode(reference);
+      while (prev && prev !== other) {
+        prev = previousNode(prev);
+      }
+      if (prev === other) {
+        assert_equals(result, Node.DOCUMENT_POSITION_PRECEDING);
+        return;
+      }
+
+      // "Return DOCUMENT_POSITION_FOLLOWING."
+      assert_equals(result, Node.DOCUMENT_POSITION_FOLLOWING);
+    }, referenceName + ".compareDocumentPosition(" + otherName + ")");
+  });
+});
+
+testDiv.parentNode.removeChild(testDiv);
+</script>
+<!-- vim: set expandtab tabstop=2 shiftwidth=2: -->
diff --git a/testing/web-platform/tests/dom/nodes/Node-constants.html b/testing/web-platform/tests/dom/nodes/Node-constants.html
new file mode 100644
index 0000000000..33e7c10e73
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-constants.html
@@ -0,0 +1,39 @@
+<!doctype html>
+<title>Node constants</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../constants.js"></script>
+<div id="log"></div>
+<script>
+var objects;
+setup(function() {
+  objects = [
+    [Node, "Node interface object"],
+    [Node.prototype, "Node prototype object"],
+    [document.createElement("foo"), "Element object"],
+    [document.createTextNode("bar"), "Text object"]
+  ]
+})
+testConstants(objects, [
+  ["ELEMENT_NODE", 1],
+  ["ATTRIBUTE_NODE", 2],
+  ["TEXT_NODE", 3],
+  ["CDATA_SECTION_NODE", 4],
+  ["ENTITY_REFERENCE_NODE", 5],
+  ["ENTITY_NODE", 6],
+  ["PROCESSING_INSTRUCTION_NODE", 7],
+  ["COMMENT_NODE", 8],
+  ["DOCUMENT_NODE", 9],
+  ["DOCUMENT_TYPE_NODE", 10],
+  ["DOCUMENT_FRAGMENT_NODE", 11],
+  ["NOTATION_NODE", 12]
+], "nodeType")
+testConstants(objects, [
+  ["DOCUMENT_POSITION_DISCONNECTED", 0x01],
+  ["DOCUMENT_POSITION_PRECEDING", 0x02],
+  ["DOCUMENT_POSITION_FOLLOWING", 0x04],
+  ["DOCUMENT_POSITION_CONTAINS", 0x08],
+  ["DOCUMENT_POSITION_CONTAINED_BY", 0x10],
+  ["DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC", 0x20]
+], "createDocumentPosition")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-contains-xml.xml b/testing/web-platform/tests/dom/nodes/Node-contains-xml.xml
new file mode 100644
index 0000000000..f9b20d68d6
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-contains-xml.xml
@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Node.nodeName</title>
+<link rel="author" title="Olli Pettay" href="mailto:Olli@Pettay.fi"/>
+<link rel="author" title="Ms2ger" href="mailto:Ms2ger@gmail.com"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"/>
+<div id="test">
+  <input type="button" id="testbutton"/>
+  <a id="link">Link text</a>
+</div>
+<script>
+<![CDATA[
+test(function() {
+  assert_throws_js(TypeError, function() {
+    document.contains();
+  });
+  assert_throws_js(TypeError, function() {
+    document.contains(9);
+  });
+}, "Should throw TypeError if the arguments are wrong.");
+
+test(function() {
+  assert_equals(document.contains(null), false, "Document shouldn't contain null.");
+}, "contains(null) should be false");
+
+test(function() {
+  assert_equals(document.contains(document), true, "Document should contain itself!");
+  assert_equals(document.contains(document.createElement("foo")), false, "Document shouldn't contain element which is't in the document");
+  assert_equals(document.contains(document.createTextNode("foo")), false, "Document shouldn't contain text node which is't in the document");
+}, "document.contains");
+
+test(function() {
+  var tb = document.getElementById("testbutton");
+  assert_equals(tb.contains(tb), true, "Element should contain itself.")
+  assert_equals(document.contains(tb), true, "Document should contain element in it!");
+  assert_equals(document.documentElement.contains(tb), true, "Element should contain element in it!");
+}, "contains with a button");
+
+test(function() {
+  var link = document.getElementById("link");
+  var text = link.firstChild;
+  assert_equals(document.contains(text), true, "Document should contain a text node in it.");
+  assert_equals(link.contains(text), true, "Element should contain a text node in it.");
+  assert_equals(text.contains(text), true, "Text node should contain itself.");
+  assert_equals(text.contains(link), false, "text node shouldn't contain its parent.");
+}, "contains with a text node");
+
+test(function() {
+  var pi = document.createProcessingInstruction("adf", "asd");
+  assert_equals(pi.contains(document), false, "Processing instruction shouldn't contain document");
+  assert_equals(document.contains(pi), false, "Document shouldn't contain newly created processing instruction");
+  document.documentElement.appendChild(pi);
+  assert_equals(document.contains(pi), true, "Document should contain processing instruction");
+}, "contains with a processing instruction");
+
+test(function() {
+  if ("createContextualFragment" in document.createRange()) {
+    var df = document.createRange().createContextualFragment("<div>foo</div>");
+    assert_equals(df.contains(df.firstChild), true, "Document fragment should contain its child");
+    assert_equals(df.contains(df.firstChild.firstChild), true,
+       "Document fragment should contain its descendant");
+    assert_equals(df.contains(df), true, "Document fragment should contain itself.");
+  }
+}, "contains with a document fragment");
+
+test(function() {
+  var d = document.implementation.createHTMLDocument("");
+  assert_equals(document.contains(d), false,
+     "Document shouldn't contain another document.");
+  assert_equals(document.contains(d.createElement("div")), false,
+     "Document shouldn't contain an element from another document.");
+  assert_equals(document.contains(d.documentElement), false,
+     "Document shouldn't contain an element from another document.");
+}, "contaibs with another document");
+]]>
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Node-contains.html b/testing/web-platform/tests/dom/nodes/Node-contains.html
new file mode 100644
index 0000000000..c44f072b11
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-contains.html
@@ -0,0 +1,36 @@
+<!doctype html>
+<title>Node.contains() tests</title>
+<link rel=author title="Aryeh Gregor" href=ayg@aryeh.name>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+testNodes.forEach(function(referenceName) {
+  var reference = eval(referenceName);
+
+  test(function() {
+    assert_false(reference.contains(null));
+  }, referenceName + ".contains(null)");
+
+  testNodes.forEach(function(otherName) {
+    var other = eval(otherName);
+    test(function() {
+      var ancestor = other;
+      while (ancestor && ancestor !== reference) {
+        ancestor = ancestor.parentNode;
+      }
+      if (ancestor === reference) {
+        assert_true(reference.contains(other));
+      } else {
+        assert_false(reference.contains(other));
+      }
+    }, referenceName + ".contains(" + otherName + ")");
+  });
+});
+
+testDiv.parentNode.removeChild(testDiv);
+</script>
+<!-- vim: set expandtab tabstop=2 shiftwidth=2: -->
diff --git a/testing/web-platform/tests/dom/nodes/Node-insertBefore.html b/testing/web-platform/tests/dom/nodes/Node-insertBefore.html
new file mode 100644
index 0000000000..ecb4d18314
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-insertBefore.html
@@ -0,0 +1,297 @@
+<!DOCTYPE html>
+<title>Node.insertBefore</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<!-- First test shared pre-insertion checks that work similarly for replaceChild
+     and insertBefore -->
+<script>
+  var insertFunc = Node.prototype.insertBefore;
+</script>
+<script src="pre-insertion-validation-notfound.js"></script>
+<script src="pre-insertion-validation-hierarchy.js"></script>
+<script>
+preInsertionValidateHierarchy("insertBefore");
+
+function testLeafNode(nodeName, createNodeFunction) {
+  test(function() {
+    var node = createNodeFunction();
+    assert_throws_js(TypeError, function() { node.insertBefore(null, null) })
+  }, "Calling insertBefore with a non-Node first argument on a leaf node " + nodeName + " must throw TypeError.")
+  test(function() {
+    var node = createNodeFunction();
+    assert_throws_dom("HIERARCHY_REQUEST_ERR", function() { node.insertBefore(document.createTextNode("fail"), null) })
+    // Would be step 2.
+    assert_throws_dom("HIERARCHY_REQUEST_ERR", function() { node.insertBefore(node, null) })
+    // Would be step 3.
+    assert_throws_dom("HIERARCHY_REQUEST_ERR", function() { node.insertBefore(node, document.createTextNode("child")) })
+  }, "Calling insertBefore an a leaf node " + nodeName + " must throw HIERARCHY_REQUEST_ERR.")
+}
+
+test(function() {
+  // WebIDL: first argument.
+  assert_throws_js(TypeError, function() { document.body.insertBefore(null, null) })
+  assert_throws_js(TypeError, function() { document.body.insertBefore(null, document.body.firstChild) })
+  assert_throws_js(TypeError, function() { document.body.insertBefore({'a':'b'}, document.body.firstChild) })
+}, "Calling insertBefore with a non-Node first argument must throw TypeError.")
+
+test(function() {
+  // WebIDL: second argument.
+  assert_throws_js(TypeError, function() { document.body.insertBefore(document.createTextNode("child")) })
+  assert_throws_js(TypeError, function() { document.body.insertBefore(document.createTextNode("child"), {'a':'b'}) })
+}, "Calling insertBefore with second argument missing, or other than Node, null, or undefined, must throw TypeError.")
+
+testLeafNode("DocumentType", function () { return document.doctype; } )
+testLeafNode("Text", function () { return document.createTextNode("Foo") })
+testLeafNode("Comment", function () { return document.createComment("Foo") })
+testLeafNode("ProcessingInstruction", function () { return document.createProcessingInstruction("foo", "bar") })
+
+test(function() {
+  // Step 2.
+  assert_throws_dom("HIERARCHY_REQUEST_ERR", function() { document.body.insertBefore(document.body, document.getElementById("log")) })
+  assert_throws_dom("HIERARCHY_REQUEST_ERR", function() { document.body.insertBefore(document.documentElement, document.getElementById("log")) })
+}, "Calling insertBefore with an inclusive ancestor of the context object must throw HIERARCHY_REQUEST_ERR.")
+
+// Step 3.
+test(function() {
+  var a = document.createElement("div");
+  var b = document.createElement("div");
+  var c = document.createElement("div");
+  assert_throws_dom("NotFoundError", function() {
+    a.insertBefore(b, c);
+  });
+}, "Calling insertBefore with a reference child whose parent is not the context node must throw a NotFoundError.")
+
+// Step 4.1.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var doc2 = document.implementation.createHTMLDocument("title2");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(doc2, doc.documentElement);
+  });
+
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(doc.createTextNode("text"), doc.documentElement);
+  });
+}, "If the context node is a document, inserting a document or text node should throw a HierarchyRequestError.")
+
+// Step 4.2.1.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  doc.removeChild(doc.documentElement);
+
+  var df = doc.createDocumentFragment();
+  df.appendChild(doc.createElement("a"));
+  df.appendChild(doc.createElement("b"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, doc.firstChild);
+  });
+
+  df = doc.createDocumentFragment();
+  df.appendChild(doc.createTextNode("text"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, doc.firstChild);
+  });
+
+  df = doc.createDocumentFragment();
+  df.appendChild(doc.createComment("comment"));
+  df.appendChild(doc.createTextNode("text"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, doc.firstChild);
+  });
+}, "If the context node is a document, inserting a DocumentFragment that contains a text node or too many elements should throw a HierarchyRequestError.")
+
+// Step 4.2.2.
+test(function() {
+  // The context node has an element child.
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.appendChild(doc.createComment("foo"));
+  assert_array_equals(doc.childNodes, [doc.doctype, doc.documentElement, comment]);
+
+  var df = doc.createDocumentFragment();
+  df.appendChild(doc.createElement("a"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, doc.doctype);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, doc.documentElement);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, comment);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, null);
+  });
+}, "If the context node is a document, inserting a DocumentFragment with an element if there already is an element child should throw a HierarchyRequestError.")
+test(function() {
+  // /child/ is a doctype.
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.insertBefore(doc.createComment("foo"), doc.firstChild);
+  doc.removeChild(doc.documentElement);
+  assert_array_equals(doc.childNodes, [comment, doc.doctype]);
+
+  var df = doc.createDocumentFragment();
+  df.appendChild(doc.createElement("a"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, doc.doctype);
+  });
+}, "If the context node is a document and a doctype is following the reference child, inserting a DocumentFragment with an element should throw a HierarchyRequestError.")
+test(function() {
+  // /child/ is not null and a doctype is following /child/.
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.insertBefore(doc.createComment("foo"), doc.firstChild);
+  doc.removeChild(doc.documentElement);
+  assert_array_equals(doc.childNodes, [comment, doc.doctype]);
+
+  var df = doc.createDocumentFragment();
+  df.appendChild(doc.createElement("a"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(df, comment);
+  });
+}, "If the context node is a document, inserting a DocumentFragment with an element before the doctype should throw a HierarchyRequestError.")
+
+// Step 4.3.
+test(function() {
+  // The context node has an element child.
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.appendChild(doc.createComment("foo"));
+  assert_array_equals(doc.childNodes, [doc.doctype, doc.documentElement, comment]);
+
+  var a = doc.createElement("a");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(a, doc.doctype);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(a, doc.documentElement);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(a, comment);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(a, null);
+  });
+}, "If the context node is a document, inserting an element if there already is an element child should throw a HierarchyRequestError.")
+test(function() {
+  // /child/ is a doctype.
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.insertBefore(doc.createComment("foo"), doc.firstChild);
+  doc.removeChild(doc.documentElement);
+  assert_array_equals(doc.childNodes, [comment, doc.doctype]);
+
+  var a = doc.createElement("a");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(a, doc.doctype);
+  });
+}, "If the context node is a document, inserting an element before the doctype should throw a HierarchyRequestError.")
+test(function() {
+  // /child/ is not null and a doctype is following /child/.
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.insertBefore(doc.createComment("foo"), doc.firstChild);
+  doc.removeChild(doc.documentElement);
+  assert_array_equals(doc.childNodes, [comment, doc.doctype]);
+
+  var a = doc.createElement("a");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(a, comment);
+  });
+}, "If the context node is a document and a doctype is following the reference child, inserting an element should throw a HierarchyRequestError.")
+
+// Step 4.4.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.insertBefore(doc.createComment("foo"), doc.firstChild);
+  assert_array_equals(doc.childNodes, [comment, doc.doctype, doc.documentElement]);
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(doctype, comment);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(doctype, doc.doctype);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(doctype, doc.documentElement);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(doctype, null);
+  });
+}, "If the context node is a document, inserting a doctype if there already is a doctype child should throw a HierarchyRequestError.")
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.appendChild(doc.createComment("foo"));
+  doc.removeChild(doc.doctype);
+  assert_array_equals(doc.childNodes, [doc.documentElement, comment]);
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(doctype, comment);
+  });
+}, "If the context node is a document, inserting a doctype after the document element should throw a HierarchyRequestError.")
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.appendChild(doc.createComment("foo"));
+  doc.removeChild(doc.doctype);
+  assert_array_equals(doc.childNodes, [doc.documentElement, comment]);
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.insertBefore(doctype, null);
+  });
+}, "If the context node is a document with and element child, appending a doctype should throw a HierarchyRequestError.")
+
+// Step 5.
+test(function() {
+  var df = document.createDocumentFragment();
+  var a = df.appendChild(document.createElement("a"));
+
+  var doc = document.implementation.createHTMLDocument("title");
+  assert_throws_dom("HierarchyRequestError", function() {
+    df.insertBefore(doc, a);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    df.insertBefore(doc, null);
+  });
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    df.insertBefore(doctype, a);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    df.insertBefore(doctype, null);
+  });
+}, "If the context node is a DocumentFragment, inserting a document or a doctype should throw a HierarchyRequestError.")
+test(function() {
+  var el = document.createElement("div");
+  var a = el.appendChild(document.createElement("a"));
+
+  var doc = document.implementation.createHTMLDocument("title");
+  assert_throws_dom("HierarchyRequestError", function() {
+    el.insertBefore(doc, a);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    el.insertBefore(doc, null);
+  });
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    el.insertBefore(doctype, a);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    el.insertBefore(doctype, null);
+  });
+}, "If the context node is an element, inserting a document or a doctype should throw a HierarchyRequestError.")
+
+// Step 7.
+test(function() {
+  var a = document.createElement("div");
+  var b = document.createElement("div");
+  var c = document.createElement("div");
+  a.appendChild(b);
+  a.appendChild(c);
+  assert_array_equals(a.childNodes, [b, c]);
+  assert_equals(a.insertBefore(b, b), b);
+  assert_array_equals(a.childNodes, [b, c]);
+  assert_equals(a.insertBefore(c, c), c);
+  assert_array_equals(a.childNodes, [b, c]);
+}, "Inserting a node before itself should not move the node");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-isConnected-shadow-dom.html b/testing/web-platform/tests/dom/nodes/Node-isConnected-shadow-dom.html
new file mode 100644
index 0000000000..7d04dc32f2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-isConnected-shadow-dom.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Test of Node.isConnected in a shadow tree</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#connected">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+<script>
+"use strict";
+
+function testIsConnected(mode) {
+  test(() => {
+    const host = document.createElement("div");
+    document.body.appendChild(host);
+
+    const root = host.attachShadow({ mode });
+
+    const node = document.createElement("div");
+    root.appendChild(node);
+
+    assert_true(node.isConnected);
+  }, `Node.isConnected in a ${mode} shadow tree`);
+}
+
+for (const mode of ["closed", "open"]) {
+  testIsConnected(mode);
+}
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-isConnected.html b/testing/web-platform/tests/dom/nodes/Node-isConnected.html
new file mode 100644
index 0000000000..da0b460de4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-isConnected.html
@@ -0,0 +1,95 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<head>
+<title>Node.prototype.isConnected</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-isconnected">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+
+"use strict";
+
+test(function() {
+  var nodes = [document.createElement("div"),
+               document.createElement("div"),
+               document.createElement("div")];
+  checkNodes([], nodes);
+
+  // Append nodes[0].
+  document.body.appendChild(nodes[0]);
+  checkNodes([nodes[0]],
+             [nodes[1], nodes[2]]);
+
+  // Append nodes[1] and nodes[2] together.
+  nodes[1].appendChild(nodes[2]);
+  checkNodes([nodes[0]],
+             [nodes[1], nodes[2]]);
+
+  nodes[0].appendChild(nodes[1]);
+  checkNodes(nodes, []);
+
+  // Remove nodes[2].
+  nodes[2].remove();
+  checkNodes([nodes[0], nodes[1]],
+             [nodes[2]]);
+
+  // Remove nodes[0] and nodes[1] together.
+  nodes[0].remove();
+  checkNodes([], nodes);
+}, "Test with ordinary child nodes");
+
+test(function() {
+  var nodes = [document.createElement("iframe"),
+               document.createElement("iframe"),
+               document.createElement("iframe"),
+               document.createElement("iframe"),
+               document.createElement("div")];
+  var frames = [nodes[0],
+                nodes[1],
+                nodes[2],
+                nodes[3]];
+  checkNodes([], nodes);
+
+  // Since we cannot append anything to the contentWindow of an iframe before it
+  // is appended to the main DOM tree, we append the iframes one after another.
+  document.body.appendChild(nodes[0]);
+  checkNodes([nodes[0]],
+             [nodes[1], nodes[2], nodes[3], nodes[4]]);
+
+  frames[0].contentDocument.body.appendChild(nodes[1]);
+  checkNodes([nodes[0], nodes[1]],
+             [nodes[2], nodes[3], nodes[4]]);
+
+  frames[1].contentDocument.body.appendChild(nodes[2]);
+  checkNodes([nodes[0], nodes[1], nodes[2]],
+             [nodes[3], nodes[4]]);
+
+  frames[2].contentDocument.body.appendChild(nodes[3]);
+  checkNodes([nodes[0], nodes[1], nodes[2], nodes[3]],
+             [nodes[4]]);
+
+  frames[3].contentDocument.body.appendChild(nodes[4]);
+  checkNodes(nodes, []);
+
+  frames[3].remove();
+  // Since node[4] is still under the doument of frame[3], it's still connected.
+  checkNodes([nodes[0], nodes[1], nodes[2], nodes[4]],
+             [nodes[3]]);
+
+  frames[0].remove();
+  // Since node[1] and node[2] are still under the doument of frame[0], they are
+  // still connected.
+  checkNodes([nodes[1], nodes[2], nodes[4]],
+             [nodes[0], nodes[3]]);
+}, "Test with iframes");
+
+// This helper function is used to check whether nodes should be connected.
+function checkNodes(aConnectedNodes, aDisconnectedNodes) {
+  aConnectedNodes.forEach(node => assert_true(node.isConnected));
+  aDisconnectedNodes.forEach(node => assert_false(node.isConnected));
+}
+
+</script>
+</body>
diff --git a/testing/web-platform/tests/dom/nodes/Node-isEqualNode-iframe1.xml b/testing/web-platform/tests/dom/nodes/Node-isEqualNode-iframe1.xml
new file mode 100644
index 0000000000..8077e73c27
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-isEqualNode-iframe1.xml
@@ -0,0 +1 @@
+<!DOCTYPE foo [ <!ELEMENT foo (#PCDATA)> ]><foo/>
diff --git a/testing/web-platform/tests/dom/nodes/Node-isEqualNode-iframe2.xml b/testing/web-platform/tests/dom/nodes/Node-isEqualNode-iframe2.xml
new file mode 100644
index 0000000000..eacc9d17af
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-isEqualNode-iframe2.xml
@@ -0,0 +1 @@
+<!DOCTYPE foo [ <!ELEMENT foo EMPTY> ]><foo/>
diff --git a/testing/web-platform/tests/dom/nodes/Node-isEqualNode-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Node-isEqualNode-xhtml.xhtml
new file mode 100644
index 0000000000..3170643d2f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-isEqualNode-xhtml.xhtml
@@ -0,0 +1,84 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Node.isEqualNode</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"/>
+<script>
+function testNullHandling(node) {
+  test(function() {
+    assert_false(node.isEqualNode(null))
+    assert_false(node.isEqualNode(undefined))
+  })
+}
+[
+  document.createElement("foo"),
+  document.createTextNode("foo"),
+  document.createProcessingInstruction("foo", "bar"),
+  document.createComment("foo"),
+  document,
+  document.implementation.createDocumentType("html", "", ""),
+  document.createDocumentFragment()
+].forEach(testNullHandling)
+
+test(function() {
+  var a = document.createElement("foo")
+  a.setAttribute("a", "bar")
+  a.setAttribute("b", "baz")
+  var b = document.createElement("foo")
+  b.setAttribute("b", "baz")
+  b.setAttribute("a", "bar")
+  assert_true(a.isEqualNode(b))
+}, "isEqualNode should return true when the attributes are in a different order")
+
+test(function() {
+  var a = document.createElementNS("ns", "prefix:foo")
+  var b = document.createElementNS("ns", "prefix:foo")
+  assert_true(a.isEqualNode(b))
+}, "isEqualNode should return true if elements have same namespace, prefix, and local name")
+
+test(function() {
+  var a = document.createElementNS("ns1", "prefix:foo")
+  var b = document.createElementNS("ns2", "prefix:foo")
+  assert_false(a.isEqualNode(b))
+}, "isEqualNode should return false if elements have different namespace")
+
+test(function() {
+  var a = document.createElementNS("ns", "prefix1:foo")
+  var b = document.createElementNS("ns", "prefix2:foo")
+  assert_false(a.isEqualNode(b))
+}, "isEqualNode should return false if elements have different prefix")
+
+test(function() {
+  var a = document.createElementNS("ns", "prefix:foo1")
+  var b = document.createElementNS("ns", "prefix:foo2")
+  assert_false(a.isEqualNode(b))
+}, "isEqualNode should return false if elements have different local name")
+
+test(function() {
+  var a = document.createElement("foo")
+  a.setAttributeNS("ns", "x:a", "bar")
+  var b = document.createElement("foo")
+  b.setAttributeNS("ns", "y:a", "bar")
+  assert_true(a.isEqualNode(b))
+}, "isEqualNode should return true when the attributes have different prefixes")
+var internalSubset = async_test("isEqualNode should return true when only the internal subsets of DocumentTypes differ.")
+var wait = 2;
+function iframeLoaded() {
+  if (!--wait) {
+    internalSubset.step(function() {
+      var doc1 = document.getElementById("subset1").contentDocument
+      var doc2 = document.getElementById("subset2").contentDocument
+      assert_true(doc1.doctype.isEqualNode(doc2.doctype), "doc1.doctype.isEqualNode(doc2.doctype)")
+      assert_true(doc1.isEqualNode(doc2), "doc1.isEqualNode(doc2)")
+    })
+    internalSubset.done()
+  }
+}
+</script>
+<iframe id="subset1" onload="iframeLoaded()" src="Node-isEqualNode-iframe1.xml" />
+<iframe id="subset2" onload="iframeLoaded()" src="Node-isEqualNode-iframe2.xml" />
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Node-isEqualNode.html b/testing/web-platform/tests/dom/nodes/Node-isEqualNode.html
new file mode 100644
index 0000000000..9ff4c5b03c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-isEqualNode.html
@@ -0,0 +1,161 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Node.prototype.isEqualNode</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-isequalnode">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(function() {
+
+  var doctype1 = document.implementation.createDocumentType("qualifiedName", "publicId", "systemId");
+  var doctype2 = document.implementation.createDocumentType("qualifiedName", "publicId", "systemId");
+  var doctype3 = document.implementation.createDocumentType("qualifiedName2", "publicId", "systemId");
+  var doctype4 = document.implementation.createDocumentType("qualifiedName", "publicId2", "systemId");
+  var doctype5 = document.implementation.createDocumentType("qualifiedName", "publicId", "systemId3");
+
+  assert_true(doctype1.isEqualNode(doctype1), "self-comparison");
+  assert_true(doctype1.isEqualNode(doctype2), "same properties");
+  assert_false(doctype1.isEqualNode(doctype3), "different name");
+  assert_false(doctype1.isEqualNode(doctype4), "different public ID");
+  assert_false(doctype1.isEqualNode(doctype5), "different system ID");
+
+}, "doctypes should be compared on name, public ID, and system ID");
+
+test(function() {
+
+  var element1 = document.createElementNS("namespace", "prefix:localName");
+  var element2 = document.createElementNS("namespace", "prefix:localName");
+  var element3 = document.createElementNS("namespace2", "prefix:localName");
+  var element4 = document.createElementNS("namespace", "prefix2:localName");
+  var element5 = document.createElementNS("namespace", "prefix:localName2");
+
+  var element6 = document.createElementNS("namespace", "prefix:localName");
+  element6.setAttribute("foo", "bar");
+
+  assert_true(element1.isEqualNode(element1), "self-comparison");
+  assert_true(element1.isEqualNode(element2), "same properties");
+  assert_false(element1.isEqualNode(element3), "different namespace");
+  assert_false(element1.isEqualNode(element4), "different prefix");
+  assert_false(element1.isEqualNode(element5), "different local name");
+  assert_false(element1.isEqualNode(element6), "different number of attributes");
+
+}, "elements should be compared on namespace, namespace prefix, local name, and number of attributes");
+
+test(function() {
+
+  var element1 = document.createElement("element");
+  element1.setAttributeNS("namespace", "prefix:localName", "value");
+
+  var element2 = document.createElement("element");
+  element2.setAttributeNS("namespace", "prefix:localName", "value");
+
+  var element3 = document.createElement("element");
+  element3.setAttributeNS("namespace2", "prefix:localName", "value");
+
+  var element4 = document.createElement("element");
+  element4.setAttributeNS("namespace", "prefix2:localName", "value");
+
+  var element5 = document.createElement("element");
+  element5.setAttributeNS("namespace", "prefix:localName2", "value");
+
+  var element6 = document.createElement("element");
+  element6.setAttributeNS("namespace", "prefix:localName", "value2");
+
+  assert_true(element1.isEqualNode(element1), "self-comparison");
+  assert_true(element1.isEqualNode(element2), "attribute with same properties");
+  assert_false(element1.isEqualNode(element3), "attribute with different namespace");
+  assert_true(element1.isEqualNode(element4), "attribute with different prefix");
+  assert_false(element1.isEqualNode(element5), "attribute with different local name");
+  assert_false(element1.isEqualNode(element6), "attribute with different value");
+
+}, "elements should be compared on attribute namespace, local name, and value");
+
+test(function() {
+
+  var pi1 = document.createProcessingInstruction("target", "data");
+  var pi2 = document.createProcessingInstruction("target", "data");
+  var pi3 = document.createProcessingInstruction("target2", "data");
+  var pi4 = document.createProcessingInstruction("target", "data2");
+
+  assert_true(pi1.isEqualNode(pi1), "self-comparison");
+  assert_true(pi1.isEqualNode(pi2), "same properties");
+  assert_false(pi1.isEqualNode(pi3), "different target");
+  assert_false(pi1.isEqualNode(pi4), "different data");
+
+}, "processing instructions should be compared on target and data");
+
+test(function() {
+
+  var text1 = document.createTextNode("data");
+  var text2 = document.createTextNode("data");
+  var text3 = document.createTextNode("data2");
+
+  assert_true(text1.isEqualNode(text1), "self-comparison");
+  assert_true(text1.isEqualNode(text2), "same properties");
+  assert_false(text1.isEqualNode(text3), "different data");
+
+}, "text nodes should be compared on data");
+
+test(function() {
+
+  var comment1 = document.createComment("data");
+  var comment2 = document.createComment("data");
+  var comment3 = document.createComment("data2");
+
+  assert_true(comment1.isEqualNode(comment1), "self-comparison");
+  assert_true(comment1.isEqualNode(comment2), "same properties");
+  assert_false(comment1.isEqualNode(comment3), "different data");
+
+}, "comments should be compared on data");
+
+test(function() {
+
+  var documentFragment1 = document.createDocumentFragment();
+  var documentFragment2 = document.createDocumentFragment();
+
+  assert_true(documentFragment1.isEqualNode(documentFragment1), "self-comparison");
+  assert_true(documentFragment1.isEqualNode(documentFragment2), "same properties");
+
+}, "document fragments should not be compared based on properties");
+
+test(function() {
+
+  var document1 = document.implementation.createDocument("", "");
+  var document2 = document.implementation.createDocument("", "");
+
+  assert_true(document1.isEqualNode(document1), "self-comparison");
+  assert_true(document1.isEqualNode(document2), "another empty XML document");
+
+  var htmlDoctype = document.implementation.createDocumentType("html", "", "");
+  var document3 = document.implementation.createDocument("http://www.w3.org/1999/xhtml", "html", htmlDoctype);
+  document3.documentElement.appendChild(document3.createElement("head"));
+  document3.documentElement.appendChild(document3.createElement("body"));
+  var document4 = document.implementation.createHTMLDocument();
+  assert_true(document3.isEqualNode(document4), "default HTML documents, created different ways");
+
+}, "documents should not be compared based on properties");
+
+test(function() {
+
+  testDeepEquality(function() { return document.createElement("foo") });
+  testDeepEquality(function() { return document.createDocumentFragment() });
+  testDeepEquality(function() { return document.implementation.createDocument("", "") });
+  testDeepEquality(function() { return document.implementation.createHTMLDocument() });
+
+  function testDeepEquality(parentFactory) {
+    // Some ad-hoc tests of deep equality
+
+    var parentA = parentFactory();
+    var parentB = parentFactory();
+
+    parentA.appendChild(document.createComment("data"));
+    assert_false(parentA.isEqualNode(parentB));
+    parentB.appendChild(document.createComment("data"));
+    assert_true(parentA.isEqualNode(parentB));
+  }
+
+}, "node equality testing should test descendant equality too");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-isSameNode.html b/testing/web-platform/tests/dom/nodes/Node-isSameNode.html
new file mode 100644
index 0000000000..b37442ac80
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-isSameNode.html
@@ -0,0 +1,111 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Node.prototype.isSameNode</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-issamenode">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+"use strict";
+
+test(function() {
+
+  var doctype1 = document.implementation.createDocumentType("qualifiedName", "publicId", "systemId");
+  var doctype2 = document.implementation.createDocumentType("qualifiedName", "publicId", "systemId");
+
+  assert_true(doctype1.isSameNode(doctype1), "self-comparison");
+  assert_false(doctype1.isSameNode(doctype2), "same properties");
+  assert_false(doctype1.isSameNode(null), "with null other node");
+}, "doctypes should be compared on reference");
+
+test(function() {
+
+  var element1 = document.createElementNS("namespace", "prefix:localName");
+  var element2 = document.createElementNS("namespace", "prefix:localName");
+
+  assert_true(element1.isSameNode(element1), "self-comparison");
+  assert_false(element1.isSameNode(element2), "same properties");
+  assert_false(element1.isSameNode(null), "with null other node");
+
+}, "elements should be compared on reference (namespaced element)");
+
+test(function() {
+
+  var element1 = document.createElement("element");
+  element1.setAttributeNS("namespace", "prefix:localName", "value");
+
+  var element2 = document.createElement("element");
+  element2.setAttributeNS("namespace", "prefix:localName", "value");
+
+  assert_true(element1.isSameNode(element1), "self-comparison");
+  assert_false(element1.isSameNode(element2), "same properties");
+  assert_false(element1.isSameNode(null), "with null other node");
+
+}, "elements should be compared on reference (namespaced attribute)");
+
+test(function() {
+
+  var pi1 = document.createProcessingInstruction("target", "data");
+  var pi2 = document.createProcessingInstruction("target", "data");
+
+  assert_true(pi1.isSameNode(pi1), "self-comparison");
+  assert_false(pi1.isSameNode(pi2), "different target");
+  assert_false(pi1.isSameNode(null), "with null other node");
+
+}, "processing instructions should be compared on reference");
+
+test(function() {
+
+  var text1 = document.createTextNode("data");
+  var text2 = document.createTextNode("data");
+
+  assert_true(text1.isSameNode(text1), "self-comparison");
+  assert_false(text1.isSameNode(text2), "same properties");
+  assert_false(text1.isSameNode(null), "with null other node");
+
+}, "text nodes should be compared on reference");
+
+test(function() {
+
+  var comment1 = document.createComment("data");
+  var comment2 = document.createComment("data");
+
+  assert_true(comment1.isSameNode(comment1), "self-comparison");
+  assert_false(comment1.isSameNode(comment2), "same properties");
+  assert_false(comment1.isSameNode(null), "with null other node");
+
+}, "comments should be compared on reference");
+
+test(function() {
+
+  var documentFragment1 = document.createDocumentFragment();
+  var documentFragment2 = document.createDocumentFragment();
+
+  assert_true(documentFragment1.isSameNode(documentFragment1), "self-comparison");
+  assert_false(documentFragment1.isSameNode(documentFragment2), "same properties");
+  assert_false(documentFragment1.isSameNode(null), "with null other node");
+
+}, "document fragments should be compared on reference");
+
+test(function() {
+
+  var document1 = document.implementation.createDocument("", "");
+  var document2 = document.implementation.createDocument("", "");
+
+  assert_true(document1.isSameNode(document1), "self-comparison");
+  assert_false(document1.isSameNode(document2), "another empty XML document");
+  assert_false(document1.isSameNode(null), "with null other node");
+
+}, "documents should be compared on reference");
+
+test(function() {
+
+  var attr1 = document.createAttribute('href');
+  var attr2 = document.createAttribute('href');
+
+  assert_true(attr1.isSameNode(attr1), "self-comparison");
+  assert_false(attr1.isSameNode(attr2), "same name");
+  assert_false(attr1.isSameNode(null), "with null other node");
+
+}, "attributes should be compared on reference");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-lookupNamespaceURI.html b/testing/web-platform/tests/dom/nodes/Node-lookupNamespaceURI.html
new file mode 100644
index 0000000000..925c528362
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-lookupNamespaceURI.html
@@ -0,0 +1,139 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>LookupNamespaceURI and IsDefaultNamespace tests</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+</head>
+<body>
+<h1>LookupNamespaceURI and IsDefaultNamespace</h1>
+<div id="log"/>
+<script>
+function lookupNamespaceURI(node, prefix, expected, name) {
+  test(function() {
+    assert_equals(node.lookupNamespaceURI(prefix), expected);
+  }, name);
+}
+
+function isDefaultNamespace(node, namespace, expected, name) {
+  test(function() {
+    assert_equals(node.isDefaultNamespace(namespace), expected);
+  }, name);
+}
+
+
+var frag = document.createDocumentFragment();
+lookupNamespaceURI(frag, null, null, 'DocumentFragment should have null namespace, prefix null');
+lookupNamespaceURI(frag, '', null, 'DocumentFragment should have null namespace, prefix ""');
+lookupNamespaceURI(frag, 'foo', null, 'DocumentFragment should have null namespace, prefix "foo"');
+lookupNamespaceURI(frag, 'xml', null, 'DocumentFragment should have null namespace, prefix "xml"');
+lookupNamespaceURI(frag, 'xmlns', null, 'DocumentFragment should have null namespace, prefix "xmlns"');
+isDefaultNamespace(frag, null, true, 'DocumentFragment is in default namespace, prefix null');
+isDefaultNamespace(frag, '', true, 'DocumentFragment is in default namespace, prefix ""');
+isDefaultNamespace(frag, 'foo', false, 'DocumentFragment is in default namespace, prefix "foo"');
+isDefaultNamespace(frag, 'xmlns', false, 'DocumentFragment is in default namespace, prefix "xmlns"');
+
+var docType = document.doctype;
+lookupNamespaceURI(docType, null, null, 'DocumentType should have null namespace, prefix null');
+lookupNamespaceURI(docType, '', null, 'DocumentType should have null namespace, prefix ""');
+lookupNamespaceURI(docType, 'foo', null, 'DocumentType should have null namespace, prefix "foo"');
+lookupNamespaceURI(docType, 'xml', null, 'DocumentType should have null namespace, prefix "xml"');
+lookupNamespaceURI(docType, 'xmlns', null, 'DocumentType should have null namespace, prefix "xmlns"');
+isDefaultNamespace(docType, null, true, 'DocumentType is in default namespace, prefix null');
+isDefaultNamespace(docType, '', true, 'DocumentType is in default namespace, prefix ""');
+isDefaultNamespace(docType, 'foo', false, 'DocumentType is in default namespace, prefix "foo"');
+isDefaultNamespace(docType, 'xmlns', false, 'DocumentType is in default namespace, prefix "xmlns"');
+
+var fooElem = document.createElementNS('fooNamespace', 'prefix:elem');
+fooElem.setAttribute('bar', 'value');
+const XMLNS_NS = 'http://www.w3.org/2000/xmlns/';
+const XML_NS =  'http://www.w3.org/XML/1998/namespace';
+lookupNamespaceURI(fooElem, null, null, 'Element should have null namespace, prefix null');
+lookupNamespaceURI(fooElem, '', null, 'Element should have null namespace, prefix ""');
+lookupNamespaceURI(fooElem, 'fooNamespace', null, 'Element should not have namespace matching prefix with namespaceURI value');
+lookupNamespaceURI(fooElem, 'xml', XML_NS, 'Element should have XML namespace');
+lookupNamespaceURI(fooElem, 'xmlns', XMLNS_NS, 'Element should have XMLNS namespace');
+lookupNamespaceURI(fooElem, 'prefix', 'fooNamespace', 'Element has namespace URI matching prefix');
+isDefaultNamespace(fooElem, null, true, 'Empty namespace is not default, prefix null');
+isDefaultNamespace(fooElem, '', true, 'Empty namespace is not default, prefix ""');
+isDefaultNamespace(fooElem, 'fooNamespace', false, 'fooNamespace is not default');
+isDefaultNamespace(fooElem, XMLNS_NS, false, 'xmlns namespace is not default');
+
+fooElem.setAttributeNS(XMLNS_NS, 'xmlns:bar', 'barURI');
+fooElem.setAttributeNS(XMLNS_NS, 'xmlns', 'bazURI');
+
+lookupNamespaceURI(fooElem, null, 'bazURI', 'Element should have baz namespace, prefix null');
+lookupNamespaceURI(fooElem, '', 'bazURI', 'Element should have baz namespace, prefix ""');
+lookupNamespaceURI(fooElem, 'xmlns', XMLNS_NS, 'Element should have namespace with xmlns prefix');
+lookupNamespaceURI(fooElem, 'bar', 'barURI', 'Element has bar namespace');
+
+isDefaultNamespace(fooElem, null, false, 'Empty namespace is not default on fooElem, prefix null');
+isDefaultNamespace(fooElem, '', false, 'Empty namespace is not default on fooElem, prefix ""');
+isDefaultNamespace(fooElem, 'barURI', false, 'bar namespace is not default');
+isDefaultNamespace(fooElem, 'bazURI', true, 'baz namespace is default');
+
+var comment = document.createComment('comment');
+fooElem.appendChild(comment);
+
+lookupNamespaceURI(comment, null, 'bazURI', 'Comment should inherit baz namespace');
+lookupNamespaceURI(comment, '', 'bazURI', 'Comment should inherit  baz namespace');
+lookupNamespaceURI(comment, 'prefix', 'fooNamespace', 'Comment should inherit namespace URI matching prefix');
+lookupNamespaceURI(comment, 'bar', 'barURI', 'Comment should inherit bar namespace');
+
+isDefaultNamespace(comment, null, false, 'For comment, empty namespace is not default, prefix null');
+isDefaultNamespace(comment, '', false, 'For comment, empty namespace is not default, prefix ""');
+isDefaultNamespace(comment, 'fooNamespace', false, 'For comment, fooNamespace is not default');
+isDefaultNamespace(comment, XMLNS_NS, false, 'For comment, xmlns namespace is not default');
+isDefaultNamespace(comment, 'barURI', false, 'For comment, inherited bar namespace is not default');
+isDefaultNamespace(comment, 'bazURI', true, 'For comment, inherited baz namespace is default');
+
+var fooChild = document.createElementNS('childNamespace', 'childElem');
+fooElem.appendChild(fooChild);
+
+lookupNamespaceURI(fooChild, null, 'childNamespace', 'Child element should inherit baz namespace');
+lookupNamespaceURI(fooChild, '', 'childNamespace', 'Child element should have null namespace');
+lookupNamespaceURI(fooChild, 'xmlns', XMLNS_NS, 'Child element should have XMLNS namespace');
+lookupNamespaceURI(fooChild, 'prefix', 'fooNamespace', 'Child element has namespace URI matching prefix');
+
+isDefaultNamespace(fooChild, null, false, 'Empty namespace is not default for child, prefix null');
+isDefaultNamespace(fooChild, '', false, 'Empty namespace is not default for child, prefix ""');
+isDefaultNamespace(fooChild, 'fooNamespace', false, 'fooNamespace is not default for child');
+isDefaultNamespace(fooChild, XMLNS_NS, false, 'xmlns namespace is not default for child');
+isDefaultNamespace(fooChild, 'barURI', false, 'bar namespace is not default for child');
+isDefaultNamespace(fooChild, 'bazURI', false, 'baz namespace is default for child');
+isDefaultNamespace(fooChild, 'childNamespace', true, 'childNamespace is default for child');
+
+document.documentElement.setAttributeNS(XMLNS_NS, 'xmlns:bar', 'barURI');
+document.documentElement.setAttributeNS(XMLNS_NS, 'xmlns', 'bazURI');
+
+lookupNamespaceURI(document, null, 'http://www.w3.org/1999/xhtml', 'Document should have xhtml namespace, prefix null');
+lookupNamespaceURI(document, '', 'http://www.w3.org/1999/xhtml', 'Document should have xhtml namespace, prefix ""');
+lookupNamespaceURI(document, 'prefix', null, 'Document has no namespace URI matching prefix');
+lookupNamespaceURI(document, 'bar', 'barURI', 'Document has bar namespace');
+
+isDefaultNamespace(document, null, false, 'For document, empty namespace is not default, prefix null');
+isDefaultNamespace(document, '', false, 'For document, empty namespace is not default, prefix ""');
+isDefaultNamespace(document, 'fooNamespace', false, 'For document, fooNamespace is not default');
+isDefaultNamespace(document, XMLNS_NS, false, 'For document, xmlns namespace is not default');
+isDefaultNamespace(document, 'barURI', false, 'For document, bar namespace is not default');
+isDefaultNamespace(document, 'bazURI', false, 'For document, baz namespace is not default');
+isDefaultNamespace(document, 'http://www.w3.org/1999/xhtml', true, 'For document, xhtml namespace is default');
+
+const doc = new Document();
+lookupNamespaceURI(doc, 'xml', null, 'Document without documentElement has no namespace URI matching "xml"');
+lookupNamespaceURI(doc, 'xmlns', null, 'Document without documentElement has no namespace URI matching "xmlns"');
+
+const attr = document.createAttribute('foo');
+lookupNamespaceURI(attr, 'xml', null, 'Disconnected Attr has no namespace URI matching "xml"');
+lookupNamespaceURI(attr, 'xmlns', null, 'Disconnected Attr has no namespace URI matching "xmlns"');
+document.body.setAttributeNode(attr);
+lookupNamespaceURI(attr, 'xml', XML_NS, 'Connected Attr has namespace URI matching "xml"');
+lookupNamespaceURI(attr, 'xmlns', XMLNS_NS, 'Connected Attr no namespace URI matching "xmlns"');
+
+var comment = document.createComment('comment');
+document.appendChild(comment);
+lookupNamespaceURI(comment, 'bar', null, 'Comment does not have bar namespace');
+
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Node-lookupPrefix.xhtml b/testing/web-platform/tests/dom/nodes/Node-lookupPrefix.xhtml
new file mode 100644
index 0000000000..50a487c58c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-lookupPrefix.xhtml
@@ -0,0 +1,31 @@
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:x="test">
+<head>
+<title>Node.lookupPrefix</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body xmlns:s="test">
+<div id="log"/>
+<x xmlns:t="test"><!--comment--><?test test?>TEST<x/></x>
+<script>
+function lookupPrefix(node, ns, prefix) {
+  test(function() {
+    assert_equals(node.lookupPrefix(ns), prefix)
+  })
+}
+var x = document.getElementsByTagName("x")[0];
+lookupPrefix(document, "test", "x") // XXX add test for when there is no documentElement
+lookupPrefix(document, null, null)
+lookupPrefix(x, "http://www.w3.org/1999/xhtml", null)
+lookupPrefix(x, "something", null)
+lookupPrefix(x, null, null)
+lookupPrefix(x, "test", "t")
+lookupPrefix(x.parentNode, "test", "s")
+lookupPrefix(x.firstChild, "test", "t")
+lookupPrefix(x.childNodes[1], "test", "t")
+lookupPrefix(x.childNodes[2], "test", "t")
+lookupPrefix(x.lastChild, "test", "t")
+x.parentNode.removeChild(x)
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Node-mutation-adoptNode.html b/testing/web-platform/tests/dom/nodes/Node-mutation-adoptNode.html
new file mode 100644
index 0000000000..9c9594c07b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-mutation-adoptNode.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Node-manipulation-adopted</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-domimplementation-createhtmldocument">
+<link rel=help href="https://dom.spec.whatwg.org/#mutation-algorithms">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+"use strict";
+
+test(() => {
+  const old = document.implementation.createHTMLDocument("");
+  const div = old.createElement("div");
+  div.appendChild(old.createTextNode("text"));
+  assert_equals(div.ownerDocument, old);
+  assert_equals(div.firstChild.ownerDocument, old);
+  document.body.appendChild(div);
+  assert_equals(div.ownerDocument, document);
+  assert_equals(div.firstChild.ownerDocument, document);
+}, "simple append of foreign div with text");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-nodeName-xhtml.xhtml b/testing/web-platform/tests/dom/nodes/Node-nodeName-xhtml.xhtml
new file mode 100644
index 0000000000..bc478af8b6
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-nodeName-xhtml.xhtml
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>Node.nodeName</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"/>
+<script>
+test(function() {
+  var HTMLNS = "http://www.w3.org/1999/xhtml",
+      SVGNS = "http://www.w3.org/2000/svg"
+  assert_equals(document.createElementNS(HTMLNS, "I").nodeName, "I")
+  assert_equals(document.createElementNS(HTMLNS, "i").nodeName, "i")
+  assert_equals(document.createElementNS(SVGNS, "svg").nodeName, "svg")
+  assert_equals(document.createElementNS(SVGNS, "SVG").nodeName, "SVG")
+  assert_equals(document.createElementNS(HTMLNS, "x:b").nodeName, "x:b")
+}, "For Element nodes, nodeName should return the same as tagName.")
+test(function() {
+  assert_equals(document.createTextNode("foo").nodeName, "#text")
+}, "For Text nodes, nodeName should return \"#text\".")
+test(function() {
+  assert_equals(document.createProcessingInstruction("foo", "bar").nodeName,
+                "foo")
+}, "For ProcessingInstruction nodes, nodeName should return the target.")
+test(function() {
+  assert_equals(document.createComment("foo").nodeName, "#comment")
+}, "For Comment nodes, nodeName should return \"#comment\".")
+test(function() {
+  assert_equals(document.nodeName, "#document")
+}, "For Document nodes, nodeName should return \"#document\".")
+test(function() {
+  assert_equals(document.doctype.nodeName, "html")
+}, "For DocumentType nodes, nodeName should return the name.")
+test(function() {
+  assert_equals(document.createDocumentFragment().nodeName,
+                "#document-fragment")
+}, "For DocumentFragment nodes, nodeName should return \"#document-fragment\".")
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Node-nodeName.html b/testing/web-platform/tests/dom/nodes/Node-nodeName.html
new file mode 100644
index 0000000000..911f93455c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-nodeName.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<title>Node.nodeName</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var HTMLNS = "http://www.w3.org/1999/xhtml",
+      SVGNS = "http://www.w3.org/2000/svg"
+  assert_equals(document.createElementNS(HTMLNS, "I").nodeName, "I")
+  assert_equals(document.createElementNS(HTMLNS, "i").nodeName, "I")
+  assert_equals(document.createElementNS(SVGNS, "svg").nodeName, "svg")
+  assert_equals(document.createElementNS(SVGNS, "SVG").nodeName, "SVG")
+  assert_equals(document.createElementNS(HTMLNS, "x:b").nodeName, "X:B")
+}, "For Element nodes, nodeName should return the same as tagName.")
+test(function() {
+  assert_equals(document.createTextNode("foo").nodeName, "#text")
+}, "For Text nodes, nodeName should return \"#text\".")
+test(function() {
+  assert_equals(document.createComment("foo").nodeName, "#comment")
+}, "For Comment nodes, nodeName should return \"#comment\".")
+test(function() {
+  assert_equals(document.nodeName, "#document")
+}, "For Document nodes, nodeName should return \"#document\".")
+test(function() {
+  assert_equals(document.doctype.nodeName, "html")
+}, "For DocumentType nodes, nodeName should return the name.")
+test(function() {
+  assert_equals(document.createDocumentFragment().nodeName,
+                "#document-fragment")
+}, "For DocumentFragment nodes, nodeName should return \"#document-fragment\".")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-nodeValue.html b/testing/web-platform/tests/dom/nodes/Node-nodeValue.html
new file mode 100644
index 0000000000..79ce80b875
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-nodeValue.html
@@ -0,0 +1,71 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Node.nodeValue</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-node-nodevalue">
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+test(function() {
+  var the_text = document.createTextNode("A span!");
+  assert_equals(the_text.nodeValue, "A span!");
+  assert_equals(the_text.data, "A span!");
+  the_text.nodeValue = "test again";
+  assert_equals(the_text.nodeValue, "test again");
+  assert_equals(the_text.data, "test again");
+  the_text.nodeValue = null;
+  assert_equals(the_text.nodeValue, "");
+  assert_equals(the_text.data, "");
+}, "Text.nodeValue");
+
+test(function() {
+  var the_comment = document.createComment("A comment!");
+  assert_equals(the_comment.nodeValue, "A comment!");
+  assert_equals(the_comment.data, "A comment!");
+  the_comment.nodeValue = "test again";
+  assert_equals(the_comment.nodeValue, "test again");
+  assert_equals(the_comment.data, "test again");
+  the_comment.nodeValue = null;
+  assert_equals(the_comment.nodeValue, "");
+  assert_equals(the_comment.data, "");
+}, "Comment.nodeValue");
+
+test(function() {
+  var the_pi = document.createProcessingInstruction("pi", "A PI!");
+  assert_equals(the_pi.nodeValue, "A PI!");
+  assert_equals(the_pi.data, "A PI!");
+  the_pi.nodeValue = "test again";
+  assert_equals(the_pi.nodeValue, "test again");
+  assert_equals(the_pi.data, "test again");
+  the_pi.nodeValue = null;
+  assert_equals(the_pi.nodeValue, "");
+  assert_equals(the_pi.data, "");
+}, "ProcessingInstruction.nodeValue");
+
+test(function() {
+  var the_link = document.createElement("a");
+  assert_equals(the_link.nodeValue, null);
+  the_link.nodeValue = "foo";
+  assert_equals(the_link.nodeValue, null);
+}, "Element.nodeValue");
+
+test(function() {
+  assert_equals(document.nodeValue, null);
+  document.nodeValue = "foo";
+  assert_equals(document.nodeValue, null);
+}, "Document.nodeValue");
+
+test(function() {
+  var the_frag = document.createDocumentFragment();
+  assert_equals(the_frag.nodeValue, null);
+  the_frag.nodeValue = "foo";
+  assert_equals(the_frag.nodeValue, null);
+}, "DocumentFragment.nodeValue");
+
+test(function() {
+  var the_doctype = document.doctype;
+  assert_equals(the_doctype.nodeValue, null);
+  the_doctype.nodeValue = "foo";
+  assert_equals(the_doctype.nodeValue, null);
+}, "DocumentType.nodeValue");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-normalize.html b/testing/web-platform/tests/dom/nodes/Node-normalize.html
new file mode 100644
index 0000000000..4d455996e5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-normalize.html
@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<title>Node.normalize()</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script>
+test(function() {
+  var df = document.createDocumentFragment(),
+      t1 = document.createTextNode("1"),
+      t2 = document.createTextNode("2"),
+      t3 = document.createTextNode("3"),
+      t4 = document.createTextNode("4")
+  df.appendChild(t1)
+  df.appendChild(t2)
+  assert_equals(df.childNodes.length, 2)
+  assert_equals(df.textContent, "12")
+  var el = document.createElement('x')
+  df.appendChild(el)
+  el.appendChild(t3)
+  el.appendChild(t4)
+  document.normalize()
+  assert_equals(el.childNodes.length, 2)
+  assert_equals(el.textContent, "34")
+  assert_equals(df.childNodes.length, 3)
+  assert_equals(t1.data, "1")
+  df.normalize()
+  assert_equals(df.childNodes.length, 2)
+  assert_equals(df.firstChild, t1)
+  assert_equals(t1.data, "12")
+  assert_equals(t2.data, "2")
+  assert_equals(el.firstChild, t3)
+  assert_equals(t3.data, "34")
+  assert_equals(t4.data, "4")
+})
+
+// https://www.w3.org/Bugs/Public/show_bug.cgi?id=19837
+test(function() {
+  var div = document.createElement("div")
+  var t1 = div.appendChild(document.createTextNode(""))
+  var t2 = div.appendChild(document.createTextNode("a"))
+  var t3 = div.appendChild(document.createTextNode(""))
+  assert_array_equals(div.childNodes, [t1, t2, t3])
+  div.normalize();
+  assert_array_equals(div.childNodes, [t2])
+}, "Empty text nodes separated by a non-empty text node")
+test(function() {
+  var div = document.createElement("div")
+  var t1 = div.appendChild(document.createTextNode(""))
+  var t2 = div.appendChild(document.createTextNode(""))
+  assert_array_equals(div.childNodes, [t1, t2])
+  div.normalize();
+  assert_array_equals(div.childNodes, [])
+}, "Empty text nodes")
+
+// The specification for normalize is clear that only "exclusive Text
+// nodes" are to be modified. This excludes CDATASection nodes, which
+// derive from Text. Naïve implementations may fail to skip
+// CDATASection nodes, or even worse, try to test textContent or
+// nodeValue without taking care to check the node type. They will
+// fail this test.
+test(function() {
+  // We create an XML document so that we can create CDATASection.
+  // Except for the CDATASection the result should be the same for
+  // an HTML document. (No non-Text node should be touched.)
+  var doc = new DOMParser().parseFromString("<div/>", "text/xml")
+  var div = doc.documentElement
+  var t1 = div.appendChild(doc.createTextNode("a"))
+  // The first parameter is the "target" of the processing
+  // instruction, and the 2nd is the text content.
+  var t2 = div.appendChild(doc.createProcessingInstruction("pi", ""))
+  var t3 = div.appendChild(doc.createTextNode("b"))
+  var t4 = div.appendChild(doc.createCDATASection(""))
+  var t5 = div.appendChild(doc.createTextNode("c"))
+  var t6 = div.appendChild(doc.createComment(""))
+  var t7 = div.appendChild(doc.createTextNode("d"))
+  var t8 = div.appendChild(doc.createElement("el"))
+  var t9 = div.appendChild(doc.createTextNode("e"))
+  var expected = [t1, t2, t3, t4, t5, t6, t7, t8, t9]
+  assert_array_equals(div.childNodes, expected)
+  div.normalize()
+  assert_array_equals(div.childNodes, expected)
+}, "Non-text nodes with empty textContent values.")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-parentElement.html b/testing/web-platform/tests/dom/nodes/Node-parentElement.html
new file mode 100644
index 0000000000..bc564bee0e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-parentElement.html
@@ -0,0 +1,82 @@
+<!DOCTYPE html>
+<title>Node.parentElement</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  assert_equals(document.parentElement, null)
+}, "When the parent is null, parentElement should be null")
+test(function() {
+  assert_equals(document.doctype.parentElement, null)
+}, "When the parent is a document, parentElement should be null (doctype)")
+test(function() {
+  assert_equals(document.documentElement.parentElement, null)
+}, "When the parent is a document, parentElement should be null (element)")
+test(function() {
+  var comment = document.appendChild(document.createComment("foo"))
+  assert_equals(comment.parentElement, null)
+}, "When the parent is a document, parentElement should be null (comment)")
+test(function() {
+  var df = document.createDocumentFragment()
+  assert_equals(df.parentElement, null)
+  var el = document.createElement("div")
+  assert_equals(el.parentElement, null)
+  df.appendChild(el)
+  assert_equals(el.parentNode, df)
+  assert_equals(el.parentElement, null)
+}, "parentElement should return null for children of DocumentFragments (element)")
+test(function() {
+  var df = document.createDocumentFragment()
+  assert_equals(df.parentElement, null)
+  var text = document.createTextNode("bar")
+  assert_equals(text.parentElement, null)
+  df.appendChild(text)
+  assert_equals(text.parentNode, df)
+  assert_equals(text.parentElement, null)
+}, "parentElement should return null for children of DocumentFragments (text)")
+test(function() {
+  var df = document.createDocumentFragment()
+  var parent = document.createElement("div")
+  df.appendChild(parent)
+  var el = document.createElement("div")
+  assert_equals(el.parentElement, null)
+  parent.appendChild(el)
+  assert_equals(el.parentElement, parent)
+}, "parentElement should work correctly with DocumentFragments (element)")
+test(function() {
+  var df = document.createDocumentFragment()
+  var parent = document.createElement("div")
+  df.appendChild(parent)
+  var text = document.createTextNode("bar")
+  assert_equals(text.parentElement, null)
+  parent.appendChild(text)
+  assert_equals(text.parentElement, parent)
+}, "parentElement should work correctly with DocumentFragments (text)")
+test(function() {
+  var parent = document.createElement("div")
+  var el = document.createElement("div")
+  assert_equals(el.parentElement, null)
+  parent.appendChild(el)
+  assert_equals(el.parentElement, parent)
+}, "parentElement should work correctly in disconnected subtrees (element)")
+test(function() {
+  var parent = document.createElement("div")
+  var text = document.createTextNode("bar")
+  assert_equals(text.parentElement, null)
+  parent.appendChild(text)
+  assert_equals(text.parentElement, parent)
+}, "parentElement should work correctly in disconnected subtrees (text)")
+test(function() {
+  var el = document.createElement("div")
+  assert_equals(el.parentElement, null)
+  document.body.appendChild(el)
+  assert_equals(el.parentElement, document.body)
+}, "parentElement should work correctly in a document (element)")
+test(function() {
+  var text = document.createElement("div")
+  assert_equals(text.parentElement, null)
+  document.body.appendChild(text)
+  assert_equals(text.parentElement, document.body)
+}, "parentElement should work correctly in a document (text)")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-parentNode-iframe.html b/testing/web-platform/tests/dom/nodes/Node-parentNode-iframe.html
new file mode 100644
index 0000000000..88bc5ab436
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-parentNode-iframe.html
@@ -0,0 +1 @@
+<a name='c'>c</a>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/Node-parentNode.html b/testing/web-platform/tests/dom/nodes/Node-parentNode.html
new file mode 100644
index 0000000000..cff6178627
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-parentNode.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<title>Node.parentNode</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+// XXX need to test for more node types
+test(function() {
+  assert_equals(document.parentNode, null)
+}, "Document")
+test(function() {
+  assert_equals(document.doctype.parentNode, document)
+}, "Doctype")
+test(function() {
+  assert_equals(document.documentElement.parentNode, document)
+}, "Root element")
+test(function() {
+  var el = document.createElement("div")
+  assert_equals(el.parentNode, null)
+  document.body.appendChild(el)
+  assert_equals(el.parentNode, document.body)
+}, "Element")
+var t = async_test("Removed iframe");
+function testIframe(iframe) {
+  t.step(function() {
+    var doc = iframe.contentDocument;
+    iframe.parentNode.removeChild(iframe);
+    assert_equals(doc.firstChild.parentNode, doc);
+  });
+  t.done();
+}
+</script>
+<iframe id=a src="Node-parentNode-iframe.html" onload="testIframe(this)"></iframe>
diff --git a/testing/web-platform/tests/dom/nodes/Node-properties.html b/testing/web-platform/tests/dom/nodes/Node-properties.html
new file mode 100644
index 0000000000..10f92e7d7e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-properties.html
@@ -0,0 +1,688 @@
+<!doctype html>
+<title>Node assorted property tests</title>
+<link rel=author title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta charset=utf-8>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+/**
+ * First we define a data structure to tell us what tests to run.  The keys
+ * will be eval()ed, and are mostly global variables defined in common.js.  The
+ * values are objects, which maps properties to expected values.  So
+ *
+ *     foo: {
+ *         bar: "baz",
+ *         quz: 7,
+ *     },
+ *
+ * will test that eval("foo.bar") === "baz" and eval("foo.quz") === 7.  "foo"
+ * and "bar" could thus be expressions, like "document.documentElement" and
+ * "childNodes[4]" respectively.
+ *
+ * To avoid repetition, some values are automatically added based on others.
+ * For instance, if we specify nodeType: Node.TEXT_NODE, we'll automatically
+ * also test nodeName: "#text".  This is handled by code after this variable is
+ * defined.
+ */
+var expected = {
+    testDiv: {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: document.body,
+        parentElement: document.body,
+        "childNodes.length": 6,
+        "childNodes[0]": paras[0],
+        "childNodes[1]": paras[1],
+        "childNodes[2]": paras[2],
+        "childNodes[3]": paras[3],
+        "childNodes[4]": paras[4],
+        "childNodes[5]": comment,
+        previousSibling: null,
+        nextSibling: document.getElementById("log"),
+        textContent: "A\u0308b\u0308c\u0308d\u0308e\u0308f\u0308g\u0308h\u0308\nIjklmnop\nQrstuvwxYzabcdefGhijklmn",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "div",
+        tagName: "DIV",
+        id: "test",
+        "children[0]": paras[0],
+        "children[1]": paras[1],
+        "children[2]": paras[2],
+        "children[3]": paras[3],
+        "children[4]": paras[4],
+        previousElementSibling: null,
+        // nextSibling isn't explicitly set
+        //nextElementSibling: ,
+        childElementCount: 5,
+    },
+    detachedDiv: {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: null,
+        parentElement: null,
+        "childNodes.length": 2,
+        "childNodes[0]": detachedPara1,
+        "childNodes[1]": detachedPara2,
+        previousSibling: null,
+        nextSibling: null,
+        textContent: "OpqrstuvWxyzabcd",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "div",
+        tagName: "DIV",
+        "children[0]": detachedPara1,
+        "children[1]": detachedPara2,
+        previousElementSibling: null,
+        nextElementSibling: null,
+        childElementCount: 2,
+    },
+    detachedPara1: {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: detachedDiv,
+        parentElement: detachedDiv,
+        "childNodes.length": 1,
+        previousSibling: null,
+        nextSibling: detachedPara2,
+        textContent: "Opqrstuv",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        previousElementSibling: null,
+        nextElementSibling: detachedPara2,
+        childElementCount: 0,
+    },
+    detachedPara2: {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: detachedDiv,
+        parentElement: detachedDiv,
+        "childNodes.length": 1,
+        previousSibling: detachedPara1,
+        nextSibling: null,
+        textContent: "Wxyzabcd",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        previousElementSibling: detachedPara1,
+        nextElementSibling: null,
+        childElementCount: 0,
+    },
+    document: {
+        // Node
+        nodeType: Node.DOCUMENT_NODE,
+        "childNodes.length": 2,
+        "childNodes[0]": document.doctype,
+        "childNodes[1]": document.documentElement,
+
+        // Document
+        URL: String(location),
+        compatMode: "CSS1Compat",
+        characterSet: "UTF-8",
+        contentType: "text/html",
+        doctype: doctype,
+        //documentElement: ,
+    },
+    foreignDoc: {
+        // Node
+        nodeType: Node.DOCUMENT_NODE,
+        "childNodes.length": 3,
+        "childNodes[0]": foreignDoc.doctype,
+        "childNodes[1]": foreignDoc.documentElement,
+        "childNodes[2]": foreignComment,
+
+        // Document
+        URL: "about:blank",
+        compatMode: "CSS1Compat",
+        characterSet: "UTF-8",
+        contentType: "text/html",
+        //doctype: ,
+        //documentElement: ,
+    },
+    foreignPara1: {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: foreignDoc,
+        parentNode: foreignDoc.body,
+        parentElement: foreignDoc.body,
+        "childNodes.length": 1,
+        previousSibling: null,
+        nextSibling: foreignPara2,
+        textContent: "Efghijkl",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        previousElementSibling: null,
+        nextElementSibling: foreignPara2,
+        childElementCount: 0,
+    },
+    foreignPara2: {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: foreignDoc,
+        parentNode: foreignDoc.body,
+        parentElement: foreignDoc.body,
+        "childNodes.length": 1,
+        previousSibling: foreignPara1,
+        nextSibling: foreignTextNode,
+        textContent: "Mnopqrst",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        previousElementSibling: foreignPara1,
+        nextElementSibling: null,
+        childElementCount: 0,
+    },
+    xmlDoc: {
+        // Node
+        nodeType: Node.DOCUMENT_NODE,
+        "childNodes.length": 4,
+        "childNodes[0]": xmlDoctype,
+        "childNodes[1]": xmlElement,
+        "childNodes[2]": processingInstruction,
+        "childNodes[3]": xmlComment,
+
+        // Document
+        URL: "about:blank",
+        compatMode: "CSS1Compat",
+        characterSet: "UTF-8",
+        contentType: "application/xml",
+        //doctype: ,
+        //documentElement: ,
+    },
+    xmlElement: {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: xmlDoc,
+        parentElement: null,
+        "childNodes.length": 1,
+        "childNodes[0]": xmlTextNode,
+        previousSibling: xmlDoctype,
+        nextSibling: processingInstruction,
+        textContent: "do re mi fa so la ti",
+
+        // Element
+        namespaceURI: null,
+        prefix: null,
+        localName: "igiveuponcreativenames",
+        tagName: "igiveuponcreativenames",
+        previousElementSibling: null,
+        nextElementSibling: null,
+        childElementCount: 0,
+    },
+    detachedXmlElement: {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: null,
+        parentElement: null,
+        "childNodes.length": 0,
+        previousSibling: null,
+        nextSibling: null,
+        textContent: "",
+
+        // Element
+        namespaceURI: null,
+        prefix: null,
+        localName: "everyone-hates-hyphenated-element-names",
+        tagName: "everyone-hates-hyphenated-element-names",
+        previousElementSibling: null,
+        nextElementSibling: null,
+        childElementCount: 0,
+    },
+    detachedTextNode: {
+        // Node
+        nodeType: Node.TEXT_NODE,
+        ownerDocument: document,
+        parentNode: null,
+        parentElement: null,
+        previousSibling: null,
+        nextSibling: null,
+        nodeValue: "Uvwxyzab",
+
+        // Text
+        wholeText: "Uvwxyzab",
+    },
+    foreignTextNode: {
+        // Node
+        nodeType: Node.TEXT_NODE,
+        ownerDocument: foreignDoc,
+        parentNode: foreignDoc.body,
+        parentElement: foreignDoc.body,
+        previousSibling: foreignPara2,
+        nextSibling: null,
+        nodeValue: "I admit that I harbor doubts about whether we really need so many things to test, but it's too late to stop now.",
+
+        // Text
+        wholeText: "I admit that I harbor doubts about whether we really need so many things to test, but it's too late to stop now.",
+    },
+    detachedForeignTextNode: {
+        // Node
+        nodeType: Node.TEXT_NODE,
+        ownerDocument: foreignDoc,
+        parentNode: null,
+        parentElement: null,
+        previousSibling: null,
+        nextSibling: null,
+        nodeValue: "Cdefghij",
+
+        // Text
+        wholeText: "Cdefghij",
+    },
+    xmlTextNode: {
+        // Node
+        nodeType: Node.TEXT_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: xmlElement,
+        parentElement: xmlElement,
+        previousSibling: null,
+        nextSibling: null,
+        nodeValue: "do re mi fa so la ti",
+
+        // Text
+        wholeText: "do re mi fa so la ti",
+    },
+    detachedXmlTextNode: {
+        // Node
+        nodeType: Node.TEXT_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: null,
+        parentElement: null,
+        previousSibling: null,
+        nextSibling: null,
+        nodeValue: "Klmnopqr",
+
+        // Text
+        wholeText: "Klmnopqr",
+    },
+    processingInstruction: {
+        // Node
+        nodeType: Node.PROCESSING_INSTRUCTION_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: xmlDoc,
+        parentElement: null,
+        previousSibling: xmlElement,
+        nextSibling: xmlComment,
+        nodeValue: 'Did you know that ":syn sync fromstart" is very useful when using vim to edit large amounts of JavaScript embedded in HTML?',
+
+        // ProcessingInstruction
+        target: "somePI",
+    },
+    detachedProcessingInstruction: {
+        // Node
+        nodeType: Node.PROCESSING_INSTRUCTION_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: null,
+        parentElement: null,
+        previousSibling: null,
+        nextSibling: null,
+        nodeValue: "chirp chirp chirp",
+
+        // ProcessingInstruction
+        target: "whippoorwill",
+    },
+    comment: {
+        // Node
+        nodeType: Node.COMMENT_NODE,
+        ownerDocument: document,
+        parentNode: testDiv,
+        parentElement: testDiv,
+        previousSibling: paras[4],
+        nextSibling: null,
+        nodeValue: "Alphabet soup?",
+    },
+    detachedComment: {
+        // Node
+        nodeType: Node.COMMENT_NODE,
+        ownerDocument: document,
+        parentNode: null,
+        parentElement: null,
+        previousSibling: null,
+        nextSibling: null,
+        nodeValue: "Stuvwxyz",
+    },
+    foreignComment: {
+        // Node
+        nodeType: Node.COMMENT_NODE,
+        ownerDocument: foreignDoc,
+        parentNode: foreignDoc,
+        parentElement: null,
+        previousSibling: foreignDoc.documentElement,
+        nextSibling: null,
+        nodeValue: '"Commenter" and "commentator" mean different things.  I\'ve seen non-native speakers trip up on this.',
+    },
+    detachedForeignComment: {
+        // Node
+        nodeType: Node.COMMENT_NODE,
+        ownerDocument: foreignDoc,
+        parentNode: null,
+        parentElement: null,
+        previousSibling: null,
+        nextSibling: null,
+        nodeValue: "אריה יהודה",
+    },
+    xmlComment: {
+        // Node
+        nodeType: Node.COMMENT_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: xmlDoc,
+        parentElement: null,
+        previousSibling: processingInstruction,
+        nextSibling: null,
+        nodeValue: "I maliciously created a comment that will break incautious XML serializers, but Firefox threw an exception, so all I got was this lousy T-shirt",
+    },
+    detachedXmlComment: {
+        // Node
+        nodeType: Node.COMMENT_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: null,
+        parentElement: null,
+        previousSibling: null,
+        nextSibling: null,
+        nodeValue: "בן חיים אליעזר",
+    },
+    docfrag: {
+        // Node
+        nodeType: Node.DOCUMENT_FRAGMENT_NODE,
+        ownerDocument: document,
+        "childNodes.length": 0,
+        textContent: "",
+    },
+    foreignDocfrag: {
+        // Node
+        nodeType: Node.DOCUMENT_FRAGMENT_NODE,
+        ownerDocument: foreignDoc,
+        "childNodes.length": 0,
+        textContent: "",
+    },
+    xmlDocfrag: {
+        // Node
+        nodeType: Node.DOCUMENT_FRAGMENT_NODE,
+        ownerDocument: xmlDoc,
+        "childNodes.length": 0,
+        textContent: "",
+    },
+    doctype: {
+        // Node
+        nodeType: Node.DOCUMENT_TYPE_NODE,
+        ownerDocument: document,
+        parentNode: document,
+        previousSibling: null,
+        nextSibling: document.documentElement,
+
+        // DocumentType
+        name: "html",
+        publicId: "",
+        systemId: "",
+    },
+    foreignDoctype: {
+        // Node
+        nodeType: Node.DOCUMENT_TYPE_NODE,
+        ownerDocument: foreignDoc,
+        parentNode: foreignDoc,
+        previousSibling: null,
+        nextSibling: foreignDoc.documentElement,
+
+        // DocumentType
+        name: "html",
+        publicId: "",
+        systemId: "",
+    },
+    xmlDoctype: {
+        // Node
+        nodeType: Node.DOCUMENT_TYPE_NODE,
+        ownerDocument: xmlDoc,
+        parentNode: xmlDoc,
+        previousSibling: null,
+        nextSibling: xmlElement,
+
+        // DocumentType
+        name: "qorflesnorf",
+        publicId: "abcde",
+        systemId: "x\"'y",
+    },
+    "paras[0]": {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: testDiv,
+        parentElement: testDiv,
+        "childNodes.length": 1,
+        previousSibling: null,
+        nextSibling: paras[1],
+        textContent: "A\u0308b\u0308c\u0308d\u0308e\u0308f\u0308g\u0308h\u0308\n",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        id: "a",
+        previousElementSibling: null,
+        nextElementSibling: paras[1],
+        childElementCount: 0,
+    },
+    "paras[1]": {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: testDiv,
+        parentElement: testDiv,
+        "childNodes.length": 1,
+        previousSibling: paras[0],
+        nextSibling: paras[2],
+        textContent: "Ijklmnop\n",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        id: "b",
+        previousElementSibling: paras[0],
+        nextElementSibling: paras[2],
+        childElementCount: 0,
+    },
+    "paras[2]": {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: testDiv,
+        parentElement: testDiv,
+        "childNodes.length": 1,
+        previousSibling: paras[1],
+        nextSibling: paras[3],
+        textContent: "Qrstuvwx",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        id: "c",
+        previousElementSibling: paras[1],
+        nextElementSibling: paras[3],
+        childElementCount: 0,
+    },
+    "paras[3]": {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: testDiv,
+        parentElement: testDiv,
+        "childNodes.length": 1,
+        previousSibling: paras[2],
+        nextSibling: paras[4],
+        textContent: "Yzabcdef",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        id: "d",
+        previousElementSibling: paras[2],
+        nextElementSibling: paras[4],
+        childElementCount: 0,
+    },
+    "paras[4]": {
+        // Node
+        nodeType: Node.ELEMENT_NODE,
+        ownerDocument: document,
+        parentNode: testDiv,
+        parentElement: testDiv,
+        "childNodes.length": 1,
+        previousSibling: paras[3],
+        nextSibling: comment,
+        textContent: "Ghijklmn",
+
+        // Element
+        namespaceURI: "http://www.w3.org/1999/xhtml",
+        prefix: null,
+        localName: "p",
+        tagName: "P",
+        id: "e",
+        previousElementSibling: paras[3],
+        nextElementSibling: null,
+        childElementCount: 0,
+    },
+};
+
+for (var node in expected) {
+    // Now we set various default values by node type.
+    switch (expected[node].nodeType) {
+    case Node.ELEMENT_NODE:
+        expected[node].nodeName = expected[node].tagName;
+        expected[node].nodeValue = null;
+        expected[node]["children.length"] = expected[node].childElementCount;
+
+        if (expected[node].id === undefined) {
+            expected[node].id = "";
+        }
+        if (expected[node].className === undefined) {
+            expected[node].className = "";
+        }
+
+        var len = expected[node].childElementCount;
+        if (len === 0) {
+            expected[node].firstElementChild =
+            expected[node].lastElementChild = null;
+        } else {
+            // If we have expectations for the first/last child in children,
+            // use those.  Otherwise, at least check that .firstElementChild ==
+            // .children[0] and .lastElementChild == .children[len - 1], even
+            // if we aren't sure what they should be.
+            expected[node].firstElementChild = expected[node]["children[0]"]
+                ? expected[node]["children[0]"]
+                : eval(node).children[0];
+            expected[node].lastElementChild =
+                expected[node]["children[" + (len - 1) + "]"]
+                ? expected[node]["children[" + (len - 1) + "]"]
+                : eval(node).children[len - 1];
+        }
+        break;
+
+    case Node.TEXT_NODE:
+        expected[node].nodeName = "#text";
+        expected[node]["childNodes.length"] = 0;
+        expected[node].textContent = expected[node].data =
+            expected[node].nodeValue;
+        expected[node].length = expected[node].nodeValue.length;
+        break;
+
+    case Node.PROCESSING_INSTRUCTION_NODE:
+        expected[node].nodeName = expected[node].target;
+        expected[node]["childNodes.length"] = 0;
+        expected[node].textContent = expected[node].data =
+            expected[node].nodeValue;
+        expected[node].length = expected[node].nodeValue.length;
+        break;
+
+    case Node.COMMENT_NODE:
+        expected[node].nodeName = "#comment";
+        expected[node]["childNodes.length"] = 0;
+        expected[node].textContent = expected[node].data =
+            expected[node].nodeValue;
+        expected[node].length = expected[node].nodeValue.length;
+        break;
+
+    case Node.DOCUMENT_NODE:
+        expected[node].nodeName = "#document";
+        expected[node].ownerDocument = expected[node].parentNode =
+            expected[node].parentElement = expected[node].previousSibling =
+            expected[node].nextSibling = expected[node].nodeValue =
+            expected[node].textContent = null;
+        expected[node].documentURI = expected[node].URL;
+        expected[node].charset = expected[node].inputEncoding =
+            expected[node].characterSet;
+        break;
+
+    case Node.DOCUMENT_TYPE_NODE:
+        expected[node].nodeName = expected[node].name;
+        expected[node]["childNodes.length"] = 0;
+        expected[node].parentElement = expected[node].nodeValue =
+            expected[node].textContent = null;
+        break;
+
+    case Node.DOCUMENT_FRAGMENT_NODE:
+        expected[node].nodeName = "#document-fragment";
+        expected[node].parentNode = expected[node].parentElement =
+            expected[node].previousSibling = expected[node].nextSibling =
+            expected[node].nodeValue = null;
+        break;
+    }
+
+    // Now we set some further default values that are independent of node
+    // type.
+    var len = expected[node]["childNodes.length"];
+    if (len === 0) {
+        expected[node].firstChild = expected[node].lastChild = null;
+    } else {
+        // If we have expectations for the first/last child in childNodes, use
+        // those.  Otherwise, at least check that .firstChild == .childNodes[0]
+        // and .lastChild == .childNodes[len - 1], even if we aren't sure what
+        // they should be.
+        expected[node].firstChild = expected[node]["childNodes[0]"]
+            ? expected[node]["childNodes[0]"]
+            : eval(node).childNodes[0];
+        expected[node].lastChild =
+            expected[node]["childNodes[" + (len - 1) + "]"]
+            ? expected[node]["childNodes[" + (len - 1) + "]"]
+            : eval(node).childNodes[len - 1];
+    }
+    expected[node]["hasChildNodes()"] = !!expected[node]["childNodes.length"];
+
+    // Finally, we test!
+    for (var prop in expected[node]) {
+        test(function() {
+            assert_equals(eval(node + "." + prop), expected[node][prop]);
+        }, node + "." + prop);
+    }
+}
+
+testDiv.parentNode.removeChild(testDiv);
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-removeChild.html b/testing/web-platform/tests/dom/nodes/Node-removeChild.html
new file mode 100644
index 0000000000..6158423359
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-removeChild.html
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<title>Node.removeChild</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="creators.js"></script>
+<div id="log"></div>
+<iframe src=about:blank></iframe>
+<script>
+var documents = [
+  [function() { return document }, "the main document"],
+  [function() { return frames[0].document }, "a frame document"],
+  [function() { return document.implementation.createHTMLDocument() },
+   "a synthetic document"],
+];
+
+documents.forEach(function(d) {
+  var get = d[0], description = d[1]
+  for (var p in creators) {
+    var creator = creators[p];
+    test(function() {
+      var doc = get();
+      var s = doc[creator]("a")
+      assert_equals(s.ownerDocument, doc)
+      assert_throws_dom("NOT_FOUND_ERR", function() { document.body.removeChild(s) })
+      assert_equals(s.ownerDocument, doc)
+    }, "Passing a detached " + p + " from " + description +
+       " to removeChild should not affect it.")
+
+    test(function() {
+      var doc = get();
+      var s = doc[creator]("b")
+      doc.documentElement.appendChild(s)
+      assert_equals(s.ownerDocument, doc)
+      assert_throws_dom("NOT_FOUND_ERR", function() { document.body.removeChild(s) })
+      assert_equals(s.ownerDocument, doc)
+    }, "Passing a non-detached " + p + " from " + description +
+       " to removeChild should not affect it.")
+
+    test(function() {
+      var doc = get();
+      var s = doc[creator]("test")
+      doc.body.appendChild(s)
+      assert_equals(s.ownerDocument, doc)
+      assert_throws_dom(
+        "NOT_FOUND_ERR",
+        (doc.defaultView || self).DOMException,
+        function() { s.removeChild(doc) }
+      );
+    }, "Calling removeChild on a " + p + " from " + description +
+       " with no children should throw NOT_FOUND_ERR.")
+  }
+});
+
+test(function() {
+  assert_throws_js(TypeError, function() { document.body.removeChild(null) })
+  assert_throws_js(TypeError, function() { document.body.removeChild({'a':'b'}) })
+}, "Passing a value that is not a Node reference to removeChild should throw TypeError.")
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-replaceChild.html b/testing/web-platform/tests/dom/nodes/Node-replaceChild.html
new file mode 100644
index 0000000000..74aac67d43
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-replaceChild.html
@@ -0,0 +1,349 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Node.replaceChild</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body><a><b></b><c></c></a>
+<div id="log"></div>
+<!-- First test shared pre-insertion checks that work similarly for replaceChild
+     and insertBefore -->
+<script>
+  var insertFunc = Node.prototype.replaceChild;
+</script>
+<script src="pre-insertion-validation-notfound.js"></script>
+<script>
+// IDL.
+test(function() {
+  var a = document.createElement("div");
+  assert_throws_js(TypeError, function() {
+    a.replaceChild(null, null);
+  });
+
+  var b = document.createElement("div");
+  assert_throws_js(TypeError, function() {
+    a.replaceChild(b, null);
+  });
+  assert_throws_js(TypeError, function() {
+    a.replaceChild(null, b);
+  });
+}, "Passing null to replaceChild should throw a TypeError.")
+
+// Step 3.
+test(function() {
+  var a = document.createElement("div");
+  var b = document.createElement("div");
+  var c = document.createElement("div");
+  assert_throws_dom("NotFoundError", function() {
+    a.replaceChild(b, c);
+  });
+
+  var d = document.createElement("div");
+  d.appendChild(b);
+  assert_throws_dom("NotFoundError", function() {
+    a.replaceChild(b, c);
+  });
+  assert_throws_dom("NotFoundError", function() {
+    a.replaceChild(b, a);
+  });
+}, "If child's parent is not the context node, a NotFoundError exception should be thrown");
+
+// Step 1.
+test(function() {
+  var nodes = getNonParentNodes();
+
+  var a = document.createElement("div");
+  var b = document.createElement("div");
+  nodes.forEach(function(node) {
+    assert_throws_dom("HierarchyRequestError", function() {
+      node.replaceChild(a, b);
+    });
+  });
+}, "If the context node is not a node that can contain children, a HierarchyRequestError exception should be thrown")
+
+// Step 2.
+test(function() {
+  var a = document.createElement("div");
+  var b = document.createElement("div");
+
+  assert_throws_dom("HierarchyRequestError", function() {
+    a.replaceChild(a, a);
+  });
+
+  a.appendChild(b);
+  assert_throws_dom("HierarchyRequestError", function() {
+    a.replaceChild(a, b);
+  });
+
+  var c = document.createElement("div");
+  c.appendChild(a);
+  assert_throws_dom("HierarchyRequestError", function() {
+    a.replaceChild(c, b);
+  });
+}, "If node is an inclusive ancestor of the context node, a HierarchyRequestError should be thrown.")
+
+// Steps 4/5.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var doc2 = document.implementation.createHTMLDocument("title2");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(doc2, doc.documentElement);
+  });
+
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(doc.createTextNode("text"), doc.documentElement);
+  });
+}, "If the context node is a document, inserting a document or text node should throw a HierarchyRequestError.")
+
+// Step 6.1.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+
+  var df = doc.createDocumentFragment();
+  df.appendChild(doc.createElement("a"));
+  df.appendChild(doc.createElement("b"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(df, doc.documentElement);
+  });
+
+  df = doc.createDocumentFragment();
+  df.appendChild(doc.createTextNode("text"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(df, doc.documentElement);
+  });
+
+  df = doc.createDocumentFragment();
+  df.appendChild(doc.createComment("comment"));
+  df.appendChild(doc.createTextNode("text"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(df, doc.documentElement);
+  });
+}, "If the context node is a document, inserting a DocumentFragment that contains a text node or too many elements should throw a HierarchyRequestError.")
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  doc.removeChild(doc.documentElement);
+
+  var df = doc.createDocumentFragment();
+  df.appendChild(doc.createElement("a"));
+  df.appendChild(doc.createElement("b"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(df, doc.doctype);
+  });
+}, "If the context node is a document (without element children), inserting a DocumentFragment that contains multiple elements should throw a HierarchyRequestError.")
+
+// Step 6.1.
+test(function() {
+  // The context node has an element child that is not /child/.
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.appendChild(doc.createComment("foo"));
+  assert_array_equals(doc.childNodes, [doc.doctype, doc.documentElement, comment]);
+
+  var df = doc.createDocumentFragment();
+  df.appendChild(doc.createElement("a"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(df, comment);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(df, doc.doctype);
+  });
+}, "If the context node is a document, inserting a DocumentFragment with an element if there already is an element child should throw a HierarchyRequestError.")
+test(function() {
+  // A doctype is following /child/.
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.insertBefore(doc.createComment("foo"), doc.firstChild);
+  doc.removeChild(doc.documentElement);
+  assert_array_equals(doc.childNodes, [comment, doc.doctype]);
+
+  var df = doc.createDocumentFragment();
+  df.appendChild(doc.createElement("a"));
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(df, comment);
+  });
+}, "If the context node is a document, inserting a DocumentFragment with an element before the doctype should throw a HierarchyRequestError.")
+
+// Step 6.2.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.appendChild(doc.createComment("foo"));
+  assert_array_equals(doc.childNodes, [doc.doctype, doc.documentElement, comment]);
+
+  var a = doc.createElement("a");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(a, comment);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(a, doc.doctype);
+  });
+}, "If the context node is a document, inserting an element if there already is an element child should throw a HierarchyRequestError.")
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.insertBefore(doc.createComment("foo"), doc.firstChild);
+  doc.removeChild(doc.documentElement);
+  assert_array_equals(doc.childNodes, [comment, doc.doctype]);
+
+  var a = doc.createElement("a");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(a, comment);
+  });
+}, "If the context node is a document, inserting an element before the doctype should throw a HierarchyRequestError.")
+
+// Step 6.3.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.insertBefore(doc.createComment("foo"), doc.firstChild);
+  assert_array_equals(doc.childNodes, [comment, doc.doctype, doc.documentElement]);
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(doctype, comment);
+  });
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(doctype, doc.documentElement);
+  });
+}, "If the context node is a document, inserting a doctype if there already is a doctype child should throw a HierarchyRequestError.")
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var comment = doc.appendChild(doc.createComment("foo"));
+  doc.removeChild(doc.doctype);
+  assert_array_equals(doc.childNodes, [doc.documentElement, comment]);
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    doc.replaceChild(doctype, comment);
+  });
+}, "If the context node is a document, inserting a doctype after the document element should throw a HierarchyRequestError.")
+
+// Steps 4/5.
+test(function() {
+  var df = document.createDocumentFragment();
+  var a = df.appendChild(document.createElement("a"));
+
+  var doc = document.implementation.createHTMLDocument("title");
+  assert_throws_dom("HierarchyRequestError", function() {
+    df.replaceChild(doc, a);
+  });
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    df.replaceChild(doctype, a);
+  });
+}, "If the context node is a DocumentFragment, inserting a document or a doctype should throw a HierarchyRequestError.")
+test(function() {
+  var el = document.createElement("div");
+  var a = el.appendChild(document.createElement("a"));
+
+  var doc = document.implementation.createHTMLDocument("title");
+  assert_throws_dom("HierarchyRequestError", function() {
+    el.replaceChild(doc, a);
+  });
+
+  var doctype = document.implementation.createDocumentType("html", "", "");
+  assert_throws_dom("HierarchyRequestError", function() {
+    el.replaceChild(doctype, a);
+  });
+}, "If the context node is an element, inserting a document or a doctype should throw a HierarchyRequestError.")
+
+// Step 6.
+test(function() {
+  var a = document.createElement("div");
+  var b = document.createElement("div");
+  var c = document.createElement("div");
+  a.appendChild(b);
+  a.appendChild(c);
+  assert_array_equals(a.childNodes, [b, c]);
+  assert_equals(a.replaceChild(c, b), b);
+  assert_array_equals(a.childNodes, [c]);
+}, "Replacing a node with its next sibling should work (2 children)");
+test(function() {
+  var a = document.createElement("div");
+  var b = document.createElement("div");
+  var c = document.createElement("div");
+  var d = document.createElement("div");
+  var e = document.createElement("div");
+  a.appendChild(b);
+  a.appendChild(c);
+  a.appendChild(d);
+  a.appendChild(e);
+  assert_array_equals(a.childNodes, [b, c, d, e]);
+  assert_equals(a.replaceChild(d, c), c);
+  assert_array_equals(a.childNodes, [b, d, e]);
+}, "Replacing a node with its next sibling should work (4 children)");
+test(function() {
+  var a = document.createElement("div");
+  var b = document.createElement("div");
+  var c = document.createElement("div");
+  a.appendChild(b);
+  a.appendChild(c);
+  assert_array_equals(a.childNodes, [b, c]);
+  assert_equals(a.replaceChild(b, b), b);
+  assert_array_equals(a.childNodes, [b, c]);
+  assert_equals(a.replaceChild(c, c), c);
+  assert_array_equals(a.childNodes, [b, c]);
+}, "Replacing a node with itself should not move the node");
+
+// Step 7.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var doctype = doc.doctype;
+  assert_array_equals(doc.childNodes, [doctype, doc.documentElement]);
+
+  var doc2 = document.implementation.createHTMLDocument("title2");
+  var doctype2 = doc2.doctype;
+  assert_array_equals(doc2.childNodes, [doctype2, doc2.documentElement]);
+
+  doc.replaceChild(doc2.doctype, doc.doctype);
+  assert_array_equals(doc.childNodes, [doctype2, doc.documentElement]);
+  assert_array_equals(doc2.childNodes, [doc2.documentElement]);
+  assert_equals(doctype.parentNode, null);
+  assert_equals(doctype.ownerDocument, doc);
+  assert_equals(doctype2.parentNode, doc);
+  assert_equals(doctype2.ownerDocument, doc);
+}, "If the context node is a document, inserting a new doctype should work.")
+
+// Bugs.
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var df = doc.createDocumentFragment();
+  var a = df.appendChild(doc.createElement("a"));
+  assert_equals(doc.documentElement, doc.replaceChild(df, doc.documentElement));
+  assert_array_equals(doc.childNodes, [doc.doctype, a]);
+}, "Replacing the document element with a DocumentFragment containing a single element should work.");
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var df = doc.createDocumentFragment();
+  var a = df.appendChild(doc.createComment("a"));
+  var b = df.appendChild(doc.createElement("b"));
+  var c = df.appendChild(doc.createComment("c"));
+  assert_equals(doc.documentElement, doc.replaceChild(df, doc.documentElement));
+  assert_array_equals(doc.childNodes, [doc.doctype, a, b, c]);
+}, "Replacing the document element with a DocumentFragment containing a single element and comments should work.");
+test(function() {
+  var doc = document.implementation.createHTMLDocument("title");
+  var a = doc.createElement("a");
+  assert_equals(doc.documentElement, doc.replaceChild(a, doc.documentElement));
+  assert_array_equals(doc.childNodes, [doc.doctype, a]);
+}, "Replacing the document element with a single element should work.");
+test(function() {
+  document.addEventListener("DOMNodeRemoved", function(e) {
+    document.body.appendChild(document.createElement("x"));
+  }, false);
+  var a = document.body.firstChild, b = a.firstChild, c = b.nextSibling;
+  assert_equals(a.replaceChild(c, b), b);
+  assert_equals(b.parentNode, null);
+  assert_equals(a.firstChild, c);
+  assert_equals(c.parentNode, a);
+}, "replaceChild should work in the presence of mutation events.")
+test(function() {
+  var TEST_ID = "findme";
+  var gBody = document.getElementsByTagName("body")[0];
+  var parent = document.createElement("div");
+  gBody.appendChild(parent);
+  var child = document.createElement("div");
+  parent.appendChild(child);
+  var df = document.createDocumentFragment();
+  var fragChild = df.appendChild(document.createElement("div"));
+  fragChild.setAttribute("id", TEST_ID);
+  parent.replaceChild(df, child);
+  assert_equals(document.getElementById(TEST_ID), fragChild, "should not be null");
+}, "Replacing an element with a DocumentFragment should allow a child of the DocumentFragment to be found by Id.")
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Node-textContent.html b/testing/web-platform/tests/dom/nodes/Node-textContent.html
new file mode 100644
index 0000000000..cf2e072087
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Node-textContent.html
@@ -0,0 +1,265 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Node.textContent</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+// XXX mutation observers?
+// XXX Range gravitation?
+
+var documents, doctypes;
+setup(function() {
+  documents = [
+    [document, "parser"],
+    [document.implementation.createDocument("", "test", null), "createDocument"],
+    [document.implementation.createHTMLDocument("title"), "createHTMLDocument"],
+  ]
+  doctypes = [
+    [document.doctype, "parser"],
+    [document.implementation.createDocumentType("x", "", ""), "script"],
+  ]
+})
+
+// Getting
+// DocumentFragment, Element:
+test(function() {
+  var element = document.createElement("div")
+  assert_equals(element.textContent, "")
+}, "For an empty Element, textContent should be the empty string")
+
+test(function() {
+  assert_equals(document.createDocumentFragment().textContent, "")
+}, "For an empty DocumentFragment, textContent should be the empty string")
+
+test(function() {
+  var el = document.createElement("div")
+  el.appendChild(document.createComment(" abc "))
+  el.appendChild(document.createTextNode("\tDEF\t"))
+  el.appendChild(document.createProcessingInstruction("x", " ghi "))
+  assert_equals(el.textContent, "\tDEF\t")
+}, "Element with children")
+
+test(function() {
+  var el = document.createElement("div")
+  var child = document.createElement("div")
+  el.appendChild(child)
+  child.appendChild(document.createComment(" abc "))
+  child.appendChild(document.createTextNode("\tDEF\t"))
+  child.appendChild(document.createProcessingInstruction("x", " ghi "))
+  assert_equals(el.textContent, "\tDEF\t")
+}, "Element with descendants")
+
+test(function() {
+  var df = document.createDocumentFragment()
+  df.appendChild(document.createComment(" abc "))
+  df.appendChild(document.createTextNode("\tDEF\t"))
+  df.appendChild(document.createProcessingInstruction("x", " ghi "))
+  assert_equals(df.textContent, "\tDEF\t")
+}, "DocumentFragment with children")
+
+test(function() {
+  var df = document.createDocumentFragment()
+  var child = document.createElement("div")
+  df.appendChild(child)
+  child.appendChild(document.createComment(" abc "))
+  child.appendChild(document.createTextNode("\tDEF\t"))
+  child.appendChild(document.createProcessingInstruction("x", " ghi "))
+  assert_equals(df.textContent, "\tDEF\t")
+}, "DocumentFragment with descendants")
+
+// Text, ProcessingInstruction, Comment:
+test(function() {
+  assert_equals(document.createTextNode("").textContent, "")
+}, "For an empty Text, textContent should be the empty string")
+
+test(function() {
+  assert_equals(document.createProcessingInstruction("x", "").textContent, "")
+}, "For an empty ProcessingInstruction, textContent should be the empty string")
+
+test(function() {
+  assert_equals(document.createComment("").textContent, "")
+}, "For an empty Comment, textContent should be the empty string")
+
+test(function() {
+  assert_equals(document.createTextNode("abc").textContent, "abc")
+}, "For a Text with data, textContent should be that data")
+
+test(function() {
+  assert_equals(document.createProcessingInstruction("x", "abc").textContent,
+                "abc")
+}, "For a ProcessingInstruction with data, textContent should be that data")
+
+test(function() {
+  assert_equals(document.createComment("abc").textContent, "abc")
+}, "For a Comment with data, textContent should be that data")
+
+// Any other node:
+documents.forEach(function(argument) {
+  var doc = argument[0], creator = argument[1]
+  test(function() {
+    assert_equals(doc.textContent, null)
+  }, "For Documents created by " + creator + ", textContent should be null")
+})
+
+doctypes.forEach(function(argument) {
+  var doctype = argument[0], creator = argument[1]
+  test(function() {
+    assert_equals(doctype.textContent, null)
+  }, "For DocumentType created by " + creator + ", textContent should be null")
+})
+
+// Setting
+// DocumentFragment, Element:
+var testArgs = [
+  [null, null],
+  [undefined, null],
+  ["", null],
+  [42, "42"],
+  ["abc", "abc"],
+  ["<b>xyz<\/b>", "<b>xyz<\/b>"],
+  ["d\0e", "d\0e"]
+  // XXX unpaired surrogate?
+]
+testArgs.forEach(function(aValue) {
+  var argument = aValue[0], expectation = aValue[1]
+  var check = function(aElementOrDocumentFragment) {
+    if (expectation === null) {
+      assert_equals(aElementOrDocumentFragment.textContent, "")
+      assert_equals(aElementOrDocumentFragment.firstChild, null)
+    } else {
+      assert_equals(aElementOrDocumentFragment.textContent, expectation)
+      assert_equals(aElementOrDocumentFragment.childNodes.length, 1,
+                    "Should have one child")
+      var firstChild = aElementOrDocumentFragment.firstChild
+      assert_true(firstChild instanceof Text, "child should be a Text")
+      assert_equals(firstChild.data, expectation)
+    }
+  }
+
+  test(function() {
+    var el = document.createElement("div")
+    el.textContent = argument
+    check(el)
+  }, "Element without children set to " + format_value(argument))
+
+  test(function() {
+    var el = document.createElement("div")
+    var text = el.appendChild(document.createTextNode(""))
+    el.textContent = argument
+    check(el)
+    assert_equals(text.parentNode, null,
+                  "Preexisting Text should have been removed")
+  }, "Element with empty text node as child set to " + format_value(argument))
+
+  test(function() {
+    var el = document.createElement("div")
+    el.appendChild(document.createComment(" abc "))
+    el.appendChild(document.createTextNode("\tDEF\t"))
+    el.appendChild(document.createProcessingInstruction("x", " ghi "))
+    el.textContent = argument
+    check(el)
+  }, "Element with children set to " + format_value(argument))
+
+  test(function() {
+    var el = document.createElement("div")
+    var child = document.createElement("div")
+    el.appendChild(child)
+    child.appendChild(document.createComment(" abc "))
+    child.appendChild(document.createTextNode("\tDEF\t"))
+    child.appendChild(document.createProcessingInstruction("x", " ghi "))
+    el.textContent = argument
+    check(el)
+    assert_equals(child.childNodes.length, 3,
+                  "Should not have changed the internal structure of the removed nodes.")
+  }, "Element with descendants set to " + format_value(argument))
+
+  test(function() {
+    var df = document.createDocumentFragment()
+    df.textContent = argument
+    check(df)
+  }, "DocumentFragment without children set to " + format_value(argument))
+
+  test(function() {
+    var df = document.createDocumentFragment()
+    var text = df.appendChild(document.createTextNode(""))
+    df.textContent = argument
+    check(df)
+    assert_equals(text.parentNode, null,
+                  "Preexisting Text should have been removed")
+  }, "DocumentFragment with empty text node as child set to " + format_value(argument))
+
+  test(function() {
+    var df = document.createDocumentFragment()
+    df.appendChild(document.createComment(" abc "))
+    df.appendChild(document.createTextNode("\tDEF\t"))
+    df.appendChild(document.createProcessingInstruction("x", " ghi "))
+    df.textContent = argument
+    check(df)
+  }, "DocumentFragment with children set to " + format_value(argument))
+
+  test(function() {
+    var df = document.createDocumentFragment()
+    var child = document.createElement("div")
+    df.appendChild(child)
+    child.appendChild(document.createComment(" abc "))
+    child.appendChild(document.createTextNode("\tDEF\t"))
+    child.appendChild(document.createProcessingInstruction("x", " ghi "))
+    df.textContent = argument
+    check(df)
+    assert_equals(child.childNodes.length, 3,
+                  "Should not have changed the internal structure of the removed nodes.")
+  }, "DocumentFragment with descendants set to " + format_value(argument))
+})
+
+// Text, ProcessingInstruction, Comment:
+test(function() {
+  var text = document.createTextNode("abc")
+  text.textContent = "def"
+  assert_equals(text.textContent, "def")
+  assert_equals(text.data, "def")
+}, "For a Text, textContent should set the data")
+
+test(function() {
+  var pi = document.createProcessingInstruction("x", "abc")
+  pi.textContent = "def"
+  assert_equals(pi.textContent, "def")
+  assert_equals(pi.data, "def")
+  assert_equals(pi.target, "x")
+}, "For a ProcessingInstruction, textContent should set the data")
+
+test(function() {
+  var comment = document.createComment("abc")
+  comment.textContent = "def"
+  assert_equals(comment.textContent, "def")
+  assert_equals(comment.data, "def")
+}, "For a Comment, textContent should set the data")
+
+// Any other node:
+documents.forEach(function(argument) {
+  var doc = argument[0], creator = argument[1]
+  test(function() {
+    var root = doc.documentElement
+    doc.textContent = "a"
+    assert_equals(doc.textContent, null)
+    assert_equals(doc.documentElement, root)
+  }, "For Documents created by " + creator + ", setting textContent should do nothing")
+})
+
+doctypes.forEach(function(argument) {
+  var doctype = argument[0], creator = argument[1]
+  test(function() {
+    var props = {
+      name: doctype.name,
+      publicId: doctype.publicId,
+      systemId: doctype.systemId,
+    }
+    doctype.textContent = "b"
+    assert_equals(doctype.textContent, null)
+    assert_equals(doctype.name, props.name, "name should not change")
+    assert_equals(doctype.publicId, props.publicId, "publicId should not change")
+    assert_equals(doctype.systemId, props.systemId, "systemId should not change")
+  }, "For DocumentType created by " + creator + ", setting textContent should do nothing")
+})
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/NodeList-Iterable.html b/testing/web-platform/tests/dom/nodes/NodeList-Iterable.html
new file mode 100644
index 0000000000..fcbee175cb
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/NodeList-Iterable.html
@@ -0,0 +1,61 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>NodeList Iterable Test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+    <p id="1"></p>
+    <p id="2"></p>
+    <p id="3"></p>
+    <p id="4"></p>
+    <p id="5"></p>
+
+    <div id="live"><b id="b1">1</b><b id="b2">2</b><b id="b3">3</b></div>
+<script>
+    var paragraphs;
+    setup(function() {
+        paragraphs = document.querySelectorAll('p');
+    })
+    test(function() {
+        assert_true('length' in paragraphs);
+    }, 'NodeList has length method.');
+    test(function() {
+        assert_true('values' in paragraphs);
+    }, 'NodeList has values method.');
+    test(function() {
+        assert_true('entries' in paragraphs);
+    }, 'NodeList has entries method.');
+    test(function() {
+        assert_true('forEach' in paragraphs);
+    }, 'NodeList has forEach method.');
+    test(function() {
+        assert_true(Symbol.iterator in paragraphs);
+    }, 'NodeList has Symbol.iterator.');
+    test(function() {
+        var ids = "12345", idx=0;
+        for(var node of paragraphs){
+            assert_equals(node.getAttribute('id'), ids[idx++]);
+        }
+    }, 'NodeList is iterable via for-of loop.');
+
+    test(function() {
+        assert_array_equals(Object.keys(paragraphs), ['0', '1', '2', '3', '4']);
+    }, 'NodeList responds to Object.keys correctly');
+
+    test(function() {
+        var container = document.getElementById('live');
+        var nodeList = container.childNodes;
+
+        var ids = [];
+        for (var el of nodeList) {
+            ids.push(el.id);
+            assert_equals(el.localName, 'b');
+            if (ids.length < 3) {
+                var newEl = document.createElement('b');
+                newEl.id = 'after' + el.id;
+                container.appendChild(newEl);
+            }
+        }
+
+        assert_array_equals(ids, ['b1', 'b2', 'b3', 'afterb1', 'afterb2']);
+    }, 'live NodeLists are for-of iterable and update appropriately');
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/NodeList-live-mutations.window.js b/testing/web-platform/tests/dom/nodes/NodeList-live-mutations.window.js
new file mode 100644
index 0000000000..a11fed1e38
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/NodeList-live-mutations.window.js
@@ -0,0 +1,79 @@
+function testNodeList(name, hooks) {
+  test(() => {
+    const nodes = {
+      root: document.createElement("div"),
+      div1: document.createElement("div"),
+      div2: document.createElement("div"),
+      p: document.createElement("p")
+    };
+
+    const list = nodes.root.childNodes;
+
+    hooks.initial(list, nodes);
+
+    nodes.root.appendChild(nodes.div1);
+    nodes.root.appendChild(nodes.p);
+    nodes.root.appendChild(nodes.div2);
+
+    hooks.afterInsertion(list, nodes);
+
+    nodes.root.removeChild(nodes.div1);
+
+    hooks.afterRemoval(list, nodes);
+  }, `NodeList live mutations: ${name}`);
+}
+
+testNodeList("NodeList.length", {
+  initial(list) {
+    assert_equals(list.length, 0);
+  },
+  afterInsertion(list) {
+    assert_equals(list.length, 3);
+  },
+  afterRemoval(list) {
+    assert_equals(list.length, 2);
+  }
+});
+
+testNodeList("NodeList.item(index)", {
+  initial(list) {
+    assert_equals(list.item(0), null);
+  },
+  afterInsertion(list, nodes) {
+    assert_equals(list.item(0), nodes.div1);
+    assert_equals(list.item(1), nodes.p);
+    assert_equals(list.item(2), nodes.div2);
+  },
+  afterRemoval(list, nodes) {
+    assert_equals(list.item(0), nodes.p);
+    assert_equals(list.item(1), nodes.div2);
+  }
+});
+
+testNodeList("NodeList[index]", {
+  initial(list) {
+    assert_equals(list[0], undefined);
+  },
+  afterInsertion(list, nodes) {
+    assert_equals(list[0], nodes.div1);
+    assert_equals(list[1], nodes.p);
+    assert_equals(list[2], nodes.div2);
+  },
+  afterRemoval(list, nodes) {
+    assert_equals(list[0], nodes.p);
+    assert_equals(list[1], nodes.div2);
+  }
+});
+
+testNodeList("NodeList ownPropertyNames", {
+  initial(list) {
+    assert_object_equals(Object.getOwnPropertyNames(list), []);
+  },
+  afterInsertion(list) {
+    assert_object_equals(Object.getOwnPropertyNames(list), ["0", "1", "2"]);
+  },
+  afterRemoval(list) {
+    assert_object_equals(Object.getOwnPropertyNames(list), ["0", "1"]);
+  }
+});
+
diff --git a/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-1.html b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-1.html
new file mode 100644
index 0000000000..c5c58f9d12
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-1.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<meta charset="utf-8">
+<meta name=timeout content=long>
+<title>NodeList (static collection) "length" getter tampered</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="support/NodeList-static-length-tampered.js"></script>
+<script>
+test(() => {
+    const nodeList = makeStaticNodeList(100);
+
+    for (var i = 0; i < 50; i++) {
+        if (i === 25)
+            Object.defineProperty(nodeList, "length", { get() { return 10; } });
+
+        assert_equals(indexOfNodeList(nodeList), i >= 25 ? -1 : 50);
+    }
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-2.html b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-2.html
new file mode 100644
index 0000000000..bac0511202
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-2.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<meta charset="utf-8">
+<meta name=timeout content=long>
+<title>NodeList (static collection) "length" getter tampered</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="support/NodeList-static-length-tampered.js"></script>
+<script>
+test(() => {
+    const nodeList = makeStaticNodeList(100);
+
+    for (var i = 0; i < 50; i++) {
+        if (i === 25)
+            Object.setPrototypeOf(nodeList, { get length() { return 10; } });
+
+        assert_equals(indexOfNodeList(nodeList), i >= 25 ? -1 : 50);
+    }
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-3.html b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-3.html
new file mode 100644
index 0000000000..9690aab3c1
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-3.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<meta charset="utf-8">
+<meta name=timeout content=long>
+<title>NodeList (static collection) "length" getter tampered</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="support/NodeList-static-length-tampered.js"></script>
+<script>
+test(() => {
+    const nodeList = makeStaticNodeList(100);
+
+    for (var i = 0; i < 50; i++) {
+        if (i === 25)
+            Object.defineProperty(NodeList.prototype, "length", { get() { return 10; } });
+
+        assert_equals(indexOfNodeList(nodeList), i >= 25 ? -1 : 50);
+    }
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-1.html b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-1.html
new file mode 100644
index 0000000000..5ce4146757
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-1.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<meta charset="utf-8">
+<meta name=timeout content=long>
+<title>NodeList (static collection) "length" getter tampered (Array.prototype.indexOf)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="support/NodeList-static-length-tampered.js"></script>
+<script>
+test(() => {
+    const nodeList = makeStaticNodeList(100);
+
+    for (var i = 0; i < 50; i++) {
+        if (i === 25)
+            Object.defineProperty(nodeList, "length", { get() { return 10; } });
+
+        assert_equals(arrayIndexOfNodeList(nodeList), i >= 25 ? -1 : 50);
+    }
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-2.html b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-2.html
new file mode 100644
index 0000000000..57814ed5ac
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-2.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<meta charset="utf-8">
+<meta name=timeout content=long>
+<title>NodeList (static collection) "length" getter tampered (Array.prototype.indexOf)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="support/NodeList-static-length-tampered.js"></script>
+<script>
+test(() => {
+    const nodeList = makeStaticNodeList(100);
+
+    for (var i = 0; i < 50; i++) {
+        if (i === 25)
+            Object.setPrototypeOf(nodeList, { get length() { return 10; } });
+
+        assert_equals(arrayIndexOfNodeList(nodeList), i >= 25 ? -1 : 50);
+    }
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-3.html b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-3.html
new file mode 100644
index 0000000000..838f376dd2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/NodeList-static-length-getter-tampered-indexOf-3.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<meta charset="utf-8">
+<meta name=timeout content=long>
+<title>NodeList (static collection) "length" getter tampered (Array.prototype.indexOf)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script src="support/NodeList-static-length-tampered.js"></script>
+<script>
+test(() => {
+    const nodeList = makeStaticNodeList(100);
+
+    for (var i = 0; i < 50; i++) {
+        if (i === 25)
+            Object.defineProperty(NodeList.prototype, "length", { get() { return 10; } });
+
+        assert_equals(arrayIndexOfNodeList(nodeList), i >= 25 ? -1 : 50);
+    }
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-append.html b/testing/web-platform/tests/dom/nodes/ParentNode-append.html
new file mode 100644
index 0000000000..4e101f73a2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-append.html
@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>ParentNode.append</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-parentnode-append">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="pre-insertion-validation-hierarchy.js"></script>
+<script>
+preInsertionValidateHierarchy("append");
+
+function test_append(node, nodeName) {
+    test(function() {
+        const parent = node.cloneNode();
+        parent.append();
+        assert_array_equals(parent.childNodes, []);
+    }, nodeName + '.append() without any argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        parent.append(null);
+        assert_equals(parent.childNodes[0].textContent, 'null');
+    }, nodeName + '.append() with null as an argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        parent.append(undefined);
+        assert_equals(parent.childNodes[0].textContent, 'undefined');
+    }, nodeName + '.append() with undefined as an argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        parent.append('text');
+        assert_equals(parent.childNodes[0].textContent, 'text');
+    }, nodeName + '.append() with only text as an argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        const x = document.createElement('x');
+        parent.append(x);
+        assert_array_equals(parent.childNodes, [x]);
+    }, nodeName + '.append() with only one element as an argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        const child = document.createElement('test');
+        parent.appendChild(child);
+        parent.append(null);
+        assert_equals(parent.childNodes[0], child);
+        assert_equals(parent.childNodes[1].textContent, 'null');
+    }, nodeName + '.append() with null as an argument, on a parent having a child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        const x = document.createElement('x');
+        const child = document.createElement('test');
+        parent.appendChild(child);
+        parent.append(x, 'text');
+        assert_equals(parent.childNodes[0], child);
+        assert_equals(parent.childNodes[1], x);
+        assert_equals(parent.childNodes[2].textContent, 'text');
+    }, nodeName + '.append() with one element and text as argument, on a parent having a child.');
+}
+
+test_append(document.createElement('div'), 'Element');
+test_append(document.createDocumentFragment(), 'DocumentFragment');
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-children.html b/testing/web-platform/tests/dom/nodes/ParentNode-children.html
new file mode 100644
index 0000000000..6621e7d9de
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-children.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>ParentNode.children</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-parentnode-children">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div style="display: none">
+  <ul><li id='test'>1</li><li>2</li><li>3</li><li>4</li></ul>
+</div>
+<script>
+test(() => {
+  var node = document.getElementById("test");
+  var parentNode = node.parentNode;
+  var children = parentNode.children;
+  assert_true(children instanceof HTMLCollection);
+  var li = document.createElement("li");
+  assert_equals(children.length, 4);
+
+  parentNode.appendChild(li);
+  assert_equals(children.length, 5);
+
+  parentNode.removeChild(li);
+  assert_equals(children.length, 4);
+}, "ParentNode.children should be a live collection");
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-prepend.html b/testing/web-platform/tests/dom/nodes/ParentNode-prepend.html
new file mode 100644
index 0000000000..f6aa38a2dd
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-prepend.html
@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>ParentNode.prepend</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-parentnode-prepend">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="pre-insertion-validation-hierarchy.js"></script>
+<script>
+preInsertionValidateHierarchy("prepend");
+
+function test_prepend(node, nodeName) {
+    test(function() {
+        const parent = node.cloneNode();
+        parent.prepend();
+        assert_array_equals(parent.childNodes, []);
+    }, nodeName + '.prepend() without any argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        parent.prepend(null);
+        assert_equals(parent.childNodes[0].textContent, 'null');
+    }, nodeName + '.prepend() with null as an argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        parent.prepend(undefined);
+        assert_equals(parent.childNodes[0].textContent, 'undefined');
+    }, nodeName + '.prepend() with undefined as an argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        parent.prepend('text');
+        assert_equals(parent.childNodes[0].textContent, 'text');
+    }, nodeName + '.prepend() with only text as an argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        const x = document.createElement('x');
+        parent.prepend(x);
+        assert_array_equals(parent.childNodes, [x]);
+    }, nodeName + '.prepend() with only one element as an argument, on a parent having no child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        const child = document.createElement('test');
+        parent.appendChild(child);
+        parent.prepend(null);
+        assert_equals(parent.childNodes[0].textContent, 'null');
+        assert_equals(parent.childNodes[1], child);
+    }, nodeName + '.prepend() with null as an argument, on a parent having a child.');
+
+    test(function() {
+        const parent = node.cloneNode();
+        const x = document.createElement('x');
+        const child = document.createElement('test');
+        parent.appendChild(child);
+        parent.prepend(x, 'text');
+        assert_equals(parent.childNodes[0], x);
+        assert_equals(parent.childNodes[1].textContent, 'text');
+        assert_equals(parent.childNodes[2], child);
+    }, nodeName + '.prepend() with one element and text as argument, on a parent having a child.');
+}
+
+test_prepend(document.createElement('div'), 'Element');
+test_prepend(document.createDocumentFragment(), 'DocumentFragment');
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-content.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-content.html
new file mode 100644
index 0000000000..8dc1354551
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-content.html
@@ -0,0 +1,377 @@
+<!DOCTYPE html>
+<html id="html" lang="en">
+<head id="head">
+  <meta id="meta" charset="UTF-8">
+  <title id="title">Selectors-API Test Suite: HTML with Selectors Level 2 using TestHarness: Test Document</title>
+
+  <!-- Links for :link and :visited pseudo-class test -->
+  <link id="pseudo-link-link1" href="">
+  <link id="pseudo-link-link2" href="http://example.org/">
+  <link id="pseudo-link-link3">
+  <style>
+  @namespace ns "http://www.w3.org/1999/xhtml";
+   /* Declare the namespace prefix used in tests. This declaration should not be used by the API. */
+  </style>
+</head>
+<body id="body">
+<div id="root">
+  <div id="target"></div>
+
+  <div id="universal">
+    <p id="universal-p1">Universal selector tests inside element with <code id="universal-code1">id="universal"</code>.</p>
+    <hr id="universal-hr1">
+    <pre id="universal-pre1">Some preformatted text with some <span id="universal-span1">embedded code</span></pre>
+    <p id="universal-p2">This is a normal link: <a id="universal-a1" href="http://www.w3.org/">W3C</a></p>
+    <address id="universal-address1">Some more nested elements <code id="universal-code2"><a href="#" id="universal-a2">code hyperlink</a></code></address>
+  </div>
+
+  <div id="attr-presence">
+    <div class="attr-presence-div1" id="attr-presence-div1" align="center"></div>
+    <div class="attr-presence-div2" id="attr-presence-div2" align=""></div>
+    <div class="attr-presence-div3" id="attr-presence-div3" valign="center"></div>
+    <div class="attr-presence-div4" id="attr-presence-div4" alignv="center"></div>
+    <p id="attr-presence-p1"><a  id="attr-presence-a1" tItLe=""></a><span id="attr-presence-span1" TITLE="attr-presence-span1"></span><i id="attr-presence-i1"></i></p>
+    <pre id="attr-presence-pre1" data-attr-presence="pre1"></pre>
+    <blockquote id="attr-presence-blockquote1" data-attr-presence="blockquote1"></blockquote>
+    <ul id="attr-presence-ul1" data-中文=""></ul>
+
+    <select id="attr-presence-select1">
+      <option id="attr-presence-select1-option1">A</option>
+      <option id="attr-presence-select1-option2">B</option>
+      <option id="attr-presence-select1-option3">C</option>
+      <option id="attr-presence-select1-option4">D</option>
+    </select>
+    <select id="attr-presence-select2">
+      <option id="attr-presence-select2-option1">A</option>
+      <option id="attr-presence-select2-option2">B</option>
+      <option id="attr-presence-select2-option3">C</option>
+      <option id="attr-presence-select2-option4" selected="selected">D</option>
+    </select>
+    <select id="attr-presence-select3" multiple="multiple">
+      <option id="attr-presence-select3-option1">A</option>
+      <option id="attr-presence-select3-option2" selected="">B</option>
+      <option id="attr-presence-select3-option3" selected="selected">C</option>
+      <option id="attr-presence-select3-option4">D</option>
+    </select>
+  </div>
+
+  <div id="attr-value">
+    <div id="attr-value-div1" align="center"></div>
+      <div id="attr-value-div2" align=""></div>
+      <div id="attr-value-div3" data-attr-value="&#xE9;"></div>
+      <div id="attr-value-div4" data-attr-value_foo="&#xE9;"></div>
+
+    <form id="attr-value-form1">
+      <input id="attr-value-input1" type="text">
+      <input id="attr-value-input2" type="password">
+      <input id="attr-value-input3" type="hidden">
+      <input id="attr-value-input4" type="radio">
+      <input id="attr-value-input5" type="checkbox">
+      <input id="attr-value-input6" type="radio">
+      <input id="attr-value-input7" type="text">
+      <input id="attr-value-input8" type="hidden">
+      <input id="attr-value-input9" type="radio">
+    </form>
+
+    <div id="attr-value-div5" data-attr-value="中文"></div>
+  </div>
+
+  <div id="attr-whitespace">
+    <div id="attr-whitespace-div1" class="foo div1 bar"></div>
+      <div id="attr-whitespace-div2" class=""></div>
+      <div id="attr-whitespace-div3" class="foo div3 bar"></div>
+
+      <div id="attr-whitespace-div4" data-attr-whitespace="foo &#xE9; bar"></div>
+      <div id="attr-whitespace-div5" data-attr-whitespace_foo="&#xE9; foo"></div>
+
+    <a id="attr-whitespace-a1" rel="next bookmark"></a>
+    <a id="attr-whitespace-a2" rel="tag nofollow"></a>
+    <a id="attr-whitespace-a3" rel="tag bookmark"></a>
+    <a id="attr-whitespace-a4" rel="book mark"></a> <!-- Intentional space in "book mark" -->
+    <a id="attr-whitespace-a5" rel="nofollow"></a>
+    <a id="attr-whitespace-a6" rev="bookmark nofollow"></a>
+    <a id="attr-whitespace-a7" rel="prev next tag alternate nofollow author help icon noreferrer prefetch search stylesheet tag"></a>
+
+    <p id="attr-whitespace-p1" title="Chinese 中文 characters"></p>
+  </div>
+
+  <div id="attr-hyphen">
+    <div id="attr-hyphen-div1"></div>
+      <div id="attr-hyphen-div2" lang="fr"></div>
+      <div id="attr-hyphen-div3" lang="en-AU"></div>
+      <div id="attr-hyphen-div4" lang="es"></div>
+  </div>
+
+  <div id="attr-begins">
+    <a id="attr-begins-a1" href="http://www.example.org"></a>
+    <a id="attr-begins-a2" href="http://example.org/"></a>
+    <a id="attr-begins-a3" href="http://www.example.com/"></a>
+
+      <div id="attr-begins-div1" lang="fr"></div>
+      <div id="attr-begins-div2" lang="en-AU"></div>
+      <div id="attr-begins-div3" lang="es"></div>
+      <div id="attr-begins-div4" lang="en-US"></div>
+      <div id="attr-begins-div5" lang="en"></div>
+
+    <p id="attr-begins-p1" class=" apple"></p> <!-- Intentional space in class value " apple". -->
+  </div>
+
+  <div id="attr-ends">
+    <a id="attr-ends-a1" href="http://www.example.org"></a>
+    <a id="attr-ends-a2" href="http://example.org/"></a>
+    <a id="attr-ends-a3" href="http://www.example.org"></a>
+
+      <div id="attr-ends-div1" lang="fr"></div>
+      <div id="attr-ends-div2" lang="de-CH"></div>
+      <div id="attr-ends-div3" lang="es"></div>
+      <div id="attr-ends-div4" lang="fr-CH"></div>
+
+    <p id="attr-ends-p1" class="apple "></p> <!-- Intentional space in class value "apple ". -->
+  </div>
+
+  <div id="attr-contains">
+    <a id="attr-contains-a1" href="http://www.example.org"></a>
+    <a id="attr-contains-a2" href="http://example.org/"></a>
+    <a id="attr-contains-a3" href="http://www.example.com/"></a>
+
+      <div id="attr-contains-div1" lang="fr"></div>
+      <div id="attr-contains-div2" lang="en-AU"></div>
+      <div id="attr-contains-div3" lang="de-CH"></div>
+      <div id="attr-contains-div4" lang="es"></div>
+      <div id="attr-contains-div5" lang="fr-CH"></div>
+      <div id="attr-contains-div6" lang="en-US"></div>
+
+    <p id="attr-contains-p1" class=" apple banana orange "></p>
+  </div>
+
+  <div id="pseudo-nth">
+    <table id="pseudo-nth-table1">
+      <tr id="pseudo-nth-tr1"><td id="pseudo-nth-td1"></td><td id="pseudo-nth-td2"></td><td id="pseudo-nth-td3"></td><td id="pseudo-nth-td4"></td><td id="pseudo-nth--td5"></td><td id="pseudo-nth-td6"></td></tr>
+      <tr id="pseudo-nth-tr2"><td id="pseudo-nth-td7"></td><td id="pseudo-nth-td8"></td><td id="pseudo-nth-td9"></td><td id="pseudo-nth-td10"></td><td id="pseudo-nth-td11"></td><td id="pseudo-nth-td12"></td></tr>
+      <tr id="pseudo-nth-tr3"><td id="pseudo-nth-td13"></td><td id="pseudo-nth-td14"></td><td id="pseudo-nth-td15"></td><td id="pseudo-nth-td16"></td><td id="pseudo-nth-td17"></td><td id="pseudo-nth-td18"></td></tr>
+    </table>
+
+    <ol id="pseudo-nth-ol1">
+      <li id="pseudo-nth-li1"></li>
+      <li id="pseudo-nth-li2"></li>
+      <li id="pseudo-nth-li3"></li>
+      <li id="pseudo-nth-li4"></li>
+      <li id="pseudo-nth-li5"></li>
+      <li id="pseudo-nth-li6"></li>
+      <li id="pseudo-nth-li7"></li>
+      <li id="pseudo-nth-li8"></li>
+      <li id="pseudo-nth-li9"></li>
+      <li id="pseudo-nth-li10"></li>
+      <li id="pseudo-nth-li11"></li>
+      <li id="pseudo-nth-li12"></li>
+    </ol>
+
+    <p id="pseudo-nth-p1">
+      <span id="pseudo-nth-span1">span1</span>
+      <em id="pseudo-nth-em1">em1</em>
+      <!-- comment node-->
+      <em id="pseudo-nth-em2">em2</em>
+      <span id="pseudo-nth-span2">span2</span>
+      <strong id="pseudo-nth-strong1">strong1</strong>
+      <em id="pseudo-nth-em3">em3</em>
+      <span id="pseudo-nth-span3">span3</span>
+      <span id="pseudo-nth-span4">span4</span>
+      <strong id="pseudo-nth-strong2">strong2</strong>
+      <em id="pseudo-nth-em4">em4</em>
+    </p>
+  </div>
+
+  <div id="pseudo-first-child">
+    <div id="pseudo-first-child-div1"></div>
+    <div id="pseudo-first-child-div2"></div>
+    <div id="pseudo-first-child-div3"></div>
+
+    <p id="pseudo-first-child-p1"><span id="pseudo-first-child-span1"></span><span id="pseudo-first-child-span2"></span></p>
+    <p id="pseudo-first-child-p2"><span id="pseudo-first-child-span3"></span><span id="pseudo-first-child-span4"></span></p>
+    <p id="pseudo-first-child-p3"><span id="pseudo-first-child-span5"></span><span id="pseudo-first-child-span6"></span></p>
+  </div>
+
+  <div id="pseudo-last-child">
+    <p id="pseudo-last-child-p1"><span id="pseudo-last-child-span1"></span><span id="pseudo-last-child-span2"></span></p>
+    <p id="pseudo-last-child-p2"><span id="pseudo-last-child-span3"></span><span id="pseudo-last-child-span4"></span></p>
+    <p id="pseudo-last-child-p3"><span id="pseudo-last-child-span5"></span><span id="pseudo-last-child-span6"></span></p>
+
+    <div id="pseudo-last-child-div1"></div>
+    <div id="pseudo-last-child-div2"></div>
+    <div id="pseudo-last-child-div3"></div>
+  </div>
+
+  <div id="pseudo-only">
+    <p id="pseudo-only-p1">
+      <span id="pseudo-only-span1"></span>
+    </p>
+    <p id="pseudo-only-p2">
+      <span id="pseudo-only-span2"></span>
+      <span id="pseudo-only-span3"></span>
+    </p>
+    <p id="pseudo-only-p3">
+      <span id="pseudo-only-span4"></span>
+      <em id="pseudo-only-em1"></em>
+      <span id="pseudo-only-span5"></span>
+    </p>
+  </div>>
+
+  <div id="pseudo-empty">
+    <p id="pseudo-empty-p1"></p>
+    <p id="pseudo-empty-p2"><!-- comment node --></p>
+    <p id="pseudo-empty-p3"> </p>
+    <p id="pseudo-empty-p4">Text node</p>
+    <p id="pseudo-empty-p5"><span id="pseudo-empty-span1"></span></p>
+  </div>
+
+  <div id="pseudo-link">
+    <a id="pseudo-link-a1" href="">with href</a>
+    <a id="pseudo-link-a2" href="http://example.org/">with href</a>
+    <a id="pseudo-link-a3">without href</a>
+    <map name="pseudo-link-map1" id="pseudo-link-map1">
+      <area id="pseudo-link-area1" href="">
+      <area id="pseudo-link-area2">
+    </map>
+  </div>
+
+  <div id="pseudo-lang">
+    <div id="pseudo-lang-div1"></div>
+      <div id="pseudo-lang-div2" lang="fr"></div>
+      <div id="pseudo-lang-div3" lang="en-AU"></div>
+      <div id="pseudo-lang-div4" lang="es"></div>
+  </div>
+
+  <div id="pseudo-ui">
+    <input id="pseudo-ui-input1" type="text">
+    <input id="pseudo-ui-input2" type="password">
+    <input id="pseudo-ui-input3" type="radio">
+    <input id="pseudo-ui-input4" type="radio" checked="checked">
+    <input id="pseudo-ui-input5" type="checkbox">
+    <input id="pseudo-ui-input6" type="checkbox" checked="checked">
+    <input id="pseudo-ui-input7" type="submit">
+    <input id="pseudo-ui-input8" type="button">
+    <input id="pseudo-ui-input9" type="hidden">
+    <textarea id="pseudo-ui-textarea1"></textarea>
+    <button id="pseudo-ui-button1">Enabled</button>
+
+    <input id="pseudo-ui-input10" disabled="disabled" type="text">
+    <input id="pseudo-ui-input11" disabled="disabled" type="password">
+    <input id="pseudo-ui-input12" disabled="disabled" type="radio">
+    <input id="pseudo-ui-input13" disabled="disabled" type="radio" checked="checked">
+    <input id="pseudo-ui-input14" disabled="disabled" type="checkbox">
+    <input id="pseudo-ui-input15" disabled="disabled" type="checkbox" checked="checked">
+    <input id="pseudo-ui-input16" disabled="disabled" type="submit">
+    <input id="pseudo-ui-input17" disabled="disabled" type="button">
+    <input id="pseudo-ui-input18" disabled="disabled" type="hidden">
+    <textarea id="pseudo-ui-textarea2" disabled="disabled"></textarea>
+    <button id="pseudo-ui-button2" disabled="disabled">Disabled</button>
+  </div>
+
+  <div id="not">
+    <div id="not-div1"></div>
+    <div id="not-div2"></div>
+    <div id="not-div3"></div>
+
+    <p id="not-p1"><span id="not-span1"></span><em id="not-em1"></em></p>
+    <p id="not-p2"><span id="not-span2"></span><em id="not-em2"></em></p>
+    <p id="not-p3"><span id="not-span3"></span><em id="not-em3"></em></p>
+  </div>
+
+  <div id="pseudo-element">All pseudo-element tests</div>
+
+  <div id="class">
+    <p id="class-p1" class="foo class-p bar"></p>
+    <p id="class-p2" class="class-p foo bar"></p>
+    <p id="class-p3" class="foo bar class-p"></p>
+
+    <!-- All permutations of the classes should match -->
+    <div id="class-div1" class="apple orange banana"></div>
+    <div id="class-div2" class="apple banana orange"></div>
+    <p id="class-p4" class="orange apple banana"></p>
+    <div id="class-div3" class="orange banana apple"></div>
+    <p id="class-p6" class="banana apple orange"></p>
+    <div id="class-div4" class="banana orange apple"></div>
+    <div id="class-div5" class="apple orange"></div>
+    <div id="class-div6" class="apple banana"></div>
+    <div id="class-div7" class="orange banana"></div>
+
+    <span id="class-span1" class="台北Táiběi 台北"></span>
+    <span id="class-span2" class="台北"></span>
+
+    <span id="class-span3" class="foo:bar"></span>
+    <span id="class-span4" class="test.foo[5]bar"></span>
+  </div>
+
+  <div id="id">
+    <div id="id-div1"></div>
+    <div id="id-div2"></div>
+
+    <ul id="id-ul1">
+      <li id="id-li-duplicate"></li>
+      <li id="id-li-duplicate"></li>
+      <li id="id-li-duplicate"></li>
+      <li id="id-li-duplicate"></li>
+    </ul>
+
+    <span id="台北Táiběi"></span>
+    <span id="台北"></span>
+
+    <span id="#foo:bar"></span>
+    <span id="test.foo[5]bar"></span>
+  </div>
+
+  <div id="descendant">
+    <div id="descendant-div1" class="descendant-div1">
+      <div id="descendant-div2" class="descendant-div2">
+        <div id="descendant-div3" class="descendant-div3">
+        </div>
+      </div>
+    </div>
+    <div id="descendant-div4" class="descendant-div4"></div>
+  </div>
+
+  <div id="child">
+    <div id="child-div1" class="child-div1">
+      <div id="child-div2" class="child-div2">
+        <div id="child-div3" class="child-div3">
+        </div>
+      </div>
+    </div>
+    <div id="child-div4" class="child-div4"></div>
+  </div>
+
+  <div id="adjacent">
+    <div id="adjacent-div1" class="adjacent-div1"></div>
+    <div id="adjacent-div2" class="adjacent-div2">
+      <div id="adjacent-div3" class="adjacent-div3"></div>
+    </div>
+    <div id="adjacent-div4" class="adjacent-div4">
+      <p id="adjacent-p1" class="adjacent-p1"></p>
+      <div id="adjacent-div5" class="adjacent-div5"></div>
+    </div>
+    <div id="adjacent-div6" class="adjacent-div6"></div>
+    <p id="adjacent-p2" class="adjacent-p2"></p>
+    <p id="adjacent-p3" class="adjacent-p3"></p>
+  </div>
+
+  <div id="sibling">
+    <div id="sibling-div1" class="sibling-div"></div>
+    <div id="sibling-div2" class="sibling-div">
+      <div id="sibling-div3" class="sibling-div"></div>
+    </div>
+    <div id="sibling-div4" class="sibling-div">
+      <p id="sibling-p1" class="sibling-p"></p>
+      <div id="sibling-div5" class="sibling-div"></div>
+    </div>
+    <div id="sibling-div6" class="sibling-div"></div>
+    <p id="sibling-p2" class="sibling-p"></p>
+    <p id="sibling-p3" class="sibling-p"></p>
+  </div>
+
+  <div id="group">
+    <em id="group-em1"></em>
+    <strong id="group-strong1"></strong>
+  </div>
+</div>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-content.xht b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-content.xht
new file mode 100644
index 0000000000..0e9b925f58
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-content.xht
@@ -0,0 +1,372 @@
+<!DOCTYPE html>
+<html id="html" lang="en" xmlns="http://www.w3.org/1999/xhtml">
+<head id="head">
+  <title id="title">Selectors-API Test Suite: HTML with Selectors Level 2 using TestHarness: Test Document</title>
+
+  <!-- Links for :link and :visited pseudo-class test -->
+  <link id="pseudo-link-link1" href=""/>
+  <link id="pseudo-link-link2" href="http://example.org/"/>
+  <link id="pseudo-link-link3"/>
+</head>
+<body id="body">
+<div id="root">
+  <div id="target"></div>
+
+  <div id="universal">
+    <p id="universal-p1">Universal selector tests inside element with <code id="universal-code1">id="universal"</code>.</p>
+    <hr id="universal-hr1"/>
+    <pre id="universal-pre1">Some preformatted text with some <span id="universal-span1">embedded code</span></pre>
+    <p id="universal-p2">This is a normal link: <a id="universal-a1" href="http://www.w3.org/">W3C</a></p>
+    <address id="universal-address1">Some more nested elements <code id="universal-code2"><a href="#" id="universal-a2">code hyperlink</a></code></address>
+  </div>
+
+  <div id="attr-presence">
+    <div class="attr-presence-div1" id="attr-presence-div1" align="center"></div>
+    <div class="attr-presence-div2" id="attr-presence-div2" align=""></div>
+    <div class="attr-presence-div3" id="attr-presence-div3" valign="center"></div>
+    <div class="attr-presence-div4" id="attr-presence-div4" alignv="center"></div>
+    <p id="attr-presence-p1"><a  id="attr-presence-a1" tItLe=""></a><span id="attr-presence-span1" TITLE="attr-presence-span1"></span><i id="attr-presence-i1"></i></p>
+    <pre id="attr-presence-pre1" data-attr-presence="pre1"></pre>
+    <blockquote id="attr-presence-blockquote1" data-attr-presence="blockquote1"></blockquote>
+    <ul id="attr-presence-ul1" data-中文=""></ul>
+
+    <select id="attr-presence-select1">
+      <option id="attr-presence-select1-option1">A</option>
+      <option id="attr-presence-select1-option2">B</option>
+      <option id="attr-presence-select1-option3">C</option>
+      <option id="attr-presence-select1-option4">D</option>
+    </select>
+    <select id="attr-presence-select2">
+      <option id="attr-presence-select2-option1">A</option>
+      <option id="attr-presence-select2-option2">B</option>
+      <option id="attr-presence-select2-option3">C</option>
+      <option id="attr-presence-select2-option4" selected="selected">D</option>
+    </select>
+    <select id="attr-presence-select3" multiple="multiple">
+      <option id="attr-presence-select3-option1">A</option>
+      <option id="attr-presence-select3-option2" selected="">B</option>
+      <option id="attr-presence-select3-option3" selected="selected">C</option>
+      <option id="attr-presence-select3-option4">D</option>
+    </select>
+  </div>
+
+  <div id="attr-value">
+    <div id="attr-value-div1" align="center"></div>
+      <div id="attr-value-div2" align=""></div>
+      <div id="attr-value-div3" data-attr-value="&#xE9;"></div>
+      <div id="attr-value-div4" data-attr-value_foo="&#xE9;"></div>
+
+    <form id="attr-value-form1">
+      <input id="attr-value-input1" type="text"/>
+      <input id="attr-value-input2" type="password"/>
+      <input id="attr-value-input3" type="hidden"/>
+      <input id="attr-value-input4" type="radio"/>
+      <input id="attr-value-input5" type="checkbox"/>
+      <input id="attr-value-input6" type="radio"/>
+      <input id="attr-value-input7" type="text"/>
+      <input id="attr-value-input8" type="hidden"/>
+      <input id="attr-value-input9" type="radio"/>
+    </form>
+
+    <div id="attr-value-div5" data-attr-value="中文"></div>
+  </div>
+
+  <div id="attr-whitespace">
+    <div id="attr-whitespace-div1" class="foo div1 bar"></div>
+      <div id="attr-whitespace-div2" class=""></div>
+      <div id="attr-whitespace-div3" class="foo div3 bar"></div>
+
+      <div id="attr-whitespace-div4" data-attr-whitespace="foo &#xE9; bar"></div>
+      <div id="attr-whitespace-div5" data-attr-whitespace_foo="&#xE9; foo"></div>
+
+    <a id="attr-whitespace-a1" rel="next bookmark"></a>
+    <a id="attr-whitespace-a2" rel="tag nofollow"></a>
+    <a id="attr-whitespace-a3" rel="tag bookmark"></a>
+    <a id="attr-whitespace-a4" rel="book mark"></a> <!-- Intentional space in "book mark" -->
+    <a id="attr-whitespace-a5" rel="nofollow"></a>
+    <a id="attr-whitespace-a6" rev="bookmark nofollow"></a>
+    <a id="attr-whitespace-a7" rel="prev next tag alternate nofollow author help icon noreferrer prefetch search stylesheet tag"></a>
+
+    <p id="attr-whitespace-p1" title="Chinese 中文 characters"></p>
+  </div>
+
+  <div id="attr-hyphen">
+    <div id="attr-hyphen-div1"></div>
+      <div id="attr-hyphen-div2" lang="fr"></div>
+      <div id="attr-hyphen-div3" lang="en-AU"></div>
+      <div id="attr-hyphen-div4" lang="es"></div>
+  </div>
+
+  <div id="attr-begins">
+    <a id="attr-begins-a1" href="http://www.example.org"></a>
+    <a id="attr-begins-a2" href="http://example.org/"></a>
+    <a id="attr-begins-a3" href="http://www.example.com/"></a>
+
+      <div id="attr-begins-div1" lang="fr"></div>
+      <div id="attr-begins-div2" lang="en-AU"></div>
+      <div id="attr-begins-div3" lang="es"></div>
+      <div id="attr-begins-div4" lang="en-US"></div>
+      <div id="attr-begins-div5" lang="en"></div>
+
+    <p id="attr-begins-p1" class=" apple"></p> <!-- Intentional space in class value " apple". -->
+  </div>
+
+  <div id="attr-ends">
+    <a id="attr-ends-a1" href="http://www.example.org"></a>
+    <a id="attr-ends-a2" href="http://example.org/"></a>
+    <a id="attr-ends-a3" href="http://www.example.org"></a>
+
+      <div id="attr-ends-div1" lang="fr"></div>
+      <div id="attr-ends-div2" lang="de-CH"></div>
+      <div id="attr-ends-div3" lang="es"></div>
+      <div id="attr-ends-div4" lang="fr-CH"></div>
+
+    <p id="attr-ends-p1" class="apple "></p> <!-- Intentional space in class value "apple ". -->
+  </div>
+
+  <div id="attr-contains">
+    <a id="attr-contains-a1" href="http://www.example.org"></a>
+    <a id="attr-contains-a2" href="http://example.org/"></a>
+    <a id="attr-contains-a3" href="http://www.example.com/"></a>
+
+      <div id="attr-contains-div1" lang="fr"></div>
+      <div id="attr-contains-div2" lang="en-AU"></div>
+      <div id="attr-contains-div3" lang="de-CH"></div>
+      <div id="attr-contains-div4" lang="es"></div>
+      <div id="attr-contains-div5" lang="fr-CH"></div>
+      <div id="attr-contains-div6" lang="en-US"></div>
+
+    <p id="attr-contains-p1" class=" apple banana orange "></p>
+  </div>
+
+  <div id="pseudo-nth">
+    <table id="pseudo-nth-table1">
+      <tr id="pseudo-nth-tr1"><td id="pseudo-nth-td1"></td><td id="pseudo-nth-td2"></td><td id="pseudo-nth-td3"></td><td id="pseudo-nth-td4"></td><td id="pseudo-nth--td5"></td><td id="pseudo-nth-td6"></td></tr>
+      <tr id="pseudo-nth-tr2"><td id="pseudo-nth-td7"></td><td id="pseudo-nth-td8"></td><td id="pseudo-nth-td9"></td><td id="pseudo-nth-td10"></td><td id="pseudo-nth-td11"></td><td id="pseudo-nth-td12"></td></tr>
+      <tr id="pseudo-nth-tr3"><td id="pseudo-nth-td13"></td><td id="pseudo-nth-td14"></td><td id="pseudo-nth-td15"></td><td id="pseudo-nth-td16"></td><td id="pseudo-nth-td17"></td><td id="pseudo-nth-td18"></td></tr>
+    </table>
+
+    <ol id="pseudo-nth-ol1">
+      <li id="pseudo-nth-li1"></li>
+      <li id="pseudo-nth-li2"></li>
+      <li id="pseudo-nth-li3"></li>
+      <li id="pseudo-nth-li4"></li>
+      <li id="pseudo-nth-li5"></li>
+      <li id="pseudo-nth-li6"></li>
+      <li id="pseudo-nth-li7"></li>
+      <li id="pseudo-nth-li8"></li>
+      <li id="pseudo-nth-li9"></li>
+      <li id="pseudo-nth-li10"></li>
+      <li id="pseudo-nth-li11"></li>
+      <li id="pseudo-nth-li12"></li>
+    </ol>
+
+    <p id="pseudo-nth-p1">
+      <span id="pseudo-nth-span1">span1</span>
+      <em id="pseudo-nth-em1">em1</em>
+      <!-- comment node-->
+      <em id="pseudo-nth-em2">em2</em>
+      <span id="pseudo-nth-span2">span2</span>
+      <strong id="pseudo-nth-strong1">strong1</strong>
+      <em id="pseudo-nth-em3">em3</em>
+      <span id="pseudo-nth-span3">span3</span>
+      <span id="pseudo-nth-span4">span4</span>
+      <strong id="pseudo-nth-strong2">strong2</strong>
+      <em id="pseudo-nth-em4">em4</em>
+    </p>
+  </div>
+
+  <div id="pseudo-first-child">
+    <div id="pseudo-first-child-div1"></div>
+    <div id="pseudo-first-child-div2"></div>
+    <div id="pseudo-first-child-div3"></div>
+
+    <p id="pseudo-first-child-p1"><span id="pseudo-first-child-span1"></span><span id="pseudo-first-child-span2"></span></p>
+    <p id="pseudo-first-child-p2"><span id="pseudo-first-child-span3"></span><span id="pseudo-first-child-span4"></span></p>
+    <p id="pseudo-first-child-p3"><span id="pseudo-first-child-span5"></span><span id="pseudo-first-child-span6"></span></p>
+  </div>
+
+  <div id="pseudo-last-child">
+    <p id="pseudo-last-child-p1"><span id="pseudo-last-child-span1"></span><span id="pseudo-last-child-span2"></span></p>
+    <p id="pseudo-last-child-p2"><span id="pseudo-last-child-span3"></span><span id="pseudo-last-child-span4"></span></p>
+    <p id="pseudo-last-child-p3"><span id="pseudo-last-child-span5"></span><span id="pseudo-last-child-span6"></span></p>
+
+    <div id="pseudo-last-child-div1"></div>
+    <div id="pseudo-last-child-div2"></div>
+    <div id="pseudo-last-child-div3"></div>
+  </div>
+
+  <div id="pseudo-only">
+    <p id="pseudo-only-p1">
+      <span id="pseudo-only-span1"></span>
+    </p>
+    <p id="pseudo-only-p2">
+      <span id="pseudo-only-span2"></span>
+      <span id="pseudo-only-span3"></span>
+    </p>
+    <p id="pseudo-only-p3">
+      <span id="pseudo-only-span4"></span>
+      <em id="pseudo-only-em1"></em>
+      <span id="pseudo-only-span5"></span>
+    </p>
+  </div>>
+
+  <div id="pseudo-empty">
+    <p id="pseudo-empty-p1"></p>
+    <p id="pseudo-empty-p2"><!-- comment node --></p>
+    <p id="pseudo-empty-p3"> </p>
+    <p id="pseudo-empty-p4">Text node</p>
+    <p id="pseudo-empty-p5"><span id="pseudo-empty-span1"></span></p>
+  </div>
+
+  <div id="pseudo-link">
+    <a id="pseudo-link-a1" href="">with href</a>
+    <a id="pseudo-link-a2" href="http://example.org/">with href</a>
+    <a id="pseudo-link-a3">without href</a>
+    <map name="pseudo-link-map1" id="pseudo-link-map1">
+      <area id="pseudo-link-area1" href=""/>
+      <area id="pseudo-link-area2"/>
+    </map>
+  </div>
+
+  <div id="pseudo-lang">
+    <div id="pseudo-lang-div1"></div>
+      <div id="pseudo-lang-div2" lang="fr"></div>
+      <div id="pseudo-lang-div3" lang="en-AU"></div>
+      <div id="pseudo-lang-div4" lang="es"></div>
+  </div>
+
+  <div id="pseudo-ui">
+    <input id="pseudo-ui-input1" type="text"/>
+    <input id="pseudo-ui-input2" type="password"/>
+    <input id="pseudo-ui-input3" type="radio"/>
+    <input id="pseudo-ui-input4" type="radio" checked="checked"/>
+    <input id="pseudo-ui-input5" type="checkbox"/>
+    <input id="pseudo-ui-input6" type="checkbox" checked="checked"/>
+    <input id="pseudo-ui-input7" type="submit"/>
+    <input id="pseudo-ui-input8" type="button"/>
+    <input id="pseudo-ui-input9" type="hidden"/>
+    <textarea id="pseudo-ui-textarea1"></textarea>
+    <button id="pseudo-ui-button1">Enabled</button>
+
+    <input id="pseudo-ui-input10" disabled="disabled" type="text"/>
+    <input id="pseudo-ui-input11" disabled="disabled" type="password"/>
+    <input id="pseudo-ui-input12" disabled="disabled" type="radio"/>
+    <input id="pseudo-ui-input13" disabled="disabled" type="radio" checked="checked"/>
+    <input id="pseudo-ui-input14" disabled="disabled" type="checkbox"/>
+    <input id="pseudo-ui-input15" disabled="disabled" type="checkbox" checked="checked"/>
+    <input id="pseudo-ui-input16" disabled="disabled" type="submit"/>
+    <input id="pseudo-ui-input17" disabled="disabled" type="button"/>
+    <input id="pseudo-ui-input18" disabled="disabled" type="hidden"/>
+    <textarea id="pseudo-ui-textarea2" disabled="disabled"></textarea>
+    <button id="pseudo-ui-button2" disabled="disabled">Disabled</button>
+  </div>
+
+  <div id="not">
+    <div id="not-div1"></div>
+    <div id="not-div2"></div>
+    <div id="not-div3"></div>
+
+    <p id="not-p1"><span id="not-span1"></span><em id="not-em1"></em></p>
+    <p id="not-p2"><span id="not-span2"></span><em id="not-em2"></em></p>
+    <p id="not-p3"><span id="not-span3"></span><em id="not-em3"></em></p>
+  </div>
+
+  <div id="pseudo-element">All pseudo-element tests</div>
+
+  <div id="class">
+    <p id="class-p1" class="foo class-p bar"></p>
+    <p id="class-p2" class="class-p foo bar"></p>
+    <p id="class-p3" class="foo bar class-p"></p>
+
+    <!-- All permutations of the classes should match -->
+    <div id="class-div1" class="apple orange banana"></div>
+    <div id="class-div2" class="apple banana orange"></div>
+    <p id="class-p4" class="orange apple banana"></p>
+    <div id="class-div3" class="orange banana apple"></div>
+    <p id="class-p6" class="banana apple orange"></p>
+    <div id="class-div4" class="banana orange apple"></div>
+    <div id="class-div5" class="apple orange"></div>
+    <div id="class-div6" class="apple banana"></div>
+    <div id="class-div7" class="orange banana"></div>
+
+    <span id="class-span1" class="台北Táiběi 台北"></span>
+    <span id="class-span2" class="台北"></span>
+
+    <span id="class-span3" class="foo:bar"></span>
+    <span id="class-span4" class="test.foo[5]bar"></span>
+  </div>
+
+  <div id="id">
+    <div id="id-div1"></div>
+    <div id="id-div2"></div>
+
+    <ul id="id-ul1">
+      <li id="id-li-duplicate"></li>
+      <li id="id-li-duplicate"></li>
+      <li id="id-li-duplicate"></li>
+      <li id="id-li-duplicate"></li>
+    </ul>
+
+    <span id="台北Táiběi"></span>
+    <span id="台北"></span>
+
+    <span id="#foo:bar"></span>
+    <span id="test.foo[5]bar"></span>
+  </div>
+
+  <div id="descendant">
+    <div id="descendant-div1" class="descendant-div1">
+      <div id="descendant-div2" class="descendant-div2">
+        <div id="descendant-div3" class="descendant-div3">
+        </div>
+      </div>
+    </div>
+    <div id="descendant-div4" class="descendant-div4"></div>
+  </div>
+
+  <div id="child">
+    <div id="child-div1" class="child-div1">
+      <div id="child-div2" class="child-div2">
+        <div id="child-div3" class="child-div3">
+        </div>
+      </div>
+    </div>
+    <div id="child-div4" class="child-div4"></div>
+  </div>
+
+  <div id="adjacent">
+    <div id="adjacent-div1" class="adjacent-div1"></div>
+    <div id="adjacent-div2" class="adjacent-div2">
+      <div id="adjacent-div3" class="adjacent-div3"></div>
+    </div>
+    <div id="adjacent-div4" class="adjacent-div4">
+      <p id="adjacent-p1" class="adjacent-p1"></p>
+      <div id="adjacent-div5" class="adjacent-div5"></div>
+    </div>
+    <div id="adjacent-div6" class="adjacent-div6"></div>
+    <p id="adjacent-p2" class="adjacent-p2"></p>
+    <p id="adjacent-p3" class="adjacent-p3"></p>
+  </div>
+
+  <div id="sibling">
+    <div id="sibling-div1" class="sibling-div"></div>
+    <div id="sibling-div2" class="sibling-div">
+      <div id="sibling-div3" class="sibling-div"></div>
+    </div>
+    <div id="sibling-div4" class="sibling-div">
+      <p id="sibling-p1" class="sibling-p"></p>
+      <div id="sibling-div5" class="sibling-div"></div>
+    </div>
+    <div id="sibling-div6" class="sibling-div"></div>
+    <p id="sibling-p2" class="sibling-p"></p>
+    <p id="sibling-p3" class="sibling-p"></p>
+  </div>
+
+  <div id="group">
+    <em id="group-em1"></em>
+    <strong id="group-strong1"></strong>
+  </div>
+</div>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-xht.xht b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-xht.xht
new file mode 100644
index 0000000000..f2d94da1da
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All-xht.xht
@@ -0,0 +1,124 @@
+<!DOCTYPE html>
+<html id="html" lang="en" xmlns="http://www.w3.org/1999/xhtml">
+<head id="head">
+<meta name="timeout" content="long" />
+<title>Selectors-API Test Suite: XHTML</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="selectors.js"></script>
+<script src="ParentNode-querySelector-All.js"></script>
+<style>iframe { visibility: hidden; position: absolute; }</style>
+</head>
+<body>
+<div id="log">This test requires JavaScript.</div>
+
+<script><![CDATA[
+async_test(function() {
+  var frame = document.createElement("iframe");
+  var self = this;
+  frame.onload = function() {
+    // :target doesn't work before a page rendering on some browsers.  We run
+    // tests after an animation frame because it may be later than the first
+    // page rendering.
+    requestAnimationFrame(self.step_func_done(init.bind(self, frame)));
+  };
+  frame.src = "ParentNode-querySelector-All-content.xht#target";
+  document.body.appendChild(frame);
+})
+
+function init(target) {
+  /*
+   * This test suite tests Selectors API methods in 4 different contexts:
+   * 1. Document node
+   * 2. In-document Element node
+   * 3. Detached Element node (an element with no parent, not in the document)
+   * 4. Document Fragment node
+   *
+   * For each context, the following tests are run:
+   *
+   * The interface check tests ensure that each type of node exposes the Selectors API methods
+   *
+   * The special selector tests verify the result of passing special values for the selector parameter,
+   * to ensure that the correct WebIDL processing is performed, such as stringification of null and
+   * undefined and missing parameter. The universal selector is also tested here, rather than with the
+   * rest of ordinary selectors for practical reasons.
+   *
+   * The static list verification tests ensure that the node lists returned by the method remain unchanged
+   * due to subsequent document modication, and that a new list is generated each time the method is
+   * invoked based on the current state of the document.
+   *
+   * The invalid selector tests ensure that SyntaxError is thrown for invalid forms of selectors
+   *
+   * The valid selector tests check the result from querying many different types of selectors, with a
+   * list of expected elements. This checks that querySelector() always returns the first result from
+   * querySelectorAll(), and that all matching elements are correctly returned in tree-order. The tests
+   * can be limited by specifying the test types to run, using the testType variable. The constants for this
+   * can be found in selectors.js.
+   *
+   * All the selectors tested for both the valid and invalid selector tests are found in selectors.js.
+   * See comments in that file for documentation of the format used.
+   *
+   * The ParentNode-querySelector-All.js file contains all the common test functions for running each of the aforementioned tests
+   */
+
+  var testType = TEST_QSA;
+  var docType  = "xhtml"; // Only run tests suitable for XHTML
+
+  // Prepare the nodes for testing
+  var doc = target.contentDocument;                 // Document Node tests
+
+  var element = doc.getElementById("root");   // In-document Element Node tests
+
+  //Setup the namespace tests
+  setupSpecialElements(doc, element);
+
+  var outOfScope = element.cloneNode(true);   // Append this to the body before running the in-document
+                                               // Element tests, but after running the Document tests. This
+                                               // tests that no elements that are not descendants of element
+                                               // are selected.
+
+  traverse(outOfScope, function(elem) {        // Annotate each element as being a clone; used for verifying
+    elem.setAttribute("data-clone", "");     // that none of these elements ever match.
+  });
+
+
+  var detached = element.cloneNode(true);     // Detached Element Node tests
+
+  var fragment = doc.createDocumentFragment(); // Fragment Node tests
+  fragment.appendChild(element.cloneNode(true));
+
+  var empty = document.createElement("div"); // Empty Node tests
+
+  // Setup Tests
+  interfaceCheck("Document", doc);
+  interfaceCheck("Detached Element", detached);
+  interfaceCheck("Fragment", fragment);
+  interfaceCheck("In-document Element", element);
+
+  runSpecialSelectorTests("Document", doc);
+  runSpecialSelectorTests("Detached Element", detached);
+  runSpecialSelectorTests("Fragment", fragment);
+  runSpecialSelectorTests("In-document Element", element);
+
+  verifyStaticList("Document", doc, doc);
+  verifyStaticList("Detached Element", doc, detached);
+  verifyStaticList("Fragment", doc, fragment);
+  verifyStaticList("In-document Element", doc, element);
+
+  runInvalidSelectorTest("Document", doc, invalidSelectors);
+  runInvalidSelectorTest("Detached Element", detached, invalidSelectors);
+  runInvalidSelectorTest("Fragment", fragment, invalidSelectors);
+  runInvalidSelectorTest("In-document Element", element, invalidSelectors);
+  runInvalidSelectorTest("Empty Element", empty, invalidSelectors);
+
+  runValidSelectorTest("Document", doc, validSelectors, testType, docType);
+  runValidSelectorTest("Detached Element", detached, validSelectors, testType, docType);
+  runValidSelectorTest("Fragment", fragment, validSelectors, testType, docType);
+
+  doc.body.appendChild(outOfScope); // Append before in-document Element tests.
+                                    // None of these elements should match
+  runValidSelectorTest("In-document Element", element, validSelectors, testType, docType);
+}
+]]></script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All.html
new file mode 100644
index 0000000000..7d68e7f297
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All.html
@@ -0,0 +1,120 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<meta name=timeout content=long>
+<title>Selectors-API Test Suite: HTML</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="selectors.js"></script>
+<script src="ParentNode-querySelector-All.js"></script>
+<style>iframe { visibility: hidden; position: absolute; }</style>
+
+<div id="log">This test requires JavaScript.</div>
+
+<script>
+async_test(function() {
+  var frame = document.createElement("iframe");
+  var self = this;
+  frame.onload = function() {
+    // :target doesn't work before a page rendering on some browsers.  We run
+    // tests after an animation frame because it may be later than the first
+    // page rendering.
+    requestAnimationFrame(self.step_func_done(init.bind(self, frame)));
+  };
+  frame.src = "ParentNode-querySelector-All-content.html#target";
+  document.body.appendChild(frame);
+});
+
+function init(target) {
+  /*
+   * This test suite tests Selectors API methods in 4 different contexts:
+   * 1. Document node
+   * 2. In-document Element node
+   * 3. Detached Element node (an element with no parent, not in the document)
+   * 4. Document Fragment node
+   *
+   * For each context, the following tests are run:
+   *
+   * The interface check tests ensure that each type of node exposes the Selectors API methods
+   *
+   * The special selector tests verify the result of passing special values for the selector parameter,
+   * to ensure that the correct WebIDL processing is performed, such as stringification of null and
+   * undefined and missing parameter. The universal selector is also tested here, rather than with the
+   * rest of ordinary selectors for practical reasons.
+   *
+   * The static list verification tests ensure that the node lists returned by the method remain unchanged
+   * due to subsequent document modication, and that a new list is generated each time the method is
+   * invoked based on the current state of the document.
+   *
+   * The invalid selector tests ensure that SyntaxError is thrown for invalid forms of selectors
+   *
+   * The valid selector tests check the result from querying many different types of selectors, with a
+   * list of expected elements. This checks that querySelector() always returns the first result from
+   * querySelectorAll(), and that all matching elements are correctly returned in tree-order. The tests
+   * can be limited by specifying the test types to run, using the testType variable. The constants for this
+   * can be found in selectors.js.
+   *
+   * All the selectors tested for both the valid and invalid selector tests are found in selectors.js.
+   * See comments in that file for documentation of the format used.
+   *
+   * The ParentNode-querySelector-All.js file contains all the common test functions for running each of the aforementioned tests
+   */
+
+  var testType = TEST_QSA;
+  var docType  = "html"; // Only run tests suitable for HTML
+
+  // Prepare the nodes for testing
+  var doc = target.contentDocument;                 // Document Node tests
+
+  var element = doc.getElementById("root");   // In-document Element Node tests
+
+  //Setup the namespace tests
+  setupSpecialElements(doc, element);
+
+  var outOfScope = element.cloneNode(true);   // Append this to the body before running the in-document
+                                               // Element tests, but after running the Document tests. This
+                                               // tests that no elements that are not descendants of element
+                                               // are selected.
+
+  traverse(outOfScope, function(elem) {        // Annotate each element as being a clone; used for verifying
+    elem.setAttribute("data-clone", "");     // that none of these elements ever match.
+  });
+
+
+  var detached = element.cloneNode(true);     // Detached Element Node tests
+
+  var fragment = doc.createDocumentFragment(); // Fragment Node tests
+  fragment.appendChild(element.cloneNode(true));
+
+  var empty = document.createElement("div"); // Empty Node tests
+
+  // Setup Tests
+  interfaceCheck("Document", doc);
+  interfaceCheck("Detached Element", detached);
+  interfaceCheck("Fragment", fragment);
+  interfaceCheck("In-document Element", element);
+
+  runSpecialSelectorTests("Document", doc);
+  runSpecialSelectorTests("Detached Element", detached);
+  runSpecialSelectorTests("Fragment", fragment);
+  runSpecialSelectorTests("In-document Element", element);
+
+  verifyStaticList("Document", doc, doc);
+  verifyStaticList("Detached Element", doc, detached);
+  verifyStaticList("Fragment", doc, fragment);
+  verifyStaticList("In-document Element", doc, element);
+
+  runInvalidSelectorTest("Document", doc, invalidSelectors);
+  runInvalidSelectorTest("Detached Element", detached, invalidSelectors);
+  runInvalidSelectorTest("Fragment", fragment, invalidSelectors);
+  runInvalidSelectorTest("In-document Element", element, invalidSelectors);
+  runInvalidSelectorTest("Empty Element", empty, invalidSelectors);
+
+  runValidSelectorTest("Document", doc, validSelectors, testType, docType);
+  runValidSelectorTest("Detached Element", detached, validSelectors, testType, docType);
+  runValidSelectorTest("Fragment", fragment, validSelectors, testType, docType);
+
+  doc.body.appendChild(outOfScope); // Append before in-document Element tests.
+                                    // None of these elements should match
+  runValidSelectorTest("In-document Element", element, validSelectors, testType, docType);
+}
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All.js b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All.js
new file mode 100644
index 0000000000..3c6c503179
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-All.js
@@ -0,0 +1,261 @@
+// Require selectors.js to be included before this.
+
+/*
+ * Create and append special elements that cannot be created correctly with HTML markup alone.
+ */
+function setupSpecialElements(doc, parent) {
+  // Setup null and undefined tests
+  parent.appendChild(doc.createElement("null"));
+  parent.appendChild(doc.createElement("undefined"));
+
+  // Setup namespace tests
+  var anyNS = doc.createElement("div");
+  var noNS = doc.createElement("div");
+  anyNS.id = "any-namespace";
+  noNS.id = "no-namespace";
+
+  var divs;
+  div = [doc.createElement("div"),
+         doc.createElementNS("http://www.w3.org/1999/xhtml", "div"),
+         doc.createElementNS("", "div"),
+         doc.createElementNS("http://www.example.org/ns", "div")];
+
+  div[0].id = "any-namespace-div1";
+  div[1].id = "any-namespace-div2";
+  div[2].setAttribute("id", "any-namespace-div3"); // Non-HTML elements can't use .id property
+  div[3].setAttribute("id", "any-namespace-div4");
+
+  for (var i = 0; i < div.length; i++) {
+    anyNS.appendChild(div[i])
+  }
+
+  div = [doc.createElement("div"),
+         doc.createElementNS("http://www.w3.org/1999/xhtml", "div"),
+         doc.createElementNS("", "div"),
+         doc.createElementNS("http://www.example.org/ns", "div")];
+
+  div[0].id = "no-namespace-div1";
+  div[1].id = "no-namespace-div2";
+  div[2].setAttribute("id", "no-namespace-div3"); // Non-HTML elements can't use .id property
+  div[3].setAttribute("id", "no-namespace-div4");
+
+  for (i = 0; i < div.length; i++) {
+    noNS.appendChild(div[i])
+  }
+
+  parent.appendChild(anyNS);
+  parent.appendChild(noNS);
+
+  var span = doc.getElementById("attr-presence-i1");
+  span.setAttributeNS("http://www.example.org/ns", "title", "");
+}
+
+/*
+ * Check that the querySelector and querySelectorAll methods exist on the given Node
+ */
+function interfaceCheck(type, obj) {
+  test(function() {
+    var q = typeof obj.querySelector === "function";
+    assert_true(q, type + " supports querySelector.");
+  }, type + " supports querySelector")
+
+  test(function() {
+    var qa = typeof obj.querySelectorAll === "function";
+    assert_true( qa, type + " supports querySelectorAll.");
+  }, type + " supports querySelectorAll")
+
+  test(function() {
+    var list = obj.querySelectorAll("div");
+    if (obj.ownerDocument) { // The object is not a Document
+      assert_true(list instanceof obj.ownerDocument.defaultView.NodeList, "The result should be an instance of a NodeList")
+    } else { // The object is a Document
+      assert_true(list instanceof obj.defaultView.NodeList, "The result should be an instance of a NodeList")
+    }
+  }, type + ".querySelectorAll returns NodeList instance")
+}
+
+/*
+ * Verify that the NodeList returned by querySelectorAll is static and and that a new list is created after
+ * each call. A static list should not be affected by subsequent changes to the DOM.
+ */
+function verifyStaticList(type, doc, root) {
+  var pre, post, preLength;
+
+  test(function() {
+    pre = root.querySelectorAll("div");
+    preLength = pre.length;
+
+    var div = doc.createElement("div");
+    (root.body || root).appendChild(div);
+
+    assert_equals(pre.length, preLength, "The length of the NodeList should not change.")
+  }, type + ": static NodeList")
+
+  test(function() {
+    post = root.querySelectorAll("div"),
+    assert_equals(post.length, preLength + 1, "The length of the new NodeList should be 1 more than the previous list.")
+  }, type + ": new NodeList")
+}
+
+/*
+ * Verify handling of special values for the selector parameter, including stringification of
+ * null and undefined, and the handling of the empty string.
+ */
+function runSpecialSelectorTests(type, root) {
+  let global = (root.ownerDocument || root).defaultView;
+
+  test(function() { // 1
+    assert_equals(root.querySelectorAll(null).length, 1, "This should find one element with the tag name 'NULL'.");
+  }, type + ".querySelectorAll null")
+
+  test(function() { // 2
+    assert_equals(root.querySelectorAll(undefined).length, 1, "This should find one element with the tag name 'UNDEFINED'.");
+  }, type + ".querySelectorAll undefined")
+
+  test(function() { // 3
+    assert_throws_js(global.TypeError, function() {
+      root.querySelectorAll();
+    }, "This should throw a TypeError.")
+  }, type + ".querySelectorAll no parameter")
+
+  test(function() { // 4
+    var elm = root.querySelector(null)
+    assert_not_equals(elm, null, "This should find an element.");
+    assert_equals(elm.tagName.toUpperCase(), "NULL", "The tag name should be 'NULL'.")
+  }, type + ".querySelector null")
+
+  test(function() { // 5
+    var elm = root.querySelector(undefined)
+    assert_not_equals(elm, undefined, "This should find an element.");
+    assert_equals(elm.tagName.toUpperCase(), "UNDEFINED", "The tag name should be 'UNDEFINED'.")
+  }, type + ".querySelector undefined")
+
+  test(function() { // 6
+    assert_throws_js(global.TypeError, function() {
+      root.querySelector();
+    }, "This should throw a TypeError.")
+  }, type + ".querySelector no parameter")
+
+  test(function() { // 7
+    result = root.querySelectorAll("*");
+    var i = 0;
+    traverse(root, function(elem) {
+      if (elem !== root) {
+        assert_equals(elem, result[i], "The result in index " + i + " should be in tree order.");
+        i++;
+      }
+    })
+  }, type + ".querySelectorAll tree order");
+}
+
+/*
+ * Execute queries with the specified valid selectors for both querySelector() and querySelectorAll()
+ * Only run these tests when results are expected. Don't run for syntax error tests.
+ */
+function runValidSelectorTest(type, root, selectors, testType, docType) {
+  var nodeType = "";
+  switch (root.nodeType) {
+    case Node.DOCUMENT_NODE:
+      nodeType = "document";
+      break;
+    case Node.ELEMENT_NODE:
+      nodeType = root.parentNode ? "element" : "detached";
+      break;
+    case Node.DOCUMENT_FRAGMENT_NODE:
+      nodeType = "fragment";
+      break;
+    default:
+      assert_unreached();
+      nodeType = "unknown"; // This should never happen.
+  }
+
+  for (var i = 0; i < selectors.length; i++) {
+    var s = selectors[i];
+    var n = s["name"];
+    var q = s["selector"];
+    var e = s["expect"];
+
+    if ((!s["exclude"] || (s["exclude"].indexOf(nodeType) === -1 && s["exclude"].indexOf(docType) === -1))
+     && (s["testType"] & testType) ) {
+      var foundall, found;
+
+      test(function() {
+        foundall = root.querySelectorAll(q);
+        assert_not_equals(foundall, null, "The method should not return null.")
+        assert_equals(foundall.length, e.length, "The method should return the expected number of matches.")
+
+        for (var i = 0; i < e.length; i++) {
+          assert_not_equals(foundall[i], null, "The item in index " + i + " should not be null.")
+          assert_equals(foundall[i].getAttribute("id"), e[i], "The item in index " + i + " should have the expected ID.");
+          assert_false(foundall[i].hasAttribute("data-clone"), "This should not be a cloned element.");
+        }
+      }, type + ".querySelectorAll: " + n + ": " + q);
+
+      test(function() {
+        found = root.querySelector(q);
+
+        if (e.length > 0) {
+          assert_not_equals(found, null, "The method should return a match.")
+          assert_equals(found.getAttribute("id"), e[0], "The method should return the first match.");
+          assert_equals(found, foundall[0], "The result should match the first item from querySelectorAll.");
+          assert_false(found.hasAttribute("data-clone"), "This should not be annotated as a cloned element.");
+        } else {
+          assert_equals(found, null, "The method should not match anything.");
+        }
+      }, type + ".querySelector: " + n + ": " + q);
+    }
+  }
+}
+
+function windowFor(root) {
+  return root.defaultView || root.ownerDocument.defaultView;
+}
+
+/*
+ * Execute queries with the specified invalid selectors for both querySelector() and querySelectorAll()
+ * Only run these tests when errors are expected. Don't run for valid selector tests.
+ */
+function runInvalidSelectorTest(type, root, selectors) {
+  for (var i = 0; i < selectors.length; i++) {
+    var s = selectors[i];
+    var n = s["name"];
+    var q = s["selector"];
+
+    test(function() {
+      assert_throws_dom("SyntaxError", windowFor(root).DOMException, function() {
+        root.querySelector(q)
+      });
+    }, type + ".querySelector: " + n + ": " + q);
+
+    test(function() {
+      assert_throws_dom("SyntaxError", windowFor(root).DOMException, function() {
+        root.querySelectorAll(q)
+      });
+    }, type + ".querySelectorAll: " + n + ": " + q);
+  }
+}
+
+function traverse(elem, fn) {
+  if (elem.nodeType === elem.ELEMENT_NODE) {
+    fn(elem);
+  }
+  elem = elem.firstChild;
+  while (elem) {
+    traverse(elem, fn);
+    elem = elem.nextSibling;
+  }
+}
+
+function getNodeType(node) {
+  switch (node.nodeType) {
+    case Node.DOCUMENT_NODE:
+      return "document";
+    case Node.ELEMENT_NODE:
+      return node.parentNode ? "element" : "detached";
+    case Node.DOCUMENT_FRAGMENT_NODE:
+      return "fragment";
+    default:
+      assert_unreached();
+      return "unknown"; // This should never happen.
+  }
+}
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-case-insensitive.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-case-insensitive.html
new file mode 100644
index 0000000000..e461ee5016
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-case-insensitive.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>querySelector(All) must work with the i and *= selectors</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!-- Regression test for https://github.com/jsdom/jsdom/issues/2551 -->
+
+<input name="User" id="testInput"></input>
+
+<script>
+"use strict";
+const input = document.getElementById("testInput");
+
+test(() => {
+  assert_equals(document.querySelector("input[name*=user i]"), input);
+}, "querySelector");
+
+test(() => {
+  assert_array_equals(document.querySelectorAll("input[name*=user i]"), [input]);
+}, "querySelectorAll");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-escapes.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-escapes.html
new file mode 100644
index 0000000000..65a75e5c03
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-escapes.html
@@ -0,0 +1,123 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>querySelector() with CSS escapes</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-parentnode-queryselector">
+<link rel="help" href="https://drafts.csswg.org/css-syntax/#consume-escaped-code-point">
+<link rel="author" title="Domenic Denicola" href="mailto:d@domenic.me">
+<link rel="author" title="bellbind" href="mailto:bellbind@gmail.com">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+function testMatched(id, selector) {
+  test(() => {
+    const container = document.createElement("div");
+    const child = document.createElement("span");
+    child.id = id;
+
+    container.appendChild(child);
+
+    assert_equals(container.querySelector(selector), child);
+  }, `${JSON.stringify(id)} should match with ${JSON.stringify(selector)}`);
+}
+
+function testNeverMatched(id, selector) {
+  test(() => {
+    const container = document.createElement("div");
+    const child = document.createElement("span");
+    child.id = id;
+
+    container.appendChild(child);
+
+    assert_equals(container.querySelector(selector), null);
+  }, `${JSON.stringify(id)} should never match with ${JSON.stringify(selector)}`);
+}
+
+// 4.3.7 from https://drafts.csswg.org/css-syntax/#consume-escaped-code-point
+testMatched("nonescaped", "#nonescaped");
+
+// - escape hex digit
+testMatched("0nextIsWhiteSpace", "#\\30 nextIsWhiteSpace");
+testMatched("0nextIsNotHexLetters", "#\\30nextIsNotHexLetters");
+testMatched("0connectHexMoreThan6Hex", "#\\000030connectHexMoreThan6Hex");
+testMatched("0spaceMoreThan6Hex", "#\\000030 spaceMoreThan6Hex");
+
+// - hex digit special replacement
+// 1. zero points
+testMatched("zero\u{fffd}", "#zero\\0");
+testNeverMatched("zero\u{0}", "#zero\\0");
+testMatched("zero\u{fffd}", "#zero\\000000");
+testNeverMatched("zero\u{0}", "#zero\\000000");
+// 2. surrogate points
+testMatched("\u{fffd}surrogateFirst", "#\\d83d surrogateFirst");
+testNeverMatched("\ud83dsurrogateFirst", "#\\d83d surrogateFirst");
+testMatched("surrogateSecond\u{fffd}", "#surrogateSecond\\dd11");
+testNeverMatched("surrogateSecond\udd11", "#surrogateSecond\\dd11");
+testMatched("surrogatePair\u{fffd}\u{fffd}", "#surrogatePair\\d83d\\dd11");
+testNeverMatched("surrogatePair\u{1f511}", "#surrogatePair\\d83d\\dd11");
+// 3. out of range points
+testMatched("outOfRange\u{fffd}", "#outOfRange\\110000");
+testMatched("outOfRange\u{fffd}", "#outOfRange\\110030");
+testNeverMatched("outOfRange\u{30}", "#outOfRange\\110030");
+testMatched("outOfRange\u{fffd}", "#outOfRange\\555555");
+testMatched("outOfRange\u{fffd}", "#outOfRange\\ffffff");
+
+// - escape EOF
+testNeverMatched("eof\\", "#eof\\");
+
+// - escape anythong else
+testMatched(".comma", "#\\.comma");
+testMatched("-minus", "#\\-minus");
+testMatched("g", "#\\g");
+
+// non edge cases
+testMatched("aBMPRegular", "#\\61 BMPRegular");
+testMatched("\u{1f511}nonBMP", "#\\1f511 nonBMP");
+testMatched("00continueEscapes", "#\\30\\30 continueEscapes");
+testMatched("00continueEscapes", "#\\30 \\30 continueEscapes");
+testMatched("continueEscapes00", "#continueEscapes\\30 \\30 ");
+testMatched("continueEscapes00", "#continueEscapes\\30 \\30");
+testMatched("continueEscapes00", "#continueEscapes\\30\\30 ");
+testMatched("continueEscapes00", "#continueEscapes\\30\\30");
+
+// ident tests case from CSS tests of chromium source: https://goo.gl/3Cxdov
+testMatched("hello", "#hel\\6Co");
+testMatched("&B", "#\\26 B");
+testMatched("hello", "#hel\\6C o");
+testMatched("spaces", "#spac\\65\r\ns");
+testMatched("spaces", "#sp\\61\tc\\65\fs");
+testMatched("test\u{D799}", "#test\\D799");
+testMatched("\u{E000}", "#\\E000");
+testMatched("test", "#te\\s\\t");
+testMatched("spaces in\tident", "#spaces\\ in\\\tident");
+testMatched(".,:!", "#\\.\\,\\:\\!");
+testMatched("null\u{fffd}", "#null\\0");
+testMatched("null\u{fffd}", "#null\\0000");
+testMatched("large\u{fffd}", "#large\\110000");
+testMatched("large\u{fffd}", "#large\\23456a");
+testMatched("surrogate\u{fffd}", "#surrogate\\D800");
+testMatched("surrogate\u{fffd}", "#surrogate\\0DBAC");
+testMatched("\u{fffd}surrogate", "#\\00DFFFsurrogate");
+testMatched("\u{10ffff}", "#\\10fFfF");
+testMatched("\u{10ffff}0", "#\\10fFfF0");
+testMatched("\u{100000}00", "#\\10000000");
+testMatched("eof\u{fffd}", "#eof\\");
+
+testMatched("simple-ident", "#simple-ident");
+testMatched("testing123", "#testing123");
+testMatched("_underscore", "#_underscore");
+testMatched("-text", "#-text");
+testMatched("-m", "#-\\6d");
+testMatched("--abc", "#--abc");
+testMatched("--", "#--");
+testMatched("--11", "#--11");
+testMatched("---", "#---");
+testMatched("\u{2003}", "#\u{2003}");
+testMatched("\u{A0}", "#\u{A0}");
+testMatched("\u{1234}", "#\u{1234}");
+testMatched("\u{12345}", "#\u{12345}");
+testMatched("\u{fffd}", "#\u{0}");
+testMatched("ab\u{fffd}c", "#ab\u{0}c");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-scope.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-scope.html
new file mode 100644
index 0000000000..d984956d6c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelector-scope.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>querySelector(All) scoped to a root element</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<div><h1 id="test"></h1><p><span>hello</span></p></div>
+
+<script>
+"use strict";
+const div = document.querySelector("div");
+const p = document.querySelector("p");
+
+test(() => {
+  assert_equals(div.querySelector(":scope > p"), p);
+  assert_equals(div.querySelector(":scope > span"), null);
+}, "querySelector with :scope");
+
+test(() => {
+  assert_equals(div.querySelector("#test + p"), p);
+  assert_equals(p.querySelector("#test + p"), null);
+}, "querySelector with id and sibling");
+
+test(() => {
+  assert_array_equals(div.querySelectorAll(":scope > p"), [p]);
+  assert_array_equals(div.querySelectorAll(":scope > span"), []);
+}, "querySelectorAll with :scope");
+
+test(() => {
+  assert_array_equals(div.querySelectorAll("#test + p"), [p]);
+  assert_array_equals(p.querySelectorAll("#test + p"), []);
+}, "querySelectorAll with id and sibling");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelectorAll-removed-elements.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelectorAll-removed-elements.html
new file mode 100644
index 0000000000..3cefc80906
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelectorAll-removed-elements.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>querySelectorAll must not return removed elements</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!-- Regression test for https://github.com/jsdom/jsdom/issues/2519 -->
+
+<div id="container"></div>
+
+<script>
+"use strict";
+
+setup({ single_test: true });
+
+const container = document.querySelector("#container");
+function getIDs() {
+  return [...container.querySelectorAll("a.test")].map(el => el.id);
+}
+
+container.innerHTML = `<a id="link-a" class="test">a link</a>`;
+assert_array_equals(getIDs(), ["link-a"], "Sanity check: initial setup");
+
+container.innerHTML = `<a id="link-b" class="test"><img src="foo.jpg"></a>`;
+assert_array_equals(getIDs(), ["link-b"], "After replacement");
+
+container.innerHTML = `<a id="link-a" class="test">a link</a>`;
+assert_array_equals(getIDs(), ["link-a"], "After changing back to the original HTML");
+
+done();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-exclusive.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-exclusive.html
new file mode 100644
index 0000000000..5cff9367cf
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-exclusive.html
@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>querySelector/querySelectorAll should not include their thisArg</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!-- Regression test for https://github.com/jsdom/jsdom/issues/2296 -->
+
+<script>
+"use strict";
+
+setup({ single_test: true });
+
+const button = document.createElement("button");
+
+assert_equals(button.querySelector("*"), null, "querySelector, '*', before modification");
+assert_equals(button.querySelector("button"), null, "querySelector, 'button', before modification");
+assert_equals(button.querySelector("button, span"), null, "querySelector, 'button, span', before modification");
+assert_array_equals(button.querySelectorAll("*"), [], "querySelectorAll, '*', before modification");
+assert_array_equals(button.querySelectorAll("button"), [], "querySelectorAll, 'button', before modification");
+assert_array_equals(
+  button.querySelectorAll("button, span"), [],
+  "querySelectorAll, 'button, span', before modification"
+);
+
+
+button.innerHTML = "text";
+
+assert_equals(button.querySelector("*"), null, "querySelector, '*', after modification");
+assert_equals(button.querySelector("button"), null, "querySelector, 'button', after modification");
+assert_equals(button.querySelector("button, span"), null, "querySelector, 'button, span', after modification");
+assert_array_equals(button.querySelectorAll("*"), [], "querySelectorAll, '*', after modification");
+assert_array_equals(button.querySelectorAll("button"), [], "querySelectorAll, 'button', after modification");
+assert_array_equals(
+  button.querySelectorAll("button, span"), [],
+  "querySelectorAll, 'button, span', after modification"
+);
+
+done();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-namespaces.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-namespaces.html
new file mode 100644
index 0000000000..714999b3f0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-namespaces.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>querySelectorAll must work with namespace attribute selectors on SVG</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!-- Regression test for https://github.com/jsdom/jsdom/issues/2028 -->
+
+<svg id="thesvg" xlink:href="foo"></svg>
+
+<script>
+"use strict";
+
+setup({ single_test: true });
+
+const el = document.getElementById("thesvg");
+
+assert_equals(document.querySelector("[*|href]"), el);
+assert_array_equals(document.querySelectorAll("[*|href]"), [el]);
+
+done();
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-space-and-dash-attribute-value.html b/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-space-and-dash-attribute-value.html
new file mode 100644
index 0000000000..e08c6e6db1
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-querySelectors-space-and-dash-attribute-value.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>querySelector(All) must work for attribute values that contain spaces and dashes</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<!-- Regression test for https://github.com/jsdom/jsdom/issues/2542 -->
+
+<a title="test with - dash and space" id="testme">Test One</a>
+
+<script>
+"use strict";
+const el = document.getElementById("testme");
+
+test(() => {
+  assert_equals(document.querySelector("a[title='test with - dash and space']"), el);
+}, "querySelector");
+
+test(() => {
+  assert_equals(document.querySelector("a[title='test with - dash and space']"), el);
+}, "querySelectorAll");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/ParentNode-replaceChildren.html b/testing/web-platform/tests/dom/nodes/ParentNode-replaceChildren.html
new file mode 100644
index 0000000000..ee22009fcb
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ParentNode-replaceChildren.html
@@ -0,0 +1,205 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>ParentNode.replaceChildren</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-parentnode-replacechildren">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="pre-insertion-validation-hierarchy.js"></script>
+<script>
+  preInsertionValidateHierarchy("replaceChildren");
+
+  function test_replacechildren(node, nodeName) {
+    test(() => {
+      const parent = node.cloneNode();
+      parent.replaceChildren();
+      assert_array_equals(parent.childNodes, []);
+    }, `${nodeName}.replaceChildren() without any argument, on a parent having no child.`);
+
+    test(() => {
+      const parent = node.cloneNode();
+      parent.replaceChildren(null);
+      assert_equals(parent.childNodes[0].textContent, 'null');
+    }, `${nodeName}.replaceChildren() with null as an argument, on a parent having no child.`);
+
+    test(() => {
+      const parent = node.cloneNode();
+      parent.replaceChildren(undefined);
+      assert_equals(parent.childNodes[0].textContent, 'undefined');
+    }, `${nodeName}.replaceChildren() with undefined as an argument, on a parent having no child.`);
+
+    test(() => {
+      const parent = node.cloneNode();
+      parent.replaceChildren('text');
+      assert_equals(parent.childNodes[0].textContent, 'text');
+    }, `${nodeName}.replaceChildren() with only text as an argument, on a parent having no child.`);
+
+    test(() => {
+      const parent = node.cloneNode();
+      const x = document.createElement('x');
+      parent.replaceChildren(x);
+      assert_array_equals(parent.childNodes, [x]);
+    }, `${nodeName}.replaceChildren() with only one element as an argument, on a parent having no child.`);
+
+    test(() => {
+      const parent = node.cloneNode();
+      const child = document.createElement('test');
+      parent.appendChild(child);
+      parent.replaceChildren();
+      assert_array_equals(parent.childNodes, []);
+    }, `${nodeName}.replaceChildren() without any argument, on a parent having a child.`);
+
+    test(() => {
+      const parent = node.cloneNode();
+      const child = document.createElement('test');
+      parent.appendChild(child);
+      parent.replaceChildren(null);
+      assert_equals(parent.childNodes.length, 1);
+      assert_equals(parent.childNodes[0].textContent, 'null');
+    }, `${nodeName}.replaceChildren() with null as an argument, on a parent having a child.`);
+
+    test(() => {
+      const parent = node.cloneNode();
+      const x = document.createElement('x');
+      const child = document.createElement('test');
+      parent.appendChild(child);
+      parent.replaceChildren(x, 'text');
+      assert_equals(parent.childNodes.length, 2);
+      assert_equals(parent.childNodes[0], x);
+      assert_equals(parent.childNodes[1].textContent, 'text');
+    }, `${nodeName}.replaceChildren() with one element and text as argument, on a parent having a child.`);
+
+    async_test(t => {
+      let phase = 0;
+
+      const previousParent = node.cloneNode();
+      const insertions = [
+        document.createElement("test1"),
+        document.createElement("test2")
+      ];
+      previousParent.append(...insertions);
+
+      const parent = node.cloneNode();
+      const children = [
+        document.createElement("test3"),
+        document.createElement("test4")
+      ];
+      parent.append(...children);
+
+      const previousObserver = new MutationObserver(mutations => {
+        t.step(() => {
+          assert_equals(phase, 0);
+          assert_equals(mutations.length, 2);
+          for (const [i, mutation] of Object.entries(mutations)) {
+            assert_equals(mutation.type, "childList");
+            assert_equals(mutation.addedNodes.length, 0);
+            assert_equals(mutation.removedNodes.length, 1);
+            assert_equals(mutation.removedNodes[0], insertions[i]);
+          }
+          phase = 1;
+        });
+      });
+      previousObserver.observe(previousParent, { childList: true });
+
+      const observer = new MutationObserver(mutations => {
+        t.step(() => {
+          assert_equals(phase, 1, "phase");
+          assert_equals(mutations.length, 1, "mutations.length");
+          const mutation = mutations[0];
+          assert_equals(mutation.type, "childList", "mutation.type");
+          assert_equals(mutation.addedNodes.length, 2, "added nodes length");
+          assert_array_equals([...mutation.addedNodes], insertions, "added nodes");
+          assert_equals(mutation.removedNodes.length, 2, "removed nodes length");
+          assert_array_equals([...mutation.removedNodes], children, "removed nodes");
+        });
+        t.done();
+      });
+      observer.observe(parent, { childList: true });
+
+      parent.replaceChildren(...previousParent.children);
+    }, `${nodeName}.replaceChildren() should move nodes in the right order`);
+  }
+
+  test_replacechildren(document.createElement('div'), 'Element');
+  test_replacechildren(document.createDocumentFragment(), 'DocumentFragment');
+
+  async_test(t => {
+    let root = document.createElement("div");
+    root.innerHTML = "<div id='a'>text<div id='b'>text2</div></div>";
+    const a = root.firstChild;
+    const b = a.lastChild;
+    const txt = b.previousSibling;
+    const txt2 = b.firstChild;
+
+    const observer = new MutationObserver((mutations) => {
+
+      assert_equals(mutations.length, 2, "mutations.length");
+
+      assert_equals(mutations[0].target.id, "a", "Target of the removal");
+      assert_equals(mutations[0].addedNodes.length, 0, "Should not have added nodes");
+      assert_equals(mutations[0].removedNodes.length, 1, "Should have 1 removed node");
+      assert_equals(mutations[0].removedNodes[0], txt, "Should have removed txt node");
+
+      assert_equals(mutations[1].target.id, "b", "Target of the replaceChildren");
+      assert_equals(mutations[1].removedNodes.length, 1, "Should have removed 1 node");
+      assert_equals(mutations[1].removedNodes[0], txt2, "Should have removed txt2 node");
+      assert_equals(mutations[1].addedNodes.length, 1, "Should have added a node");
+      assert_equals(mutations[1].addedNodes[0], txt, "Should have added txt node");
+
+      observer.disconnect();
+      t.done();
+    });
+
+    observer.observe(a,  {
+      subtree: true,
+      childList: true
+    });
+
+    b.replaceChildren(txt);
+  }, "There should be a MutationRecord for the node removed from another parent node.");
+
+  async_test(t => {
+    // This is almost the same test as above, but passes two nodes to replaceChildren.
+
+    let root = document.createElement("div");
+    root.innerHTML = "<div id='a'><div id='c'></div>text<div id='b'>text2</div></div>";
+    const a = root.firstChild;
+    const b = a.lastChild;
+    const c = a.firstChild;
+    const txt = b.previousSibling;
+    const txt2 = b.firstChild;
+
+    const observer = new MutationObserver((mutations) => {
+
+      assert_equals(mutations.length, 3, "mutations.length");
+
+      assert_equals(mutations[0].target.id, "a", "Target of the removal");
+      assert_equals(mutations[0].addedNodes.length, 0, "Should not have added nodes");
+      assert_equals(mutations[0].removedNodes.length, 1, "Should have 1 removed node");
+      assert_equals(mutations[0].removedNodes[0], c, "Should have removed c node");
+
+      assert_equals(mutations[1].target.id, "a", "Target of the removal");
+      assert_equals(mutations[1].addedNodes.length, 0, "Should not have added nodes");
+      assert_equals(mutations[1].removedNodes.length, 1, "Should have 1 removed node");
+      assert_equals(mutations[1].removedNodes[0], txt, "Should have removed txt node");
+
+      assert_equals(mutations[2].target.id, "b", "Target of the replaceChildren");
+      assert_equals(mutations[2].removedNodes.length, 1, "Should have removed 1 node");
+      assert_equals(mutations[2].removedNodes[0], txt2, "Should have removed txt2 node");
+      assert_equals(mutations[2].addedNodes.length, 2, "Should have added a node");
+      assert_equals(mutations[2].addedNodes[0], c, "Should have added c node");
+      assert_equals(mutations[2].addedNodes[1], txt, "Should have added txt node");
+
+      observer.disconnect();
+      t.done();
+    });
+
+    observer.observe(a,  {
+      subtree: true,
+      childList: true
+    });
+
+    b.replaceChildren(c, txt);
+  }, "There should be MutationRecords for the nodes removed from another parent node.");
+</script>
+
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ProcessingInstruction-escapes-1.xhtml b/testing/web-platform/tests/dom/nodes/ProcessingInstruction-escapes-1.xhtml
new file mode 100644
index 0000000000..d629a8464b
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ProcessingInstruction-escapes-1.xhtml
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<?xml-stylesheet href="support/style.css" type="text/css"?>
+<?xml-stylesheet href="data:text/css,&#x41;&amp;&apos;" type="text/css"?>
+<?xml-stylesheet href="data:text/css,&#65;&amp;&apos;" type="text/css"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>ProcessingInstruction numeric escapes</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-processinginstruction-target"/>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-characterdata-data"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"/>
+<script>
+<![CDATA[
+test(function() {
+  var pienc = document.firstChild.nextSibling;
+  assert_true(pienc instanceof ProcessingInstruction)
+  assert_equals(pienc.target, "xml-stylesheet")
+  assert_equals(pienc.data, 'href="data:text/css,&#x41;&amp;&apos;" type="text/css"')
+  assert_equals(pienc.sheet.href, "data:text/css,A&'");
+
+  pienc = pienc.nextSibling;
+  assert_true(pienc instanceof ProcessingInstruction)
+  assert_equals(pienc.target, "xml-stylesheet")
+  assert_equals(pienc.data, 'href="data:text/css,&#65;&amp;&apos;" type="text/css"')
+  assert_equals(pienc.sheet.href, "data:text/css,A&'");
+})
+]]>
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ProcessingInstruction-in-doctype.xhtml b/testing/web-platform/tests/dom/nodes/ProcessingInstruction-in-doctype.xhtml
new file mode 100644
index 0000000000..c35e710f9c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ProcessingInstruction-in-doctype.xhtml
@@ -0,0 +1,15 @@
+<!DOCTYPE html [<?x y?>]><html xmlns="http://www.w3.org/1999/xhtml">
+  <head>
+    <title>XML: Processing instruction in doctype internal subset</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+  </head>
+  <body>
+    <script>
+      test(() => {
+        assert_equals(document.documentElement.previousSibling, document.firstChild);
+        assert_equals(document.firstChild.nodeType, Node.DOCUMENT_TYPE_NODE);
+      });
+    </script>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ProcessingInstruction-literal-1.xhtml b/testing/web-platform/tests/dom/nodes/ProcessingInstruction-literal-1.xhtml
new file mode 100644
index 0000000000..4eaf86cbdc
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ProcessingInstruction-literal-1.xhtml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>&lt;?xml?> is not a ProcessingInstruction</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"/>
+<script>
+test(function() {
+  assert_equals(document.firstChild, document.documentElement)
+})
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/ProcessingInstruction-literal-2.xhtml b/testing/web-platform/tests/dom/nodes/ProcessingInstruction-literal-2.xhtml
new file mode 100644
index 0000000000..d878c697c0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/ProcessingInstruction-literal-2.xhtml
@@ -0,0 +1,21 @@
+<?xml-stylesheet href="support/style.css" type="text/css"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<title>ProcessingInstruction literals</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-processinginstruction-target"/>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-characterdata-data"/>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<div id="log"/>
+<script>
+test(function() {
+  var pienc = document.firstChild;
+  assert_true(pienc instanceof ProcessingInstruction)
+  assert_equals(pienc.target, "xml-stylesheet")
+  assert_equals(pienc.data, 'href="support/style.css" type="text/css"')
+})
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/Text-constructor.html b/testing/web-platform/tests/dom/nodes/Text-constructor.html
new file mode 100644
index 0000000000..dbd9a0be01
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Text-constructor.html
@@ -0,0 +1,11 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Text constructor</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-text">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="Comment-Text-constructor.js"></script>
+<div id="log"></div>
+<script>
+test_constructor("Text");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Text-splitText.html b/testing/web-platform/tests/dom/nodes/Text-splitText.html
new file mode 100644
index 0000000000..2dd23018cb
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Text-splitText.html
@@ -0,0 +1,53 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Text.splitText()</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-text-splittextoffset">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+test(function() {
+  var text = document.createTextNode("camembert");
+  assert_throws_dom("INDEX_SIZE_ERR", function () { text.splitText(10) });
+}, "Split text after end of data");
+
+test(function() {
+  var text = document.createTextNode("");
+  var new_text = text.splitText(0);
+  assert_equals(text.data, "");
+  assert_equals(new_text.data, "");
+}, "Split empty text");
+
+test(function() {
+  var text = document.createTextNode("comté");
+  var new_text = text.splitText(0);
+  assert_equals(text.data, "");
+  assert_equals(new_text.data, "comté");
+}, "Split text at beginning");
+
+test(function() {
+  var text = document.createTextNode("comté");
+  var new_text = text.splitText(5);
+  assert_equals(text.data, "comté");
+  assert_equals(new_text.data, "");
+}, "Split text at end");
+
+test(function() {
+  var text = document.createTextNode("comté");
+  var new_text = text.splitText(3);
+  assert_equals(text.data, "com");
+  assert_equals(new_text.data, "té");
+  assert_equals(new_text.parentNode, null);
+}, "Split root");
+
+test(function() {
+  var parent = document.createElement('div');
+  var text = document.createTextNode("bleu");
+  parent.appendChild(text);
+  var new_text = text.splitText(2);
+  assert_equals(text.data, "bl");
+  assert_equals(new_text.data, "eu");
+  assert_equals(text.nextSibling, new_text);
+  assert_equals(new_text.parentNode, parent);
+}, "Split child");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/Text-wholeText.html b/testing/web-platform/tests/dom/nodes/Text-wholeText.html
new file mode 100644
index 0000000000..2467930da8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/Text-wholeText.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Text - wholeText</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-text-wholetext">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+"use strict";
+
+test(() => {
+  const parent = document.createElement("div");
+
+  const t1 = document.createTextNode("a");
+  const t2 = document.createTextNode("b");
+  const t3 = document.createTextNode("c");
+
+  assert_equals(t1.wholeText, t1.textContent);
+
+  parent.appendChild(t1);
+
+  assert_equals(t1.wholeText, t1.textContent);
+
+  parent.appendChild(t2);
+
+  assert_equals(t1.wholeText, t1.textContent + t2.textContent);
+  assert_equals(t2.wholeText, t1.textContent + t2.textContent);
+
+  parent.appendChild(t3);
+
+  assert_equals(t1.wholeText, t1.textContent + t2.textContent + t3.textContent);
+  assert_equals(t2.wholeText, t1.textContent + t2.textContent + t3.textContent);
+  assert_equals(t3.wholeText, t1.textContent + t2.textContent + t3.textContent);
+
+  const a = document.createElement("a");
+  a.textContent = "I'm an Anchor";
+  parent.insertBefore(a, t3);
+
+  const span = document.createElement("span");
+  span.textContent = "I'm a Span";
+  parent.appendChild(document.createElement("span"));
+
+  assert_equals(t1.wholeText, t1.textContent + t2.textContent);
+  assert_equals(t2.wholeText, t1.textContent + t2.textContent);
+  assert_equals(t3.wholeText, t3.textContent);
+}, "wholeText returns text of all Text nodes logically adjacent to the node, in document order.");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/adoption.window.js b/testing/web-platform/tests/dom/nodes/adoption.window.js
new file mode 100644
index 0000000000..ad90aaf375
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/adoption.window.js
@@ -0,0 +1,58 @@
+// Testing DocumentFragment with host separately as it has a different node document by design
+test(() => {
+  const df = document.createElement("template").content;
+  const child = df.appendChild(new Text('hi'));
+  assert_not_equals(df.ownerDocument, document);
+  const nodeDocument = df.ownerDocument;
+  document.body.appendChild(df);
+  assert_equals(df.childNodes.length, 0);
+  assert_equals(child.ownerDocument, document);
+  assert_equals(df.ownerDocument, nodeDocument);
+}, `appendChild() and DocumentFragment with host`);
+
+test(() => {
+  const df = document.createElement("template").content;
+  const child = df.appendChild(new Text('hi'));
+  const nodeDocument = df.ownerDocument;
+  document.adoptNode(df);
+  assert_equals(df.childNodes.length, 1);
+  assert_equals(child.ownerDocument, nodeDocument);
+  assert_equals(df.ownerDocument, nodeDocument);
+}, `adoptNode() and DocumentFragment with host`);
+
+[
+  {
+    "name": "DocumentFragment",
+    "creator": doc => doc.createDocumentFragment()
+  },
+  {
+    "name": "ShadowRoot",
+    "creator": doc => doc.createElementNS("http://www.w3.org/1999/xhtml", "div").attachShadow({mode: "closed"})
+  }
+].forEach(dfTest => {
+  test(() => {
+    const doc = new Document();
+    const df = dfTest.creator(doc);
+    const child = df.appendChild(new Text('hi'));
+    assert_equals(df.ownerDocument, doc);
+
+    document.body.appendChild(df);
+    assert_equals(df.childNodes.length, 0);
+    assert_equals(child.ownerDocument, document);
+    assert_equals(df.ownerDocument, doc);
+  }, `appendChild() and ${dfTest.name}`);
+
+  test(() => {
+    const doc = new Document();
+    const df = dfTest.creator(doc);
+    const child = df.appendChild(new Text('hi'));
+    if (dfTest.name === "ShadowRoot") {
+      assert_throws_dom("HierarchyRequestError", () => document.adoptNode(df));
+    } else {
+      document.adoptNode(df);
+      assert_equals(df.childNodes.length, 1);
+      assert_equals(child.ownerDocument, document);
+      assert_equals(df.ownerDocument, document);
+    }
+  }, `adoptNode() and ${dfTest.name}`);
+});
diff --git a/testing/web-platform/tests/dom/nodes/append-on-Document.html b/testing/web-platform/tests/dom/nodes/append-on-Document.html
new file mode 100644
index 0000000000..78f278b381
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/append-on-Document.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>DocumentType.append</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-parentnode-append">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+function test_append_on_Document() {
+
+    var node = document.implementation.createDocument(null, null);
+    test(function() {
+        var parent = node.cloneNode();
+        parent.append();
+        assert_array_equals(parent.childNodes, []);
+    }, 'Document.append() without any argument, on a Document having no child.');
+
+    test(function() {
+        var parent = node.cloneNode();
+        var x = document.createElement('x');
+        parent.append(x);
+        assert_array_equals(parent.childNodes, [x]);
+    }, 'Document.append() with only one element as an argument, on a Document having no child.');
+
+    test(function() {
+        var parent = node.cloneNode();
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        parent.appendChild(x);
+        assert_throws_dom('HierarchyRequestError', function() { parent.append(y); });
+        assert_array_equals(parent.childNodes, [x]);
+    }, 'Document.append() with only one element as an argument, on a Document having one child.');
+
+    test(function() {
+        var parent = node.cloneNode();
+        assert_throws_dom('HierarchyRequestError', function() { parent.append('text'); });
+        assert_array_equals(parent.childNodes, []);
+    }, 'Document.append() with text as an argument, on a Document having no child.');
+
+    test(function() {
+        var parent = node.cloneNode();
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        assert_throws_dom('HierarchyRequestError', function() { parent.append(x, y); });
+        assert_array_equals(parent.childNodes, []);
+    }, 'Document.append() with two elements as the argument, on a Document having no child.');
+
+}
+
+test_append_on_Document();
+
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/attributes-namednodemap.html b/testing/web-platform/tests/dom/nodes/attributes-namednodemap.html
new file mode 100644
index 0000000000..96f9d30703
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/attributes-namednodemap.html
@@ -0,0 +1,120 @@
+<!DOCTYPE HTML>
+<title>Tests of some tricky semantics around NamedNodeMap and the element.attributes collection</title>
+<link rel="author" title="Domenic Denicola" href="mailto:d@domenic.me">
+<link rel="help" href="https://dom.spec.whatwg.org/#interface-namednodemap">
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-element-attributes">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+
+  const element = document.createElement("div");
+  element.setAttribute("x", "first");
+
+  assert_equals(element.attributes.length, 1, "one attribute");
+  assert_equals(element.attributes.x.value, "first");
+
+}, "an attribute set by setAttribute should be accessible as a field on the `attributes` field of an Element");
+
+test(() => {
+
+  const element = document.createElement("div");
+  const map = element.attributes;
+
+  assert_equals(map.length, 0);
+
+  const attr1 = document.createAttribute("attr1");
+  map.setNamedItem(attr1);
+  assert_equals(map.attr1, attr1);
+  assert_equals(map.length, 1);
+
+  const attr2 = document.createAttribute("attr2");
+  map.setNamedItem(attr2);
+  assert_equals(map.attr2, attr2);
+  assert_equals(map.length, 2);
+
+  const rm1 = map.removeNamedItem("attr1");
+  assert_equals(rm1, attr1);
+  assert_equals(map.length, 1);
+
+  const rm2 = map.removeNamedItem("attr2");
+  assert_equals(rm2, attr2);
+  assert_equals(map.length, 0);
+
+}, "setNamedItem and removeNamedItem on `attributes` should add and remove fields from `attributes`");
+
+test(() => {
+
+  const element = document.createElement("div");
+  const map = element.attributes;
+
+  const fooAttribute = document.createAttribute("foo");
+  map.setNamedItem(fooAttribute);
+
+  const itemAttribute = document.createAttribute("item");
+  map.setNamedItem(itemAttribute);
+
+  assert_equals(map.foo, fooAttribute);
+  assert_equals(map.item, NamedNodeMap.prototype.item);
+  assert_equals(typeof map.item, "function");
+
+  map.removeNamedItem("item");
+  assert_equals(map.item, NamedNodeMap.prototype.item);
+  assert_equals(typeof map.item, "function");
+
+}, "setNamedItem and removeNamedItem on `attributes` should not interfere with existing method names");
+
+test(() => {
+
+  const element = document.createElement("div");
+  element.setAttributeNS(null, "x", "first");
+
+  assert_equals(element.attributes.length, 1, "one attribute");
+  assert_equals(element.attributes.x.value, "first");
+
+}, "an attribute with a null namespace should be accessible as a field on the `attributes` field of an Element");
+
+test(() => {
+
+  const element = document.createElement("div");
+  element.setAttributeNS("foo", "x", "first");
+
+  assert_equals(element.attributes.length, 1, "one attribute");
+  assert_equals(element.attributes.x.value, "first");
+
+}, "an attribute with a set namespace should be accessible as a field on the `attributes` field of an Element");
+
+test(() => {
+
+  const element = document.createElement("div");
+  element.setAttributeNS("foo", "setNamedItem", "first");
+
+  assert_equals(element.attributes.length, 1, "one attribute");
+  assert_equals(typeof element.attributes.setNamedItem, "function");
+
+}, "setting an attribute should not overwrite the methods of an `NamedNodeMap` object");
+
+test(() => {
+
+  const element = document.createElement("div");
+  element.setAttributeNS("foo", "toString", "first");
+
+  assert_equals(element.attributes.length, 1, "one attribute");
+  assert_equals(typeof element.attributes.toString, "function");
+
+}, "setting an attribute should not overwrite the methods defined by prototype ancestors of an `NamedNodeMap` object");
+
+test(() => {
+
+  const element = document.createElement("div");
+  element.setAttributeNS("foo", "length", "first");
+
+  assert_equals(element.attributes.length, 1, "one attribute");
+
+}, "setting an attribute should not overwrite the the length property of an `NamedNodeMap` object");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/attributes.html b/testing/web-platform/tests/dom/nodes/attributes.html
new file mode 100644
index 0000000000..c6db7eb8aa
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/attributes.html
@@ -0,0 +1,858 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Attributes tests</title>
+<link rel=help href="https://dom.spec.whatwg.org/#attr">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-setattribute">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-setattributens">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="attributes.js"></script>
+<script src="productions.js"></script>
+<div id="log"></div>
+<span id="test1"></span>
+<span class="&amp;&lt;&gt;foo"></span>
+<span id="test2">
+  <span ~=""></span>
+  <span ~></span>
+  <span></span>
+</span>
+<script>
+var XML = "http://www.w3.org/XML/1998/namespace"
+var XMLNS = "http://www.w3.org/2000/xmlns/"
+
+// toggleAttribute exhaustive tests
+// Step 1
+test(function() {
+  var el = document.createElement("foo")
+  for (var i = 0; i < invalid_names.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() { el.toggleAttribute(invalid_names[i], true) })
+  }
+  for (var i = 0; i < invalid_names.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() { el.toggleAttribute(invalid_names[i]) })
+  }
+  for (var i = 0; i < invalid_names.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() { el.toggleAttribute(invalid_names[i], false) })
+  }
+}, "When qualifiedName does not match the Name production, an " +
+   "INVALID_CHARACTER_ERR exception is to be thrown. (toggleAttribute)")
+test(function() {
+  var el = document.getElementById("test2")
+  for (var i = 0; i < el.children.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
+      el.children[i].toggleAttribute("~", false)
+    })
+  }
+  for (var i = 0; i < el.children.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
+      el.children[i].toggleAttribute("~")
+    })
+  }
+  for (var i = 0; i < el.children.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
+      el.children[i].toggleAttribute("~", true)
+    })
+  }
+}, "When qualifiedName does not match the Name production, an " +
+   "INVALID_CHARACTER_ERR exception is to be thrown, even if the attribute " +
+   "is already present. (toggleAttribute)")
+
+// Step 2
+test(function() {
+  var el = document.createElement("div")
+  assert_true(el.toggleAttribute("ALIGN"))
+  assert_true(!el.hasAttributeNS("", "ALIGN"))
+  assert_true(el.hasAttributeNS("", "align"))
+  assert_true(el.hasAttribute("align"))
+  assert_true(!el.toggleAttribute("ALIGN"))
+  assert_true(!el.hasAttributeNS("", "ALIGN"))
+  assert_true(!el.hasAttributeNS("", "align"))
+  assert_true(!el.hasAttribute("align"))
+}, "toggleAttribute should lowercase its name argument (upper case attribute)")
+test(function() {
+  var el = document.createElement("div")
+  assert_true(el.toggleAttribute("CHEEseCaKe"))
+  assert_true(!el.hasAttributeNS("", "CHEEseCaKe"))
+  assert_true(el.hasAttributeNS("", "cheesecake"))
+  assert_true(el.hasAttribute("cheesecake"))
+}, "toggleAttribute should lowercase its name argument (mixed case attribute)")
+
+// Step 3
+test(function() {
+  var el = document.createElement("foo")
+  var tests = ["xmlns", "xmlns:a", "xmlnsx", "xmlns0"]
+  for (var i = 0; i < tests.length; i++) {
+    assert_true(el.toggleAttribute(tests[i]));
+    assert_true(el.hasAttribute(tests[i]));
+  }
+}, "toggleAttribute should not throw even when qualifiedName starts with 'xmlns'")
+
+// Step 4
+test(function() {
+  var el = document.createElement("foo")
+  for (var i = 0; i < valid_names.length; i++) {
+    assert_true(el.toggleAttribute(valid_names[i]))
+    assert_true(el.hasAttribute(valid_names[i]))
+    assert_true(!el.toggleAttribute(valid_names[i]))
+    assert_true(!el.hasAttribute(valid_names[i]))
+    // Check using force attr
+    assert_true(el.toggleAttribute(valid_names[i], true))
+    assert_true(el.hasAttribute(valid_names[i]))
+    assert_true(el.toggleAttribute(valid_names[i], true))
+    assert_true(el.hasAttribute(valid_names[i]))
+    assert_true(!el.toggleAttribute(valid_names[i], false))
+    assert_true(!el.hasAttribute(valid_names[i]))
+  }
+}, "Basic functionality should be intact. (toggleAttribute)")
+
+// Step 5
+test(function() {
+  var el = document.createElement("foo")
+  el.toggleAttribute("a")
+  el.toggleAttribute("b")
+  el.setAttribute("a", "thing")
+  el.toggleAttribute("c")
+  attributes_are(el, [["a", "thing"],
+                      ["b", ""],
+                      ["c", ""]])
+}, "toggleAttribute should not change the order of previously set attributes.")
+test(function() {
+  var el = document.createElement("baz")
+  el.setAttributeNS("ab", "attr", "fail")
+  el.setAttributeNS("kl", "attr", "pass")
+  el.toggleAttribute("attr")
+  attributes_are(el, [["attr", "pass", "kl"]])
+}, "toggleAttribute should set the first attribute with the given name")
+test(function() {
+  // Based on a test by David Flanagan.
+  var el = document.createElement("baz")
+  el.setAttributeNS("foo", "foo:bar", "1");
+  el.setAttributeNS("foo", "foo:bat", "2");
+  assert_equals(el.getAttribute("foo:bar"), "1")
+  assert_equals(el.getAttribute("foo:bat"), "2")
+  attr_is(el.attributes[0], "1", "bar", "foo", "foo", "foo:bar")
+  attr_is(el.attributes[1], "2", "bat", "foo", "foo", "foo:bat")
+  el.toggleAttribute("foo:bar");
+  assert_true(!el.hasAttribute("foo:bar"))
+  attr_is(el.attributes[0], "2", "bat", "foo", "foo", "foo:bat")
+}, "toggleAttribute should set the attribute with the given qualified name")
+
+test(function() {
+  var el = document.createElement("foo")
+  el.style = "color: red; background-color: green"
+  assert_equals(el.toggleAttribute("style"), false)
+}, "Toggling element with inline style should make inline style disappear")
+
+// setAttribute exhaustive tests
+// Step 1
+test(function() {
+  var el = document.createElement("foo")
+  for (var i = 0; i < invalid_names.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() { el.setAttribute(invalid_names[i], "test") })
+  }
+}, "When qualifiedName does not match the Name production, an " +
+   "INVALID_CHARACTER_ERR exception is to be thrown. (setAttribute)")
+test(function() {
+  var el = document.getElementById("test2")
+  for (var i = 0; i < el.children.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
+      el.children[i].setAttribute("~", "test")
+    })
+  }
+}, "When qualifiedName does not match the Name production, an " +
+   "INVALID_CHARACTER_ERR exception is to be thrown, even if the attribute " +
+   "is already present. (setAttribute)")
+
+// Step 2
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("ALIGN", "left")
+  assert_equals(el.getAttributeNS("", "ALIGN"), null)
+  assert_equals(el.getAttributeNS("", "align"), "left")
+  assert_equals(el.getAttribute("align"), "left")
+}, "setAttribute should lowercase its name argument (upper case attribute)")
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("CHEEseCaKe", "tasty")
+  assert_equals(el.getAttributeNS("", "CHEEseCaKe"), null)
+  assert_equals(el.getAttributeNS("", "cheesecake"), "tasty")
+  assert_equals(el.getAttribute("cheesecake"), "tasty")
+}, "setAttribute should lowercase its name argument (mixed case attribute)")
+
+// Step 3
+test(function() {
+  var el = document.createElement("foo")
+  var tests = ["xmlns", "xmlns:a", "xmlnsx", "xmlns0"]
+  for (var i = 0; i < tests.length; i++) {
+    el.setAttribute(tests[i], "success");
+  }
+}, "setAttribute should not throw even when qualifiedName starts with 'xmlns'")
+
+// Step 4
+test(function() {
+  var el = document.createElement("foo")
+  for (var i = 0; i < valid_names.length; i++) {
+    el.setAttribute(valid_names[i], "test")
+    assert_equals(el.getAttribute(valid_names[i]), "test")
+  }
+}, "Basic functionality should be intact.")
+
+// Step 5
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttribute("a", "1")
+  el.setAttribute("b", "2")
+  el.setAttribute("a", "3")
+  el.setAttribute("c", "4")
+  attributes_are(el, [["a", "3"],
+                      ["b", "2"],
+                      ["c", "4"]])
+}, "setAttribute should not change the order of previously set attributes.")
+test(function() {
+  var el = document.createElement("baz")
+  el.setAttributeNS("ab", "attr", "fail")
+  el.setAttributeNS("kl", "attr", "pass")
+  el.setAttribute("attr", "pass")
+  attributes_are(el, [["attr", "pass", "ab"],
+                      ["attr", "pass", "kl"]])
+}, "setAttribute should set the first attribute with the given name")
+test(function() {
+  // Based on a test by David Flanagan.
+  var el = document.createElement("baz")
+  el.setAttributeNS("foo", "foo:bar", "1");
+  assert_equals(el.getAttribute("foo:bar"), "1")
+  attr_is(el.attributes[0], "1", "bar", "foo", "foo", "foo:bar")
+  el.setAttribute("foo:bar", "2");
+  assert_equals(el.getAttribute("foo:bar"), "2")
+  attr_is(el.attributes[0], "2", "bar", "foo", "foo", "foo:bar")
+}, "setAttribute should set the attribute with the given qualified name")
+
+// setAttributeNS exhaustive tests
+// Step 1
+test(function() {
+  var el = document.createElement("foo")
+  for (var i = 0, il = invalid_names.length; i < il; ++i) {
+    assert_throws_dom("INVALID_CHARACTER_ERR",
+                      function() { el.setAttributeNS("a", invalid_names[i], "fail") })
+  }
+}, "When qualifiedName does not match the Name production, an " +
+   "INVALID_CHARACTER_ERR exception is to be thrown. (setAttributeNS)")
+
+test(function() {
+  var el = document.getElementById("test2")
+  for (var i = 0; i < el.children.length; i++) {
+    assert_throws_dom("INVALID_CHARACTER_ERR", function() {
+      el.children[i].setAttributeNS(null, "~", "test")
+    })
+  }
+}, "When qualifiedName does not match the Name production, an " +
+   "INVALID_CHARACTER_ERR exception is to be thrown, even if the attribute " +
+   "is already present. (setAttributeNS)")
+
+// Step 2
+test(function() {
+  var el = document.createElement("foo")
+  for (var i = 0, il = invalid_qnames.length; i < il; ++i) {
+    assert_throws_dom("INVALID_CHARACTER_ERR",
+                      function() { el.setAttributeNS("a", invalid_qnames[i], "fail") },
+                      "Expected exception for " + invalid_qnames[i] + ".")
+  }
+}, "When qualifiedName does not match the QName production, an " +
+   "INVALID_CHARACTER_ERR exception is to be thrown.")
+
+// Step 3
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttributeNS(null, "aa", "bb")
+  el.setAttributeNS("", "xx", "bb")
+  attributes_are(el, [["aa", "bb"],
+                      ["xx", "bb"]])
+}, "null and the empty string should result in a null namespace.")
+
+// Step 4
+test(function() {
+  var el = document.createElement("foo")
+  assert_throws_dom("NAMESPACE_ERR",
+                    function() { el.setAttributeNS("", "aa:bb", "fail") })
+  assert_throws_dom("NAMESPACE_ERR",
+                    function() { el.setAttributeNS(null, "aa:bb", "fail") })
+}, "A namespace is required to use a prefix.")
+
+// Step 5
+test(function() {
+  var el = document.createElement("foo")
+  assert_throws_dom("NAMESPACE_ERR",
+                    function() { el.setAttributeNS("a", "xml:bb", "fail") })
+}, "The xml prefix should not be allowed for arbitrary namespaces")
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttributeNS(XML, "a:bb", "pass")
+  assert_equals(el.attributes.length, 1)
+  attr_is(el.attributes[0], "pass", "bb", XML, "a", "a:bb")
+}, "XML-namespaced attributes don't need an xml prefix")
+
+// Step 6
+test(function() {
+  var el = document.createElement("foo")
+  assert_throws_dom("NAMESPACE_ERR",
+                    function() { el.setAttributeNS("a", "xmlns:bb", "fail") })
+}, "The xmlns prefix should not be allowed for arbitrary namespaces")
+test(function() {
+  var el = document.createElement("foo")
+  assert_throws_dom("NAMESPACE_ERR",
+                    function() { el.setAttributeNS("a", "xmlns", "fail") })
+}, "The xmlns qualified name should not be allowed for arbitrary namespaces")
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttributeNS("ns", "a:xmlns", "pass")
+  assert_equals(el.attributes.length, 1)
+  attr_is(el.attributes[0], "pass", "xmlns", "ns", "a", "a:xmlns")
+}, "xmlns should be allowed as local name")
+
+// Step 7
+test(function() {
+  var el = document.createElement("foo")
+  assert_throws_dom("NAMESPACE_ERR",
+                    function() { el.setAttributeNS(XMLNS, "a:xmlns", "fail") })
+  assert_throws_dom("NAMESPACE_ERR",
+                    function() { el.setAttributeNS(XMLNS, "b:foo", "fail") })
+}, "The XMLNS namespace should require xmlns as prefix or qualified name")
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttributeNS(XMLNS, "xmlns:a", "pass")
+  assert_equals(el.attributes.length, 1)
+  attr_is(el.attributes[0], "pass", "a", XMLNS, "xmlns", "xmlns:a")
+}, "xmlns should be allowed as prefix in the XMLNS namespace")
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttributeNS(XMLNS, "xmlns", "pass")
+  assert_equals(el.attributes.length, 1)
+  attr_is(el.attributes[0], "pass", "xmlns", XMLNS, null, "xmlns")
+}, "xmlns should be allowed as qualified name in the XMLNS namespace")
+
+// Step 8-9
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttributeNS("a", "foo:bar", "X")
+  assert_equals(el.attributes.length, 1)
+  attr_is(el.attributes[0], "X", "bar", "a", "foo", "foo:bar")
+
+  el.setAttributeNS("a", "quux:bar", "Y")
+  assert_equals(el.attributes.length, 1)
+  attr_is(el.attributes[0], "Y", "bar", "a", "foo", "foo:bar")
+  el.removeAttributeNS("a", "bar")
+}, "Setting the same attribute with another prefix should not change the prefix")
+
+// Miscellaneous tests
+test(function() {
+  var el = document.createElement("iframe")
+  el.setAttribute("src", "file:///home")
+  assert_equals(el.getAttribute("src"), "file:///home")
+}, "setAttribute should not throw even if a load is not allowed")
+test(function() {
+  var docFragment = document.createDocumentFragment()
+  var newOne = document.createElement("newElement")
+  newOne.setAttribute("newdomestic", "Yes")
+  docFragment.appendChild(newOne)
+  var domesticNode = docFragment.firstChild
+  var attr = domesticNode.attributes.item(0)
+  attr_is(attr, "Yes", "newdomestic", null, null, "newdomestic")
+}, "Attributes should work in document fragments.")
+test(function() {
+  var el = document.createElement("foo")
+  el.setAttribute("x", "y")
+  var attr = el.attributes[0]
+  attr.value = "Y&lt;"
+  attr_is(attr, "Y&lt;", "x", null, null, "x")
+  assert_equals(el.getAttribute("x"), "Y&lt;")
+}, "Attribute values should not be parsed.")
+test(function() {
+  var el = document.getElementsByTagName("span")[0]
+  attr_is(el.attributes[0], "test1", "id", null, null, "id")
+}, "Specified attributes should be accessible.")
+test(function() {
+  var el = document.getElementsByTagName("span")[1]
+  attr_is(el.attributes[0], "&<>foo", "class", null, null, "class")
+}, "Entities in attributes should have been expanded while parsing.")
+
+test(function() {
+  var el = document.createElement("div")
+  assert_equals(el.hasAttribute("bar"), false)
+  assert_equals(el.hasAttributeNS(null, "bar"), false)
+  assert_equals(el.hasAttributeNS("", "bar"), false)
+  assert_equals(el.getAttribute("bar"), null)
+  assert_equals(el.getAttributeNS(null, "bar"), null)
+  assert_equals(el.getAttributeNS("", "bar"), null)
+}, "Unset attributes return null")
+test(function() {
+  var el = document.createElement("div")
+  el.setAttributeNS("ab", "attr", "t1")
+  el.setAttributeNS("kl", "attr", "t2")
+  assert_equals(el.hasAttribute("attr"), true)
+  assert_equals(el.hasAttributeNS("ab", "attr"), true)
+  assert_equals(el.hasAttributeNS("kl", "attr"), true)
+  assert_equals(el.getAttribute("attr"), "t1")
+  assert_equals(el.getAttributeNS("ab", "attr"), "t1")
+  assert_equals(el.getAttributeNS("kl", "attr"), "t2")
+  assert_equals(el.getAttributeNS(null, "attr"), null)
+  assert_equals(el.getAttributeNS("", "attr"), null)
+}, "First set attribute is returned by getAttribute")
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("style", "color:#fff;")
+  assert_equals(el.hasAttribute("style"), true)
+  assert_equals(el.hasAttributeNS(null, "style"), true)
+  assert_equals(el.hasAttributeNS("", "style"), true)
+  assert_equals(el.getAttribute("style"), "color:#fff;")
+  assert_equals(el.getAttributeNS(null, "style"), "color:#fff;")
+  assert_equals(el.getAttributeNS("", "style"), "color:#fff;")
+}, "Style attributes are not normalized")
+test(function() {
+  var el = document.createElement("div")
+  el.setAttributeNS("", "ALIGN", "left")
+  assert_equals(el.hasAttribute("ALIGN"), false)
+  assert_equals(el.hasAttribute("align"), false)
+  assert_equals(el.hasAttributeNS(null, "ALIGN"), true)
+  assert_equals(el.hasAttributeNS(null, "align"), false)
+  assert_equals(el.hasAttributeNS("", "ALIGN"), true)
+  assert_equals(el.hasAttributeNS("", "align"), false)
+  assert_equals(el.getAttribute("ALIGN"), null)
+  assert_equals(el.getAttribute("align"), null)
+  assert_equals(el.getAttributeNS(null, "ALIGN"), "left")
+  assert_equals(el.getAttributeNS("", "ALIGN"), "left")
+  assert_equals(el.getAttributeNS(null, "align"), null)
+  assert_equals(el.getAttributeNS("", "align"), null)
+  el.removeAttributeNS("", "ALIGN")
+}, "Only lowercase attributes are returned on HTML elements (upper case attribute)")
+test(function() {
+  var el = document.createElement("div")
+  el.setAttributeNS("", "CHEEseCaKe", "tasty")
+  assert_equals(el.hasAttribute("CHEESECAKE"), false)
+  assert_equals(el.hasAttribute("CHEEseCaKe"), false)
+  assert_equals(el.hasAttribute("cheesecake"), false)
+  assert_equals(el.hasAttributeNS("", "CHEESECAKE"), false)
+  assert_equals(el.hasAttributeNS("", "CHEEseCaKe"), true)
+  assert_equals(el.hasAttributeNS("", "cheesecake"), false)
+  assert_equals(el.hasAttributeNS(null, "CHEESECAKE"), false)
+  assert_equals(el.hasAttributeNS(null, "CHEEseCaKe"), true)
+  assert_equals(el.hasAttributeNS(null, "cheesecake"), false)
+  assert_equals(el.getAttribute("CHEESECAKE"), null)
+  assert_equals(el.getAttribute("CHEEseCaKe"), null)
+  assert_equals(el.getAttribute("cheesecake"), null)
+  assert_equals(el.getAttributeNS(null, "CHEESECAKE"), null)
+  assert_equals(el.getAttributeNS("", "CHEESECAKE"), null)
+  assert_equals(el.getAttributeNS(null, "CHEEseCaKe"), "tasty")
+  assert_equals(el.getAttributeNS("", "CHEEseCaKe"), "tasty")
+  assert_equals(el.getAttributeNS(null, "cheesecake"), null)
+  assert_equals(el.getAttributeNS("", "cheesecake"), null)
+  el.removeAttributeNS("", "CHEEseCaKe")
+}, "Only lowercase attributes are returned on HTML elements (mixed case attribute)")
+test(function() {
+  var el = document.createElement("div")
+  document.body.appendChild(el)
+  el.setAttributeNS("", "align", "left")
+  el.setAttributeNS("xx", "align", "right")
+  el.setAttributeNS("", "foo", "left")
+  el.setAttributeNS("xx", "foo", "right")
+  assert_equals(el.hasAttribute("align"), true)
+  assert_equals(el.hasAttribute("foo"), true)
+  assert_equals(el.hasAttributeNS("xx", "align"), true)
+  assert_equals(el.hasAttributeNS(null, "foo"), true)
+  assert_equals(el.getAttribute("align"), "left")
+  assert_equals(el.getAttribute("foo"), "left")
+  assert_equals(el.getAttributeNS("xx", "align"), "right")
+  assert_equals(el.getAttributeNS(null, "foo"), "left")
+  assert_equals(el.getAttributeNS("", "foo"), "left")
+  el.removeAttributeNS("", "align")
+  el.removeAttributeNS("xx", "align")
+  el.removeAttributeNS("", "foo")
+  el.removeAttributeNS("xx", "foo")
+  document.body.removeChild(el)
+}, "First set attribute is returned with mapped attribute set first")
+test(function() {
+  var el = document.createElement("div")
+  el.setAttributeNS("xx", "align", "right")
+  el.setAttributeNS("", "align", "left")
+  el.setAttributeNS("xx", "foo", "right")
+  el.setAttributeNS("", "foo", "left")
+  assert_equals(el.hasAttribute("align"), true)
+  assert_equals(el.hasAttribute("foo"), true)
+  assert_equals(el.hasAttributeNS("xx", "align"), true)
+  assert_equals(el.hasAttributeNS(null, "foo"), true)
+  assert_equals(el.getAttribute("align"), "right")
+  assert_equals(el.getAttribute("foo"), "right")
+  assert_equals(el.getAttributeNS("xx", "align"), "right")
+  assert_equals(el.getAttributeNS(null, "foo"), "left")
+  assert_equals(el.getAttributeNS("", "foo"), "left")
+  el.removeAttributeNS("", "align")
+  el.removeAttributeNS("xx", "align")
+  el.removeAttributeNS("", "foo")
+  el.removeAttributeNS("xx", "foo")
+}, "First set attribute is returned with mapped attribute set later")
+
+test(function() {
+  var el = document.createElementNS("http://www.example.com", "foo")
+  el.setAttribute("A", "test")
+  assert_equals(el.hasAttribute("A"), true, "hasAttribute()")
+  assert_equals(el.hasAttributeNS("", "A"), true, "el.hasAttributeNS(\"\")")
+  assert_equals(el.hasAttributeNS(null, "A"), true, "el.hasAttributeNS(null)")
+  assert_equals(el.hasAttributeNS(undefined, "A"), true, "el.hasAttributeNS(undefined)")
+  assert_equals(el.hasAttributeNS("foo", "A"), false, "el.hasAttributeNS(\"foo\")")
+
+  assert_equals(el.getAttribute("A"), "test", "getAttribute()")
+  assert_equals(el.getAttributeNS("", "A"), "test", "el.getAttributeNS(\"\")")
+  assert_equals(el.getAttributeNS(null, "A"), "test", "el.getAttributeNS(null)")
+  assert_equals(el.getAttributeNS(undefined, "A"), "test", "el.getAttributeNS(undefined)")
+  assert_equals(el.getAttributeNS("foo", "A"), null, "el.getAttributeNS(\"foo\")")
+}, "Non-HTML element with upper-case attribute")
+
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("pre:fix", "value 1")
+  el.setAttribute("fix", "value 2")
+
+  var prefixed = el.attributes[0]
+  assert_equals(prefixed.localName, "pre:fix", "prefixed local name")
+  assert_equals(prefixed.namespaceURI, null, "prefixed namespace")
+
+  var unprefixed = el.attributes[1]
+  assert_equals(unprefixed.localName, "fix", "unprefixed local name")
+  assert_equals(unprefixed.namespaceURI, null, "unprefixed namespace")
+
+  el.removeAttributeNS(null, "pre:fix")
+  assert_equals(el.attributes[0], unprefixed)
+}, "Attribute with prefix in local name")
+
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("foo", "bar")
+  var attr = el.attributes[0]
+  assert_equals(attr.ownerElement, el)
+  el.removeAttribute("foo")
+  assert_equals(attr.ownerElement, null)
+}, "Attribute loses its owner when removed")
+
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("foo", "bar")
+  var attr = el.attributes[0]
+  var attrNode = el.getAttributeNode("foo");
+  var attrNodeNS = el.getAttributeNodeNS("", "foo");
+  assert_equals(attr, attrNode);
+  assert_equals(attr, attrNodeNS);
+  el.setAttributeNS("x", "foo2", "bar2");
+  var attr2 = el.attributes[1];
+  var attrNodeNS2 = el.getAttributeNodeNS("x", "foo2");
+  assert_equals(attr2, attrNodeNS2);
+}, "Basic functionality of getAttributeNode/getAttributeNodeNS")
+
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("foo", "bar")
+  var attrNode = el.getAttributeNode("foo");
+  var attrNodeNS = el.getAttributeNodeNS("", "foo");
+  assert_equals(attrNode, attrNodeNS);
+  el.removeAttribute("foo");
+  var el2 = document.createElement("div");
+  el2.setAttributeNode(attrNode);
+  assert_equals(attrNode, el2.getAttributeNode("foo"));
+  assert_equals(attrNode, el2.attributes[0]);
+  assert_equals(attrNode.ownerElement, el2);
+  assert_equals(attrNode.value, "bar");
+
+   var el3 = document.createElement("div");
+   el2.removeAttribute("foo");
+   el3.setAttribute("foo", "baz");
+   el3.setAttributeNode(attrNode);
+   assert_equals(el3.getAttribute("foo"), "bar");
+}, "Basic functionality of setAttributeNode")
+
+test(function() {
+  var el = document.createElement("div");
+  var attr1 = document.createAttributeNS("ns1", "p1:name");
+  attr1.value = "value1";
+  var attr2 = document.createAttributeNS("ns2", "p2:name");
+  attr2.value = "value2";
+  el.setAttributeNode(attr1);
+  el.setAttributeNode(attr2);
+  assert_equals(el.getAttributeNodeNS("ns1", "name").value, "value1");
+  assert_equals(el.getAttributeNodeNS("ns2", "name").value, "value2");
+}, "setAttributeNode should distinguish attributes with same local name and different namespaces")
+
+test(function() {
+  var el = document.createElement("div");
+  var attr1 = document.createAttributeNS("ns1", "p1:name");
+  attr1.value = "value1";
+  var attr2 = document.createAttributeNS("ns1", "p1:NAME");
+  attr2.value = "VALUE2";
+  el.setAttributeNode(attr1);
+  el.setAttributeNode(attr2);
+  assert_equals(el.getAttributeNodeNS("ns1", "name").value, "value1");
+  assert_equals(el.getAttributeNodeNS("ns1", "NAME").value, "VALUE2");
+}, "setAttributeNode doesn't have case-insensitivity even with an HTMLElement")
+
+test(function() {
+  var el = document.createElement("div")
+  el.setAttributeNS("x", "foo", "bar")
+  var attrNode = el.getAttributeNodeNS("x", "foo");
+  el.removeAttribute("foo");
+  var el2 = document.createElement("div");
+  el2.setAttributeNS("x", "foo", "baz");
+  el2.setAttributeNodeNS(attrNode);
+  assert_equals(el2.getAttributeNS("x", "foo"), "bar");
+}, "Basic functionality of setAttributeNodeNS")
+
+test(function() {
+  var el = document.createElement("div");
+  var other = document.createElement("div");
+  var attr = document.createAttribute("foo");
+  assert_equals(el.setAttributeNode(attr), null);
+  assert_equals(attr.ownerElement, el);
+  assert_throws_dom("INUSE_ATTRIBUTE_ERR",
+                  function() { other.setAttributeNode(attr) },
+                  "Attribute already associated with el")
+}, "If attr’s element is neither null nor element, throw an InUseAttributeError.");
+
+test(function() {
+  var el = document.createElement("div");
+  var attr = document.createAttribute("foo");
+  assert_equals(el.setAttributeNode(attr), null);
+  el.setAttribute("bar", "qux");
+  assert_equals(el.setAttributeNode(attr), attr);
+  assert_equals(el.attributes[0], attr);
+}, "Replacing an attr by itself");
+
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("foo", "bar")
+  var attrNode = el.getAttributeNode("foo");
+  el.removeAttributeNode(attrNode);
+  var el2 = document.createElement("div");
+  el2.setAttributeNode(attrNode);
+  assert_equals(el2.attributes[0], attrNode);
+  assert_equals(el.attributes.length, 0);
+}, "Basic functionality of removeAttributeNode")
+
+test(function() {
+  var el = document.createElement("div")
+  el.setAttribute("foo", "bar")
+  var attrNode = el.getAttributeNode("foo");
+  var el2 = document.createElement("div");
+  assert_throws_dom("INUSE_ATTRIBUTE_ERR", function(){el2.setAttributeNode(attrNode)});
+}, "setAttributeNode on bound attribute should throw InUseAttributeError")
+
+// Have to use an async_test to see what a DOMAttrModified listener sees,
+// because otherwise the event dispatch code will swallow our exceptions.  And
+// we want to make sure this test always happens, even when no mutation events
+// run.
+var setAttributeNode_mutation_test = async_test("setAttributeNode, if it fires mutation events, should fire one with the new node when resetting an existing attribute");
+
+test(function(){
+  var el = document.createElement("div")
+  var attrNode1 = document.createAttribute("foo");
+  attrNode1.value = "bar";
+  el.setAttributeNode(attrNode1);
+  var attrNode2 = document.createAttribute("foo");
+  attrNode2.value = "baz";
+
+  el.addEventListener("DOMAttrModified", function(e) {
+    // If this never gets called, that's OK, I guess.  But if it gets called, it
+    // better represent a single modification with attrNode2 as the relatedNode.
+    // We have to do an inner test() call here, because otherwise the exceptions
+    // our asserts trigger will get swallowed by the event dispatch code.
+    setAttributeNode_mutation_test.step(function() {
+      assert_equals(e.attrName, "foo");
+      assert_equals(e.attrChange, MutationEvent.MODIFICATION);
+      assert_equals(e.prevValue, "bar");
+      assert_equals(e.newValue, "baz");
+      assert_equals(e.relatedNode, attrNode2);
+    });
+  });
+
+  var oldNode = el.setAttributeNode(attrNode2);
+  assert_equals(oldNode, attrNode1,
+                "Must return the old attr node from a setAttributeNode call");
+}, "setAttributeNode, if it fires mutation events, should fire one with the new node when resetting an existing attribute (outer shell)");
+setAttributeNode_mutation_test.done();
+
+test(function(){
+  var el = document.createElement("div")
+  el.setAttribute("a", "b");
+  el.setAttribute("c", "d");
+
+  assert_array_equals(Array.prototype.map.call(el.attributes, function(a) { return a.name }),
+                      ["a", "c"]);
+  assert_array_equals(Array.prototype.map.call(el.attributes, function(a) { return a.value }),
+                      ["b", "d"]);
+
+  var attrNode = document.createAttribute("a");
+  attrNode.value = "e";
+  el.setAttributeNode(attrNode);
+
+  assert_array_equals(Array.prototype.map.call(el.attributes, function(a) { return a.name }),
+                      ["a", "c"]);
+  assert_array_equals(Array.prototype.map.call(el.attributes, function(a) { return a.value }),
+                      ["e", "d"]);
+}, "setAttributeNode called with an Attr that has the same name as an existing one should not change attribute order");
+
+test(function() {
+  var el = document.createElement("div");
+  el.setAttribute("foo", "bar");
+  assert_equals(el.getAttributeNames().length, 1);
+  assert_equals(el.getAttributeNames()[0], el.attributes[0].name);
+  assert_equals(el.getAttributeNames()[0], "foo");
+
+  el.removeAttribute("foo");
+  assert_equals(el.getAttributeNames().length, 0);
+
+  el.setAttribute("foo", "bar");
+  el.setAttributeNS("", "FOO", "bar");
+  el.setAttributeNS("dummy1", "foo", "bar");
+  el.setAttributeNS("dummy2", "dummy:foo", "bar");
+  assert_equals(el.getAttributeNames().length, 4);
+  assert_equals(el.getAttributeNames()[0], "foo");
+  assert_equals(el.getAttributeNames()[1], "FOO");
+  assert_equals(el.getAttributeNames()[2], "foo");
+  assert_equals(el.getAttributeNames()[3], "dummy:foo");
+  assert_equals(el.getAttributeNames()[0], el.attributes[0].name);
+  assert_equals(el.getAttributeNames()[1], el.attributes[1].name);
+  assert_equals(el.getAttributeNames()[2], el.attributes[2].name);
+  assert_equals(el.getAttributeNames()[3], el.attributes[3].name);
+
+  el.removeAttributeNS("", "FOO");
+  assert_equals(el.getAttributeNames().length, 3);
+  assert_equals(el.getAttributeNames()[0], "foo");
+  assert_equals(el.getAttributeNames()[1], "foo");
+  assert_equals(el.getAttributeNames()[2], "dummy:foo");
+  assert_equals(el.getAttributeNames()[0], el.attributes[0].name);
+  assert_equals(el.getAttributeNames()[1], el.attributes[1].name);
+  assert_equals(el.getAttributeNames()[2], el.attributes[2].name);
+}, "getAttributeNames tests");
+
+function getEnumerableOwnProps1(obj) {
+  var arr = [];
+  for (var prop in obj) {
+    if (obj.hasOwnProperty(prop)) {
+      arr.push(prop);
+    }
+  }
+  return arr;
+}
+
+function getEnumerableOwnProps2(obj) {
+  return Object.getOwnPropertyNames(obj).filter(
+    function (name) { return Object.getOwnPropertyDescriptor(obj, name).enumerable; })
+}
+
+test(function() {
+  var el = document.createElement("div");
+  el.setAttribute("a", "");
+  el.setAttribute("b", "");
+  assert_array_equals(getEnumerableOwnProps1(el.attributes),
+                      ["0", "1"])
+  assert_array_equals(getEnumerableOwnProps2(el.attributes),
+                      ["0", "1"])
+  assert_array_equals(Object.getOwnPropertyNames(el.attributes),
+                      ["0", "1", "a", "b"])
+}, "Own property correctness with basic attributes");
+
+test(function() {
+  var el = document.createElement("div");
+  el.setAttributeNS("", "a", "");
+  el.setAttribute("b", "");
+  el.setAttributeNS("foo", "a", "");
+  assert_array_equals(getEnumerableOwnProps1(el.attributes),
+                      ["0", "1", "2"])
+  assert_array_equals(getEnumerableOwnProps2(el.attributes),
+                      ["0", "1", "2"])
+  assert_array_equals(Object.getOwnPropertyNames(el.attributes),
+                      ["0", "1", "2", "a", "b"])
+  for (var propName of Object.getOwnPropertyNames(el.attributes)) {
+    assert_true(el.attributes[propName] instanceof Attr,
+                "el.attributes has an Attr for property name " + propName);
+  }
+}, "Own property correctness with non-namespaced attribute before same-name namespaced one");
+
+test(function() {
+  var el = document.createElement("div");
+  el.setAttributeNS("foo", "a", "");
+  el.setAttribute("b", "");
+  el.setAttributeNS("", "a", "");
+  assert_array_equals(getEnumerableOwnProps1(el.attributes),
+                      ["0", "1", "2"])
+  assert_array_equals(getEnumerableOwnProps2(el.attributes),
+                      ["0", "1", "2"])
+  assert_array_equals(Object.getOwnPropertyNames(el.attributes),
+                      ["0", "1", "2", "a", "b"])
+  for (var propName of Object.getOwnPropertyNames(el.attributes)) {
+    assert_true(el.attributes[propName] instanceof Attr,
+                "el.attributes has an Attr for property name " + propName);
+  }
+}, "Own property correctness with namespaced attribute before same-name non-namespaced one");
+
+test(function() {
+  var el = document.createElement("div");
+  el.setAttributeNS("foo", "a:b", "");
+  el.setAttributeNS("foo", "c:d", "");
+  el.setAttributeNS("bar", "a:b", "");
+  assert_array_equals(getEnumerableOwnProps1(el.attributes),
+                      ["0", "1", "2"])
+  assert_array_equals(getEnumerableOwnProps2(el.attributes),
+                      ["0", "1", "2"])
+  assert_array_equals(Object.getOwnPropertyNames(el.attributes),
+                      ["0", "1", "2", "a:b", "c:d"])
+  for (var propName of Object.getOwnPropertyNames(el.attributes)) {
+    assert_true(el.attributes[propName] instanceof Attr,
+                "el.attributes has an Attr for property name " + propName);
+  }
+}, "Own property correctness with two namespaced attributes with the same name-with-prefix");
+
+test(function() {
+  var el = document.createElement("div");
+  el.setAttributeNS("foo", "A:B", "");
+  el.setAttributeNS("bar", "c:D", "");
+  el.setAttributeNS("baz", "e:F", "");
+  el.setAttributeNS("qux", "g:h", "");
+  el.setAttributeNS("", "I", "");
+  el.setAttributeNS("", "j", "");
+  assert_array_equals(Object.getOwnPropertyNames(el.attributes),
+                      ["0", "1", "2", "3", "4", "5", "g:h", "j"])
+  for (var propName of Object.getOwnPropertyNames(el.attributes)) {
+    assert_true(el.attributes[propName] instanceof Attr,
+                "el.attributes has an Attr for property name " + propName);
+  }
+}, "Own property names should only include all-lowercase qualified names for an HTML element in an HTML document");
+
+test(function() {
+  var el = document.createElementNS("", "div");
+  el.setAttributeNS("foo", "A:B", "");
+  el.setAttributeNS("bar", "c:D", "");
+  el.setAttributeNS("baz", "e:F", "");
+  el.setAttributeNS("qux", "g:h", "");
+  el.setAttributeNS("", "I", "");
+  el.setAttributeNS("", "j", "");
+  assert_array_equals(Object.getOwnPropertyNames(el.attributes),
+                      ["0", "1", "2", "3", "4", "5", "A:B", "c:D", "e:F", "g:h", "I", "j"])
+  for (var propName of Object.getOwnPropertyNames(el.attributes)) {
+    assert_true(el.attributes[propName] instanceof Attr,
+                "el.attributes has an Attr for property name " + propName);
+  }
+}, "Own property names should include all qualified names for a non-HTML element in an HTML document");
+
+test(function() {
+  var doc = document.implementation.createDocument(null, "");
+  assert_equals(doc.contentType, "application/xml");
+  var el = doc.createElementNS("http://www.w3.org/1999/xhtml", "div");
+  el.setAttributeNS("foo", "A:B", "");
+  el.setAttributeNS("bar", "c:D", "");
+  el.setAttributeNS("baz", "e:F", "");
+  el.setAttributeNS("qux", "g:h", "");
+  el.setAttributeNS("", "I", "");
+  el.setAttributeNS("", "j", "");
+  assert_array_equals(Object.getOwnPropertyNames(el.attributes),
+                      ["0", "1", "2", "3", "4", "5", "A:B", "c:D", "e:F", "g:h", "I", "j"])
+  for (var propName of Object.getOwnPropertyNames(el.attributes)) {
+    assert_true(el.attributes[propName] instanceof Attr,
+                "el.attributes has an Attr for property name " + propName);
+  }
+}, "Own property names should include all qualified names for an HTML element in a non-HTML document");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/attributes.js b/testing/web-platform/tests/dom/nodes/attributes.js
new file mode 100644
index 0000000000..ef32bf6a67
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/attributes.js
@@ -0,0 +1,18 @@
+function attr_is(attr, v, ln, ns, p, n) {
+  assert_equals(attr.value, v)
+  assert_equals(attr.nodeValue, v)
+  assert_equals(attr.textContent, v)
+  assert_equals(attr.localName, ln)
+  assert_equals(attr.namespaceURI, ns)
+  assert_equals(attr.prefix, p)
+  assert_equals(attr.name, n)
+  assert_equals(attr.nodeName, n);
+  assert_equals(attr.specified, true)
+}
+
+function attributes_are(el, l) {
+  for (var i = 0, il = l.length; i < il; i++) {
+    attr_is(el.attributes[i], l[i][1], l[i][0], (l[i].length < 3) ? null : l[i][2], null, l[i][0])
+    assert_equals(el.attributes[i].ownerElement, el)
+  }
+}
diff --git a/testing/web-platform/tests/dom/nodes/case.html b/testing/web-platform/tests/dom/nodes/case.html
new file mode 100644
index 0000000000..c3c195141c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/case.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Tests for case-sensitivity in APIs</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createelement">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-createelementns">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementsbytagname">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementsbytagnamens">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-setattribute">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-setattributens">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-hasattribute">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-hasattributens">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-getelementsbytagname">
+<link rel=help href="https://dom.spec.whatwg.org/#dom-element-getelementsbytagnamens">
+<script>var is_html = true;</script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="case.js"></script>
+<div id="log"></div>
diff --git a/testing/web-platform/tests/dom/nodes/case.js b/testing/web-platform/tests/dom/nodes/case.js
new file mode 100644
index 0000000000..8c2da4a44a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/case.js
@@ -0,0 +1,186 @@
+/*
+ * document.createElement(NS)
+ *
+ * document.getElementsByTagName(NS)
+ *
+ * Element.setAttribute(NS)
+ *
+ * Element.getAttribute(NS)
+ * Element.hasAttribute(NS)
+ * Element.getElementsByTagName(NS)
+ */
+
+var tests = [];
+setup(function() {
+        var name_inputs = ["abc", "Abc", "ABC", "ä", "Ä"];
+        var namespaces = ["http://www.w3.org/1999/xhtml", "http://www.w3.org/2000/svg", "http://FOO"];
+        name_inputs.forEach(function(x) {
+                              tests.push(["createElement " + x, test_create_element, [x]]);
+                              tests.push(["setAttribute " +x, test_set_attribute, [x]]);
+                              tests.push(["getAttribute " +x, test_get_attribute, [x]]);
+                              tests.push(["getElementsByTagName a:" +x, test_get_elements_tag_name,
+                                          [outer_product(namespaces, ["a"], name_inputs),
+                                           x]]);
+                              tests.push(["getElementsByTagName " +x, test_get_elements_tag_name,
+                                          [outer_product(namespaces, [null], name_inputs),
+                                           x]]);
+                            });
+        outer_product(namespaces, name_inputs, name_inputs).forEach(function(x) {
+                                                                      tests.push(["createElementNS " + x, test_create_element_ns, x]);
+                                                                      tests.push(["setAttributeNS " + x, test_set_attribute_ns, x]);
+                                                                      tests.push(["getAttributeNS " + x, test_get_attribute_ns, x]);
+                                                                    });
+        outer_product([null].concat(namespaces), name_inputs).forEach(function(x) {
+                                                                        tests.push(["getElementsByTagNameNS " + x, test_get_elements_tag_name_ns,
+                                                                        outer_product(namespaces, name_inputs), x]);
+                                                                      });
+        name_inputs.forEach(function(x) {
+                              tests.push(["createElementNS " + x, test_create_element_ns, [null, null, x]]);
+                              tests.push(["setAttributeNS " + x, test_set_attribute_ns, [null, null, x]]);
+                              tests.push(["getAttributeNS " + x, test_get_attribute_ns, [null, null, x]]);
+                            });
+
+      });
+function outer_product() {
+  var rv = [];
+  function compute_outer_product() {
+    var args = Array.prototype.slice.call(arguments);
+    var index = args[0];
+    if (index < args.length) {
+      args[index].forEach(function(x) {
+                           compute_outer_product.apply(this, [index+1].concat(args.slice(1, index), x, args.slice(index+1)));
+                          });
+    } else {
+      rv.push(args.slice(1));
+    }
+  }
+  compute_outer_product.apply(this, [1].concat(Array.prototype.slice.call(arguments)));
+  return rv;
+}
+
+function expected_case(input) {
+  //is_html gets set by a global on the page loading the tests
+  if (is_html) {
+    return ascii_lowercase(input);
+  } else {
+    return input;
+  }
+}
+
+function ascii_lowercase(input) {
+  return input.replace(/[A-Z]/g, function(x) {
+                         return x.toLowerCase();
+                       });
+}
+
+function get_qualified_name(el) {
+  if (el.prefix) {
+    return el.prefix + ":" + el.localName;
+  }
+  return el.localName;
+}
+
+function test_create_element(name) {
+  var node = document.createElement(name);
+  assert_equals(node.localName, expected_case(name));
+}
+
+function test_create_element_ns(namespace, prefix, local_name) {
+  var qualified_name = prefix ? prefix + ":" + local_name : local_name;
+  var node = document.createElementNS(namespace, qualified_name);
+  assert_equals(node.prefix, prefix, "prefix");
+  assert_equals(node.localName, local_name, "localName");
+}
+
+function test_set_attribute(name) {
+  var node = document.createElement("div");
+  node.setAttribute(name, "test");
+  assert_equals(node.attributes[0].localName, expected_case(name));
+}
+
+function test_set_attribute_ns(namespace, prefix, local_name) {
+  var qualified_name = prefix ? prefix + ":" + local_name : local_name;
+  var node = document.createElement("div");
+  node.setAttributeNS(namespace, qualified_name, "test");
+  var attr = node.attributes[0];
+  assert_equals(attr.prefix, prefix, "prefix");
+  assert_equals(attr.localName, local_name, "localName");
+}
+
+function test_get_attribute(name) {
+  var node = document.createElement("div");
+  node.setAttribute(name, "test");
+  var expected_name = expected_case(name);
+  assert_equals(node.getAttribute(expected_name), "test");
+  if (expected_name != name) {
+    assert_equals(node.getAttribute(expected_name), "test");
+  } else if (name !== ascii_lowercase(name)) {
+    assert_equals(node.getAttribute(ascii_lowercase(name)), null);
+  }
+}
+
+function test_get_attribute_ns(namespace, prefix, local_name) {
+  var qualified_name = prefix ? prefix + ":" + local_name : local_name;
+  var node = document.createElement("div");
+  node.setAttributeNS(namespace, qualified_name, "test");
+  var expected_name = local_name;
+  assert_equals(node.getAttributeNS(namespace, expected_name), "test");
+  if (local_name !== ascii_lowercase(local_name)) {
+    assert_equals(node.getAttributeNS(namespace, ascii_lowercase(local_name)), null);
+  }
+}
+
+function test_get_elements_tag_name(elements_to_create, search_string) {
+  var container = document.createElement("div");
+  elements_to_create.forEach(function(x) {
+                               var qualified_name = x[1] ? x[1] + ":" + x[2] : x[2];
+                               var element = document.createElementNS(x[0], qualified_name);
+                               container.appendChild(element);
+                             });
+  var expected = Array.prototype.filter.call(container.childNodes,
+                                            function(node) {
+                                              if (is_html && node.namespaceURI === "http://www.w3.org/1999/xhtml") {
+                                                return get_qualified_name(node) === expected_case(search_string);
+                                              } else {
+                                                return get_qualified_name(node) === search_string;
+                                              }
+                                            });
+  document.documentElement.appendChild(container);
+  try {
+    assert_array_equals(document.getElementsByTagName(search_string), expected);
+  } finally {
+    document.documentElement.removeChild(container);
+  }
+}
+
+function test_get_elements_tag_name_ns(elements_to_create, search_input) {
+  var search_uri = search_input[0];
+  var search_name = search_input[1];
+  var container = document.createElement("div");
+  elements_to_create.forEach(function(x) {
+                               var qualified_name = x[1] ? x[1] + ":" + x[2] : x[2];
+                               var element = document.createElementNS(x[0], qualified_name);
+                               container.appendChild(element);
+                             });
+  var expected = Array.prototype.filter.call(container.childNodes,
+                                            function(node) {
+                                              return node.namespaceURI === search_uri;
+                                              return node.localName === search_name;
+                                            });
+  document.documentElement.appendChild(container);
+  try {
+    assert_array_equals(document.getElementsByTagNameNS(search_uri, search_name), expected);
+  } catch(e) {
+    throw e;
+  } finally {
+    document.documentElement.removeChild(container);
+  }
+}
+
+function test_func() {
+  var func = arguments[0];
+  var rest = arguments[1];
+  func.apply(this, rest);
+}
+
+generate_tests(test_func, tests);
diff --git a/testing/web-platform/tests/dom/nodes/characterset-helper.js b/testing/web-platform/tests/dom/nodes/characterset-helper.js
new file mode 100644
index 0000000000..ecbe556ae2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/characterset-helper.js
@@ -0,0 +1,62 @@
+function runCharacterSetTests(encodingMap) {
+  // Add spaces and mix up case
+  Object.keys(encodingMap).forEach(function(name) {
+    var lower = encodingMap[name];
+    var upper = encodingMap[name].map(function(s) { return s.toUpperCase() });
+    var mixed = encodingMap[name].map(function(s) {
+      var ret = "";
+      for (var i = 0; i < s.length; i += 2) {
+        ret += s[i].toUpperCase();
+        if (i + 1 < s.length) {
+          ret += s[i + 1];
+        }
+      }
+      return ret;
+    });
+    var spacey = encodingMap[name].map(function(s) {
+      return " \t\n\f\r" + s + " \t\n\f\r";
+    });
+    encodingMap[name] = [];
+    for (var i = 0; i < lower.length; i++) {
+      encodingMap[name].push(lower[i]);
+      /*
+      if (lower[i] != upper[i]) {
+        encodingMap[name].push(upper[i]);
+      }
+      if (lower[i] != mixed[i] && upper[i] != mixed[i]) {
+        encodingMap[name].push(mixed[i]);
+      }
+      encodingMap[name].push(spacey[i]);
+      */
+    }
+  });
+
+  Object.keys(encodingMap).forEach(function(name) {
+    encodingMap[name].forEach(function(label) {
+      var iframe = document.createElement("iframe");
+      var t = async_test("Name " + format_value(name) +
+                        " has label " + format_value(label) + " (characterSet)");
+      var t2 = async_test("Name " + format_value(name) +
+                        " has label " + format_value(label) + " (inputEncoding)");
+      var t3 = async_test("Name " + format_value(name) +
+                        " has label " + format_value(label) + " (charset)");
+      iframe.src = "encoding.py?label=" + label;
+      iframe.onload = function() {
+        t.step(function() {
+          assert_equals(iframe.contentDocument.characterSet, name);
+        });
+        t2.step(function() {
+          assert_equals(iframe.contentDocument.inputEncoding, name);
+        });
+        t3.step(function() {
+          assert_equals(iframe.contentDocument.charset, name);
+        });
+        document.body.removeChild(iframe);
+        t.done();
+        t2.done();
+        t3.done();
+      };
+      document.body.appendChild(iframe);
+    });
+  });
+}
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/nodes/creators.js b/testing/web-platform/tests/dom/nodes/creators.js
new file mode 100644
index 0000000000..8b7415d13f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/creators.js
@@ -0,0 +1,5 @@
+var creators = {
+  "element": "createElement",
+  "text": "createTextNode",
+  "comment": "createComment"
+};
diff --git a/testing/web-platform/tests/dom/nodes/encoding.py b/testing/web-platform/tests/dom/nodes/encoding.py
new file mode 100644
index 0000000000..15edff7061
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/encoding.py
@@ -0,0 +1,7 @@
+from html import escape
+
+from wptserve.utils import isomorphic_decode
+
+def main(request, response):
+    label = request.GET.first(b'label')
+    return u"""<!doctype html><meta charset="%s">""" % escape(isomorphic_decode(label))
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-01.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-01.htm
new file mode 100644
index 0000000000..457d6c400f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-01.htm
@@ -0,0 +1,13 @@
+<!doctype html>
+<html class="a">
+ <head>
+  <title>document.getElementsByClassName(): simple</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a">
+  <div id="log"></div>
+  <script> test(function() {assert_array_equals(document.getElementsByClassName("\ta\n"),
+                                                [document.documentElement, document.body])}) </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-02.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-02.htm
new file mode 100644
index 0000000000..d5e513fa88
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-02.htm
@@ -0,0 +1,14 @@
+<!doctype html>
+<html class="a
+b">
+ <head>
+  <title>document.getElementsByClassName(): also simple</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a
+">
+  <div id="log"></div>
+  <script> test(function() {assert_array_equals(document.getElementsByClassName("a\n"), [document.documentElement, document.body])}) </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-03.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-03.htm
new file mode 100644
index 0000000000..a9e2d3af1a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-03.htm
@@ -0,0 +1,18 @@
+<!doctype html>
+<html class="a">
+ <head>
+  <title>document.getElementsByClassName(): changing classes</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a">
+  <div id="log"></div>
+  <script>
+   test(function() {
+          var collection = document.getElementsByClassName("a")
+          document.body.className = "b"
+          assert_array_equals(collection, [document.documentElement])
+        })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-04.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-04.htm
new file mode 100644
index 0000000000..0c62fed2c5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-04.htm
@@ -0,0 +1,18 @@
+<!doctype html>
+<html class="a">
+ <head>
+  <title>document.getElementsByClassName(): changing classes</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a">
+  <div id="log"></div>
+  <script>
+   test(function() {
+          var collection = document.getElementsByClassName("a");
+          document.body.className += "\tb";
+          assert_array_equals(collection, [document.documentElement, document.body]);
+        })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-05.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-05.htm
new file mode 100644
index 0000000000..98245f6427
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-05.htm
@@ -0,0 +1,18 @@
+<!doctype html>
+<html class="a">
+ <head>
+  <title>document.getElementsByClassName(): changing classes</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a">
+  <div id="log"></div>
+  <script>
+   test(function() {
+          var collection = document.getElementsByClassName("a");
+          document.body.removeAttribute("class");
+          assert_array_equals(collection, [document.documentElement]);
+        })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-06.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-06.htm
new file mode 100644
index 0000000000..4975a89e09
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-06.htm
@@ -0,0 +1,20 @@
+<!doctype html>
+<html>
+ <head>
+  <title>document.getElementsByClassName(): adding element with class</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a">
+  <div id="log"></div>
+  <script>
+   test(function() {
+          var collection = document.getElementsByClassName("a");
+          var ele = document.createElement("foo");
+          ele.setAttribute("class", "a");
+          document.body.appendChild(ele);
+          assert_array_equals(collection, [document.body, ele]);
+        })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-07.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-07.htm
new file mode 100644
index 0000000000..b0102fb2e6
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-07.htm
@@ -0,0 +1,15 @@
+<!doctype html>
+<html>
+ <head>
+  <title>document.getElementsByClassName(): multiple classes</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a b">
+  <div id="log"></div>
+  <script> test(function() {
+                  assert_array_equals(document.getElementsByClassName("b\t\f\n\na\rb"), [document.body]);
+               })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-08.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-08.htm
new file mode 100644
index 0000000000..a248af4929
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-08.htm
@@ -0,0 +1,15 @@
+<!doctype html>
+<html>
+ <head>
+  <title>document.getElementsByClassName(): multiple classes</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a">
+  <div id="log"></div>
+  <script> test(function() {
+                  document.getElementsByClassName("a\fa"), [document.body]
+                })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-09.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-09.htm
new file mode 100644
index 0000000000..9011f3068c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-09.htm
@@ -0,0 +1,15 @@
+<!doctype html>
+<html class="a A">
+ <head>
+  <title>document.getElementsByClassName(): case sensitive</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a a">
+  <div id="log"></div>
+  <script>test(function() {
+                 assert_array_equals(document.getElementsByClassName("A a"), [document.documentElement])
+               })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-10.xml b/testing/web-platform/tests/dom/nodes/getElementsByClassName-10.xml
new file mode 100644
index 0000000000..b3e3122cb0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-10.xml
@@ -0,0 +1,19 @@
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:g="http://www.w3.org/2000/svg">
+ <head>
+  <title>document.getElementsByClassName(): compound</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body>
+  <div id="log"/>
+  <div id="tests">
+    <x class="a"/>
+    <g:x class="a"/>
+  </div>
+  <script>test(function() {
+                 assert_array_equals(document.getElementsByClassName("a"),
+                                     document.getElementById("tests").children);
+               })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-11.xml b/testing/web-platform/tests/dom/nodes/getElementsByClassName-11.xml
new file mode 100644
index 0000000000..8593fa7a0e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-11.xml
@@ -0,0 +1,24 @@
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:g="http://www.w3.org/2000/svg" xmlns:h="http://www.w3.org/1999/xhtml" xmlns:t="http://tc.labs.opera.com/#test">
+ <head>
+  <title>document.getElementsByClassName(): "tricky" compound</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body>
+  <div id="log" />
+  <div id="tests">
+    <x class="a"/>
+    <g:x class="a"/>
+    <x t:class="a" h:class="a" g:class="a"/>
+    <g:x t:class="a" h:class="a" g:class="a"/>
+    <t:x class="a" t:class="a" h:class="a" g:class="a"/>
+  </div>
+  <script>
+   test(function() {
+          var collection = document.getElementsByClassName("a");
+          var test = document.getElementById("tests").children;
+          assert_array_equals(collection, [test[0], test[1], test[4]]);
+         })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-12.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-12.htm
new file mode 100644
index 0000000000..3b7f328b47
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-12.htm
@@ -0,0 +1,15 @@
+<!doctype html>
+<html class="a">
+ <head>
+  <title>element.getElementsByClassName(): simple</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a">
+  <div id="log"></div>
+  <script>test(function() {
+                 assert_array_equals(document.body.getElementsByClassName("a"), [])
+               })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-13.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-13.htm
new file mode 100644
index 0000000000..f3af106aed
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-13.htm
@@ -0,0 +1,19 @@
+<!doctype html>
+<html class="a">
+ <head>
+  <title>element.getElementsByClassName(): adding an element</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a">
+  <div id="log"></div>
+  <script>test(function() {
+                 var collection = document.body.getElementsByClassName("a");
+                 var ele = document.createElement("x-y-z");
+                 ele.className = "a";
+                 document.body.appendChild(ele);
+                 assert_array_equals(collection, [ele]);
+               })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-14.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-14.htm
new file mode 100644
index 0000000000..83addb7ba5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-14.htm
@@ -0,0 +1,26 @@
+<!-- quirks mode -->
+<html class="a A">
+ <head>
+  <title>document.getElementsByClassName(): case-insensitive (quirks mode)</title>
+  <link rel="help" href="https://dom.spec.whatwg.org/#concept-getelementsbyclassname">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a a">
+  <div id="log"></div>
+  <div class="k"></div>
+  <div class="K"></div>
+  <div class="&#x212a;" id="kelvin"></div>
+  <script>
+test(function() {
+  assert_array_equals(document.getElementsByClassName("A a"),
+                      [document.documentElement, document.body]);
+})
+
+test(function() {
+  assert_array_equals(document.getElementsByClassName("\u212a"),
+                      [document.getElementById("kelvin")]);
+}, 'Unicode-case should be sensitive even in quirks mode.');
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-15.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-15.htm
new file mode 100644
index 0000000000..89614de30d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-15.htm
@@ -0,0 +1,18 @@
+<!doctype html>
+<html class="a
+b">
+ <head>
+  <title>document.getElementsByClassName(array): "a\n"</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a
+">
+  <div id="log"></div>
+  <script>test(function () {
+                 assert_array_equals(document.getElementsByClassName(["a\n"]),
+                                    [document.documentElement, document.body]);
+          })
+ </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-16.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-16.htm
new file mode 100644
index 0000000000..3f987a7ae0
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-16.htm
@@ -0,0 +1,16 @@
+<!doctype html>
+<html class="a
+b">
+ <head>
+  <title>document.getElementsByClassName(array): "b","a"</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="b,a">
+  <div id="log"></div>
+  <script>test(function() {
+                 assert_array_equals(document.getElementsByClassName(["b", "a"]), [document.body]);
+               })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-17.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-17.htm
new file mode 100644
index 0000000000..ae5ebda6e2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-17.htm
@@ -0,0 +1,15 @@
+<!doctype html>
+<html>
+ <head>
+  <title>document.getElementsByClassName(array): "b a"</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a b">
+  <div id="log"></div>
+  <script>test(function() {
+                 assert_array_equals(document.getElementsByClassName(["b a"]), [document.body]);
+          })
+ </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-18.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-18.htm
new file mode 100644
index 0000000000..9f6cf75a50
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-18.htm
@@ -0,0 +1,17 @@
+<!doctype html>
+<html class="a,b">
+ <head>
+  <title>element.getElementsByClassName(array): "a", "b"</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+ </head>
+ <body class="a,b x">
+  <div id="log"></div>
+  <p id="r" class="a,bx"></p>
+  <script class="xa,b">test(function() {
+                             assert_array_equals(document.documentElement.getElementsByClassName(["\fa","b\n"]),
+                                                 [document.body])
+                            })
+  </script>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-19.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-19.htm
new file mode 100644
index 0000000000..da233c743a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-19.htm
@@ -0,0 +1,54 @@
+<!DOCTYPE html>
+<html><head>
+    <title>getElementsByClassName</title>
+    <meta content="get elements in document" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+       <div id="log"></div>
+        <div>
+            <div>
+                <a class="text link" href="#foo">test link #foo</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <table>
+            <caption class="text caption">text caption</caption>
+            <thead>
+                <tr>
+                    <td class="TEXT head">TEXT head</td>
+                </tr>
+            </thead>
+            <tbody>
+                <tr>
+                    <td class="td text1">td text1</td>
+                </tr>
+                <tr>
+                    <td class="td text">td text</td>
+                </tr>
+                <tr>
+                    <td class="td te xt">td te xt</td>
+                </tr>
+            </tbody>
+            <tfoot>
+                <tr>
+                    <td class="TEXT foot">TEXT foot</td>
+                </tr>
+            </tfoot>
+        </table>
+        <div class="xt te">xt te</div>
+
+        <script type="text/javascript">
+    test(function ()
+          {
+           var collection = document.getElementsByClassName("text");
+           assert_equals(collection.length, 4);
+           assert_equals(collection[0].parentNode.nodeName, "DIV");
+           assert_equals(collection[1].parentNode.nodeName, "DIV");
+           assert_equals(collection[2].parentNode.nodeName, "TABLE");
+           assert_equals(collection[3].parentNode.nodeName, "TR");
+          }, "get elements in document");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-20.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-20.htm
new file mode 100644
index 0000000000..6429e37bb5
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-20.htm
@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<html><head>
+        <title>getElementsByClassName</title>
+        <meta content="get elements in document then add element to collection" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+        <div id="log"></div>
+        <div>
+            <div>
+                <a class="text link" href="#foo">test link #foo</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <table>
+            <caption class="text caption">text caption</caption>
+            <thead>
+                <tr>
+                    <td class="TEXT head">TEXT head</td>
+                </tr>
+            </thead>
+            <tbody>
+                <tr>
+                    <td class="td text1">td text1</td>
+                </tr>
+                <tr>
+                    <td class="td text">td text</td>
+                </tr>
+                <tr>
+                    <td class="td te xt">td te xt</td>
+                </tr>
+            </tbody>
+            <tfoot>
+                <tr>
+                    <td class="TEXT foot">TEXT foot</td>
+                </tr>
+            </tfoot>
+        </table>
+        <div class="xt te">xt te</div>
+
+        <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByClassName("text");
+                assert_equals(collection.length, 4);
+                var newDiv = document.createElement("div");
+                newDiv.setAttribute("class", "text");
+                newDiv.innerHTML = "text newDiv";
+                document.getElementsByTagName("table")[0].tBodies[0].rows[0].cells[0].appendChild(newDiv);
+
+                assert_equals(collection.length, 5);
+                assert_equals(collection[0].parentNode.nodeName, "DIV");
+                assert_equals(collection[1].parentNode.nodeName, "DIV");
+                assert_equals(collection[2].parentNode.nodeName, "TABLE");
+                assert_equals(collection[3].parentNode.nodeName, "TD");
+                assert_equals(collection[4].parentNode.nodeName, "TR");
+            }, "get elements in document then add element to collection");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-21.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-21.htm
new file mode 100644
index 0000000000..339ff2d3e1
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-21.htm
@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<html><head>
+        <title>getElementsByClassName</title>
+        <meta content="delete element from collection" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+        <div id="log"></div>
+        <div>
+            <div>
+                <a class="text link" href="#foo">test link #foo</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <table>
+            <caption class="text caption">text caption</caption>
+            <thead>
+                <tr>
+                    <td class="TEXT head">TEXT head</td>
+                </tr>
+            </thead>
+            <tbody>
+                <tr>
+                    <td class="td text1">td text1</td>
+                </tr>
+                <tr>
+                    <td class="td text">td text</td>
+                </tr>
+                <tr>
+                    <td class="td te xt">td te xt</td>
+                </tr>
+            </tbody>
+            <tfoot>
+                <tr>
+                    <td class="TEXT foot">TEXT foot</td>
+                </tr>
+            </tfoot>
+        </table>
+        <div class="xt te">xt te</div>
+
+        <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByClassName("text1");
+                assert_equals(collection.length, 1)
+                document.getElementsByTagName("table")[0].deleteRow(1);
+                assert_equals(collection.length, 0);
+            }, "delete element from collection");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-22.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-22.htm
new file mode 100644
index 0000000000..c203967007
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-22.htm
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<html><head>
+        <title>getElementsByClassName</title>
+        <meta content="move item in collection order" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+        <div id="log"></div>
+        <div>
+            <div>
+                <a class="text link" href="#foo">test link #foo</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <table>
+            <caption class="text caption">text caption</caption>
+            <thead>
+                <tr>
+                    <td class="TEXT head">TEXT head</td>
+                </tr>
+            </thead>
+            <tbody>
+                <tr>
+                    <td class="td text1">td text1</td>
+                </tr>
+                <tr>
+                    <td class="td text">td text</td>
+                </tr>
+                <tr>
+                    <td class="td te xt">td te xt</td>
+                </tr>
+            </tbody>
+            <tfoot>
+                <tr>
+                    <td class="TEXT foot">TEXT foot</td>
+                </tr>
+            </tfoot>
+        </table>
+        <div class="xt te">xt te</div>
+
+        <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByClassName("text");
+                assert_equals(collection.length, 4);
+                var boldText = document.getElementsByTagName("b")[0];
+                document.getElementsByTagName("table")[0].tBodies[0].rows[0].cells[0].appendChild(boldText);
+
+                assert_equals(collection.length, 4);
+                assert_equals(collection[0].parentNode.nodeName, "DIV");
+                assert_equals(collection[1].parentNode.nodeName, "TABLE");
+                assert_equals(collection[2].parentNode.nodeName, "TD");
+                assert_equals(collection[3].parentNode.nodeName, "TR");
+            }, "move item in collection order");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-23.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-23.htm
new file mode 100644
index 0000000000..0af8a09952
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-23.htm
@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<html><head>
+        <title>getElementsByClassName</title>
+        <meta content="multiple defined classes" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+        <div id="log"></div>
+        <div>
+            <div>
+                <a class="text link" href="#foo">test link #foo</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <table>
+            <caption class="text caption">text caption</caption>
+            <thead>
+                <tr>
+                    <td class="TEXT head">TEXT head</td>
+                </tr>
+            </thead>
+            <tbody>
+                <tr>
+                    <td class="td text1">td text1</td>
+                </tr>
+                <tr>
+                    <td class="td text">td text</td>
+                </tr>
+                <tr>
+                    <td class="td te xt">td te xt</td>
+                </tr>
+            </tbody>
+            <tfoot>
+                <tr>
+                    <td class="TEXT foot">TEXT foot</td>
+                </tr>
+            </tfoot>
+        </table>
+        <div class="xt te">xt te</div>
+
+        <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByClassName("te xt");
+                assert_equals(collection.length, 2);
+                assert_equals(collection[0].parentNode.nodeName, "TR");
+                assert_equals(collection[1].parentNode.nodeName, "BODY");
+            }, "multiple defined classes");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-24.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-24.htm
new file mode 100644
index 0000000000..838987ad0c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-24.htm
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html><head>
+        <meta charset='utf-8'>
+        <title>getElementsByClassName</title>
+        <meta content="handle unicode chars" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+        <div id="log"></div>
+        <div>
+            <div>
+                <a class="ΔЙあ叶葉 말 link" href="#foo">ΔЙあ叶葉 말 link</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <div class="ΔЙあ叶葉 קم">ΔЙあ叶葉 קم</div>
+
+        <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByClassName("ΔЙあ叶葉");
+                assert_equals(collection.length, 2);
+                assert_equals(collection[0].parentNode.nodeName, "DIV");
+                assert_equals(collection[1].parentNode.nodeName, "BODY");
+            }, "handle unicode chars");
+        </script>
+
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-25.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-25.htm
new file mode 100644
index 0000000000..21f2a9ff7a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-25.htm
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<html><head>
+        <title>getElementsByClassName</title>
+        <meta content="verify spacing is handled correctly" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+        <div id="log"></div>
+         <div>
+            <div>
+                <a class="text link" href="#foo">test link #foo</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <table>
+            <caption class="text caption">text caption</caption>
+            <thead>
+                <tr>
+                    <td class="TEXT head">TEXT head</td>
+                </tr>
+            </thead>
+            <tbody>
+                <tr>
+                    <td class="td text1">td text1</td>
+                </tr>
+                <tr>
+                    <td class="td text">td text</td>
+                </tr>
+                <tr>
+                    <td class="td te xt">td te xt</td>
+                </tr>
+            </tbody>
+            <tfoot>
+                <tr>
+                    <td class="TEXT foot">TEXT foot</td>
+                </tr>
+            </tfoot>
+        </table>
+        <div class="xt te">xt te</div>
+
+        <script type="text/javascript">
+          test(function()
+          {
+            var collection = document.getElementsByClassName("text ");
+            assert_equals(collection.length, 4);
+            var boldText = document.getElementsByTagName("b")[0];
+            document.getElementsByTagName("table")[0].tBodies[0].rows[0].cells[0].appendChild(boldText);
+            assert_equals(collection.length, 4);
+            assert_equals(collection[0].parentNode.nodeName, "DIV");
+            assert_equals(collection[1].parentNode.nodeName, "TABLE");
+            assert_equals(collection[2].parentNode.nodeName, "TD");
+            assert_equals(collection[3].parentNode.nodeName, "TR");
+          }, "verify spacing is handled correctly");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-26.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-26.htm
new file mode 100644
index 0000000000..0d7ff1ba1f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-26.htm
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html><head>
+        <title>getElementsByClassName</title>
+        <meta content="multiple class attributes" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+       <div id="log"></div>
+         <div class="te xt">
+            te xt
+            <div class="te">
+                te; xt
+                <a class="text link" href="#foo">test link #foo</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <div class="xt te">xt te</div>
+         <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByClassName("te xt");
+
+                assert_equals(collection.length, 2);
+                assert_equals(collection[0].parentNode.nodeName, "BODY");
+                assert_equals(collection[1].parentNode.nodeName, "BODY");
+            }, "multiple class attributes");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-27.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-27.htm
new file mode 100644
index 0000000000..95fc674428
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-27.htm
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html><head>
+        <title>getElementsByClassName</title>
+        <meta content="generic element listed" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+      <div id="log"></div>
+         <div class="te xt">
+            te xt
+            <div class="te">
+                te; xt
+                <a class="text link" href="#foo">test link #foo</a>
+                <foo class="te xt">dummy tag</foo>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <div class="xt te">xt te</div>
+        <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByClassName("te xt");
+
+                assert_equals(collection.length, 3);
+                assert_equals(collection[0].parentNode.nodeName, "BODY");
+                assert_equals(collection[1].parentNode.nodeName, "DIV");
+                assert_equals(collection[2].parentNode.nodeName, "BODY");
+            }, "generic element listed");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-28.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-28.htm
new file mode 100644
index 0000000000..1fc94d807c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-28.htm
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html><head>
+        <title>getElementsByClassName</title>
+        <meta content="generic element listed" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+        <div id="log"></div>
+        <div class="te xt">
+            te xt
+            <div class="te">
+                te; xt
+                <a class="text link" href="#foo">test link #foo</a>
+                <fooU00003Abar class="te xt namespace">te xt namespace
+            </fooU00003Abar></div>
+            <b class="text">text</b>
+        </div>
+        <div class="xt te">xt te</div>
+        <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByClassName("te xt");
+                assert_equals(collection.length, 3);
+                assert_equals(collection[0].parentNode.nodeName, "BODY");
+                assert_equals(collection[1].parentNode.nodeName, "DIV");
+                assert_equals(collection[2].parentNode.nodeName, "BODY");
+            }, "generic element listed");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-29.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-29.htm
new file mode 100644
index 0000000000..ad489752cc
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-29.htm
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<html><head>
+    <title>getElementsByClassName</title>
+    <meta content="get class from children of element" name="description">
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+    <body>
+        <div id='log'></div>
+        <div>
+            <div>
+                <a class="text link" href="#foo">test link #foo</a>
+            </div>
+            <b class="text">text</b>
+        </div>
+        <table>
+            <caption class="text caption">text caption</caption>
+            <thead>
+                <tr>
+                    <td class="TEXT head">TEXT head</td>
+                </tr>
+            </thead>
+            <tbody>
+                <tr>
+                    <td class="td text1">td text1</td>
+                </tr>
+                <tr>
+                    <td class="td text">td text</td>
+                </tr>
+                <tr>
+                    <td class="td te xt">td te xt</td>
+                </tr>
+            </tbody>
+            <tfoot>
+                <tr>
+                    <td class="TEXT foot">TEXT foot</td>
+                </tr>
+            </tfoot>
+        </table>
+        <div class="xt te">xt te</div>
+
+        <script type="text/javascript">
+            test(function()
+            {
+                var collection = document.getElementsByTagName("table")[0].getElementsByClassName("te xt");
+                assert_equals(collection.length, 1);
+                assert_equals(collection[0].parentNode.nodeName, "TR");
+            }, "get class from children of element");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-30.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-30.htm
new file mode 100644
index 0000000000..c0b4faf2d4
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-30.htm
@@ -0,0 +1,190 @@
+<!DOCTYPE html>
+<html><head class="foo">
+        <title class="foo">getElementsByClassName</title>
+        <meta class="foo" content="big element listing" name="description">
+        <link class="foo">
+        <base class="foo">
+        <script class="foo"></script>
+        <style class="foo"></style>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <link href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname" rel="help">
+</head>
+    <body class="foo">
+    <div id='log'></div>
+        <a class="foo">a</a>
+        <abbr class="foo">abbr</abbr>
+        <acronym class="foo">acronym</acronym>
+        <address class="foo">address</address>
+        <applet class="foo">applet</applet>
+        <b class="foo">b</b>
+        <bdo class="foo">bdo</bdo>
+        <big class="foo">big</big>
+        <blockquote class="foo">blockquote</blockquote>
+        <br class="foo">
+        <button class="foo">button</button>
+        <center class="foo">center</center>
+        <cite class="foo">cite</cite>
+        <code class="foo">code</code>
+        <del class="foo">del</del>
+        <dfn class="foo">dfn</dfn>
+        <dir class="foo">dir
+            <li class="foo">li</li>
+        </dir>
+        <div class="foo">div</div>
+        <dl class="foo">
+            <dt class="foo">
+                </dt><dd class="foo">dd</dd>
+        </dl>
+        <em class="foo">em</em>
+        <font class="foo">font</font>
+        <form class="foo">
+            <label class="foo">label</label>
+            <fieldset class="foo">
+                <legend class="foo">legend</legend>
+            </fieldset>
+        </form>
+        <h1 class="foo">h1</h1>
+        <hr class="foo">
+        <i class="foo">i</i>
+        <iframe class="foo">iframe</iframe>
+        <img class="foo">
+        <input class="foo">
+        <ins class="foo">ins</ins>
+        <kbd class="foo">kbd</kbd>
+        <map class="foo">
+            <area class="foo"></area>
+        </map>
+        <menu class="foo">menu</menu>
+        <noscript class="foo">noscript</noscript>
+        <object class="foo">
+            <param class="foo">
+        </object>
+        <ol class="foo">ol</ol>
+        <p class="foo">p</p>
+        <pre class="foo">pre</pre>
+        <q class="foo">q</q>
+        <s class="foo">s</s>
+        <samp class="foo">samp</samp>
+        <select class="foo">
+            <optgroup class="foo">optgroup</optgroup>
+            <option class="foo">option</option>
+        </select>
+        <small class="foo">small</small>
+        <span class="foo">span</span>
+        <strike class="foo">strike</strike>
+        <strong class="foo">strong</strong>
+        <sub class="foo">sub</sub>
+        <sup class="foo">sup</sup>
+        colgroup<table class="foo">
+            <caption class="foo">caption</caption>
+            <colgroup><col class="foo">
+            </colgroup><colgroup class="foo"></colgroup>
+            <thead class="foo">
+                <tr><th class="foo">th</th>
+            </tr></thead>
+            <tbody class="foo">
+                <tr class="foo">
+                    <td class="foo">td</td>
+                </tr>
+            </tbody>
+            <tfoot class="foo"></tfoot>
+        </table>
+        <textarea class="foo">textarea</textarea>
+        <tt class="foo">tt</tt>
+        <u class="foo">u</u>
+        <ul class="foo">ul</ul>
+        <var class="foo">var</var>
+        <script type="text/javascript">
+    test(function ()
+          {
+           var arrElements = [
+                "HEAD",
+                "TITLE",
+                "META",
+                "LINK",
+                "BASE",
+                "SCRIPT",
+                "STYLE",
+                "BODY",
+                "A",
+                "ABBR",
+                "ACRONYM",
+                "ADDRESS",
+                "APPLET",
+                "B",
+                "BDO",
+                "BIG",
+                "BLOCKQUOTE",
+                "BR",
+                "BUTTON",
+                "CENTER",
+                "CITE",
+                "CODE",
+                "DEL",
+                "DFN",
+                "DIR",
+                "LI",
+                "DIV",
+                "DL",
+                "DT",
+                "DD",
+                "EM",
+                "FONT",
+                "FORM",
+                "LABEL",
+                "FIELDSET",
+                "LEGEND",
+                "H1",
+                "HR",
+                "I",
+                "IFRAME",
+                "IMG",
+                "INPUT",
+                "INS",
+                "KBD",
+                "MAP",
+                "AREA",
+                "MENU",
+                "NOSCRIPT",
+                "OBJECT",
+                "PARAM",
+                "OL",
+                "P",
+                "PRE",
+                "Q",
+                "S",
+                "SAMP",
+                "SELECT",
+                "OPTGROUP",
+                "OPTION",
+                "SMALL",
+                "SPAN",
+                "STRIKE",
+                "STRONG",
+                "SUB",
+                "SUP",
+                "TABLE",
+                "CAPTION",
+                "COL",
+                "COLGROUP",
+                "THEAD",
+                "TH",
+                "TBODY",
+                "TR",
+                "TD",
+                "TFOOT",
+                "TEXTAREA",
+                "TT",
+                "U",
+                "UL",
+                "VAR"];
+
+                var collection = document.getElementsByClassName("foo");
+                for (var x = 0; x < collection.length; x++)
+                {
+                    assert_equals(collection[x].nodeName, arrElements[x]);
+                }
+}, "big element listing");
+        </script>
+</body></html>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-31.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassName-31.htm
new file mode 100644
index 0000000000..0e1ac014ae
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-31.htm
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html class=foo>
+<meta charset=utf-8>
+<title>getElementsByClassName across documents</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=log></div>
+<script class=foo>
+async_test(function() {
+  var iframe = document.createElement("iframe");
+  iframe.onload = this.step_func_done(function() {
+    var collection = iframe.contentDocument.getElementsByClassName("foo");
+    assert_equals(collection.length, 3);
+    assert_equals(collection[0].localName, "html");
+    assert_equals(collection[1].localName, "head");
+    assert_equals(collection[2].localName, "body");
+  });
+  iframe.src = "getElementsByClassNameFrame.htm";
+  document.body.appendChild(iframe);
+});
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-32.html b/testing/web-platform/tests/dom/nodes/getElementsByClassName-32.html
new file mode 100644
index 0000000000..29eb41353c
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-32.html
@@ -0,0 +1,68 @@
+<!DOCTYPE html>
+<html>
+<meta charset="utf-8">
+<title>Node.prototype.getElementsByClassName tests imported from jsdom</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<div class="df-article" id="1">
+</div>
+<div class="df-article" id="2">
+</div>
+<div class="df-article" id="3">
+</div>
+
+<script>
+"use strict";
+
+test(() => {
+
+  const p = document.createElement("p");
+  p.className = "unknown";
+  document.body.appendChild(p);
+
+  const elements = document.getElementsByClassName("first-p");
+  assert_array_equals(elements, []);
+
+}, "cannot find the class name");
+
+test(() => {
+
+  const p = document.createElement("p");
+  p.className = "first-p";
+  document.body.appendChild(p);
+
+  const elements = document.getElementsByClassName("first-p");
+  assert_array_equals(elements, [p]);
+
+}, "finds the class name");
+
+
+test(() => {
+
+  const p = document.createElement("p");
+  p.className = "the-p second third";
+  document.body.appendChild(p);
+
+  const elements1 = document.getElementsByClassName("the-p");
+  assert_array_equals(elements1, [p]);
+
+  const elements2 = document.getElementsByClassName("second");
+  assert_array_equals(elements2, [p]);
+
+  const elements3 = document.getElementsByClassName("third");
+  assert_array_equals(elements3, [p]);
+
+}, "finds the same element with multiple class names");
+
+test(() => {
+
+  const elements = document.getElementsByClassName("df-article");
+
+  assert_equals(elements.length, 3);
+  assert_array_equals(Array.prototype.map.call(elements, el => el.id), ["1", "2", "3"]);
+
+}, "does not get confused by numeric IDs");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-empty-set.html b/testing/web-platform/tests/dom/nodes/getElementsByClassName-empty-set.html
new file mode 100644
index 0000000000..75b8d5a9f8
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-empty-set.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html>
+<meta charset="utf-8">
+<title>Node.prototype.getElementsByClassName with no real class names</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<span class=" ">test</span>
+
+<script>
+"use strict";
+
+test(() => {
+  const elements = document.getElementsByClassName("");
+  assert_array_equals(elements, []);
+}, "Passing an empty string to getElementsByClassName should return an empty HTMLCollection");
+
+test(() => {
+  const elements = document.getElementsByClassName(" ");
+  assert_array_equals(elements, []);
+}, "Passing a space to getElementsByClassName should return an empty HTMLCollection");
+
+test(() => {
+  const elements = document.getElementsByClassName("   ");
+  assert_array_equals(elements, []);
+}, "Passing three spaces to getElementsByClassName should return an empty HTMLCollection");
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassName-whitespace-class-names.html b/testing/web-platform/tests/dom/nodes/getElementsByClassName-whitespace-class-names.html
new file mode 100644
index 0000000000..59bfd2e6b1
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassName-whitespace-class-names.html
@@ -0,0 +1,50 @@
+<!DOCTYPE html>
+<html>
+<meta charset="utf-8">
+<title>Node.prototype.getElementsByClassName with no real class names</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-document-getelementsbyclassname">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<span class="&#x000B;">LINE TABULATION</span>
+<span class="&#x0085;">NEXT LINE</span>
+<span class="&#x00A0;">NO-BREAK SPACE</span>
+<span class="&#x1680;">OGHAM SPACE MARK</span>
+<span class="&#x2000;">EN QUAD</span>
+<span class="&#x2001;">EM QUAD</span>
+<span class="&#x2002;">EN SPACE</span>
+<span class="&#x2003;">EM SPACE</span>
+<span class="&#x2004;">THREE-PER-EM SPACE</span>
+<span class="&#x2005;">FOUR-PER-EM SPACE</span>
+<span class="&#x2006;">SIX-PER-EM SPACE</span>
+<span class="&#x2007;">FIGURE SPACE</span>
+<span class="&#x2008;">PUNCTUATION SPACE</span>
+<span class="&#x2009;">THIN SPACE</span>
+<span class="&#x200A;">HAIR SPACE</span>
+<span class="&#x2028;">LINE SEPARATOR</span>
+<span class="&#x2029;">PARAGRAPH SEPARATOR</span>
+<span class="&#x202F;">NARROW NO-BREAK SPACE</span>
+<span class="&#x205F;">MEDIUM MATHEMATICAL SPACE</span>
+<span class="&#x3000;">IDEOGRAPHIC SPACE</span>
+
+<span class="&#x180E;">MONGOLIAN VOWEL SEPARATOR</span>
+<span class="&#x200B;">ZERO WIDTH SPACE</span>
+<span class="&#x200C;">ZERO WIDTH NON-JOINER</span>
+<span class="&#x200D;">ZERO WIDTH JOINER</span>
+<span class="&#x2060;">WORD JOINER</span>
+<span class="&#xFEFF;">ZERO WIDTH NON-BREAKING SPACE</span>
+
+<script>
+"use strict";
+
+const spans = document.querySelectorAll("span");
+
+for (const span of spans) {
+  test(() => {
+    const className = span.getAttribute("class");
+    assert_equals(className.length, 1, "Sanity check: the class name was retrieved and is a single character");
+    const shouldBeSpan = document.getElementsByClassName(className);
+    assert_array_equals(shouldBeSpan, [span]);
+  }, `Passing a ${span.textContent} to getElementsByClassName still finds the span`);
+}
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/getElementsByClassNameFrame.htm b/testing/web-platform/tests/dom/nodes/getElementsByClassNameFrame.htm
new file mode 100644
index 0000000000..544df60a99
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/getElementsByClassNameFrame.htm
@@ -0,0 +1,6 @@
+<!DOCTYPE html>
+<html class=foo>
+<head class=foo>
+<meta charset=utf-8>
+<title>getElementsByClassName</title>
+<body class=foo>
diff --git a/testing/web-platform/tests/dom/nodes/insert-adjacent.html b/testing/web-platform/tests/dom/nodes/insert-adjacent.html
new file mode 100644
index 0000000000..68b6f4ee66
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/insert-adjacent.html
@@ -0,0 +1,79 @@
+<!doctype html>
+<meta charset="utf-8">
+<title></title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style>
+#element {
+  display: none;
+}
+</style>
+
+<div id="element"></div>
+<div id="log"></div>
+
+<script>
+var possiblePositions = {
+    'beforebegin': 'previousSibling'
+  , 'afterbegin': 'firstChild'
+  , 'beforeend': 'lastChild'
+  , 'afterend': 'nextSibling'
+}
+var texts = {
+   'beforebegin': 'raclette'
+  , 'afterbegin': 'tartiflette'
+  , 'beforeend': 'lasagne'
+  , 'afterend': 'gateau aux pommes'
+}
+
+var el = document.querySelector('#element');
+
+Object.keys(possiblePositions).forEach(function(position) {
+  var div = document.createElement('h3');
+  test(function() {
+    div.id = texts[position];
+    el.insertAdjacentElement(position, div);
+    assert_equals(el[possiblePositions[position]].id, texts[position]);
+  }, 'insertAdjacentElement(' + position + ', ' + div + ' )');
+
+  test(function() {
+    el.insertAdjacentText(position, texts[position]);
+    assert_equals(el[possiblePositions[position]].textContent, texts[position]);
+  }, 'insertAdjacentText(' + position + ', ' + texts[position] + ' )');
+});
+
+test(function() {
+  assert_throws_js(TypeError, function() {
+    el.insertAdjacentElement('afterbegin',
+    document.implementation.createDocumentType("html"))
+  })
+}, 'invalid object argument insertAdjacentElement')
+test(function() {
+  var el = document.implementation.createHTMLDocument().documentElement;
+  assert_throws_dom("HIERARCHY_REQUEST_ERR", function() {
+    el.insertAdjacentElement('beforebegin', document.createElement('banane'))
+  })
+}, 'invalid caller object insertAdjacentElement')
+test(function() {
+  var el = document.implementation.createHTMLDocument().documentElement;
+  assert_throws_dom("HIERARCHY_REQUEST_ERR", function() {
+    el.insertAdjacentText('beforebegin', 'tomate farcie')
+  })
+}, 'invalid caller object insertAdjacentText')
+test(function() {
+  var div = document.createElement('h3');
+  assert_throws_dom("SYNTAX_ERR", function() {
+    el.insertAdjacentElement('heeeee', div)
+  })
+}, "invalid syntax for insertAdjacentElement")
+test(function() {
+  assert_throws_dom("SYNTAX_ERR", function() {
+    el.insertAdjacentText('hoooo', 'magret de canard')
+  })
+}, "invalid syntax for insertAdjacentText")
+test(function() {
+  var div = document.createElement('div');
+  assert_equals(div.insertAdjacentElement("beforebegin", el), null);
+}, 'insertAdjacentText should return null');
+
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/mutationobservers.js b/testing/web-platform/tests/dom/nodes/mutationobservers.js
new file mode 100644
index 0000000000..a95529ab39
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/mutationobservers.js
@@ -0,0 +1,76 @@
+// Compares a mutation record to a predefined one
+// mutationToCheck is a mutation record from the user agent
+// expectedRecord is a mutation record minted by the test
+//    for expectedRecord, if properties are omitted, they get default ones
+function checkRecords(target, mutationToCheck, expectedRecord) {
+  var mr1;
+  var mr2;
+
+
+  function checkField(property, isArray) {
+    var field = mr2[property];
+    if (isArray === undefined) {
+      isArray = false;
+    }
+    if (field instanceof Function) {
+      field = field();
+    } else if (field === undefined) {
+      if (isArray) {
+        field = new Array();
+      } else {
+        field = null;
+      }
+    }
+    if (isArray) {
+      assert_array_equals(mr1[property], field, property + " didn't match");
+    } else {
+      assert_equals(mr1[property], field, property + " didn't match");
+    }
+  }
+
+  assert_equals(mutationToCheck.length, expectedRecord.length, "mutation records must match");
+  for (var item = 0; item < mutationToCheck.length; item++) {
+    mr1 = mutationToCheck[item];
+    mr2 = expectedRecord[item];
+
+    if (mr2.target instanceof Function) {
+      assert_equals(mr1.target, mr2.target(), "target node must match");
+    } else if (mr2.target !== undefined) {
+      assert_equals(mr1.target, mr2.target, "target node must match");
+    } else {
+      assert_equals(mr1.target, target, "target node must match");
+    }
+
+    checkField("type");
+    checkField("addedNodes", true);
+    checkField("removedNodes", true);
+    checkField("previousSibling");
+    checkField("nextSibling");
+    checkField("attributeName");
+    checkField("attributeNamespace");
+    checkField("oldValue");
+  };
+}
+
+function runMutationTest(node, mutationObserverOptions, mutationRecordSequence, mutationFunction, description, target) {
+  var test = async_test(description);
+
+
+  function moc(mrl, obs) {
+    test.step(
+      function () {
+            if (target === undefined) target = node;
+            checkRecords(target, mrl, mutationRecordSequence);
+        test.done();
+      }
+     );
+  }
+
+  test.step(
+    function () {
+      (new MutationObserver(moc)).observe(node, mutationObserverOptions);
+      mutationFunction();
+    }
+  );
+  return mutationRecordSequence.length
+}
diff --git a/testing/web-platform/tests/dom/nodes/node-appendchild-crash.html b/testing/web-platform/tests/dom/nodes/node-appendchild-crash.html
new file mode 100644
index 0000000000..245de87f2d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/node-appendchild-crash.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="author" href="mailto:masonf@chromium.org">
+<link rel="help" href="https://crbug.com/1210480">
+<meta name="assert" content="The renderer should not crash.">
+
+<iframe id=iframe></iframe>
+<select>Text Node
+  <option id=option></option>
+</select>
+
+<script>
+  window.onload=function() {
+    iframe.addEventListener('DOMNodeInsertedIntoDocument',function() {});
+    option.remove();
+    iframe.contentDocument.body.appendChild(document.body);
+  }
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/pre-insertion-validation-hierarchy.js b/testing/web-platform/tests/dom/nodes/pre-insertion-validation-hierarchy.js
new file mode 100644
index 0000000000..6ef2576df2
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/pre-insertion-validation-hierarchy.js
@@ -0,0 +1,86 @@
+/**
+ * Validations where `child` argument is irrelevant.
+ * @param {Function} methodName
+ */
+function preInsertionValidateHierarchy(methodName) {
+  function insert(parent, node) {
+    if (parent[methodName].length > 1) {
+      // This is for insertBefore(). We can't blindly pass `null` for all methods
+      // as doing so will move nodes before validation.
+      parent[methodName](node, null);
+    } else {
+      parent[methodName](node);
+    }
+  }
+
+  // Step 2
+  test(() => {
+    const doc = document.implementation.createHTMLDocument("title");
+    assert_throws_dom("HierarchyRequestError", () => insert(doc.body, doc.body));
+    assert_throws_dom("HierarchyRequestError", () => insert(doc.body, doc.documentElement));
+  }, "If node is a host-including inclusive ancestor of parent, then throw a HierarchyRequestError DOMException.");
+
+  // Step 4
+  test(() => {
+    const doc = document.implementation.createHTMLDocument("title");
+    const doc2 = document.implementation.createHTMLDocument("title2");
+    assert_throws_dom("HierarchyRequestError", () => insert(doc, doc2));
+  }, "If node is not a DocumentFragment, DocumentType, Element, Text, ProcessingInstruction, or Comment node, then throw a HierarchyRequestError DOMException.");
+
+  // Step 5, in case of inserting a text node into a document
+  test(() => {
+    const doc = document.implementation.createHTMLDocument("title");
+    assert_throws_dom("HierarchyRequestError", () => insert(doc, doc.createTextNode("text")));
+  }, "If node is a Text node and parent is a document, then throw a HierarchyRequestError DOMException.");
+
+  // Step 5, in case of inserting a doctype into a non-document
+  test(() => {
+    const doc = document.implementation.createHTMLDocument("title");
+    const doctype = doc.childNodes[0];
+    assert_throws_dom("HierarchyRequestError", () => insert(doc.createElement("a"), doctype));
+  }, "If node is a doctype and parent is not a document, then throw a HierarchyRequestError DOMException.")
+
+  // Step 6, in case of DocumentFragment including multiple elements
+  test(() => {
+    const doc = document.implementation.createHTMLDocument("title");
+    doc.documentElement.remove();
+    const df = doc.createDocumentFragment();
+    df.appendChild(doc.createElement("a"));
+    df.appendChild(doc.createElement("b"));
+    assert_throws_dom("HierarchyRequestError", () => insert(doc, df));
+  }, "If node is a DocumentFragment with multiple elements and parent is a document, then throw a HierarchyRequestError DOMException.");
+
+  // Step 6, in case of DocumentFragment has multiple elements when document already has an element
+  test(() => {
+    const doc = document.implementation.createHTMLDocument("title");
+    const df = doc.createDocumentFragment();
+    df.appendChild(doc.createElement("a"));
+    assert_throws_dom("HierarchyRequestError", () => insert(doc, df));
+  }, "If node is a DocumentFragment with an element and parent is a document with another element, then throw a HierarchyRequestError DOMException.");
+
+  // Step 6, in case of an element
+  test(() => {
+    const doc = document.implementation.createHTMLDocument("title");
+    const el = doc.createElement("a");
+    assert_throws_dom("HierarchyRequestError", () => insert(doc, el));
+  }, "If node is an Element and parent is a document with another element, then throw a HierarchyRequestError DOMException.");
+
+  // Step 6, in case of a doctype when document already has another doctype
+  test(() => {
+    const doc = document.implementation.createHTMLDocument("title");
+    const doctype = doc.childNodes[0].cloneNode();
+    doc.documentElement.remove();
+    assert_throws_dom("HierarchyRequestError", () => insert(doc, doctype));
+  }, "If node is a doctype and parent is a document with another doctype, then throw a HierarchyRequestError DOMException.");
+
+  // Step 6, in case of a doctype when document has an element
+  if (methodName !== "prepend") {
+    // Skip `.prepend` as this doesn't throw if `child` is an element
+    test(() => {
+      const doc = document.implementation.createHTMLDocument("title");
+      const doctype = doc.childNodes[0].cloneNode();
+      doc.childNodes[0].remove();
+      assert_throws_dom("HierarchyRequestError", () => insert(doc, doctype));
+    }, "If node is a doctype and parent is a document with an element, then throw a HierarchyRequestError DOMException.");
+  }
+}
diff --git a/testing/web-platform/tests/dom/nodes/pre-insertion-validation-notfound.js b/testing/web-platform/tests/dom/nodes/pre-insertion-validation-notfound.js
new file mode 100644
index 0000000000..705283fa23
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/pre-insertion-validation-notfound.js
@@ -0,0 +1,108 @@
+function getNonParentNodes() {
+  return [
+    document.implementation.createDocumentType("html", "", ""),
+    document.createTextNode("text"),
+    document.implementation.createDocument(null, "foo", null).createProcessingInstruction("foo", "bar"),
+    document.createComment("comment"),
+    document.implementation.createDocument(null, "foo", null).createCDATASection("data"),
+  ];
+}
+
+function getNonInsertableNodes() {
+  return [
+    document.implementation.createHTMLDocument("title")
+  ];
+}
+
+function getNonDocumentParentNodes() {
+  return [
+    document.createElement("div"),
+    document.createDocumentFragment(),
+  ];
+}
+
+// Test that the steps happen in the right order, to the extent that it's
+// observable.   The variable names "parent", "child", and "node" match the
+// corresponding variables in the replaceChild algorithm in these tests.
+
+// Step 1 happens before step 3.
+test(function() {
+  var illegalParents = getNonParentNodes();
+  var child = document.createElement("div");
+  var node = document.createElement("div");
+  illegalParents.forEach(function (parent) {
+    assert_throws_dom("HierarchyRequestError", function() {
+      insertFunc.call(parent, node, child);
+    });
+  });
+}, "Should check the 'parent' type before checking whether 'child' is a child of 'parent'");
+
+// Step 2 happens before step 3.
+test(function() {
+  var parent = document.createElement("div");
+  var child = document.createElement("div");
+  var node = document.createElement("div");
+
+  node.appendChild(parent);
+  assert_throws_dom("HierarchyRequestError", function() {
+    insertFunc.call(parent, node, child);
+  });
+}, "Should check that 'node' is not an ancestor of 'parent' before checking whether 'child' is a child of 'parent'");
+
+// Step 3 happens before step 4.
+test(function() {
+  var parent = document.createElement("div");
+  var child = document.createElement("div");
+
+  var illegalChildren = getNonInsertableNodes();
+  illegalChildren.forEach(function (node) {
+    assert_throws_dom("NotFoundError", function() {
+      insertFunc.call(parent, node, child);
+    });
+  });
+}, "Should check whether 'child' is a child of 'parent' before checking whether 'node' is of a type that can have a parent.");
+
+
+// Step 3 happens before step 5.
+test(function() {
+  var child = document.createElement("div");
+
+  var node = document.createTextNode("");
+  var parent = document.implementation.createDocument(null, "foo", null);
+  assert_throws_dom("NotFoundError", function() {
+    insertFunc.call(parent, node, child);
+  });
+
+  node = document.implementation.createDocumentType("html", "", "");
+  getNonDocumentParentNodes().forEach(function (parent) {
+    assert_throws_dom("NotFoundError", function() {
+      insertFunc.call(parent, node, child);
+    });
+  });
+}, "Should check whether 'child' is a child of 'parent' before checking whether 'node' is of a type that can have a parent of the type that 'parent' is.");
+
+// Step 3 happens before step 6.
+test(function() {
+  var child = document.createElement("div");
+  var parent = document.implementation.createDocument(null, null, null);
+
+  var node = document.createDocumentFragment();
+  node.appendChild(document.createElement("div"));
+  node.appendChild(document.createElement("div"));
+  assert_throws_dom("NotFoundError", function() {
+    insertFunc.call(parent, node, child);
+  });
+
+  node = document.createElement("div");
+  parent.appendChild(document.createElement("div"));
+  assert_throws_dom("NotFoundError", function() {
+    insertFunc.call(parent, node, child);
+  });
+
+  parent.firstChild.remove();
+  parent.appendChild(document.implementation.createDocumentType("html", "", ""));
+  node = document.implementation.createDocumentType("html", "", "")
+  assert_throws_dom("NotFoundError", function() {
+    insertFunc.call(parent, node, child);
+  });
+}, "Should check whether 'child' is a child of 'parent' before checking whether 'node' can be inserted into the document given the kids the document has right now.");
diff --git a/testing/web-platform/tests/dom/nodes/prepend-on-Document.html b/testing/web-platform/tests/dom/nodes/prepend-on-Document.html
new file mode 100644
index 0000000000..1d6d43a463
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/prepend-on-Document.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>DocumentType.prepend</title>
+<link rel=help href="https://dom.spec.whatwg.org/#dom-parentnode-prepend">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+function test_prepend_on_Document() {
+
+    var node = document.implementation.createDocument(null, null);
+    test(function() {
+        var parent = node.cloneNode();
+        parent.prepend();
+        assert_array_equals(parent.childNodes, []);
+    }, 'Document.prepend() without any argument, on a Document having no child.');
+
+    test(function() {
+        var parent = node.cloneNode();
+        var x = document.createElement('x');
+        parent.prepend(x);
+        assert_array_equals(parent.childNodes, [x]);
+    }, 'Document.prepend() with only one element as an argument, on a Document having no child.');
+
+    test(function() {
+        var parent = node.cloneNode();
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        parent.appendChild(x);
+        assert_throws_dom('HierarchyRequestError', function() { parent.prepend(y); });
+        assert_array_equals(parent.childNodes, [x]);
+    }, 'Document.append() with only one element as an argument, on a Document having one child.');
+
+    test(function() {
+        var parent = node.cloneNode();
+        assert_throws_dom('HierarchyRequestError', function() { parent.prepend('text'); });
+        assert_array_equals(parent.childNodes, []);
+    }, 'Document.prepend() with text as an argument, on a Document having no child.');
+
+    test(function() {
+        var parent = node.cloneNode();
+        var x = document.createElement('x');
+        var y = document.createElement('y');
+        assert_throws_dom('HierarchyRequestError', function() { parent.prepend(x, y); });
+        assert_array_equals(parent.childNodes, []);
+    }, 'Document.prepend() with two elements as the argument, on a Document having no child.');
+
+}
+
+test_prepend_on_Document();
+
+</script>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/productions.js b/testing/web-platform/tests/dom/nodes/productions.js
new file mode 100644
index 0000000000..218797fc45
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/productions.js
@@ -0,0 +1,3 @@
+var invalid_names = ["", "invalid^Name", "\\", "'", '"', "0", "0:a"] // XXX
+var valid_names = ["x", "X", ":", "a:0"]
+var invalid_qnames = [":a", "b:", "x:y:z"] // XXX
diff --git a/testing/web-platform/tests/dom/nodes/query-target-in-load-event.html b/testing/web-platform/tests/dom/nodes/query-target-in-load-event.html
new file mode 100644
index 0000000000..2835286f96
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/query-target-in-load-event.html
@@ -0,0 +1,13 @@
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<iframe></iframe>
+
+<script>
+  let test = async_test('document.querySelector(":target") must work when called in the window.load event');
+  let iframe = document.querySelector("iframe");
+  window.addEventListener("message", test.step_func_done(event => {
+    assert_equals(event.data, "PASS");
+  }));
+  iframe.src = "./query-target-in-load-event.part.html#target";
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/query-target-in-load-event.part.html b/testing/web-platform/tests/dom/nodes/query-target-in-load-event.part.html
new file mode 100644
index 0000000000..7eb1baf15f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/query-target-in-load-event.part.html
@@ -0,0 +1,10 @@
+<!-- Used by ./query-target-in-load-event.html -->
+<script>
+  window.onload = function() {
+    let target = document.querySelector(":target");
+    let expected = document.querySelector("#target");
+    window.parent.postMessage(target == expected ? "PASS" : "FAIL", "*");
+  };
+</script>
+
+<div id="target"></div>
diff --git a/testing/web-platform/tests/dom/nodes/remove-and-adopt-thcrash.html b/testing/web-platform/tests/dom/nodes/remove-and-adopt-thcrash.html
new file mode 100644
index 0000000000..d37015ec9f
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/remove-and-adopt-thcrash.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<title>Test for a Chrome crash when adopting a node into another document</title>
+<link rel="help" href="https://crbug.com/981384">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="d1"></div>
+<div id="d2"></div>
+<script>
+  test(() => {
+    d1.appendChild(document.createElement("iframe"));
+    d2.remove();
+    const adopted_div = d1;
+    const popup = window.open();
+    assert_equals(adopted_div.ownerDocument, document);
+    popup.document.body.appendChild(document.body);
+    assert_equals(adopted_div.ownerDocument, popup.document);
+  }, "Check that removing a node and then adopting its parent into a different window/document doesn't crash.");
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/remove-from-shadow-host-and-adopt-into-iframe-ref.html b/testing/web-platform/tests/dom/nodes/remove-from-shadow-host-and-adopt-into-iframe-ref.html
new file mode 100644
index 0000000000..98de2b6883
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/remove-from-shadow-host-and-adopt-into-iframe-ref.html
@@ -0,0 +1,4 @@
+<!doctype html>
+<title>DOM Test Reference</title>
+<p>You should see the word PASS below.</p>
+<div>PASS</div>
diff --git a/testing/web-platform/tests/dom/nodes/remove-from-shadow-host-and-adopt-into-iframe.html b/testing/web-platform/tests/dom/nodes/remove-from-shadow-host-and-adopt-into-iframe.html
new file mode 100644
index 0000000000..612aed637d
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/remove-from-shadow-host-and-adopt-into-iframe.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<html class="reftest-wait">
+  <head>
+    <title>Adopting a shadow host child into an iframe</title>
+    <link rel="help" href="https://dom.spec.whatwg.org/#concept-node-adopt">
+    <link rel="match" href="remove-from-shadow-host-and-adopt-into-iframe-ref.html">
+    <style>
+      iframe { border: 0; }
+    </style>
+    <script src="/common/reftest-wait.js"></script>
+    <script>
+      onload = () => {
+        const root = host.attachShadow({mode:"open"});
+        root.innerHTML = "<slot>";
+        // force a layout
+        host.offsetTop;
+        iframe.contentWindow.document.body.style.margin = 0;
+        iframe.contentWindow.document.body.appendChild(adopted);
+        host.remove();
+        takeScreenshot();
+      }
+    </script>
+  </head>
+  <body>
+    <p>You should see the word PASS below.</p>
+    <iframe id="iframe"></iframe>
+    <div id="host"><span id="adopted">PASS</span></div>
+  </body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/remove-unscopable.html b/testing/web-platform/tests/dom/nodes/remove-unscopable.html
new file mode 100644
index 0000000000..0238b0fa97
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/remove-unscopable.html
@@ -0,0 +1,32 @@
+<!doctype html>
+<meta charset=utf-8>
+<title></title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id="testDiv" onclick="result1 = remove; result2 = this.remove;"></div>
+<script>
+var result1;
+var result2;
+var unscopables = [
+    "before",
+    "after",
+    "replaceWith",
+    "remove",
+    "prepend",
+    "append"
+];
+for (var i in unscopables) {
+    var name = unscopables[i];
+    window[name] = "Hello there";
+    result1 = result2 = undefined;
+    test(function () {
+        assert_true(Element.prototype[Symbol.unscopables][name]);
+        var div = document.querySelector('#testDiv');
+        div.setAttribute(
+            "onclick", "result1 = " + name + "; result2 = this." + name + ";");
+        div.dispatchEvent(new Event("click"));
+        assert_equals(typeof result1, "string");
+        assert_equals(typeof result2, "function");
+    }, name + "() should be unscopable");
+}
+</script>
diff --git a/testing/web-platform/tests/dom/nodes/rootNode.html b/testing/web-platform/tests/dom/nodes/rootNode.html
new file mode 100644
index 0000000000..784831da0e
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/rootNode.html
@@ -0,0 +1,96 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset=utf-8>
+<title>Node.prototype.getRootNode()</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#dom-node-getrootnode">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+
+test(function () {
+    var shadowHost = document.createElement('div');
+    document.body.appendChild(shadowHost);
+
+    var shadowRoot = shadowHost.attachShadow({mode: 'open'});
+    shadowRoot.innerHTML = '<div class="shadowChild">content</div>';
+
+    var shadowChild = shadowRoot.querySelector('.shadowChild');
+    assert_equals(shadowChild.getRootNode({composed: true}), document, "getRootNode() must return context object's shadow-including root if options's composed is true");
+    assert_equals(shadowChild.getRootNode({composed: false}), shadowRoot, "getRootNode() must return context object's root if options's composed is false");
+    assert_equals(shadowChild.getRootNode(), shadowRoot, "getRootNode() must return context object's root if options's composed is default false");
+
+}, "getRootNode() must return context object's shadow-including root if options's composed is true, and context object's root otherwise");
+
+test(function () {
+    var element = document.createElement('div');
+    assert_equals(element.getRootNode(), element, 'getRootNode() on an element without a parent must return the element itself');
+
+    var text = document.createTextNode('');
+    assert_equals(text.getRootNode(), text, 'getRootNode() on a text node without a parent must return the text node itself');
+
+    var processingInstruction = document.createProcessingInstruction('target', 'data');
+    assert_equals(processingInstruction.getRootNode(), processingInstruction, 'getRootNode() on a processing instruction node without a parent must return the processing instruction node itself');
+
+    assert_equals(document.getRootNode(), document, 'getRootNode() on a document node must return the document itself');
+
+}, 'getRootNode() must return the context object when it does not have any parent');
+
+test(function () {
+    var parent = document.createElement('div');
+
+    var element = document.createElement('div');
+    parent.appendChild(element);
+    assert_equals(element.getRootNode(), parent, 'getRootNode() on an element with a single ancestor must return the parent node');
+
+    var text = document.createTextNode('');
+    parent.appendChild(text);
+    assert_equals(text.getRootNode(), parent, 'getRootNode() on a text node with a single ancestor must return the parent node');
+
+    var processingInstruction = document.createProcessingInstruction('target', 'data');
+    parent.appendChild(processingInstruction)
+    assert_equals(processingInstruction.getRootNode(), parent, 'getRootNode() on a processing instruction node with a single ancestor must return the parent node');
+
+}, 'getRootNode() must return the parent node of the context object when the context object has a single ancestor not in a document');
+
+test(function () {
+    var parent = document.createElement('div');
+    document.body.appendChild(parent);
+
+    var element = document.createElement('div');
+    parent.appendChild(element);
+    assert_equals(element.getRootNode(), document, 'getRootNode() on an element inside a document must return the document');
+
+    var text = document.createTextNode('');
+    parent.appendChild(text);
+    assert_equals(text.getRootNode(), document, 'getRootNode() on a text node inside a document must return the document');
+
+    var processingInstruction = document.createProcessingInstruction('target', 'data');
+    parent.appendChild(processingInstruction)
+    assert_equals(processingInstruction.getRootNode(), document, 'getRootNode() on a processing instruction node inside a document must return the document');
+}, 'getRootNode() must return the document when a node is in document');
+
+test(function () {
+    var fragment = document.createDocumentFragment();
+    var parent = document.createElement('div');
+    fragment.appendChild(parent);
+
+    var element = document.createElement('div');
+    parent.appendChild(element);
+    assert_equals(element.getRootNode(), fragment, 'getRootNode() on an element inside a document fragment must return the fragment');
+
+    var text = document.createTextNode('');
+    parent.appendChild(text);
+    assert_equals(text.getRootNode(), fragment, 'getRootNode() on a text node inside a document fragment must return the fragment');
+
+    var processingInstruction = document.createProcessingInstruction('target', 'data');
+    parent.appendChild(processingInstruction)
+    assert_equals(processingInstruction.getRootNode(), fragment,
+        'getRootNode() on a processing instruction node inside a document fragment must return the fragment');
+}, 'getRootNode() must return a document fragment when a node is in the fragment');
+
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/nodes/selectors.js b/testing/web-platform/tests/dom/nodes/selectors.js
new file mode 100644
index 0000000000..5e05547c9a
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/selectors.js
@@ -0,0 +1,755 @@
+// Bit-mapped flags to indicate which tests the selector is suitable for
+var TEST_QSA              = 0x01; // querySelector() and querySelectorAll() tests
+var TEST_FIND             = 0x04; // find() and findAll() tests, may be unsuitable for querySelector[All]
+var TEST_MATCH            = 0x10; // matches() tests
+
+/*
+ * All of these invalid selectors should result in a SyntaxError being thrown by the APIs.
+ *
+ *   name:     A descriptive name of the selector being tested
+ *   selector: The selector to test
+ */
+var invalidSelectors = [
+  {name: "Empty String",                 selector: ""},
+  {name: "Invalid character",            selector: "["},
+  {name: "Invalid character",            selector: "]"},
+  {name: "Invalid character",            selector: "("},
+  {name: "Invalid character",            selector: ")"},
+  {name: "Invalid character",            selector: "{"},
+  {name: "Invalid character",            selector: "}"},
+  {name: "Invalid character",            selector: "<"},
+  {name: "Invalid character",            selector: ">"},
+  {name: "Invalid ID",                   selector: "#"},
+  {name: "Invalid group of selectors",   selector: "div,"},
+  {name: "Invalid class",                selector: "."},
+  {name: "Invalid class",                selector: ".5cm"},
+  {name: "Invalid class",                selector: "..test"},
+  {name: "Invalid class",                selector: ".foo..quux"},
+  {name: "Invalid class",                selector: ".bar."},
+  {name: "Invalid combinator",           selector: "div % address, p"},
+  {name: "Invalid combinator",           selector: "div ++ address, p"},
+  {name: "Invalid combinator",           selector: "div ~~ address, p"},
+  {name: "Invalid [att=value] selector", selector: "[*=test]"},
+  {name: "Invalid [att=value] selector", selector: "[*|*=test]"},
+  {name: "Invalid [att=value] selector", selector: "[class= space unquoted ]"},
+  {name: "Unknown pseudo-class",         selector: "div:example"},
+  {name: "Unknown pseudo-class",         selector: ":example"},
+  {name: "Unknown pseudo-class",         selector: "div:linkexample"},
+  {name: "Unknown pseudo-element",       selector: "div::example"},
+  {name: "Unknown pseudo-element",       selector: "::example"},
+  {name: "Invalid pseudo-element",       selector: ":::before"},
+  {name: "Invalid pseudo-element",       selector: ":: before"},
+  {name: "Undeclared namespace",         selector: "ns|div"},
+  {name: "Undeclared namespace",         selector: ":not(ns|div)"},
+  {name: "Invalid namespace",            selector: "^|div"},
+  {name: "Invalid namespace",            selector: "$|div"},
+  {name: "Relative selector",            selector: ">*"},
+];
+
+/*
+ * All of these should be valid selectors, expected to match zero or more elements in the document.
+ * None should throw any errors.
+ *
+ *   name:     A descriptive name of the selector being tested
+ *   selector: The selector to test
+ *   expect:   A list of IDs of the elements expected to be matched. List must be given in tree order.
+ *   exclude:  An array of contexts to exclude from testing. The valid values are:
+ *             ["document", "element", "fragment", "detached", "html", "xhtml"]
+ *             The "html" and "xhtml" values represent the type of document being queried. These are useful
+ *             for tests that are affected by differences between HTML and XML, such as case sensitivity.
+ *   level:    An integer indicating the CSS or Selectors level in which the selector being tested was introduced.
+ *   testType: A bit-mapped flag indicating the type of test.
+ *
+ * Note: Interactive pseudo-classes (:active :hover and :focus) have not been tested in this test suite.
+ */
+var validSelectors = [
+  // Type Selector
+  {name: "Type selector, matching html element", selector: "html", expect: ["html"],          exclude: ["element", "fragment", "detached"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Type selector, matching html element", selector: "html", expect: [] /*no matches*/, exclude: ["document"],                        level: 1, testType: TEST_QSA},
+  {name: "Type selector, matching body element", selector: "body", expect: ["body"],          exclude: ["element", "fragment", "detached"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Type selector, matching body element", selector: "body", expect: [] /*no matches*/, exclude: ["document"],                        level: 1, testType: TEST_QSA},
+
+  // Universal Selector
+  {name: "Universal selector, matching all elements",                                    selector: "*",              expect: ["universal", "universal-p1", "universal-code1", "universal-hr1", "universal-pre1", "universal-span1", "universal-p2", "universal-a1", "universal-address1", "universal-code2", "universal-a2"], level: 2, testType: TEST_MATCH},
+  {name: "Universal selector, matching all children of element with specified ID",       selector: "#universal>*",   expect: ["universal-p1", "universal-hr1", "universal-pre1", "universal-p2", "universal-address1"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Universal selector, matching all grandchildren of element with specified ID",  selector: "#universal>*>*", expect: ["universal-code1", "universal-span1", "universal-a1", "universal-code2"],                 level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Universal selector, matching all children of empty element with specified ID", selector: "#empty>*",       expect: [] /*no matches*/,                                                                         level: 2, testType: TEST_QSA},
+  {name: "Universal selector, matching all descendants of element with specified ID",    selector: "#universal *",   expect: ["universal-p1", "universal-code1", "universal-hr1", "universal-pre1", "universal-span1", "universal-p2", "universal-a1", "universal-address1", "universal-code2", "universal-a2"], level: 2, testType: TEST_QSA | TEST_MATCH},
+
+  // Attribute Selectors
+  // - presence                  [att]
+  {name: "Attribute presence selector, matching align attribute with value",                    selector: ".attr-presence-div1[align]",                             expect: ["attr-presence-div1"],                                                                   level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute presence selector, matching align attribute with empty value",              selector: ".attr-presence-div2[align]",                             expect: ["attr-presence-div2"],                                                                   level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute presence selector, matching title attribute, case insensitivity",           selector: "#attr-presence [*|TiTlE]",                                 expect: ["attr-presence-a1", "attr-presence-span1", "attr-presence-i1"], exclude: ["xhtml"],    level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute presence selector, not matching title attribute, case sensitivity",         selector: "#attr-presence [*|TiTlE]",                                 expect: [],                                                              exclude: ["html"],     level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute presence selector, matching custom data-* attribute",                       selector: "[data-attr-presence]",                                   expect: ["attr-presence-pre1", "attr-presence-blockquote1"],                                      level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute presence selector, not matching attribute with similar name",               selector: ".attr-presence-div3[align], .attr-presence-div4[align]", expect: [] /*no matches*/,                                                                        level: 2, testType: TEST_QSA},
+  {name: "Attribute presence selector, matching attribute with non-ASCII characters",           selector: "ul[data-中文]",                                            expect: ["attr-presence-ul1"],                                                                    level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute presence selector, not matching default option without selected attribute", selector: "#attr-presence-select1 option[selected]",                expect: [] /* no matches */,                                                                      level: 2, testType: TEST_QSA},
+  {name: "Attribute presence selector, matching option with selected attribute",                selector: "#attr-presence-select2 option[selected]",                expect: ["attr-presence-select2-option4"],                                                        level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute presence selector, matching multiple options with selected attributes",     selector: "#attr-presence-select3 option[selected]",                expect: ["attr-presence-select3-option2", "attr-presence-select3-option3"],                       level: 2, testType: TEST_QSA | TEST_MATCH},
+
+  // - value                     [att=val]
+  {name: "Attribute value selector, matching align attribute with value",                                    selector: "#attr-value [align=\"center\"]",                                     expect: ["attr-value-div1"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute value selector, matching align attribute with value, unclosed bracket",                  selector: "#attr-value [align=\"center\"",                                      expect: ["attr-value-div1"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute value selector, matching align attribute with empty value",                              selector: "#attr-value [align=\"\"]",                                           expect: ["attr-value-div2"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute value selector, not matching align attribute with partial value",                        selector: "#attr-value [align=\"c\"]",                                          expect: [] /*no matches*/,   level: 2, testType: TEST_QSA},
+  {name: "Attribute value selector, not matching align attribute with incorrect value",                      selector: "#attr-value [align=\"centera\"]",                                    expect: [] /*no matches*/,   level: 2, testType: TEST_QSA},
+  {name: "Attribute value selector, matching custom data-* attribute with unicode escaped value",            selector: "[data-attr-value=\"\\e9\"]",                                         expect: ["attr-value-div3"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute value selector, matching custom data-* attribute with escaped character",                selector: "[data-attr-value\_foo=\"\\e9\"]",                                    expect: ["attr-value-div4"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute value selector with single-quoted value, matching multiple inputs with type attributes", selector: "#attr-value input[type='hidden'],#attr-value input[type='radio']",   expect: ["attr-value-input3", "attr-value-input4", "attr-value-input6", "attr-value-input8", "attr-value-input9"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute value selector with double-quoted value, matching multiple inputs with type attributes", selector: "#attr-value input[type=\"hidden\"],#attr-value input[type='radio']", expect: ["attr-value-input3", "attr-value-input4", "attr-value-input6", "attr-value-input8", "attr-value-input9"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute value selector with unquoted value, matching multiple inputs with type attributes",      selector: "#attr-value input[type=hidden],#attr-value input[type=radio]",       expect: ["attr-value-input3", "attr-value-input4", "attr-value-input6", "attr-value-input8", "attr-value-input9"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute value selector, matching attribute with value using non-ASCII characters",               selector: "[data-attr-value=中文]",                                               expect: ["attr-value-div5"], level: 2, testType: TEST_QSA | TEST_MATCH},
+
+  // - whitespace-separated list [att~=val]
+  {name: "Attribute whitespace-separated list selector, matching class attribute with value",                                  selector: "#attr-whitespace [class~=\"div1\"]",                                        expect: ["attr-whitespace-div1"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector, not matching class attribute with empty value",                        selector: "#attr-whitespace [class~=\"\"]",                                            expect: [] /*no matches*/ ,       level: 2, testType: TEST_QSA},
+  {name: "Attribute whitespace-separated list selector, not matching class attribute with partial value",                      selector: "[data-attr-whitespace~=\"div\"]",                                           expect: [] /*no matches*/ ,       level: 2, testType: TEST_QSA},
+  {name: "Attribute whitespace-separated list selector, matching custom data-* attribute with unicode escaped value",          selector: "[data-attr-whitespace~=\"\\0000e9\"]",                                      expect: ["attr-whitespace-div4"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector, matching custom data-* attribute with escaped character",              selector: "[data-attr-whitespace\_foo~=\"\\e9\"]",                                     expect: ["attr-whitespace-div5"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector with single-quoted value, matching multiple links with rel attributes", selector: "#attr-whitespace a[rel~='bookmark'],  #attr-whitespace a[rel~='nofollow']", expect: ["attr-whitespace-a1", "attr-whitespace-a2", "attr-whitespace-a3", "attr-whitespace-a5", "attr-whitespace-a7"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector with double-quoted value, matching multiple links with rel attributes", selector: "#attr-whitespace a[rel~=\"bookmark\"],#attr-whitespace a[rel~='nofollow']", expect: ["attr-whitespace-a1", "attr-whitespace-a2", "attr-whitespace-a3", "attr-whitespace-a5", "attr-whitespace-a7"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector with unquoted value, matching multiple links with rel attributes",      selector: "#attr-whitespace a[rel~=bookmark],    #attr-whitespace a[rel~=nofollow]",   expect: ["attr-whitespace-a1", "attr-whitespace-a2", "attr-whitespace-a3", "attr-whitespace-a5", "attr-whitespace-a7"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector with double-quoted value, not matching value with space",               selector: "#attr-whitespace a[rel~=\"book mark\"]",                                    expect: [] /* no matches */,      level: 2, testType: TEST_QSA},
+  {name: "Attribute whitespace-separated list selector, matching title attribute with value using non-ASCII characters",       selector: "#attr-whitespace [title~=中文]",                                              expect: ["attr-whitespace-p1"],   level: 2, testType: TEST_QSA | TEST_MATCH},
+
+  // - hyphen-separated list     [att|=val]
+  {name: "Attribute hyphen-separated list selector, not matching unspecified lang attribute",    selector: "#attr-hyphen-div1[lang|=\"en\"]",    expect: [] /*no matches*/,    level: 2, testType: TEST_QSA},
+  {name: "Attribute hyphen-separated list selector, matching lang attribute with exact value",   selector: "#attr-hyphen-div2[lang|=\"fr\"]",    expect: ["attr-hyphen-div2"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute hyphen-separated list selector, matching lang attribute with partial value", selector: "#attr-hyphen-div3[lang|=\"en\"]",    expect: ["attr-hyphen-div3"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute hyphen-separated list selector, not matching incorrect value",               selector: "#attr-hyphen-div4[lang|=\"es-AR\"]", expect: [] /*no matches*/,    level: 2, testType: TEST_QSA},
+
+  // - substring begins-with     [att^=val] (Level 3)
+  {name: "Attribute begins with selector, matching href attributes beginning with specified substring",                             selector: "#attr-begins a[href^=\"http://www\"]", expect: ["attr-begins-a1", "attr-begins-a3"],     level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute begins with selector, matching lang attributes beginning with specified substring, ",                           selector: "#attr-begins [lang^=\"en-\"]",         expect: ["attr-begins-div2", "attr-begins-div4"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute begins with selector, not matching class attribute with empty value",                                           selector: "#attr-begins [class^=\"\"]",          expect: [] /*no matches*/,                        level: 3, testType: TEST_QSA},
+  {name: "Attribute begins with selector, not matching class attribute not beginning with specified substring",                     selector: "#attr-begins [class^=apple]",          expect: [] /*no matches*/,                        level: 3, testType: TEST_QSA},
+  {name: "Attribute begins with selector with single-quoted value, matching class attribute beginning with specified substring",    selector: "#attr-begins [class^=' apple']",       expect: ["attr-begins-p1"],                       level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute begins with selector with double-quoted value, matching class attribute beginning with specified substring",    selector: "#attr-begins [class^=\" apple\"]",     expect: ["attr-begins-p1"],                       level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute begins with selector with unquoted value, not matching class attribute not beginning with specified substring", selector: "#attr-begins [class^= apple]",         expect: [] /*no matches*/,                        level: 3, testType: TEST_QSA},
+
+  // - substring ends-with       [att$=val] (Level 3)
+  {name: "Attribute ends with selector, matching href attributes ending with specified substring",                             selector: "#attr-ends a[href$=\".org\"]",   expect: ["attr-ends-a1", "attr-ends-a3"],     level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute ends with selector, matching lang attributes ending with specified substring, ",                           selector: "#attr-ends [lang$=\"-CH\"]",     expect: ["attr-ends-div2", "attr-ends-div4"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute ends with selector, not matching class attribute with empty value",                                        selector: "#attr-ends [class$=\"\"]",       expect: [] /*no matches*/,                    level: 3, testType: TEST_QSA},
+  {name: "Attribute ends with selector, not matching class attribute not ending with specified substring",                     selector: "#attr-ends [class$=apple]",      expect: [] /*no matches*/,                    level: 3, testType: TEST_QSA},
+  {name: "Attribute ends with selector with single-quoted value, matching class attribute ending with specified substring",    selector: "#attr-ends [class$='apple ']",   expect: ["attr-ends-p1"],                     level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute ends with selector with double-quoted value, matching class attribute ending with specified substring",    selector: "#attr-ends [class$=\"apple \"]", expect: ["attr-ends-p1"],                     level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute ends with selector with unquoted value, not matching class attribute not ending with specified substring", selector: "#attr-ends [class$=apple ]",     expect: [] /*no matches*/,                    level: 3, testType: TEST_QSA},
+
+  // - substring contains        [att*=val] (Level 3)
+  {name: "Attribute contains selector, matching href attributes beginning with specified substring",                          selector: "#attr-contains a[href*=\"http://www\"]",     expect: ["attr-contains-a1", "attr-contains-a3"],     level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector, matching href attributes ending with specified substring",                             selector: "#attr-contains a[href*=\".org\"]",           expect: ["attr-contains-a1", "attr-contains-a2"],     level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector, matching href attributes containing specified substring",                              selector: "#attr-contains a[href*=\".example.\"]",      expect: ["attr-contains-a1", "attr-contains-a3"],     level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector, matching lang attributes beginning with specified substring, ",                        selector: "#attr-contains [lang*=\"en-\"]",             expect: ["attr-contains-div2", "attr-contains-div6"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector, matching lang attributes ending with specified substring, ",                           selector: "#attr-contains [lang*=\"-CH\"]",             expect: ["attr-contains-div3", "attr-contains-div5"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector, not matching class attribute with empty value",                                        selector: "#attr-contains [class*=\"\"]",               expect: [] /*no matches*/,                            level: 3, testType: TEST_QSA},
+  {name: "Attribute contains selector with single-quoted value, matching class attribute beginning with specified substring", selector: "#attr-contains [class*=' apple']",           expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector with single-quoted value, matching class attribute ending with specified substring",    selector: "#attr-contains [class*='orange ']",          expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector with single-quoted value, matching class attribute containing specified substring",     selector: "#attr-contains [class*='ple banana ora']",   expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector with double-quoted value, matching class attribute beginning with specified substring", selector: "#attr-contains [class*=\" apple\"]",         expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector with double-quoted value, matching class attribute ending with specified substring",    selector: "#attr-contains [class*=\"orange \"]",        expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector with double-quoted value, matching class attribute containing specified substring",     selector: "#attr-contains [class*=\"ple banana ora\"]", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector with unquoted value, matching class attribute beginning with specified substring",      selector: "#attr-contains [class*= apple]",             expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector with unquoted value, matching class attribute ending with specified substring",         selector: "#attr-contains [class*=orange ]",            expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "Attribute contains selector with unquoted value, matching class attribute containing specified substring",          selector: "#attr-contains [class*= banana ]",           expect: ["attr-contains-p1"],                         level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // Pseudo-classes
+  // - :root                 (Level 3)
+  {name: ":root pseudo-class selector, matching document root element",      selector: ":root", expect: ["html"],          exclude: ["element", "fragment", "detached"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":root pseudo-class selector, not matching document root element",  selector: ":root", expect: [] /*no matches*/, exclude: ["document"],                        level: 3, testType: TEST_QSA},
+
+  // - :nth-child(n)         (Level 3)
+  // XXX write descriptions
+  {name: ":nth-child selector, matching the third child element",                              selector: "#pseudo-nth-table1 :nth-child(3)", expect: ["pseudo-nth-td3", "pseudo-nth-td9", "pseudo-nth-tr3", "pseudo-nth-td15"],                    level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-child selector, matching every third child element",                            selector: "#pseudo-nth li:nth-child(3n)",     expect: ["pseudo-nth-li3", "pseudo-nth-li6", "pseudo-nth-li9", "pseudo-nth-li12"],                    level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-child selector, matching every second child element, starting from the fourth", selector: "#pseudo-nth li:nth-child(2n+4)",   expect: ["pseudo-nth-li4", "pseudo-nth-li6", "pseudo-nth-li8", "pseudo-nth-li10", "pseudo-nth-li12"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-child selector, matching every fourth child element, starting from the third",  selector: "#pseudo-nth-p1 :nth-child(4n-1)",  expect: ["pseudo-nth-em2", "pseudo-nth-span3"],                                                       level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :nth-last-child       (Level 3)
+  {name: ":nth-last-child selector, matching the third last child element",                                           selector: "#pseudo-nth-table1 :nth-last-child(3)", expect: ["pseudo-nth-tr1", "pseudo-nth-td4", "pseudo-nth-td10", "pseudo-nth-td16"],                 level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-last-child selector, matching every third child element from the end",                                 selector: "#pseudo-nth li:nth-last-child(3n)",     expect: ["pseudo-nth-li1", "pseudo-nth-li4", "pseudo-nth-li7", "pseudo-nth-li10"],                  level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-last-child selector, matching every second child element from the end, starting from the fourth last", selector: "#pseudo-nth li:nth-last-child(2n+4)",   expect: ["pseudo-nth-li1", "pseudo-nth-li3", "pseudo-nth-li5", "pseudo-nth-li7", "pseudo-nth-li9"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-last-child selector, matching every fourth element from the end, starting from the third last",        selector: "#pseudo-nth-p1 :nth-last-child(4n-1)",  expect: ["pseudo-nth-span2", "pseudo-nth-span4"],                                                   level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :nth-of-type(n)       (Level 3)
+  {name: ":nth-of-type selector, matching the third em element",                                        selector: "#pseudo-nth-p1 em:nth-of-type(3)",      expect: ["pseudo-nth-em3"],                                                                                 level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-of-type selector, matching every second element of their type",                          selector: "#pseudo-nth-p1 :nth-of-type(2n)",       expect: ["pseudo-nth-em2", "pseudo-nth-span2", "pseudo-nth-span4", "pseudo-nth-strong2", "pseudo-nth-em4"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-of-type selector, matching every second elemetn of their type, starting from the first", selector: "#pseudo-nth-p1 span:nth-of-type(2n-1)", expect: ["pseudo-nth-span1", "pseudo-nth-span3"],                                                           level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :nth-last-of-type(n)  (Level 3)
+  {name: ":nth-last-of-type selector, matching the third last em element", selector: "#pseudo-nth-p1 em:nth-last-of-type(3)",      expect: ["pseudo-nth-em2"],                                                                                 level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-last-of-type selector, matching every second last element of their type", selector: "#pseudo-nth-p1 :nth-last-of-type(2n)",       expect: ["pseudo-nth-span1", "pseudo-nth-em1", "pseudo-nth-strong1", "pseudo-nth-em3", "pseudo-nth-span3"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":nth-last-of-type selector, matching every second last element of their type, starting from the last", selector: "#pseudo-nth-p1 span:nth-last-of-type(2n-1)", expect: ["pseudo-nth-span2", "pseudo-nth-span4"],                                                           level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :first-of-type        (Level 3)
+  {name: ":first-of-type selector, matching the first em element", selector: "#pseudo-nth-p1 em:first-of-type",      expect: ["pseudo-nth-em1"],                                           level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":first-of-type selector, matching the first of every type of element", selector: "#pseudo-nth-p1 :first-of-type",        expect: ["pseudo-nth-span1", "pseudo-nth-em1", "pseudo-nth-strong1"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":first-of-type selector, matching the first td element in each table row", selector: "#pseudo-nth-table1 tr :first-of-type", expect: ["pseudo-nth-td1", "pseudo-nth-td7", "pseudo-nth-td13"],      level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :last-of-type         (Level 3)
+  {name: ":last-of-type selector, matching the last em elemnet", selector: "#pseudo-nth-p1 em:last-of-type",      expect: ["pseudo-nth-em4"],                                           level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":last-of-type selector, matching the last of every type of element", selector: "#pseudo-nth-p1 :last-of-type",        expect: ["pseudo-nth-span4", "pseudo-nth-strong2", "pseudo-nth-em4"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":last-of-type selector, matching the last td element in each table row", selector: "#pseudo-nth-table1 tr :last-of-type", expect: ["pseudo-nth-td6", "pseudo-nth-td12", "pseudo-nth-td18"],     level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :first-child
+  {name: ":first-child pseudo-class selector, matching first child div element",          selector: "#pseudo-first-child div:first-child",                                        expect: ["pseudo-first-child-div1"],                                                          level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: ":first-child pseudo-class selector, doesn't match non-first-child elements",    selector: ".pseudo-first-child-div2:first-child, .pseudo-first-child-div3:first-child", expect: [] /*no matches*/,                                                                    level: 2, testType: TEST_QSA},
+  {name: ":first-child pseudo-class selector, matching first-child of multiple elements", selector: "#pseudo-first-child span:first-child",                                       expect: ["pseudo-first-child-span1", "pseudo-first-child-span3", "pseudo-first-child-span5"], level: 2, testType: TEST_QSA | TEST_MATCH},
+
+  // - :last-child           (Level 3)
+  {name: ":last-child pseudo-class selector, matching last child div element",           selector: "#pseudo-last-child div:last-child",                                       expect: ["pseudo-last-child-div3"],                                                        level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":last-child pseudo-class selector, doesn't match non-last-child elements",     selector: ".pseudo-last-child-div1:last-child, .pseudo-last-child-div2:first-child", expect: [] /*no matches*/,                                                                 level: 3, testType: TEST_QSA},
+  {name: ":last-child pseudo-class selector, matching first-child of multiple elements", selector: "#pseudo-last-child span:last-child",                                      expect: ["pseudo-last-child-span2", "pseudo-last-child-span4", "pseudo-last-child-span6"], level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :only-child           (Level 3)
+  {name: ":pseudo-only-child pseudo-class selector, matching all only-child elements", selector: "#pseudo-only :only-child", expect: ["pseudo-only-span1"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":pseudo-only-child pseudo-class selector, matching only-child em elements",  selector: "#pseudo-only em:only-child", expect: [] /*no matches*/,   level: 3, testType: TEST_QSA},
+
+  // - :only-of-type         (Level 3)
+  {name: ":pseudo-only-of-type pseudo-class selector, matching all elements with no siblings of the same type", selector: "#pseudo-only :only-of-type", expect: ["pseudo-only-span1", "pseudo-only-em1"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":pseudo-only-of-type pseudo-class selector, matching em elements with no siblings of the same type",  selector: "#pseudo-only em:only-of-type", expect: ["pseudo-only-em1"],                    level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :empty                (Level 3)
+  {name: ":empty pseudo-class selector, matching empty p elements",   selector: "#pseudo-empty p:empty", expect: ["pseudo-empty-p1", "pseudo-empty-p2"],                       level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":empty pseudo-class selector, matching all empty elements", selector: "#pseudo-empty :empty",  expect: ["pseudo-empty-p1", "pseudo-empty-p2", "pseudo-empty-span1"], level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :link and :visited
+  // Implementations may treat all visited links as unvisited, so these cannot be tested separately.
+  // The only guarantee is that ":link,:visited" matches the set of all visited and unvisited links and that they are individually mutually exclusive sets.
+  {name: ":link and :visited pseudo-class selectors, matching a and area elements with href attributes",        selector: "#pseudo-link :link, #pseudo-link :visited", expect: ["pseudo-link-a1", "pseudo-link-a2", "pseudo-link-area1"],                                level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: ":link and :visited pseudo-class selectors, matching no elements",                                     selector: "#head :link, #head :visited",               expect: [] /*no matches*/,                          exclude: ["element", "fragment", "detached"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: ":link and :visited pseudo-class selectors, not matching link elements with href attributes",          selector: "#head :link, #head :visited",               expect: [] /*no matches*/,                          exclude: ["document"],                        level: 1, testType: TEST_QSA},
+  {name: ":link and :visited pseudo-class selectors, chained, mutually exclusive pseudo-classes match nothing", selector: ":link:visited",                             expect: [] /*no matches*/,                          exclude: ["document"],                        level: 1, testType: TEST_QSA},
+
+  // - :target               (Level 3)
+  {name: ":target pseudo-class selector, matching the element referenced by the URL fragment identifier", selector: ":target", expect: [] /*no matches*/, exclude: ["document", "element"],  level: 3, testType: TEST_QSA},
+  {name: ":target pseudo-class selector, matching the element referenced by the URL fragment identifier", selector: ":target", expect: ["target"],        exclude: ["fragment", "detached"], level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :lang()
+  {name: ":lang pseudo-class selector, matching inherited language",                     selector: "#pseudo-lang-div1:lang(en)",    expect: ["pseudo-lang-div1"], exclude: ["detached", "fragment"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: ":lang pseudo-class selector, not matching element with no inherited language", selector: "#pseudo-lang-div1:lang(en)",    expect: [] /*no matches*/,    exclude: ["document", "element"],  level: 2, testType: TEST_QSA},
+  {name: ":lang pseudo-class selector, matching specified language with exact value",    selector: "#pseudo-lang-div2:lang(fr)",    expect: ["pseudo-lang-div2"],                                    level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: ":lang pseudo-class selector, matching specified language with partial value",  selector: "#pseudo-lang-div3:lang(en)",    expect: ["pseudo-lang-div3"],                                    level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: ":lang pseudo-class selector, not matching incorrect language",                 selector: "#pseudo-lang-div4:lang(es-AR)", expect: [] /*no matches*/,                                       level: 2, testType: TEST_QSA},
+
+  // - :enabled              (Level 3)
+  {name: ":enabled pseudo-class selector, matching all enabled form controls",  selector: "#pseudo-ui :enabled",  expect: ["pseudo-ui-input1", "pseudo-ui-input2", "pseudo-ui-input3", "pseudo-ui-input4", "pseudo-ui-input5", "pseudo-ui-input6",
+                                                                                                                           "pseudo-ui-input7", "pseudo-ui-input8", "pseudo-ui-input9", "pseudo-ui-textarea1", "pseudo-ui-button1"],    level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":enabled pseudo-class selector, not matching link elements",  selector: "#pseudo-link :enabled",  expect: [] /*no matches*/, unexpected: ["pseudo-link-a1","pseudo-link-a2","pseudo-link-a3","pseudo-link-map1","pseudo-link-area1","pseudo-link-area2"],   level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :disabled             (Level 3)
+  {name: ":disabled pseudo-class selector, matching all disabled form controls", selector: "#pseudo-ui :disabled", expect: ["pseudo-ui-input10", "pseudo-ui-input11", "pseudo-ui-input12", "pseudo-ui-input13", "pseudo-ui-input14", "pseudo-ui-input15",
+                                                                                                                           "pseudo-ui-input16", "pseudo-ui-input17", "pseudo-ui-input18", "pseudo-ui-textarea2", "pseudo-ui-button2"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":disabled pseudo-class selector, not matching link elements", selector: "#pseudo-link :disabled", expect: [] /*no matches*/, unexpected: ["pseudo-link-a1","pseudo-link-a2","pseudo-link-a3","pseudo-link-map1","pseudo-link-area1","pseudo-link-area2"], level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :checked              (Level 3)
+  {name: ":checked pseudo-class selector, matching checked radio buttons and checkboxes", selector: "#pseudo-ui :checked", expect: ["pseudo-ui-input4", "pseudo-ui-input6", "pseudo-ui-input13", "pseudo-ui-input15"],  level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :not(s)               (Level 3)
+  {name: ":not pseudo-class selector, matching ", selector: "#not>:not(div)",   expect: ["not-p1", "not-p2", "not-p3"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":not pseudo-class selector, matching ", selector: "#not * :not(:first-child)",   expect: ["not-em1", "not-em2", "not-em3"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: ":not pseudo-class selector, matching nothing", selector: ":not(*)",   expect: [] /* no matches */, level: 3, testType: TEST_QSA},
+  {name: ":not pseudo-class selector, matching nothing", selector: ":not(*|*)", expect: [] /* no matches */, level: 3, testType: TEST_QSA},
+  {name: ":not pseudo-class selector argument surrounded by spaces, matching ", selector: "#not>:not( div )",   expect: ["not-p1", "not-p2", "not-p3"], level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // Pseudo-elements
+  // - ::first-line
+  {name: ":first-line pseudo-element (one-colon syntax) selector, not matching any elements",    selector: "#pseudo-element:first-line",    expect: [] /*no matches*/, level: 2, testType: TEST_QSA},
+  {name: "::first-line pseudo-element (two-colon syntax) selector, not matching any elements",   selector: "#pseudo-element::first-line",   expect: [] /*no matches*/, level: 3, testType: TEST_QSA},
+
+  // - ::first-letter
+  {name: ":first-letter pseudo-element (one-colon syntax) selector, not matching any elements",  selector: "#pseudo-element:first-letter",  expect: [] /*no matches*/, level: 2, testType: TEST_QSA},
+  {name: "::first-letter pseudo-element (two-colon syntax) selector, not matching any elements", selector: "#pseudo-element::first-letter", expect: [] /*no matches*/, level: 3, testType: TEST_QSA},
+
+  // - ::before
+  {name: ":before pseudo-element (one-colon syntax) selector, not matching any elements",        selector: "#pseudo-element:before",        expect: [] /*no matches*/, level: 2, testType: TEST_QSA},
+  {name: "::before pseudo-element (two-colon syntax) selector, not matching any elements",       selector: "#pseudo-element::before",       expect: [] /*no matches*/, level: 3, testType: TEST_QSA},
+
+  // - ::after
+  {name: ":after pseudo-element (one-colon syntax) selector, not matching any elements",         selector: "#pseudo-element:after",         expect: [] /*no matches*/, level: 2, testType: TEST_QSA},
+  {name: "::after pseudo-element (two-colon syntax) selector, not matching any elements",        selector: "#pseudo-element::after",        expect: [] /*no matches*/, level: 3, testType: TEST_QSA},
+
+  // Class Selectors
+  {name: "Class selector, matching element with specified class",                                           selector: ".class-p",                expect: ["class-p1","class-p2", "class-p3"],                                              level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Class selector, chained, matching only elements with all specified classes",                      selector: "#class .apple.orange.banana",    expect: ["class-div1", "class-div2", "class-p4", "class-div3", "class-p6", "class-div4"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Class Selector, chained, with type selector",                                                     selector: "div.apple.banana.orange", expect: ["class-div1", "class-div2", "class-div3", "class-div4"],                         level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Class selector, matching element with class value using non-ASCII characters (1)",                selector: ".\u53F0\u5317Ta\u0301ibe\u030Ci",             expect: ["class-span1"],               level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Class selector, matching multiple elements with class value using non-ASCII characters",          selector: ".\u53F0\u5317",                     expect: ["class-span1","class-span2"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Class selector, chained, matching element with multiple class values using non-ASCII characters (1)", selector: ".\u53F0\u5317Ta\u0301ibe\u030Ci.\u53F0\u5317",          expect: ["class-span1"],               level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Class selector, matching element with class with escaped character",                              selector: ".foo\\:bar",              expect: ["class-span3"],               level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Class selector, matching element with class with escaped character",                              selector: ".test\\.foo\\[5\\]bar",   expect: ["class-span4"],               level: 1, testType: TEST_QSA | TEST_MATCH},
+
+  // ID Selectors
+  {name: "ID selector, matching element with specified id",           selector: "#id #id-div1",              expect: ["id-div1"],            level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "ID selector, chained, matching element with specified id",  selector: "#id-div1, #id-div1",        expect: ["id-div1"],            level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "ID selector, chained, matching element with specified id",  selector: "#id-div1, #id-div2",        expect: ["id-div1", "id-div2"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "ID Selector, chained, with type selector",                  selector: "div#id-div1, div#id-div2",  expect: ["id-div1", "id-div2"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "ID selector, not matching non-existent descendant",         selector: "#id #none",                 expect: [] /*no matches*/,      level: 1, testType: TEST_QSA},
+  {name: "ID selector, not matching non-existent ancestor",           selector: "#none #id-div1",            expect: [] /*no matches*/,      level: 1, testType: TEST_QSA},
+  {name: "ID selector, matching multiple elements with duplicate id", selector: "#id-li-duplicate",          expect: ["id-li-duplicate", "id-li-duplicate", "id-li-duplicate", "id-li-duplicate"], level: 1, testType: TEST_QSA | TEST_MATCH},
+
+  {name: "ID selector, matching id value using non-ASCII characters (1)",    selector: "#\u53F0\u5317Ta\u0301ibe\u030Ci",           expect: ["\u53F0\u5317Ta\u0301ibe\u030Ci"],       level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "ID selector, matching id value using non-ASCII characters (2)",    selector: "#\u53F0\u5317",                   expect: ["\u53F0\u5317"],               level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "ID selector, matching id values using non-ASCII characters (1)", selector: "#\u53F0\u5317Ta\u0301ibe\u030Ci, #\u53F0\u5317",      expect: ["\u53F0\u5317Ta\u0301ibe\u030Ci", "\u53F0\u5317"], level: 1, testType: TEST_QSA | TEST_MATCH},
+
+  // XXX runMatchesTest() in level2-lib.js can't handle this because obtaining the expected nodes requires escaping characters when generating the selector from 'expect' values
+  {name: "ID selector, matching element with id with escaped character", selector: "#\\#foo\\:bar",         expect: ["#foo:bar"],         level: 1, testType: TEST_QSA},
+  {name: "ID selector, matching element with id with escaped character", selector: "#test\\.foo\\[5\\]bar", expect: ["test.foo[5]bar"],   level: 1, testType: TEST_QSA},
+
+  // Namespaces
+  // XXX runMatchesTest() in level2-lib.js can't handle these because non-HTML elements don't have a recognised id
+  {name: "Namespace selector, matching element with any namespace",        selector: "#any-namespace *|div", expect: ["any-namespace-div1", "any-namespace-div2", "any-namespace-div3", "any-namespace-div4"], level: 3, testType: TEST_QSA},
+  {name: "Namespace selector, matching div elements in no namespace only", selector: "#no-namespace |div",   expect: ["no-namespace-div3"], level: 3, testType: TEST_QSA},
+  {name: "Namespace selector, matching any elements in no namespace only", selector: "#no-namespace |*",     expect: ["no-namespace-div3"], level: 3, testType: TEST_QSA},
+
+  // Combinators
+  // - Descendant combinator ' '
+  {name: "Descendant combinator, matching element that is a descendant of an element with id",                 selector: "#descendant div",                   expect: ["descendant-div1", "descendant-div2", "descendant-div3", "descendant-div4"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Descendant combinator, matching element with id that is a descendant of an element",                 selector: "body #descendant-div1",             expect: ["descendant-div1"], exclude: ["detached", "fragment"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Descendant combinator, matching element with id that is a descendant of an element",                 selector: "div #descendant-div1",              expect: ["descendant-div1"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Descendant combinator, matching element with id that is a descendant of an element with id",         selector: "#descendant #descendant-div2",      expect: ["descendant-div2"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Descendant combinator, matching element with class that is a descendant of an element with id",      selector: "#descendant .descendant-div2",      expect: ["descendant-div2"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Descendant combinator, matching element with class that is a descendant of an element with class",   selector: ".descendant-div1 .descendant-div3", expect: ["descendant-div3"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Descendant combinator, not matching element with id that is not a descendant of an element with id", selector: "#descendant-div1 #descendant-div4", expect: [] /*no matches*/,                                      level: 1, testType: TEST_QSA},
+  {name: "Descendant combinator, whitespace characters",                                                       selector: "#descendant\t\r\n#descendant-div2", expect: ["descendant-div2"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+
+  /* The future of this combinator is uncertain, see
+   * https://github.com/w3c/csswg-drafts/issues/641
+   * These tests are commented out until a final decision is made on whether to
+   * keep the feature in the spec.
+   */
+
+  // // - Descendant combinator '>>'
+  // {name: "Descendant combinator '>>', matching element that is a descendant of an element with id",                 selector: "#descendant>>div",                   expect: ["descendant-div1", "descendant-div2", "descendant-div3", "descendant-div4"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with id that is a descendant of an element",                 selector: "body>>#descendant-div1",             expect: ["descendant-div1"], exclude: ["detached", "fragment"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with id that is a descendant of an element",                 selector: "div>>#descendant-div1",              expect: ["descendant-div1"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with id that is a descendant of an element with id",         selector: "#descendant>>#descendant-div2",      expect: ["descendant-div2"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with class that is a descendant of an element with id",      selector: "#descendant>>.descendant-div2",      expect: ["descendant-div2"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with class that is a descendant of an element with class",   selector: ".descendant-div1>>.descendant-div3", expect: ["descendant-div3"],                                    level: 1, testType: TEST_QSA | TEST_MATCH},
+  // {name: "Descendant combinator '>>', not matching element with id that is not a descendant of an element with id", selector: "#descendant-div1>>#descendant-div4", expect: [] /*no matches*/,                                      level: 1, testType: TEST_QSA},
+
+  // - Child combinator '>'
+  {name: "Child combinator, matching element that is a child of an element with id",                       selector: "#child>div",                          expect: ["child-div1", "child-div4"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Child combinator, matching element with id that is a child of an element",                       selector: "div>#child-div1",                     expect: ["child-div1"],               level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Child combinator, matching element with id that is a child of an element with id",               selector: "#child>#child-div1",                  expect: ["child-div1"],               level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Child combinator, matching element with id that is a child of an element with class",            selector: "#child-div1>.child-div2",             expect: ["child-div2"],               level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Child combinator, matching element with class that is a child of an element with class",         selector: ".child-div1>.child-div2",             expect: ["child-div2"],               level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Child combinator, not matching element with id that is not a child of an element with id",       selector: "#child>#child-div3",                  expect: [] /*no matches*/,            level: 2, testType: TEST_QSA},
+  {name: "Child combinator, not matching element with id that is not a child of an element with class",    selector: "#child-div1>.child-div3",             expect: [] /*no matches*/,            level: 2, testType: TEST_QSA},
+  {name: "Child combinator, not matching element with class that is not a child of an element with class", selector: ".child-div1>.child-div3",             expect: [] /*no matches*/,            level: 2, testType: TEST_QSA},
+  {name: "Child combinator, surrounded by whitespace",                                                     selector: "#child-div1\t\r\n>\t\r\n#child-div2", expect: ["child-div2"],               level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Child combinator, whitespace after",                                                             selector: "#child-div1>\t\r\n#child-div2",       expect: ["child-div2"],               level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Child combinator, whitespace before",                                                            selector: "#child-div1\t\r\n>#child-div2",       expect: ["child-div2"],               level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Child combinator, no whitespace",                                                                selector: "#child-div1>#child-div2",             expect: ["child-div2"],               level: 2, testType: TEST_QSA | TEST_MATCH},
+
+  // - Adjacent sibling combinator '+'
+  {name: "Adjacent sibling combinator, matching element that is an adjacent sibling of an element with id",                 selector: "#adjacent-div2+div",                                         expect: ["adjacent-div4"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching element with id that is an adjacent sibling of an element",                 selector: "div+#adjacent-div4",                                         expect: ["adjacent-div4"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching element with id that is an adjacent sibling of an element with id",         selector: "#adjacent-div2+#adjacent-div4",                              expect: ["adjacent-div4"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching element with class that is an adjacent sibling of an element with id",      selector: "#adjacent-div2+.adjacent-div4",                              expect: ["adjacent-div4"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching element with class that is an adjacent sibling of an element with class",   selector: ".adjacent-div2+.adjacent-div4",                              expect: ["adjacent-div4"], level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching p element that is an adjacent sibling of a div element",                    selector: "#adjacent div+p",                                            expect: ["adjacent-p2"],   level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, not matching element with id that is not an adjacent sibling of an element with id", selector: "#adjacent-div2+#adjacent-p2, #adjacent-div2+#adjacent-div1", expect: [] /*no matches*/, level: 2, testType: TEST_QSA},
+  {name: "Adjacent sibling combinator, surrounded by whitespace",                                                           selector: "#adjacent-p2\t\r\n+\t\r\n#adjacent-p3",                      expect: ["adjacent-p3"],   level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, whitespace after",                                                                   selector: "#adjacent-p2+\t\r\n#adjacent-p3",                            expect: ["adjacent-p3"],   level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, whitespace before",                                                                  selector: "#adjacent-p2\t\r\n+#adjacent-p3",                            expect: ["adjacent-p3"],   level: 2, testType: TEST_QSA | TEST_MATCH},
+  {name: "Adjacent sibling combinator, no whitespace",                                                                      selector: "#adjacent-p2+#adjacent-p3",                                  expect: ["adjacent-p3"],   level: 2, testType: TEST_QSA | TEST_MATCH},
+
+  // - General sibling combinator ~ (Level 3)
+  {name: "General sibling combinator, matching element that is a sibling of an element with id",                    selector: "#sibling-div2~div",                                        expect: ["sibling-div4", "sibling-div6"], level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "General sibling combinator, matching element with id that is a sibling of an element",                    selector: "div~#sibling-div4",                                        expect: ["sibling-div4"],                 level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "General sibling combinator, matching element with id that is a sibling of an element with id",            selector: "#sibling-div2~#sibling-div4",                              expect: ["sibling-div4"],                 level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "General sibling combinator, matching element with class that is a sibling of an element with id",         selector: "#sibling-div2~.sibling-div",                               expect: ["sibling-div4", "sibling-div6"],                 level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "General sibling combinator, matching p element that is a sibling of a div element",                       selector: "#sibling div~p",                                           expect: ["sibling-p2", "sibling-p3"],                   level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "General sibling combinator, not matching element with id that is not a sibling after a p element",        selector: "#sibling>p~div",                                           expect: [] /*no matches*/,                level: 3, testType: TEST_QSA},
+  {name: "General sibling combinator, not matching element with id that is not a sibling after an element with id", selector: "#sibling-div2~#sibling-div3, #sibling-div2~#sibling-div1", expect: [] /*no matches*/,                level: 3, testType: TEST_QSA},
+  {name: "General sibling combinator, surrounded by whitespace",                                                    selector: "#sibling-p2\t\r\n~\t\r\n#sibling-p3",                      expect: ["sibling-p3"],                   level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "General sibling combinator, whitespace after",                                                            selector: "#sibling-p2~\t\r\n#sibling-p3",                            expect: ["sibling-p3"],                   level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "General sibling combinator, whitespace before",                                                           selector: "#sibling-p2\t\r\n~#sibling-p3",                            expect: ["sibling-p3"],                   level: 3, testType: TEST_QSA | TEST_MATCH},
+  {name: "General sibling combinator, no whitespace",                                                               selector: "#sibling-p2~#sibling-p3",                                  expect: ["sibling-p3"],                   level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // Group of selectors (comma)
+  {name: "Syntax, group of selectors separator, surrounded by whitespace", selector: "#group em\t\r \n,\t\r \n#group strong", expect: ["group-em1", "group-strong1"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Syntax, group of selectors separator, whitespace after",         selector: "#group em,\t\r\n#group strong",         expect: ["group-em1", "group-strong1"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Syntax, group of selectors separator, whitespace before",        selector: "#group em\t\r\n,#group strong",         expect: ["group-em1", "group-strong1"], level: 1, testType: TEST_QSA | TEST_MATCH},
+  {name: "Syntax, group of selectors separator, no whitespace",            selector: "#group em,#group strong",               expect: ["group-em1", "group-strong1"], level: 1, testType: TEST_QSA | TEST_MATCH},
+
+  // ::slotted (shouldn't match anything, but is a valid selector)
+  {name: "Slotted selector", selector: "::slotted(foo)", expect: [], level: 3, testType: TEST_QSA},
+  {name: "Slotted selector (no matching closing paren)", selector: "::slotted(foo", expect: [], level: 3, testType: TEST_QSA},
+];
+
+
+/*
+ * These selectors are intended to be used with the find(), findAll() and matches() methods.  Expected results
+ * should be determined under the assumption that :scope will be prepended to the selector where appropriate,
+ * in accordance with the specification.
+ *
+ * All of these should be valid relative selectors, expected to match zero or more elements in the document.
+ * None should throw any errors.
+ *
+ *   name:      A descriptive name of the selector being tested
+ *
+ *   selector:  The selector to test
+ *
+ *   ctx:       A selector to obtain the context object to use for tests invoking context.find(),
+ *              and to use as a single reference node for tests invoking document.find().
+ *              Note: context = root.querySelector(ctx);
+ *
+ *   ref:       A selector to obtain the reference nodes to be used for the selector.
+ *              Note: If root is the document or an in-document element:
+ *                      refNodes = document.querySelectorAll(ref);
+ *                    Otherwise, if root is a fragment or detached element:
+ *                      refNodes = root.querySelectorAll(ref);
+ *
+ *   expect:    A list of IDs of the elements expected to be matched. List must be given in tree order.
+ *
+ *   unexpected: A list of IDs of some elements that are not expected to match the given selector.
+ *               This is used to verify that unexpected.matches(selector, refNode) does not match.
+ *
+ *   exclude:   An array of contexts to exclude from testing. The valid values are:
+ *              ["document", "element", "fragment", "detached", "html", "xhtml"]
+ *              The "html" and "xhtml" values represent the type of document being queried. These are useful
+ *              for tests that are affected by differences between HTML and XML, such as case sensitivity.
+ *
+ *   level:     An integer indicating the CSS or Selectors level in which the selector being tested was introduced.
+ *
+ *   testType:  A bit-mapped flag indicating the type of test.
+ *
+ * The test function for these tests accepts a specified root node, on which the methods will be invoked during the tests.
+ *
+ * Based on whether either 'context' or 'refNodes', or both, are specified the tests will execute the following methods:
+ *
+ * Where testType is TEST_FIND:
+ *
+ * context.findAll(selector, refNodes)
+ * context.findAll(selector)        // Only if refNodes is not specified
+ * root.findAll(selector, context)  // Only if refNodes is not specified
+ * root.findAll(selector, refNodes) // Only if context is not specified
+ * root.findAll(selector)           // Only if neither context nor refNodes is specified
+ *
+ * Where testType is TEST_QSA
+ *
+ * context.querySelectorAll(selector)
+ * root.querySelectorAll(selector)  // Only if neither context nor refNodes is specified
+ *
+ * Equivalent tests will be run for .find() as well.
+ * Note: Do not specify a testType of TEST_QSA where either implied :scope or explicit refNodes
+ * are required.
+ *
+ * Where testType is TEST_MATCH:
+ * For each expected result given, within the specified root:
+ *
+ * expect.matches(selector, context)    // Only where refNodes is not specified
+ * expect.matches(selector, refNodes)
+ * expect.matches(selector)             // Only if neither context nor refNodes is specified
+ *
+ * The tests involving refNodes for both find(), findAll() and matches() will each be run by passing the
+ * collection as a NodeList, an Array and, if there is only a single element, an Element node.
+ *
+ * Note: Interactive pseudo-classes (:active :hover and :focus) have not been tested in this test suite.
+ */
+
+var scopedSelectors = [
+  //{name: "", selector: "", ctx: "", ref: "", expect: [], level: 1, testType: TEST_FIND | TEST_MATCH},
+
+  // Attribute Selectors
+  // - presence                  [att]
+  {name: "Attribute presence selector, matching align attribute with value",                    selector: ".attr-presence-div1[align]",                             ctx: "#attr-presence", expect: ["attr-presence-div1"],                                             level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute presence selector, matching align attribute with empty value",              selector: ".attr-presence-div2[align]",                             ctx: "#attr-presence", expect: ["attr-presence-div2"],                                             level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute presence selector, matching title attribute, case insensitivity",           selector: "[TiTlE]",                                                ctx: "#attr-presence", expect: ["attr-presence-a1", "attr-presence-span1"], exclude: ["xhtml"],    level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute presence selector, not matching title attribute, case sensitivity",         selector: "[TiTlE]",                                                ctx: "#attr-presence", expect: [],                                          exclude: ["html"],     level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute presence selector, matching custom data-* attribute",                       selector: "[data-attr-presence]",                                   ctx: "#attr-presence", expect: ["attr-presence-pre1", "attr-presence-blockquote1"],                level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute presence selector, not matching attribute with similar name",               selector: ".attr-presence-div3[align], .attr-presence-div4[align]", ctx: "#attr-presence", expect: [] /*no matches*/,                                                  level: 2, testType: TEST_FIND},
+  {name: "Attribute presence selector, matching attribute with non-ASCII characters",           selector: "ul[data-中文]",                                            ctx: "#attr-presence", expect: ["attr-presence-ul1"],                                              level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute presence selector, not matching default option without selected attribute", selector: "#attr-presence-select1 option[selected]",                ctx: "#attr-presence", expect: [] /* no matches */,                                                level: 2, testType: TEST_FIND},
+  {name: "Attribute presence selector, matching option with selected attribute",                selector: "#attr-presence-select2 option[selected]",                ctx: "#attr-presence", expect: ["attr-presence-select2-option4"],                                  level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute presence selector, matching multiple options with selected attributes",     selector: "#attr-presence-select3 option[selected]",                ctx: "#attr-presence", expect: ["attr-presence-select3-option2", "attr-presence-select3-option3"], level: 2, testType: TEST_FIND | TEST_MATCH},
+
+  // - value                     [att=val]
+  {name: "Attribute value selector, matching align attribute with value",                                    selector: "[align=\"center\"]",                                     ctx: "#attr-value", expect: ["attr-value-div1"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute value selector, matching align attribute with empty value",                              selector: "[align=\"\"]",                                           ctx: "#attr-value", expect: ["attr-value-div2"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute value selector, not matching align attribute with partial value",                        selector: "[align=\"c\"]",                                          ctx: "#attr-value", expect: [] /*no matches*/,   level: 2, testType: TEST_FIND},
+  {name: "Attribute value selector, not matching align attribute with incorrect value",                      selector: "[align=\"centera\"]",                                    ctx: "#attr-value", expect: [] /*no matches*/,   level: 2, testType: TEST_FIND},
+  {name: "Attribute value selector, matching custom data-* attribute with unicode escaped value",            selector: "[data-attr-value=\"\\e9\"]",                             ctx: "#attr-value", expect: ["attr-value-div3"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute value selector, matching custom data-* attribute with escaped character",                selector: "[data-attr-value\_foo=\"\\e9\"]",                        ctx: "#attr-value", expect: ["attr-value-div4"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute value selector with single-quoted value, matching multiple inputs with type attributes", selector: "input[type='hidden'],#attr-value input[type='radio']",   ctx: "#attr-value", expect: ["attr-value-input3", "attr-value-input4", "attr-value-input6", "attr-value-input8", "attr-value-input9"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute value selector with double-quoted value, matching multiple inputs with type attributes", selector: "input[type=\"hidden\"],#attr-value input[type='radio']", ctx: "#attr-value", expect: ["attr-value-input3", "attr-value-input4", "attr-value-input6", "attr-value-input8", "attr-value-input9"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute value selector with unquoted value, matching multiple inputs with type attributes",      selector: "input[type=hidden],#attr-value input[type=radio]",       ctx: "#attr-value", expect: ["attr-value-input3", "attr-value-input4", "attr-value-input6", "attr-value-input8", "attr-value-input9"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute value selector, matching attribute with value using non-ASCII characters",               selector: "[data-attr-value=中文]",                                   ctx: "#attr-value", expect: ["attr-value-div5"], level: 2, testType: TEST_FIND | TEST_MATCH},
+
+  // - whitespace-separated list [att~=val]
+  {name: "Attribute whitespace-separated list selector, matching class attribute with value",                                  selector: "[class~=\"div1\"]",                                        ctx: "#attr-whitespace", expect: ["attr-whitespace-div1"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector, not matching class attribute with empty value",                        selector: "[class~=\"\"]",                                            ctx: "#attr-whitespace", expect: [] /*no matches*/ ,       level: 2, testType: TEST_FIND},
+  {name: "Attribute whitespace-separated list selector, not matching class attribute with partial value",                      selector: "[data-attr-whitespace~=\"div\"]",                                           ctx: "#attr-whitespace", expect: [] /*no matches*/ ,       level: 2, testType: TEST_FIND},
+  {name: "Attribute whitespace-separated list selector, matching custom data-* attribute with unicode escaped value",          selector: "[data-attr-whitespace~=\"\\0000e9\"]",                                      ctx: "#attr-whitespace", expect: ["attr-whitespace-div4"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector, matching custom data-* attribute with escaped character",              selector: "[data-attr-whitespace\_foo~=\"\\e9\"]",                                     ctx: "#attr-whitespace", expect: ["attr-whitespace-div5"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector with single-quoted value, matching multiple links with rel attributes", selector: "a[rel~='bookmark'],  #attr-whitespace a[rel~='nofollow']", ctx: "#attr-whitespace", expect: ["attr-whitespace-a1", "attr-whitespace-a2", "attr-whitespace-a3", "attr-whitespace-a5", "attr-whitespace-a7"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector with double-quoted value, matching multiple links with rel attributes", selector: "a[rel~=\"bookmark\"],#attr-whitespace a[rel~='nofollow']", ctx: "#attr-whitespace", expect: ["attr-whitespace-a1", "attr-whitespace-a2", "attr-whitespace-a3", "attr-whitespace-a5", "attr-whitespace-a7"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector with unquoted value, matching multiple links with rel attributes",      selector: "a[rel~=bookmark],    #attr-whitespace a[rel~=nofollow]",   ctx: "#attr-whitespace", expect: ["attr-whitespace-a1", "attr-whitespace-a2", "attr-whitespace-a3", "attr-whitespace-a5", "attr-whitespace-a7"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute whitespace-separated list selector with double-quoted value, not matching value with space",               selector: "a[rel~=\"book mark\"]",                                    ctx: "#attr-whitespace", expect: [] /* no matches */,      level: 2, testType: TEST_FIND},
+  {name: "Attribute whitespace-separated list selector, matching title attribute with value using non-ASCII characters",       selector: "[title~=中文]",                                              ctx: "#attr-whitespace", expect: ["attr-whitespace-p1"],   level: 2, testType: TEST_FIND | TEST_MATCH},
+
+  // - hyphen-separated list     [att|=val]
+  {name: "Attribute hyphen-separated list selector, not matching unspecified lang attribute",    selector: "#attr-hyphen-div1[lang|=\"en\"]",    ctx: "#attr-hyphen", expect: [] /*no matches*/,    level: 2, testType: TEST_FIND},
+  {name: "Attribute hyphen-separated list selector, matching lang attribute with exact value",   selector: "#attr-hyphen-div2[lang|=\"fr\"]",    ctx: "#attr-hyphen", expect: ["attr-hyphen-div2"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute hyphen-separated list selector, matching lang attribute with partial value", selector: "#attr-hyphen-div3[lang|=\"en\"]",    ctx: "#attr-hyphen", expect: ["attr-hyphen-div3"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute hyphen-separated list selector, not matching incorrect value",               selector: "#attr-hyphen-div4[lang|=\"es-AR\"]", ctx: "#attr-hyphen", expect: [] /*no matches*/,    level: 2, testType: TEST_FIND},
+
+  // - substring begins-with     [att^=val] (Level 3)
+  {name: "Attribute begins with selector, matching href attributes beginning with specified substring",                             selector: "a[href^=\"http://www\"]", ctx: "#attr-begins", expect: ["attr-begins-a1", "attr-begins-a3"],     level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute begins with selector, matching lang attributes beginning with specified substring, ",                           selector: "[lang^=\"en-\"]",         ctx: "#attr-begins", expect: ["attr-begins-div2", "attr-begins-div4"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute begins with selector, not matching class attribute with empty value",                                           selector: "[class^=\"\"]",          ctx: "#attr-begins", expect: [] /*no matches*/,                        level: 3, testType: TEST_FIND},
+  {name: "Attribute begins with selector, not matching class attribute not beginning with specified substring",                     selector: "[class^=apple]",          ctx: "#attr-begins", expect: [] /*no matches*/,                        level: 3, testType: TEST_FIND},
+  {name: "Attribute begins with selector with single-quoted value, matching class attribute beginning with specified substring",    selector: "[class^=' apple']",       ctx: "#attr-begins", expect: ["attr-begins-p1"],                       level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute begins with selector with double-quoted value, matching class attribute beginning with specified substring",    selector: "[class^=\" apple\"]",     ctx: "#attr-begins", expect: ["attr-begins-p1"],                       level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute begins with selector with unquoted value, not matching class attribute not beginning with specified substring", selector: "[class^= apple]",         ctx: "#attr-begins", expect: [] /*no matches*/,                        level: 3, testType: TEST_FIND},
+
+  // - substring ends-with       [att$=val] (Level 3)
+  {name: "Attribute ends with selector, matching href attributes ending with specified substring",                             selector: "a[href$=\".org\"]",   ctx: "#attr-ends", expect: ["attr-ends-a1", "attr-ends-a3"],     level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute ends with selector, matching lang attributes ending with specified substring, ",                           selector: "[lang$=\"-CH\"]",     ctx: "#attr-ends", expect: ["attr-ends-div2", "attr-ends-div4"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute ends with selector, not matching class attribute with empty value",                                        selector: "[class$=\"\"]",       ctx: "#attr-ends", expect: [] /*no matches*/,                    level: 3, testType: TEST_FIND},
+  {name: "Attribute ends with selector, not matching class attribute not ending with specified substring",                     selector: "[class$=apple]",      ctx: "#attr-ends", expect: [] /*no matches*/,                    level: 3, testType: TEST_FIND},
+  {name: "Attribute ends with selector with single-quoted value, matching class attribute ending with specified substring",    selector: "[class$='apple ']",   ctx: "#attr-ends", expect: ["attr-ends-p1"],                     level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute ends with selector with double-quoted value, matching class attribute ending with specified substring",    selector: "[class$=\"apple \"]", ctx: "#attr-ends", expect: ["attr-ends-p1"],                     level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute ends with selector with unquoted value, not matching class attribute not ending with specified substring", selector: "[class$=apple ]",     ctx: "#attr-ends", expect: [] /*no matches*/,                    level: 3, testType: TEST_FIND},
+
+  // - substring contains        [att*=val] (Level 3)
+  {name: "Attribute contains selector, matching href attributes beginning with specified substring",                          selector: "a[href*=\"http://www\"]",     ctx: "#attr-contains", expect: ["attr-contains-a1", "attr-contains-a3"],     level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector, matching href attributes ending with specified substring",                             selector: "a[href*=\".org\"]",           ctx: "#attr-contains", expect: ["attr-contains-a1", "attr-contains-a2"],     level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector, matching href attributes containing specified substring",                              selector: "a[href*=\".example.\"]",      ctx: "#attr-contains", expect: ["attr-contains-a1", "attr-contains-a3"],     level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector, matching lang attributes beginning with specified substring, ",                        selector: "[lang*=\"en-\"]",             ctx: "#attr-contains", expect: ["attr-contains-div2", "attr-contains-div6"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector, matching lang attributes ending with specified substring, ",                           selector: "[lang*=\"-CH\"]",             ctx: "#attr-contains", expect: ["attr-contains-div3", "attr-contains-div5"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector, not matching class attribute with empty value",                                        selector: "[class*=\"\"]",               ctx: "#attr-contains", expect: [] /*no matches*/,                            level: 3, testType: TEST_FIND},
+  {name: "Attribute contains selector with single-quoted value, matching class attribute beginning with specified substring", selector: "[class*=' apple']",           ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector with single-quoted value, matching class attribute ending with specified substring",    selector: "[class*='orange ']",          ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector with single-quoted value, matching class attribute containing specified substring",     selector: "[class*='ple banana ora']",   ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector with double-quoted value, matching class attribute beginning with specified substring", selector: "[class*=\" apple\"]",         ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector with double-quoted value, matching class attribute ending with specified substring",    selector: "[class*=\"orange \"]",        ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector with double-quoted value, matching class attribute containing specified substring",     selector: "[class*=\"ple banana ora\"]", ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector with unquoted value, matching class attribute beginning with specified substring",      selector: "[class*= apple]",             ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector with unquoted value, matching class attribute ending with specified substring",         selector: "[class*=orange ]",            ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "Attribute contains selector with unquoted value, matching class attribute containing specified substring",          selector: "[class*= banana ]",           ctx: "#attr-contains", expect: ["attr-contains-p1"],                         level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // Pseudo-classes
+  // - :root                 (Level 3)
+  {name: ":root pseudo-class selector, matching document root element",      selector: ":root",               expect: ["html"],          exclude: ["element", "fragment", "detached"], level: 3, testType: TEST_FIND},
+  {name: ":root pseudo-class selector, not matching document root element",  selector: ":root",               expect: [] /*no matches*/, exclude: ["document"],                        level: 3, testType: TEST_FIND},
+  {name: ":root pseudo-class selector, not matching document root element",  selector: ":root", ctx: "#html", expect: [] /*no matches*/, exclude: ["fragment", "detached"],            level: 3, testType: TEST_FIND},
+
+  // - :nth-child(n)         (Level 3)
+  {name: ":nth-child selector, matching the third child element",                                               selector: ":nth-child(3)",                    ctx: "#pseudo-nth-table1", expect: ["pseudo-nth-td3", "pseudo-nth-td9", "pseudo-nth-tr3", "pseudo-nth-td15"],             level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-child selector, matching every third child element",                                             selector: "li:nth-child(3n)",                 ctx: "#pseudo-nth", expect: ["pseudo-nth-li3", "pseudo-nth-li6", "pseudo-nth-li9", "pseudo-nth-li12"],                    level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-child selector, matching every second child element, starting from the fourth",                  selector: "li:nth-child(2n+4)",               ctx: "#pseudo-nth", expect: ["pseudo-nth-li4", "pseudo-nth-li6", "pseudo-nth-li8", "pseudo-nth-li10", "pseudo-nth-li12"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-child selector, matching every second child element, starting from the fourth, with whitespace", selector: "li:nth-child(2n \t\r\n+ \t\r\n4)", ctx: "#pseudo-nth", expect: ["pseudo-nth-li4", "pseudo-nth-li6", "pseudo-nth-li8", "pseudo-nth-li10", "pseudo-nth-li12"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-child selector, matching every fourth child element, starting from the third",                   selector: ":nth-child(4n-1)",                 ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-em2", "pseudo-nth-span3"],                                                    level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-child selector, matching every fourth child element, starting from the third, with whitespace",  selector: ":nth-child(4n \t\r\n- \t\r\n1)",   ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-em2", "pseudo-nth-span3"],                                                    level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-child selector used twice, matching ",                                                           selector: ":nth-child(1) :nth-child(1)",      ctx: "#pseudo-nth", expect: ["pseudo-nth-table1", "pseudo-nth-tr1"],                                                      level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :nth-last-child       (Level 3)
+  {name: ":nth-last-child selector, matching the third last child element",                                           selector: ":nth-last-child(3)",      ctx: "#pseudo-nth-table1", expect: ["pseudo-nth-tr1", "pseudo-nth-td4", "pseudo-nth-td10", "pseudo-nth-td16"],         level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-last-child selector, matching every third child element from the end",                                 selector: "li:nth-last-child(3n)",   ctx: "pseudo-nth", expect: ["pseudo-nth-li1", "pseudo-nth-li4", "pseudo-nth-li7", "pseudo-nth-li10"],                  level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-last-child selector, matching every second child element from the end, starting from the fourth last", selector: "li:nth-last-child(2n+4)", ctx: "pseudo-nth", expect: ["pseudo-nth-li1", "pseudo-nth-li3", "pseudo-nth-li5", "pseudo-nth-li7", "pseudo-nth-li9"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-last-child selector, matching every fourth element from the end, starting from the third last",        selector: ":nth-last-child(4n-1)",   ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-span2", "pseudo-nth-span4"],                                               level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :nth-of-type(n)       (Level 3)
+  {name: ":nth-of-type selector, matching the third em element",                                        selector: "em:nth-of-type(3)",      ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-em3"],                                                                                 level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-of-type selector, matching every second element of their type",                          selector: ":nth-of-type(2n)",       ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-em2", "pseudo-nth-span2", "pseudo-nth-span4", "pseudo-nth-strong2", "pseudo-nth-em4"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-of-type selector, matching every second elemetn of their type, starting from the first", selector: "span:nth-of-type(2n-1)", ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-span1", "pseudo-nth-span3"],                                                           level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :nth-last-of-type(n)  (Level 3)
+  {name: ":nth-last-of-type selector, matching the third last em element",                                       selector: "em:nth-last-of-type(3)",      ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-em2"],                                                                                 level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-last-of-type selector, matching every second last element of their type",                         selector: ":nth-last-of-type(2n)",       ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-span1", "pseudo-nth-em1", "pseudo-nth-strong1", "pseudo-nth-em3", "pseudo-nth-span3"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":nth-last-of-type selector, matching every second last element of their type, starting from the last", selector: "span:nth-last-of-type(2n-1)", ctx: "#pseudo-nth-p1", expect: ["pseudo-nth-span2", "pseudo-nth-span4"],                                                           level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :first-of-type        (Level 3)
+  {name: ":first-of-type selector, matching the first em element",                   selector: "em:first-of-type",  ctx: "#pseudo-nth-p1",     expect: ["pseudo-nth-em1"],                                           level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":first-of-type selector, matching the first of every type of element",     selector: ":first-of-type",    ctx: "#pseudo-nth-p1",     expect: ["pseudo-nth-span1", "pseudo-nth-em1", "pseudo-nth-strong1"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":first-of-type selector, matching the first td element in each table row", selector: "tr :first-of-type", ctx: "#pseudo-nth-table1", expect: ["pseudo-nth-td1", "pseudo-nth-td7", "pseudo-nth-td13"],      level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :last-of-type         (Level 3)
+  {name: ":last-of-type selector, matching the last em elemnet",                     selector: "em:last-of-type",   ctx: "#pseudo-nth-p1",     expect: ["pseudo-nth-em4"],                                           level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":last-of-type selector, matching the last of every type of element",       selector: ":last-of-type",     ctx: "#pseudo-nth-p1",     expect: ["pseudo-nth-span4", "pseudo-nth-strong2", "pseudo-nth-em4"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":last-of-type selector, matching the last td element in each table row",   selector: "tr :last-of-type",  ctx: "#pseudo-nth-table1", expect: ["pseudo-nth-td6", "pseudo-nth-td12", "pseudo-nth-td18"],     level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :first-child
+  {name: ":first-child pseudo-class selector, matching first child div element",          selector: "div:first-child",                                                            ctx: "#pseudo-first-child", expect: ["pseudo-first-child-div1"],                                                          level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: ":first-child pseudo-class selector, doesn't match non-first-child elements",    selector: ".pseudo-first-child-div2:first-child, .pseudo-first-child-div3:first-child", ctx: "#pseudo-first-child", expect: [] /*no matches*/,                                                                    level: 2, testType: TEST_FIND},
+  {name: ":first-child pseudo-class selector, matching first-child of multiple elements", selector: "span:first-child",                                                           ctx: "#pseudo-first-child", expect: ["pseudo-first-child-span1", "pseudo-first-child-span3", "pseudo-first-child-span5"], level: 2, testType: TEST_FIND | TEST_MATCH},
+
+  // - :last-child           (Level 3)
+  {name: ":last-child pseudo-class selector, matching last child div element",           selector: "div:last-child",                                                          ctx: "#pseudo-last-child", expect: ["pseudo-last-child-div3"],                                                        level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":last-child pseudo-class selector, doesn't match non-last-child elements",     selector: ".pseudo-last-child-div1:last-child, .pseudo-last-child-div2:first-child", ctx: "#pseudo-last-child", expect: [] /*no matches*/,                                                                 level: 3, testType: TEST_FIND},
+  {name: ":last-child pseudo-class selector, matching first-child of multiple elements", selector: "span:last-child",                                                         ctx: "#pseudo-last-child", expect: ["pseudo-last-child-span2", "pseudo-last-child-span4", "pseudo-last-child-span6"], level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :only-child           (Level 3)
+  {name: ":pseudo-only-child pseudo-class selector, matching all only-child elements", selector: ":only-child",   ctx: "#pseudo-only", expect: ["pseudo-only-span1"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":pseudo-only-child pseudo-class selector, matching only-child em elements",  selector: "em:only-child", ctx: "#pseudo-only", expect: [] /*no matches*/,     level: 3, testType: TEST_FIND},
+
+  // - :only-of-type         (Level 3)
+  {name: ":pseudo-only-of-type pseudo-class selector, matching all elements with no siblings of the same type", selector: " :only-of-type",   ctx: "#pseudo-only", expect: ["pseudo-only-span1", "pseudo-only-em1"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":pseudo-only-of-type pseudo-class selector, matching em elements with no siblings of the same type",  selector: " em:only-of-type", ctx: "#pseudo-only", expect: ["pseudo-only-em1"],                    level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :empty                (Level 3)
+  {name: ":empty pseudo-class selector, matching empty p elements",   selector: "p:empty", ctx: "#pseudo-empty", expect: ["pseudo-empty-p1", "pseudo-empty-p2"],                       level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":empty pseudo-class selector, matching all empty elements", selector: ":empty",  ctx: "#pseudo-empty", expect: ["pseudo-empty-p1", "pseudo-empty-p2", "pseudo-empty-span1"], level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :link and :visited
+  // Implementations may treat all visited links as unvisited, so these cannot be tested separately.
+  // The only guarantee is that ":link,:visited" matches the set of all visited and unvisited links and that they are individually mutually exclusive sets.
+  {name: ":link and :visited pseudo-class selectors, matching a and area elements with href attributes",        selector: " :link, #pseudo-link :visited", ctx: "#pseudo-link", expect: ["pseudo-link-a1", "pseudo-link-a2", "pseudo-link-area1"],                                level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: ":link and :visited pseudo-class selectors, matching no elements",                                     selector: " :link, #head :visited",        ctx: "#head",        expect: [] /*no matches*/,                          exclude: ["element", "fragment", "detached"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: ":link and :visited pseudo-class selectors, not matching link elements with href attributes",          selector: " :link, #head :visited",        ctx: "#head",        expect: [] /*no matches*/,                          exclude: ["document"],                        level: 1, testType: TEST_FIND},
+  {name: ":link and :visited pseudo-class selectors, chained, mutually exclusive pseudo-classes match nothing", selector: ":link:visited",                 ctx: "#html",        expect: [] /*no matches*/,                          exclude: ["document"],                        level: 1, testType: TEST_FIND},
+
+// XXX Figure out context or refNodes for this
+  // - :target               (Level 3)
+  {name: ":target pseudo-class selector, matching the element referenced by the URL fragment identifier", selector: ":target", ctx: "", expect: [] /*no matches*/, exclude: ["document", "element"],  level: 3, testType: TEST_FIND},
+  {name: ":target pseudo-class selector, matching the element referenced by the URL fragment identifier", selector: ":target", ctx: "", expect: ["target"],        exclude: ["fragment", "detached"], level: 3, testType: TEST_FIND},
+
+// XXX Fix ctx in tests below
+
+  // - :lang()
+  {name: ":lang pseudo-class selector, matching inherited language (1)",                     selector: "#pseudo-lang-div1:lang(en)",    ctx: "", expect: ["pseudo-lang-div1"], exclude: ["detached", "fragment"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: ":lang pseudo-class selector, not matching element with no inherited language", selector: "#pseudo-lang-div1:lang(en)",    ctx: "", expect: [] /*no matches*/,    exclude: ["document", "element"],  level: 2, testType: TEST_FIND},
+  {name: ":lang pseudo-class selector, matching specified language with exact value (1)",    selector: "#pseudo-lang-div2:lang(fr)",    ctx: "", expect: ["pseudo-lang-div2"],                                    level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: ":lang pseudo-class selector, matching specified language with partial value (1)",  selector: "#pseudo-lang-div3:lang(en)",    ctx: "", expect: ["pseudo-lang-div3"],                                    level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: ":lang pseudo-class selector, not matching incorrect language",                 selector: "#pseudo-lang-div4:lang(es-AR)", ctx: "", expect: [] /*no matches*/,                                       level: 2, testType: TEST_FIND},
+
+  // - :enabled              (Level 3)
+  {name: ":enabled pseudo-class selector, matching all enabled form controls (1)",  selector: "#pseudo-ui :enabled",  ctx: "", expect: ["pseudo-ui-input1", "pseudo-ui-input2", "pseudo-ui-input3", "pseudo-ui-input4", "pseudo-ui-input5", "pseudo-ui-input6",
+                                                                                                                           "pseudo-ui-input7", "pseudo-ui-input8", "pseudo-ui-input9", "pseudo-ui-textarea1", "pseudo-ui-button1"],    level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":enabled pseudo-class selector, not matching link elements (1)",  selector: "#pseudo-link :enabled",  ctx: "", expect: [] /*no matches*/, unexpected: ["pseudo-link-a1","pseudo-link-a2","pseudo-link-a3","pseudo-link-map1","pseudo-link-area1","pseudo-link-area2"],   level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :disabled             (Level 3)
+  {name: ":disabled pseudo-class selector, matching all disabled form controls (1)", selector: "#pseudo-ui :disabled", ctx: "", expect: ["pseudo-ui-input10", "pseudo-ui-input11", "pseudo-ui-input12", "pseudo-ui-input13", "pseudo-ui-input14", "pseudo-ui-input15",
+                                                                                                                           "pseudo-ui-input16", "pseudo-ui-input17", "pseudo-ui-input18", "pseudo-ui-textarea2", "pseudo-ui-button2"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":disabled pseudo-class selector, not matching link elements (1)", selector: "#pseudo-link :disabled", ctx: "", expect: [] /*no matches*/, unexpected: ["pseudo-link-a1","pseudo-link-a2","pseudo-link-a3","pseudo-link-map1","pseudo-link-area1","pseudo-link-area2"], level: 3, testType: TEST_QSA | TEST_MATCH},
+
+  // - :checked              (Level 3)
+  {name: ":checked pseudo-class selector, matching checked radio buttons and checkboxes (1)", selector: "#pseudo-ui :checked", ctx: "", expect: ["pseudo-ui-input4", "pseudo-ui-input6", "pseudo-ui-input13", "pseudo-ui-input15"],  level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // - :not(s)               (Level 3)
+  {name: ":not pseudo-class selector, matching (1)", selector: "#not>:not(div)",   ctx: "", expect: ["not-p1", "not-p2", "not-p3"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":not pseudo-class selector, matching (1)", selector: "#not * :not(:first-child)",   ctx: "", expect: ["not-em1", "not-em2", "not-em3"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: ":not pseudo-class selector, matching nothing", selector: ":not(*)",   ctx: "", expect: [] /* no matches */, level: 3, testType: TEST_FIND},
+  {name: ":not pseudo-class selector, matching nothing", selector: ":not(*|*)", ctx: "", expect: [] /* no matches */, level: 3, testType: TEST_FIND},
+
+  // Pseudo-elements
+  // - ::first-line
+  {name: ":first-line pseudo-element (one-colon syntax) selector, not matching any elements",    selector: "#pseudo-element:first-line",    ctx: "", expect: [] /*no matches*/, level: 2, testType: TEST_FIND},
+  {name: "::first-line pseudo-element (two-colon syntax) selector, not matching any elements",   selector: "#pseudo-element::first-line",   ctx: "", expect: [] /*no matches*/, level: 3, testType: TEST_FIND},
+
+  // - ::first-letter
+  {name: ":first-letter pseudo-element (one-colon syntax) selector, not matching any elements",  selector: "#pseudo-element:first-letter",  ctx: "", expect: [] /*no matches*/, level: 2, testType: TEST_FIND},
+  {name: "::first-letter pseudo-element (two-colon syntax) selector, not matching any elements", selector: "#pseudo-element::first-letter", ctx: "", expect: [] /*no matches*/, level: 3, testType: TEST_FIND},
+
+  // - ::before
+  {name: ":before pseudo-element (one-colon syntax) selector, not matching any elements",        selector: "#pseudo-element:before",        ctx: "", expect: [] /*no matches*/, level: 2, testType: TEST_FIND},
+  {name: "::before pseudo-element (two-colon syntax) selector, not matching any elements",       selector: "#pseudo-element::before",       ctx: "", expect: [] /*no matches*/, level: 3, testType: TEST_FIND},
+
+  // - ::after
+  {name: ":after pseudo-element (one-colon syntax) selector, not matching any elements",         selector: "#pseudo-element:after",         ctx: "", expect: [] /*no matches*/, level: 2, testType: TEST_FIND},
+  {name: "::after pseudo-element (two-colon syntax) selector, not matching any elements",        selector: "#pseudo-element::after",        ctx: "", expect: [] /*no matches*/, level: 3, testType: TEST_FIND},
+
+  // Class Selectors
+  {name: "Class selector, matching element with specified class (1)",                                           selector: ".class-p",                ctx: "", expect: ["class-p1","class-p2", "class-p3"],                                              level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Class selector, chained, matching only elements with all specified classes (1)",                      selector: "#class .apple.orange.banana",    ctx: "", expect: ["class-div1", "class-div2", "class-p4", "class-div3", "class-p6", "class-div4"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Class Selector, chained, with type selector (1)",                                                     selector: "div.apple.banana.orange", ctx: "", expect: ["class-div1", "class-div2", "class-div3", "class-div4"],                         level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Class selector, matching element with class value using non-ASCII characters (2)",                    selector: ".\u53F0\u5317Ta\u0301ibe\u030Ci",             ctx: "", expect: ["class-span1"],               level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Class selector, matching multiple elements with class value using non-ASCII characters (1)",          selector: ".\u53F0\u5317",                     ctx: "", expect: ["class-span1","class-span2"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Class selector, chained, matching element with multiple class values using non-ASCII characters (2)", selector: ".\u53F0\u5317Ta\u0301ibe\u030Ci.\u53F0\u5317",          ctx: "", expect: ["class-span1"],               level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Class selector, matching element with class with escaped character (1)",                              selector: ".foo\\:bar",              ctx: "", expect: ["class-span3"],               level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Class selector, matching element with class with escaped character (1)",                              selector: ".test\\.foo\\[5\\]bar",   ctx: "", expect: ["class-span4"],               level: 1, testType: TEST_FIND | TEST_MATCH},
+
+  // ID Selectors
+  {name: "ID selector, matching element with specified id (1)",           selector: "#id #id-div1",              ctx: "", expect: ["id-div1"],            level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "ID selector, chained, matching element with specified id (1)",  selector: "#id-div1, #id-div1",        ctx: "", expect: ["id-div1"],            level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "ID selector, chained, matching element with specified id (1)",  selector: "#id-div1, #id-div2",        ctx: "", expect: ["id-div1", "id-div2"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "ID Selector, chained, with type selector (1)",                  selector: "div#id-div1, div#id-div2",  ctx: "", expect: ["id-div1", "id-div2"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "ID selector, not matching non-existent descendant",         selector: "#id #none",                 ctx: "", expect: [] /*no matches*/,      level: 1, testType: TEST_FIND},
+  {name: "ID selector, not matching non-existent ancestor",           selector: "#none #id-div1",            ctx: "", expect: [] /*no matches*/,      level: 1, testType: TEST_FIND},
+  {name: "ID selector, matching multiple elements with duplicate id (1)", selector: "#id-li-duplicate",          ctx: "", expect: ["id-li-duplicate", "id-li-duplicate", "id-li-duplicate", "id-li-duplicate"], level: 1, testType: TEST_FIND | TEST_MATCH},
+
+  {name: "ID selector, matching id value using non-ASCII characters (3)",    selector: "#\u53F0\u5317Ta\u0301ibe\u030Ci",           ctx: "", expect: ["\u53F0\u5317Ta\u0301ibe\u030Ci"],       level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "ID selector, matching id value using non-ASCII characters (4)",    selector: "#\u53F0\u5317",                   ctx: "", expect: ["\u53F0\u5317"],               level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "ID selector, matching id values using non-ASCII characters (2)",   selector: "#\u53F0\u5317Ta\u0301ibe\u030Ci, #\u53F0\u5317",      ctx: "", expect: ["\u53F0\u5317Ta\u0301ibe\u030Ci", "\u53F0\u5317"], level: 1, testType: TEST_FIND | TEST_MATCH},
+
+  // XXX runMatchesTest() in level2-lib.js can't handle this because obtaining the expected nodes requires escaping characters when generating the selector from 'expect' values
+  {name: "ID selector, matching element with id with escaped character", selector: "#\\#foo\\:bar",         ctx: "", expect: ["#foo:bar"],         level: 1, testType: TEST_FIND},
+  {name: "ID selector, matching element with id with escaped character", selector: "#test\\.foo\\[5\\]bar", ctx: "", expect: ["test.foo[5]bar"],   level: 1, testType: TEST_FIND},
+
+  // Namespaces
+  // XXX runMatchesTest() in level2-lib.js can't handle these because non-HTML elements don't have a recognised id
+  {name: "Namespace selector, matching element with any namespace",        selector: "#any-namespace *|div", ctx: "", expect: ["any-namespace-div1", "any-namespace-div2", "any-namespace-div3", "any-namespace-div4"], level: 3, testType: TEST_FIND},
+  {name: "Namespace selector, matching div elements in no namespace only", selector: "#no-namespace |div",   ctx: "", expect: ["no-namespace-div3"], level: 3, testType: TEST_FIND},
+  {name: "Namespace selector, matching any elements in no namespace only", selector: "#no-namespace |*",     ctx: "", expect: ["no-namespace-div3"], level: 3, testType: TEST_FIND},
+
+  // Combinators
+  // - Descendant combinator ' '
+  {name: "Descendant combinator, matching element that is a descendant of an element with id (1)",                 selector: "#descendant div",                   ctx: "", expect: ["descendant-div1", "descendant-div2", "descendant-div3", "descendant-div4"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Descendant combinator, matching element with id that is a descendant of an element (1)",                 selector: "body #descendant-div1",             ctx: "", expect: ["descendant-div1"], exclude: ["detached", "fragment"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Descendant combinator, matching element with id that is a descendant of an element (1)",                 selector: "div #descendant-div1",              ctx: "", expect: ["descendant-div1"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Descendant combinator, matching element with id that is a descendant of an element with id (1)",         selector: "#descendant #descendant-div2",      ctx: "", expect: ["descendant-div2"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Descendant combinator, matching element with class that is a descendant of an element with id (1)",      selector: "#descendant .descendant-div2",      ctx: "", expect: ["descendant-div2"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Descendant combinator, matching element with class that is a descendant of an element with class (1)",   selector: ".descendant-div1 .descendant-div3", ctx: "", expect: ["descendant-div3"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Descendant combinator, not matching element with id that is not a descendant of an element with id", selector: "#descendant-div1 #descendant-div4", ctx: "", expect: [] /*no matches*/,                                      level: 1, testType: TEST_FIND},
+  {name: "Descendant combinator, whitespace characters (1)",                                                       selector: "#descendant\t\r\n#descendant-div2", ctx: "", expect: ["descendant-div2"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+
+  // // - Descendant combinator '>>'
+  // {name: "Descendant combinator '>>', matching element that is a descendant of an element with id (1)",                 selector: "#descendant>>div",                   ctx: "", expect: ["descendant-div1", "descendant-div2", "descendant-div3", "descendant-div4"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with id that is a descendant of an element (1)",                 selector: "body>>#descendant-div1",             ctx: "", expect: ["descendant-div1"], exclude: ["detached", "fragment"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with id that is a descendant of an element (1)",                 selector: "div>>#descendant-div1",              ctx: "", expect: ["descendant-div1"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with id that is a descendant of an element with id (1)",         selector: "#descendant>>#descendant-div2",      ctx: "", expect: ["descendant-div2"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+  // {name: "Descendant combinator '>>', matching element with class that is a descendant of an element with id (1)",      selector: "#descendant>>.descendant-div2",      ctx: "", expect: ["descendant-div2"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+  // {name: "Descendant combinator, '>>', matching element with class that is a descendant of an element with class (1)",   selector: ".descendant-div1>>.descendant-div3", ctx: "", expect: ["descendant-div3"],                                    level: 1, testType: TEST_FIND | TEST_MATCH},
+  // {name: "Descendant combinator '>>', not matching element with id that is not a descendant of an element with id", selector: "#descendant-div1>>#descendant-div4", ctx: "", expect: [] /*no matches*/,                                      level: 1, testType: TEST_FIND},
+
+  // - Child combinator '>'
+  {name: "Child combinator, matching element that is a child of an element with id (1)",                       selector: "#child>div",                          ctx: "", expect: ["child-div1", "child-div4"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Child combinator, matching element with id that is a child of an element (1)",                       selector: "div>#child-div1",                     ctx: "", expect: ["child-div1"],               level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Child combinator, matching element with id that is a child of an element with id (1)",               selector: "#child>#child-div1",                  ctx: "", expect: ["child-div1"],               level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Child combinator, matching element with id that is a child of an element with class (1)",            selector: "#child-div1>.child-div2",             ctx: "", expect: ["child-div2"],               level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Child combinator, matching element with class that is a child of an element with class (1)",         selector: ".child-div1>.child-div2",             ctx: "", expect: ["child-div2"],               level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Child combinator, not matching element with id that is not a child of an element with id",       selector: "#child>#child-div3",                  ctx: "", expect: [] /*no matches*/,            level: 2, testType: TEST_FIND},
+  {name: "Child combinator, not matching element with id that is not a child of an element with class",    selector: "#child-div1>.child-div3",             ctx: "", expect: [] /*no matches*/,            level: 2, testType: TEST_FIND},
+  {name: "Child combinator, not matching element with class that is not a child of an element with class", selector: ".child-div1>.child-div3",             ctx: "", expect: [] /*no matches*/,            level: 2, testType: TEST_FIND},
+  {name: "Child combinator, surrounded by whitespace (1)",                                                     selector: "#child-div1\t\r\n>\t\r\n#child-div2", ctx: "", expect: ["child-div2"],               level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Child combinator, whitespace after (1)",                                                             selector: "#child-div1>\t\r\n#child-div2",       ctx: "", expect: ["child-div2"],               level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Child combinator, whitespace before (1)",                                                            selector: "#child-div1\t\r\n>#child-div2",       ctx: "", expect: ["child-div2"],               level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Child combinator, no whitespace (1)",                                                                selector: "#child-div1>#child-div2",             ctx: "", expect: ["child-div2"],               level: 2, testType: TEST_FIND | TEST_MATCH},
+
+  // - Adjacent sibling combinator '+'
+  {name: "Adjacent sibling combinator, matching element that is an adjacent sibling of an element with id (1)",                 selector: "#adjacent-div2+div",                                         ctx: "", expect: ["adjacent-div4"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching element with id that is an adjacent sibling of an element (1)",                 selector: "div+#adjacent-div4",                                         ctx: "", expect: ["adjacent-div4"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching element with id that is an adjacent sibling of an element with id (1)",         selector: "#adjacent-div2+#adjacent-div4",                              ctx: "", expect: ["adjacent-div4"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching element with class that is an adjacent sibling of an element with id (1)",      selector: "#adjacent-div2+.adjacent-div4",                              ctx: "", expect: ["adjacent-div4"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching element with class that is an adjacent sibling of an element with class (1)",   selector: ".adjacent-div2+.adjacent-div4",                              ctx: "", expect: ["adjacent-div4"], level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, matching p element that is an adjacent sibling of a div element (1)",                    selector: "#adjacent div+p",                                            ctx: "", expect: ["adjacent-p2"],   level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, not matching element with id that is not an adjacent sibling of an element with id", selector: "#adjacent-div2+#adjacent-p2, #adjacent-div2+#adjacent-div1", ctx: "", expect: [] /*no matches*/, level: 2, testType: TEST_FIND},
+  {name: "Adjacent sibling combinator, surrounded by whitespace (1)",                                                           selector: "#adjacent-p2\t\r\n+\t\r\n#adjacent-p3",                      ctx: "", expect: ["adjacent-p3"],   level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, whitespace after (1)",                                                                   selector: "#adjacent-p2+\t\r\n#adjacent-p3",                            ctx: "", expect: ["adjacent-p3"],   level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, whitespace before (1)",                                                                  selector: "#adjacent-p2\t\r\n+#adjacent-p3",                            ctx: "", expect: ["adjacent-p3"],   level: 2, testType: TEST_FIND | TEST_MATCH},
+  {name: "Adjacent sibling combinator, no whitespace (1)",                                                                      selector: "#adjacent-p2+#adjacent-p3",                                  ctx: "", expect: ["adjacent-p3"],   level: 2, testType: TEST_FIND | TEST_MATCH},
+
+  // - General sibling combinator ~ (Level 3)
+  {name: "General sibling combinator, matching element that is a sibling of an element with id (1)",                    selector: "#sibling-div2~div",                                        ctx: "", expect: ["sibling-div4", "sibling-div6"], level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "General sibling combinator, matching element with id that is a sibling of an element (1)",                    selector: "div~#sibling-div4",                                        ctx: "", expect: ["sibling-div4"],                 level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "General sibling combinator, matching element with id that is a sibling of an element with id (1)",            selector: "#sibling-div2~#sibling-div4",                              ctx: "", expect: ["sibling-div4"],                 level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "General sibling combinator, matching element with class that is a sibling of an element with id (1)",         selector: "#sibling-div2~.sibling-div",                               ctx: "", expect: ["sibling-div4", "sibling-div6"],                 level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "General sibling combinator, matching p element that is a sibling of a div element (1)",                       selector: "#sibling div~p",                                           ctx: "", expect: ["sibling-p2", "sibling-p3"],                   level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "General sibling combinator, not matching element with id that is not a sibling after a p element (1)",        selector: "#sibling>p~div",                                           ctx: "", expect: [] /*no matches*/,                level: 3, testType: TEST_FIND},
+  {name: "General sibling combinator, not matching element with id that is not a sibling after an element with id", selector: "#sibling-div2~#sibling-div3, #sibling-div2~#sibling-div1", ctx: "", expect: [] /*no matches*/,                level: 3, testType: TEST_FIND},
+  {name: "General sibling combinator, surrounded by whitespace (1)",                                                    selector: "#sibling-p2\t\r\n~\t\r\n#sibling-p3",                      ctx: "", expect: ["sibling-p3"],                   level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "General sibling combinator, whitespace after (1)",                                                            selector: "#sibling-p2~\t\r\n#sibling-p3",                            ctx: "", expect: ["sibling-p3"],                   level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "General sibling combinator, whitespace before (1)",                                                           selector: "#sibling-p2\t\r\n~#sibling-p3",                            ctx: "", expect: ["sibling-p3"],                   level: 3, testType: TEST_FIND | TEST_MATCH},
+  {name: "General sibling combinator, no whitespace (1)",                                                               selector: "#sibling-p2~#sibling-p3",                                  ctx: "", expect: ["sibling-p3"],                   level: 3, testType: TEST_FIND | TEST_MATCH},
+
+  // Group of selectors (comma)
+  {name: "Syntax, group of selectors separator, surrounded by whitespace (1)", selector: "#group em\t\r \n,\t\r \n#group strong", ctx: "", expect: ["group-em1", "group-strong1"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Syntax, group of selectors separator, whitespace after (1)",         selector: "#group em,\t\r\n#group strong",         ctx: "", expect: ["group-em1", "group-strong1"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Syntax, group of selectors separator, whitespace before (1)",        selector: "#group em\t\r\n,#group strong",         ctx: "", expect: ["group-em1", "group-strong1"], level: 1, testType: TEST_FIND | TEST_MATCH},
+  {name: "Syntax, group of selectors separator, no whitespace (1)",            selector: "#group em,#group strong",               ctx: "", expect: ["group-em1", "group-strong1"], level: 1, testType: TEST_FIND | TEST_MATCH},
+];
diff --git a/testing/web-platform/tests/dom/nodes/support/NodeList-static-length-tampered.js b/testing/web-platform/tests/dom/nodes/support/NodeList-static-length-tampered.js
new file mode 100644
index 0000000000..51167e2ddc
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/support/NodeList-static-length-tampered.js
@@ -0,0 +1,46 @@
+"use strict";
+
+function makeStaticNodeList(length) {
+    const fooRoot = document.createElement("div");
+
+    for (var i = 0; i < length; i++) {
+        const el = document.createElement("span");
+        el.className = "foo";
+        fooRoot.append(el);
+    }
+
+    document.body.append(fooRoot);
+    return fooRoot.querySelectorAll(".foo");
+}
+
+const indexOfNodeList = new Function("nodeList", `
+    const __cacheBust = ${Math.random()};
+
+    const el = nodeList[50];
+
+    let index = -1;
+
+    for (var i = 0; i < 1e5 / 2; i++) {
+        for (var j = 0; j < nodeList.length; j++) {
+            if (nodeList[j] === el) {
+                index = j;
+                break;
+            }
+        }
+    }
+
+    return index;
+`);
+
+const arrayIndexOfNodeList = new Function("nodeList", `
+    const __cacheBust = ${Math.random()};
+
+    const el = nodeList[50];
+    const {indexOf} = Array.prototype;
+
+    for (var i = 0; i < 1e5; i++) {
+        var index = indexOf.call(nodeList, el);
+    }
+
+    return index;
+`);
diff --git a/testing/web-platform/tests/dom/nodes/svg-template-querySelector.html b/testing/web-platform/tests/dom/nodes/svg-template-querySelector.html
new file mode 100644
index 0000000000..5d2f634143
--- /dev/null
+++ b/testing/web-platform/tests/dom/nodes/svg-template-querySelector.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>querySelector on template fragments with SVG elements</title>
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<template id="template1"><div></div></template>
+<template id="template2"><svg></svg></template>
+<template id="template3"><div><svg></svg></div></template>
+
+<script>
+"use strict";
+
+test(() => {
+  const fragment = document.querySelector("#template1").content;
+  assert_not_equals(fragment.querySelector("div"), null);
+}, "querySelector works on template contents fragments with HTML elements (sanity check)");
+
+test(() => {
+  const fragment = document.querySelector("#template2").content;
+  assert_not_equals(fragment.querySelector("svg"), null);
+}, "querySelector works on template contents fragments with SVG elements");
+
+test(() => {
+  const fragment = document.querySelector("#template3").content;
+  assert_not_equals(fragment.firstChild.querySelector("svg"), null);
+}, "querySelector works on template contents fragments with nested SVG elements");
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-adopt-test.html b/testing/web-platform/tests/dom/ranges/Range-adopt-test.html
new file mode 100644
index 0000000000..3735fc38fd
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-adopt-test.html
@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<script src='/resources/testharness.js'></script>
+<script src='/resources/testharnessreport.js'></script>
+<script>
+function createRangeWithUnparentedContainerOfSingleElement() {
+    const range = document.createRange();
+    const container = document.createElement("container");
+    const element = document.createElement("element");
+    container.appendChild(element);
+    range.selectNode(element);
+    return range;
+}
+function nestRangeInOuterContainer(range) {
+    range.startContainer.ownerDocument.createElement("outer").appendChild(range.startContainer);
+}
+function moveNodeToNewlyCreatedDocumentWithAppendChild(node) {
+    document.implementation.createDocument(null, null).appendChild(node);
+}
+
+//Tests removing only element
+test(()=>{
+    const range = createRangeWithUnparentedContainerOfSingleElement();
+    range.startContainer.removeChild(range.startContainer.firstChild);
+    assert_equals(range.endOffset, 0);
+}, "Range in document: Removing the only element in the range must collapse the range");
+
+
+//Tests removing only element after parented container moved to another document
+test(()=>{
+    const range = createRangeWithUnparentedContainerOfSingleElement();
+    nestRangeInOuterContainer(range);
+    moveNodeToNewlyCreatedDocumentWithAppendChild(range.startContainer);
+    assert_equals(range.endOffset, 0);
+}, "Parented range container moved to another document with appendChild: Moving the element to the other document must collapse the range");
+
+//Tests removing only element after parentless container moved oo another document
+test(()=>{
+    const range = createRangeWithUnparentedContainerOfSingleElement();
+    moveNodeToNewlyCreatedDocumentWithAppendChild(range.startContainer);
+    range.startContainer.removeChild(range.startContainer.firstChild);
+    assert_equals(range.endOffset, 0);
+}, "Parentless range container moved to another document with appendChild: Removing the only element in the range must collapse the range");
+
+//Tests removing only element after parentless container of container moved to another document
+test(()=>{
+    const range = createRangeWithUnparentedContainerOfSingleElement();
+    nestRangeInOuterContainer(range);
+    moveNodeToNewlyCreatedDocumentWithAppendChild(range.startContainer.parentNode);
+    range.startContainer.removeChild(range.startContainer.firstChild);
+    assert_equals(range.endOffset, 0);
+}, "Range container's parentless container moved to another document with appendChild: Removing the only element in the range must collapse the range");
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-attributes.html b/testing/web-platform/tests/dom/ranges/Range-attributes.html
new file mode 100644
index 0000000000..ced47edc50
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-attributes.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<title>Range attributes</title>
+<link rel="author" title="Ms2ger" href="mailto:ms2ger@gmail.com">
+<meta name=timeout content=long>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+test(function() {
+  var r = document.createRange();
+  assert_equals(r.startContainer, document)
+  assert_equals(r.endContainer, document)
+  assert_equals(r.startOffset, 0)
+  assert_equals(r.endOffset, 0)
+  assert_true(r.collapsed)
+  r.detach()
+  assert_equals(r.startContainer, document)
+  assert_equals(r.endContainer, document)
+  assert_equals(r.startOffset, 0)
+  assert_equals(r.endOffset, 0)
+  assert_true(r.collapsed)
+})
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-cloneContents.html b/testing/web-platform/tests/dom/ranges/Range-cloneContents.html
new file mode 100644
index 0000000000..6064151f62
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-cloneContents.html
@@ -0,0 +1,461 @@
+<!doctype html>
+<title>Range.cloneContents() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<p>To debug test failures, add a query parameter "subtest" with the test id (like
+"?subtest=5").  Only that test will be run.  Then you can look at the resulting
+iframe in the DOM.
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+testDiv.parentNode.removeChild(testDiv);
+
+var actualIframe = document.createElement("iframe");
+actualIframe.style.display = "none";
+document.body.appendChild(actualIframe);
+
+var expectedIframe = document.createElement("iframe");
+expectedIframe.style.display = "none";
+document.body.appendChild(expectedIframe);
+
+function myCloneContents(range) {
+  // "Let frag be a new DocumentFragment whose ownerDocument is the same as
+  // the ownerDocument of the context object's start node."
+  var ownerDoc = range.startContainer.nodeType == Node.DOCUMENT_NODE
+    ? range.startContainer
+    : range.startContainer.ownerDocument;
+  var frag = ownerDoc.createDocumentFragment();
+
+  // "If the context object's start and end are the same, abort this method,
+  // returning frag."
+  if (range.startContainer == range.endContainer
+  && range.startOffset == range.endOffset) {
+    return frag;
+  }
+
+  // "Let original start node, original start offset, original end node, and
+  // original end offset be the context object's start and end nodes and
+  // offsets, respectively."
+  var originalStartNode = range.startContainer;
+  var originalStartOffset = range.startOffset;
+  var originalEndNode = range.endContainer;
+  var originalEndOffset = range.endOffset;
+
+  // "If original start node and original end node are the same, and they are
+  // a Text, ProcessingInstruction, or Comment node:"
+  if (range.startContainer == range.endContainer
+  && (range.startContainer.nodeType == Node.TEXT_NODE
+  || range.startContainer.nodeType == Node.COMMENT_NODE
+  || range.startContainer.nodeType == Node.PROCESSING_INSTRUCTION_NODE)) {
+    // "Let clone be the result of calling cloneNode(false) on original
+    // start node."
+    var clone = originalStartNode.cloneNode(false);
+
+    // "Set the data of clone to the result of calling
+    // substringData(original start offset, original end offset − original
+    // start offset) on original start node."
+    clone.data = originalStartNode.substringData(originalStartOffset,
+      originalEndOffset - originalStartOffset);
+
+    // "Append clone as the last child of frag."
+    frag.appendChild(clone);
+
+    // "Abort this method, returning frag."
+    return frag;
+  }
+
+  // "Let common ancestor equal original start node."
+  var commonAncestor = originalStartNode;
+
+  // "While common ancestor is not an ancestor container of original end
+  // node, set common ancestor to its own parent."
+  while (!isAncestorContainer(commonAncestor, originalEndNode)) {
+    commonAncestor = commonAncestor.parentNode;
+  }
+
+  // "If original start node is an ancestor container of original end node,
+  // let first partially contained child be null."
+  var firstPartiallyContainedChild;
+  if (isAncestorContainer(originalStartNode, originalEndNode)) {
+    firstPartiallyContainedChild = null;
+  // "Otherwise, let first partially contained child be the first child of
+  // common ancestor that is partially contained in the context object."
+  } else {
+    for (var i = 0; i < commonAncestor.childNodes.length; i++) {
+      if (isPartiallyContained(commonAncestor.childNodes[i], range)) {
+        firstPartiallyContainedChild = commonAncestor.childNodes[i];
+        break;
+      }
+    }
+    if (!firstPartiallyContainedChild) {
+      throw "Spec bug: no first partially contained child!";
+    }
+  }
+
+  // "If original end node is an ancestor container of original start node,
+  // let last partially contained child be null."
+  var lastPartiallyContainedChild;
+  if (isAncestorContainer(originalEndNode, originalStartNode)) {
+    lastPartiallyContainedChild = null;
+  // "Otherwise, let last partially contained child be the last child of
+  // common ancestor that is partially contained in the context object."
+  } else {
+    for (var i = commonAncestor.childNodes.length - 1; i >= 0; i--) {
+      if (isPartiallyContained(commonAncestor.childNodes[i], range)) {
+        lastPartiallyContainedChild = commonAncestor.childNodes[i];
+        break;
+      }
+    }
+    if (!lastPartiallyContainedChild) {
+      throw "Spec bug: no last partially contained child!";
+    }
+  }
+
+  // "Let contained children be a list of all children of common ancestor
+  // that are contained in the context object, in tree order."
+  //
+  // "If any member of contained children is a DocumentType, raise a
+  // HIERARCHY_REQUEST_ERR exception and abort these steps."
+  var containedChildren = [];
+  for (var i = 0; i < commonAncestor.childNodes.length; i++) {
+    if (isContained(commonAncestor.childNodes[i], range)) {
+      if (commonAncestor.childNodes[i].nodeType
+      == Node.DOCUMENT_TYPE_NODE) {
+        return "HIERARCHY_REQUEST_ERR";
+      }
+      containedChildren.push(commonAncestor.childNodes[i]);
+    }
+  }
+
+  // "If first partially contained child is a Text, ProcessingInstruction, or Comment node:"
+  if (firstPartiallyContainedChild
+  && (firstPartiallyContainedChild.nodeType == Node.TEXT_NODE
+  || firstPartiallyContainedChild.nodeType == Node.COMMENT_NODE
+  || firstPartiallyContainedChild.nodeType == Node.PROCESSING_INSTRUCTION_NODE)) {
+    // "Let clone be the result of calling cloneNode(false) on original
+    // start node."
+    var clone = originalStartNode.cloneNode(false);
+
+    // "Set the data of clone to the result of calling substringData() on
+    // original start node, with original start offset as the first
+    // argument and (length of original start node − original start offset)
+    // as the second."
+    clone.data = originalStartNode.substringData(originalStartOffset,
+      nodeLength(originalStartNode) - originalStartOffset);
+
+    // "Append clone as the last child of frag."
+    frag.appendChild(clone);
+  // "Otherwise, if first partially contained child is not null:"
+  } else if (firstPartiallyContainedChild) {
+    // "Let clone be the result of calling cloneNode(false) on first
+    // partially contained child."
+    var clone = firstPartiallyContainedChild.cloneNode(false);
+
+    // "Append clone as the last child of frag."
+    frag.appendChild(clone);
+
+    // "Let subrange be a new Range whose start is (original start node,
+    // original start offset) and whose end is (first partially contained
+    // child, length of first partially contained child)."
+    var subrange = ownerDoc.createRange();
+    subrange.setStart(originalStartNode, originalStartOffset);
+    subrange.setEnd(firstPartiallyContainedChild,
+      nodeLength(firstPartiallyContainedChild));
+
+    // "Let subfrag be the result of calling cloneContents() on
+    // subrange."
+    var subfrag = myCloneContents(subrange);
+
+    // "For each child of subfrag, in order, append that child to clone as
+    // its last child."
+    for (var i = 0; i < subfrag.childNodes.length; i++) {
+      clone.appendChild(subfrag.childNodes[i]);
+    }
+  }
+
+  // "For each contained child in contained children:"
+  for (var i = 0; i < containedChildren.length; i++) {
+    // "Let clone be the result of calling cloneNode(true) of contained
+    // child."
+    var clone = containedChildren[i].cloneNode(true);
+
+    // "Append clone as the last child of frag."
+    frag.appendChild(clone);
+  }
+
+  // "If last partially contained child is a Text, ProcessingInstruction, or Comment node:"
+  if (lastPartiallyContainedChild
+  && (lastPartiallyContainedChild.nodeType == Node.TEXT_NODE
+  || lastPartiallyContainedChild.nodeType == Node.COMMENT_NODE
+  || lastPartiallyContainedChild.nodeType == Node.PROCESSING_INSTRUCTION_NODE)) {
+    // "Let clone be the result of calling cloneNode(false) on original
+    // end node."
+    var clone = originalEndNode.cloneNode(false);
+
+    // "Set the data of clone to the result of calling substringData(0,
+    // original end offset) on original end node."
+    clone.data = originalEndNode.substringData(0, originalEndOffset);
+
+    // "Append clone as the last child of frag."
+    frag.appendChild(clone);
+  // "Otherwise, if last partially contained child is not null:"
+  } else if (lastPartiallyContainedChild) {
+    // "Let clone be the result of calling cloneNode(false) on last
+    // partially contained child."
+    var clone = lastPartiallyContainedChild.cloneNode(false);
+
+    // "Append clone as the last child of frag."
+    frag.appendChild(clone);
+
+    // "Let subrange be a new Range whose start is (last partially
+    // contained child, 0) and whose end is (original end node, original
+    // end offset)."
+    var subrange = ownerDoc.createRange();
+    subrange.setStart(lastPartiallyContainedChild, 0);
+    subrange.setEnd(originalEndNode, originalEndOffset);
+
+    // "Let subfrag be the result of calling cloneContents() on
+    // subrange."
+    var subfrag = myCloneContents(subrange);
+
+    // "For each child of subfrag, in order, append that child to clone as
+    // its last child."
+    for (var i = 0; i < subfrag.childNodes.length; i++) {
+      clone.appendChild(subfrag.childNodes[i]);
+    }
+  }
+
+  // "Return frag."
+  return frag;
+}
+
+function restoreIframe(iframe, i) {
+  // Most of this function is designed to work around the fact that Opera
+  // doesn't let you add a doctype to a document that no longer has one, in
+  // any way I can figure out.  I eventually compromised on something that
+  // will still let Opera pass most tests that don't actually involve
+  // doctypes.
+  while (iframe.contentDocument.firstChild
+  && iframe.contentDocument.firstChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+    iframe.contentDocument.removeChild(iframe.contentDocument.firstChild);
+  }
+
+  while (iframe.contentDocument.lastChild
+  && iframe.contentDocument.lastChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+    iframe.contentDocument.removeChild(iframe.contentDocument.lastChild);
+  }
+
+  if (!iframe.contentDocument.firstChild) {
+    // This will throw an exception in Opera if we reach here, which is why
+    // I try to avoid it.  It will never happen in a browser that obeys the
+    // spec, so it's really just insurance.  I don't think it actually gets
+    // hit by anything.
+    iframe.contentDocument.appendChild(iframe.contentDocument.implementation.createDocumentType("html", "", ""));
+  }
+  iframe.contentDocument.appendChild(referenceDoc.documentElement.cloneNode(true));
+  iframe.contentWindow.setupRangeTests();
+  iframe.contentWindow.testRangeInput = testRanges[i];
+  iframe.contentWindow.run();
+}
+
+function testCloneContents(i) {
+  restoreIframe(actualIframe, i);
+  restoreIframe(expectedIframe, i);
+
+  var actualRange = actualIframe.contentWindow.testRange;
+  var expectedRange = expectedIframe.contentWindow.testRange;
+  var actualFrag, expectedFrag;
+  var actualRoots, expectedRoots;
+
+  domTests[i].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual cloneContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated cloneContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+
+    // NOTE: We could just assume that cloneContents() doesn't change
+    // anything.  That would simplify these tests, taken in isolation.  But
+    // once we've already set up the whole apparatus for extractContents()
+    // and deleteContents(), we just reuse it here, on the theory of "why
+    // not test some more stuff if it's easy to do".
+    //
+    // Just to be pedantic, we'll test not only that the tree we're
+    // modifying is the same in expected vs. actual, but also that all the
+    // nodes originally in it were the same.  Typically some nodes will
+    // become detached when the algorithm is run, but they still exist and
+    // references can still be kept to them, so they should also remain the
+    // same.
+    //
+    // We initialize the list to all nodes, and later on remove all the
+    // ones which still have parents, since the parents will presumably be
+    // tested for isEqualNode() and checking the children would be
+    // redundant.
+    var actualAllNodes = [];
+    var node = furthestAncestor(actualRange.startContainer);
+    do {
+      actualAllNodes.push(node);
+    } while (node = nextNode(node));
+
+    var expectedAllNodes = [];
+    var node = furthestAncestor(expectedRange.startContainer);
+    do {
+      expectedAllNodes.push(node);
+    } while (node = nextNode(node));
+
+    expectedFrag = myCloneContents(expectedRange);
+    if (typeof expectedFrag == "string") {
+      assert_throws_dom(
+        expectedFrag,
+        actualIframe.contentWindow.DOMException,
+        function() {
+          actualRange.cloneContents();
+        }
+      );
+    } else {
+      actualFrag = actualRange.cloneContents();
+    }
+
+    actualRoots = [];
+    for (var j = 0; j < actualAllNodes.length; j++) {
+      if (!actualAllNodes[j].parentNode) {
+        actualRoots.push(actualAllNodes[j]);
+      }
+    }
+
+    expectedRoots = [];
+    for (var j = 0; j < expectedAllNodes.length; j++) {
+      if (!expectedAllNodes[j].parentNode) {
+        expectedRoots.push(expectedAllNodes[j]);
+      }
+    }
+
+    for (var j = 0; j < actualRoots.length; j++) {
+      assertNodesEqual(actualRoots[j], expectedRoots[j], j ? "detached node #" + j : "tree root");
+
+      if (j == 0) {
+        // Clearly something is wrong if the node lists are different
+        // lengths.  We want to report this only after we've already
+        // checked the main tree for equality, though, so it doesn't
+        // mask more interesting errors.
+        assert_equals(actualRoots.length, expectedRoots.length,
+          "Actual and expected DOMs were broken up into a different number of pieces by cloneContents() (this probably means you created or detached nodes when you weren't supposed to)");
+      }
+    }
+  });
+  domTests[i].done();
+
+  positionTests[i].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual cloneContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated cloneContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+
+    assert_true(actualRoots[0].isEqualNode(expectedRoots[0]),
+      "The resulting DOMs were not equal, so comparing positions makes no sense");
+
+    if (typeof expectedFrag == "string") {
+      // It's no longer true that, e.g., startContainer and endContainer
+      // must always be the same
+      return;
+    }
+
+    assert_equals(actualRange.startOffset, expectedRange.startOffset,
+      "Unexpected startOffset after cloneContents()");
+    // How do we decide that the two nodes are equal, since they're in
+    // different trees?  Since the DOMs are the same, it's enough to check
+    // that the index in the parent is the same all the way up the tree.
+    // But we can first cheat by just checking they're actually equal.
+    assert_true(actualRange.startContainer.isEqualNode(expectedRange.startContainer),
+      "Unexpected startContainer after cloneContents(), expected " +
+      expectedRange.startContainer.nodeName.toLowerCase() + " but got " +
+      actualRange.startContainer.nodeName.toLowerCase());
+    var currentActual = actualRange.startContainer;
+    var currentExpected = expectedRange.startContainer;
+    var actual = "";
+    var expected = "";
+    while (currentActual && currentExpected) {
+      actual = indexOf(currentActual) + "-" + actual;
+      expected = indexOf(currentExpected) + "-" + expected;
+
+      currentActual = currentActual.parentNode;
+      currentExpected = currentExpected.parentNode;
+    }
+    actual = actual.substr(0, actual.length - 1);
+    expected = expected.substr(0, expected.length - 1);
+    assert_equals(actual, expected,
+      "startContainer superficially looks right but is actually the wrong node if you trace back its index in all its ancestors (I'm surprised this actually happened");
+  });
+  positionTests[i].done();
+
+  fragTests[i].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual cloneContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated cloneContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+
+    if (typeof expectedFrag == "string") {
+      // Comparing makes no sense
+      return;
+    }
+    assertNodesEqual(actualFrag, expectedFrag,
+      "returned fragment");
+  });
+  fragTests[i].done();
+}
+
+// First test a Range that has the no-op detach() called on it, synchronously
+test(function() {
+  var range = document.createRange();
+  range.detach();
+  assert_array_equals(range.cloneContents().childNodes, []);
+}, "Range.detach()");
+
+var iStart = 0;
+var iStop = testRanges.length;
+
+if (/subtest=[0-9]+/.test(location.search)) {
+  var matches = /subtest=([0-9]+)/.exec(location.search);
+  iStart = Number(matches[1]);
+  iStop = Number(matches[1]) + 1;
+}
+
+var domTests = [];
+var positionTests = [];
+var fragTests = [];
+
+for (var i = iStart; i < iStop; i++) {
+  domTests[i] = async_test("Resulting DOM for range " + i + " " + testRanges[i]);
+  positionTests[i] = async_test("Resulting cursor position for range " + i + " " + testRanges[i]);
+  fragTests[i] = async_test("Returned fragment for range " + i + " " + testRanges[i]);
+}
+
+var referenceDoc = document.implementation.createHTMLDocument("");
+referenceDoc.removeChild(referenceDoc.documentElement);
+
+actualIframe.onload = function() {
+  expectedIframe.onload = function() {
+    for (var i = iStart; i < iStop; i++) {
+      testCloneContents(i);
+    }
+  }
+  expectedIframe.src = "Range-test-iframe.html";
+  referenceDoc.appendChild(actualIframe.contentDocument.documentElement.cloneNode(true));
+}
+actualIframe.src = "Range-test-iframe.html";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-cloneRange.html b/testing/web-platform/tests/dom/ranges/Range-cloneRange.html
new file mode 100644
index 0000000000..6c736df29f
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-cloneRange.html
@@ -0,0 +1,112 @@
+<!doctype html>
+<title>Range.cloneRange() and document.createRange() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+function testCloneRange(rangeEndpoints) {
+  var range;
+  if (rangeEndpoints == "detached") {
+    range = document.createRange();
+    range.detach();
+    var clonedRange = range.cloneRange();
+    assert_equals(clonedRange.startContainer, range.startContainer,
+      "startContainers must be equal after cloneRange()");
+    assert_equals(clonedRange.startOffset, range.startOffset,
+      "startOffsets must be equal after cloneRange()");
+    assert_equals(clonedRange.endContainer, range.endContainer,
+      "endContainers must be equal after cloneRange()");
+    assert_equals(clonedRange.endOffset, range.endOffset,
+      "endOffsets must be equal after cloneRange()");
+    return;
+  }
+
+  // Have to account for Ranges involving Documents!  We could just create
+  // the Range from the current document unconditionally, but some browsers
+  // (WebKit) don't implement setStart() and setEnd() per spec and will throw
+  // spurious exceptions at the time of this writing.  No need to mask other
+  // bugs.
+  var ownerDoc = rangeEndpoints[0].nodeType == Node.DOCUMENT_NODE
+    ? rangeEndpoints[0]
+    : rangeEndpoints[0].ownerDocument;
+  range = ownerDoc.createRange();
+  // Here we throw in some createRange() tests, because why not.  Have to
+  // test it someplace.
+  assert_equals(range.startContainer, ownerDoc,
+    "doc.createRange() must create Range whose startContainer is doc");
+  assert_equals(range.endContainer, ownerDoc,
+    "doc.createRange() must create Range whose endContainer is doc");
+  assert_equals(range.startOffset, 0,
+    "doc.createRange() must create Range whose startOffset is 0");
+  assert_equals(range.endOffset, 0,
+    "doc.createRange() must create Range whose endOffset is 0");
+
+  range.setStart(rangeEndpoints[0], rangeEndpoints[1]);
+  range.setEnd(rangeEndpoints[2], rangeEndpoints[3]);
+
+  // Make sure we bail out now if setStart or setEnd are buggy, so it doesn't
+  // create misleading failures later.
+  assert_equals(range.startContainer, rangeEndpoints[0],
+    "Sanity check on setStart()");
+  assert_equals(range.startOffset, rangeEndpoints[1],
+    "Sanity check on setStart()");
+  assert_equals(range.endContainer, rangeEndpoints[2],
+    "Sanity check on setEnd()");
+  assert_equals(range.endOffset, rangeEndpoints[3],
+    "Sanity check on setEnd()");
+
+  var clonedRange = range.cloneRange();
+
+  assert_equals(clonedRange.startContainer, range.startContainer,
+    "startContainers must be equal after cloneRange()");
+  assert_equals(clonedRange.startOffset, range.startOffset,
+    "startOffsets must be equal after cloneRange()");
+  assert_equals(clonedRange.endContainer, range.endContainer,
+    "endContainers must be equal after cloneRange()");
+  assert_equals(clonedRange.endOffset, range.endOffset,
+    "endOffsets must be equal after cloneRange()");
+
+  // Make sure that modifying one doesn't affect the other.
+  var testNode1 = ownerDoc.createTextNode("testing");
+  var testNode2 = ownerDoc.createTextNode("testing with different length");
+
+  range.setStart(testNode1, 1);
+  range.setEnd(testNode1, 2);
+  assert_equals(clonedRange.startContainer, rangeEndpoints[0],
+    "Modifying a Range must not modify its clone's startContainer");
+  assert_equals(clonedRange.startOffset, rangeEndpoints[1],
+    "Modifying a Range must not modify its clone's startOffset");
+  assert_equals(clonedRange.endContainer, rangeEndpoints[2],
+    "Modifying a Range must not modify its clone's endContainer");
+  assert_equals(clonedRange.endOffset, rangeEndpoints[3],
+    "Modifying a Range must not modify its clone's endOffset");
+
+  clonedRange.setStart(testNode2, 3);
+  clonedRange.setStart(testNode2, 4);
+
+  assert_equals(range.startContainer, testNode1,
+    "Modifying a clone must not modify the original Range's startContainer");
+  assert_equals(range.startOffset, 1,
+    "Modifying a clone must not modify the original Range's startOffset");
+  assert_equals(range.endContainer, testNode1,
+    "Modifying a clone must not modify the original Range's endContainer");
+  assert_equals(range.endOffset, 2,
+    "Modifying a clone must not modify the original Range's endOffset");
+}
+
+var tests = [];
+for (var i = 0; i < testRanges.length; i++) {
+  tests.push([
+    "Range " + i + " " + testRanges[i],
+    eval(testRanges[i])
+  ]);
+}
+generate_tests(testCloneRange, tests);
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-collapse.html b/testing/web-platform/tests/dom/ranges/Range-collapse.html
new file mode 100644
index 0000000000..141dbdf610
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-collapse.html
@@ -0,0 +1,67 @@
+<!doctype html>
+<title>Range.collapse() and .collapsed tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+function testCollapse(rangeEndpoints, toStart) {
+  // Have to account for Ranges involving Documents!
+  var ownerDoc = rangeEndpoints[0].nodeType == Node.DOCUMENT_NODE
+    ? rangeEndpoints[0]
+    : rangeEndpoints[0].ownerDocument;
+  var range = ownerDoc.createRange();
+  range.setStart(rangeEndpoints[0], rangeEndpoints[1]);
+  range.setEnd(rangeEndpoints[2], rangeEndpoints[3]);
+
+  var expectedContainer = toStart ? range.startContainer : range.endContainer;
+  var expectedOffset = toStart ? range.startOffset : range.endOffset;
+
+  assert_equals(range.collapsed, range.startContainer == range.endContainer
+    && range.startOffset == range.endOffset,
+    "collapsed must be true if and only if the start and end are equal");
+
+  if (toStart === undefined) {
+    range.collapse();
+  } else {
+    range.collapse(toStart);
+  }
+
+  assert_equals(range.startContainer, expectedContainer,
+    "Wrong startContainer");
+  assert_equals(range.endContainer, expectedContainer,
+    "Wrong endContainer");
+  assert_equals(range.startOffset, expectedOffset,
+    "Wrong startOffset");
+  assert_equals(range.endOffset, expectedOffset,
+    "Wrong endOffset");
+  assert_true(range.collapsed,
+    ".collapsed must be set after .collapsed()");
+}
+
+var tests = [];
+for (var i = 0; i < testRanges.length; i++) {
+  tests.push([
+    "Range " + i + " " + testRanges[i] + ", toStart true",
+    eval(testRanges[i]),
+    true
+  ]);
+  tests.push([
+    "Range " + i + " " + testRanges[i] + ", toStart false",
+    eval(testRanges[i]),
+    false
+  ]);
+  tests.push([
+    "Range " + i + " " + testRanges[i] + ", toStart omitted",
+    eval(testRanges[i]),
+    undefined
+  ]);
+}
+generate_tests(testCollapse, tests);
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-commonAncestorContainer-2.html b/testing/web-platform/tests/dom/ranges/Range-commonAncestorContainer-2.html
new file mode 100644
index 0000000000..f0a3e451cd
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-commonAncestorContainer-2.html
@@ -0,0 +1,33 @@
+<!doctype html>
+<title>Range.commonAncestorContainer</title>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+test(function() {
+  var range = document.createRange();
+  range.detach();
+  assert_equals(range.commonAncestorContainer, document);
+}, "Detached Range")
+test(function() {
+  var df = document.createDocumentFragment();
+  var foo = df.appendChild(document.createElement("foo"));
+  foo.appendChild(document.createTextNode("Foo"));
+  var bar = df.appendChild(document.createElement("bar"));
+  bar.appendChild(document.createComment("Bar"));
+  [
+    // start node, start offset, end node, end offset, expected cAC
+    [foo, 0, bar, 0, df],
+    [foo, 0, foo.firstChild, 3, foo],
+    [foo.firstChild, 0, bar, 0, df],
+    [foo.firstChild, 3, bar.firstChild, 2, df]
+  ].forEach(function(t) {
+    test(function() {
+      var range = document.createRange();
+      range.setStart(t[0], t[1]);
+      range.setEnd(t[2], t[3]);
+      assert_equals(range.commonAncestorContainer, t[4]);
+    })
+  });
+}, "Normal Ranges")
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-commonAncestorContainer.html b/testing/web-platform/tests/dom/ranges/Range-commonAncestorContainer.html
new file mode 100644
index 0000000000..7882ccc31f
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-commonAncestorContainer.html
@@ -0,0 +1,40 @@
+<!doctype html>
+<title>Range.commonAncestorContainer tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+testRanges.unshift("[detached]");
+
+for (var i = 0; i < testRanges.length; i++) {
+  test(function() {
+    var range;
+    if (i == 0) {
+      range = document.createRange();
+      range.detach();
+    } else {
+      range = rangeFromEndpoints(eval(testRanges[i]));
+    }
+
+    // "Let container be start node."
+    var container = range.startContainer;
+
+    // "While container is not an inclusive ancestor of end node, let
+    // container be container's parent."
+    while (container != range.endContainer
+    && !isAncestor(container, range.endContainer)) {
+      container = container.parentNode;
+    }
+
+    // "Return container."
+    assert_equals(range.commonAncestorContainer, container);
+  }, i + ": range " + testRanges[i]);
+}
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-compareBoundaryPoints.html b/testing/web-platform/tests/dom/ranges/Range-compareBoundaryPoints.html
new file mode 100644
index 0000000000..9d150ae0ab
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-compareBoundaryPoints.html
@@ -0,0 +1,182 @@
+<!doctype html>
+<title>Range.compareBoundaryPoints() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+var testRangesCached = [];
+testRangesCached.push(document.createRange());
+testRangesCached[0].detach();
+for (var i = 0; i < testRangesShort.length; i++) {
+  try {
+    testRangesCached.push(rangeFromEndpoints(eval(testRangesShort[i])));
+  } catch(e) {
+    testRangesCached.push(null);
+  }
+}
+
+var testRangesCachedClones = [];
+testRangesCachedClones.push(document.createRange());
+testRangesCachedClones[0].detach();
+for (var i = 1; i < testRangesCached.length; i++) {
+  if (testRangesCached[i]) {
+    testRangesCachedClones.push(testRangesCached[i].cloneRange());
+  } else {
+    testRangesCachedClones.push(null);
+  }
+}
+
+// We want to run a whole bunch of extra tests with invalid "how" values (not
+// 0-3), but it's excessive to run them for every single pair of ranges --
+// there are too many of them.  So just run them for a handful of the tests.
+var extraTests = [0, // detached
+  1 + testRanges.indexOf("[paras[0].firstChild, 2, paras[0].firstChild, 8]"),
+  1 + testRanges.indexOf("[paras[0].firstChild, 3, paras[3], 1]"),
+  1 + testRanges.indexOf("[testDiv, 0, comment, 5]"),
+  1 + testRanges.indexOf("[foreignDoc.documentElement, 0, foreignDoc.documentElement, 1]")];
+
+for (var i = 0; i < testRangesCached.length; i++) {
+  var range1 = testRangesCached[i];
+  var range1Desc = i + " " + (i == 0 ? "[detached]" : testRanges[i - 1]);
+  for (var j = 0; j <= testRangesCachedClones.length; j++) {
+    var range2;
+    var range2Desc;
+    if (j == testRangesCachedClones.length) {
+      range2 = range1;
+      range2Desc = "same as first range";
+    } else {
+      range2 = testRangesCachedClones[j];
+      range2Desc = j + " " + (j == 0 ? "[detached]" : testRanges[j - 1]);
+    }
+
+    var hows = [Range.START_TO_START, Range.START_TO_END, Range.END_TO_END,
+      Range.END_TO_START];
+    if (extraTests.indexOf(i) != -1 && extraTests.indexOf(j) != -1) {
+      // TODO: Make some type of reusable utility function to do this
+      // work.
+      hows.push(-1, 4, 5, NaN, -0, +Infinity, -Infinity);
+      [65536, -65536, 65536*65536, 0.5, -0.5, -72.5].forEach(function(addend) {
+        hows.push(-1 + addend, 0 + addend, 1 + addend,
+          2 + addend, 3 + addend, 4 + addend);
+      });
+      hows.forEach(function(how) { hows.push(String(how)) });
+      hows.push("6.5536e4", null, undefined, true, false, "", "quasit");
+    }
+
+    for (var k = 0; k < hows.length; k++) {
+      var how = hows[k];
+      test(function() {
+        assert_not_equals(range1, null,
+          "Creating context range threw an exception");
+        assert_not_equals(range2, null,
+          "Creating argument range threw an exception");
+
+        // Convert how per WebIDL.  TODO: Make some type of reusable
+        // utility function to do this work.
+        // "Let number be the result of calling ToNumber on the input
+        // argument."
+        var convertedHow = Number(how);
+
+        // "If number is NaN, +0, −0, +∞, or −∞, return +0."
+        if (isNaN(convertedHow)
+        || convertedHow == 0
+        || convertedHow == Infinity
+        || convertedHow == -Infinity) {
+          convertedHow = 0;
+        } else {
+          // "Let posInt be sign(number) * floor(abs(number))."
+          var posInt = (convertedHow < 0 ? -1 : 1) * Math.floor(Math.abs(convertedHow));
+
+          // "Let int16bit be posInt modulo 2^16; that is, a finite
+          // integer value k of Number type with positive sign and
+          // less than 2^16 in magnitude such that the mathematical
+          // difference of posInt and k is mathematically an integer
+          // multiple of 2^16."
+          //
+          // "Return int16bit."
+          convertedHow = posInt % 65536;
+          if (convertedHow < 0) {
+            convertedHow += 65536;
+          }
+        }
+
+        // Now to the actual algorithm.
+        // "If how is not one of
+        //   START_TO_START,
+        //   START_TO_END,
+        //   END_TO_END, and
+        //   END_TO_START,
+        // throw a "NotSupportedError" exception and terminate these
+        // steps."
+        if (convertedHow != Range.START_TO_START
+        && convertedHow != Range.START_TO_END
+        && convertedHow != Range.END_TO_END
+        && convertedHow != Range.END_TO_START) {
+          assert_throws_dom("NOT_SUPPORTED_ERR", function() {
+            range1.compareBoundaryPoints(how, range2);
+          }, "NotSupportedError required if first parameter doesn't convert to 0-3 per WebIDL");
+          return;
+        }
+
+        // "If context object's root is not the same as sourceRange's
+        // root, throw a "WrongDocumentError" exception and terminate
+        // these steps."
+        if (furthestAncestor(range1.startContainer) != furthestAncestor(range2.startContainer)) {
+          assert_throws_dom("WRONG_DOCUMENT_ERR", function() {
+            range1.compareBoundaryPoints(how, range2);
+          }, "WrongDocumentError required if the ranges don't share a root");
+          return;
+        }
+
+        // "If how is:
+        //   START_TO_START:
+        //     Let this point be the context object's start.
+        //     Let other point be sourceRange's start.
+        //   START_TO_END:
+        //     Let this point be the context object's end.
+        //     Let other point be sourceRange's start.
+        //   END_TO_END:
+        //     Let this point be the context object's end.
+        //     Let other point be sourceRange's end.
+        //   END_TO_START:
+        //     Let this point be the context object's start.
+        //     Let other point be sourceRange's end."
+        var thisPoint = convertedHow == Range.START_TO_START || convertedHow == Range.END_TO_START
+          ? [range1.startContainer, range1.startOffset]
+          : [range1.endContainer, range1.endOffset];
+        var otherPoint = convertedHow == Range.START_TO_START || convertedHow == Range.START_TO_END
+          ? [range2.startContainer, range2.startOffset]
+          : [range2.endContainer, range2.endOffset];
+
+        // "If the position of this point relative to other point is
+        //   before
+        //     Return −1.
+        //   equal
+        //     Return 0.
+        //   after
+        //     Return 1."
+        var position = getPosition(thisPoint[0], thisPoint[1], otherPoint[0], otherPoint[1]);
+        var expected;
+        if (position == "before") {
+          expected = -1;
+        } else if (position == "equal") {
+          expected = 0;
+        } else if (position == "after") {
+          expected = 1;
+        }
+
+        assert_equals(range1.compareBoundaryPoints(how, range2), expected,
+          "Wrong return value");
+      }, i + "," + j + "," + k + ": context range " + range1Desc + ", argument range " + range2Desc + ", how " + format_value(how));
+    }
+  }
+}
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-comparePoint-2.html b/testing/web-platform/tests/dom/ranges/Range-comparePoint-2.html
new file mode 100644
index 0000000000..30a6c57ad9
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-comparePoint-2.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<title>Range.comparePoint</title>
+<link rel="author" title="Ms2ger" href="mailto:ms2ger@gmail.com">
+<meta name=timeout content=long>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+test(function() {
+  var r = document.createRange();
+  r.detach()
+  assert_equals(r.comparePoint(document.body, 0), 1)
+})
+test(function() {
+  var r = document.createRange();
+  assert_throws_js(TypeError, function() { r.comparePoint(null, 0) })
+})
+test(function() {
+  var doc = document.implementation.createHTMLDocument("tralala")
+  var r = document.createRange();
+  assert_throws_dom("WRONG_DOCUMENT_ERR", function() { r.comparePoint(doc.body, 0) })
+})
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-comparePoint.html b/testing/web-platform/tests/dom/ranges/Range-comparePoint.html
new file mode 100644
index 0000000000..e18ac95c4c
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-comparePoint.html
@@ -0,0 +1,92 @@
+<!doctype html>
+<title>Range.comparePoint() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+// Will be filled in on the first run for that range
+var testRangesCached = [];
+
+for (var i = 0; i < testPoints.length; i++) {
+  var node = eval(testPoints[i])[0];
+  var offset = eval(testPoints[i])[1];
+
+  // comparePoint is an unsigned long, so per WebIDL, we need to treat it as
+  // though it wrapped to an unsigned 32-bit integer.
+  var normalizedOffset = offset % Math.pow(2, 32);
+  if (normalizedOffset < 0) {
+    normalizedOffset += Math.pow(2, 32);
+  }
+
+  for (var j = 0; j < testRanges.length; j++) {
+    test(function() {
+      if (testRangesCached[j] === undefined) {
+        try {
+          testRangesCached[j] = rangeFromEndpoints(eval(testRanges[i]));
+        } catch(e) {
+          testRangesCached[j] = null;
+        }
+      }
+      assert_not_equals(testRangesCached[j], null,
+        "Setting up the range failed");
+
+      var range = testRangesCached[j].cloneRange();
+
+      // "If node's root is different from the context object's root,
+      // throw a "WrongDocumentError" exception and terminate these
+      // steps."
+      if (furthestAncestor(node) !== furthestAncestor(range.startContainer)) {
+        assert_throws_dom("WRONG_DOCUMENT_ERR", function() {
+          range.comparePoint(node, offset);
+        }, "Must throw WrongDocumentError if node and range have different roots");
+        return;
+      }
+
+      // "If node is a doctype, throw an "InvalidNodeTypeError" exception
+      // and terminate these steps."
+      if (node.nodeType == Node.DOCUMENT_TYPE_NODE) {
+        assert_throws_dom("INVALID_NODE_TYPE_ERR", function() {
+          range.comparePoint(node, offset);
+        }, "Must throw InvalidNodeTypeError if node is a doctype");
+        return;
+      }
+
+      // "If offset is greater than node's length, throw an
+      // "IndexSizeError" exception and terminate these steps."
+      if (normalizedOffset > nodeLength(node)) {
+        assert_throws_dom("INDEX_SIZE_ERR", function() {
+          range.comparePoint(node, offset);
+        }, "Must throw IndexSizeError if offset is greater than  length");
+        return;
+      }
+
+      // "If (node, offset) is before start, return −1 and terminate
+      // these steps."
+      if (getPosition(node, normalizedOffset, range.startContainer, range.startOffset) === "before") {
+        assert_equals(range.comparePoint(node, offset), -1,
+          "Must return -1 if point is before start");
+        return;
+      }
+
+      // "If (node, offset) is after end, return 1 and terminate these
+      // steps."
+      if (getPosition(node, normalizedOffset, range.endContainer, range.endOffset) === "after") {
+        assert_equals(range.comparePoint(node, offset), 1,
+          "Must return 1 if point is after end");
+        return;
+      }
+
+      // "Return 0."
+      assert_equals(range.comparePoint(node, offset), 0,
+        "Must return 0 if point is neither before start nor after end");
+    }, "Point " + i + " " + testPoints[i] + ", range " + j + " " + testRanges[j]);
+  }
+}
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-constructor.html b/testing/web-platform/tests/dom/ranges/Range-constructor.html
new file mode 100644
index 0000000000..e8cfbef753
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-constructor.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<title>Range constructor test</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script>
+"use strict";
+
+test(function() {
+    var range = new Range();
+    assert_equals(range.startContainer, document, "startContainer");
+    assert_equals(range.endContainer, document, "endContainer");
+    assert_equals(range.startOffset, 0, "startOffset");
+    assert_equals(range.endOffset, 0, "endOffset");
+    assert_true(range.collapsed, "collapsed");
+    assert_equals(range.commonAncestorContainer, document,
+                  "commonAncestorContainer");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-deleteContents.html b/testing/web-platform/tests/dom/ranges/Range-deleteContents.html
new file mode 100644
index 0000000000..40dc400125
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-deleteContents.html
@@ -0,0 +1,337 @@
+<!doctype html>
+<title>Range.deleteContents() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<p>To debug test failures, add a query parameter "subtest" with the test id (like
+"?subtest=5").  Only that test will be run.  Then you can look at the resulting
+iframe in the DOM.
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+testDiv.parentNode.removeChild(testDiv);
+
+var actualIframe = document.createElement("iframe");
+actualIframe.style.display = "none";
+document.body.appendChild(actualIframe);
+
+var expectedIframe = document.createElement("iframe");
+expectedIframe.style.display = "none";
+document.body.appendChild(expectedIframe);
+
+function restoreIframe(iframe, i) {
+  // Most of this function is designed to work around the fact that Opera
+  // doesn't let you add a doctype to a document that no longer has one, in
+  // any way I can figure out.  I eventually compromised on something that
+  // will still let Opera pass most tests that don't actually involve
+  // doctypes.
+  while (iframe.contentDocument.firstChild
+  && iframe.contentDocument.firstChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+    iframe.contentDocument.removeChild(iframe.contentDocument.firstChild);
+  }
+
+  while (iframe.contentDocument.lastChild
+  && iframe.contentDocument.lastChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+    iframe.contentDocument.removeChild(iframe.contentDocument.lastChild);
+  }
+
+  if (!iframe.contentDocument.firstChild) {
+    // This will throw an exception in Opera if we reach here, which is why
+    // I try to avoid it.  It will never happen in a browser that obeys the
+    // spec, so it's really just insurance.  I don't think it actually gets
+    // hit by anything.
+    iframe.contentDocument.appendChild(iframe.contentDocument.implementation.createDocumentType("html", "", ""));
+  }
+  iframe.contentDocument.appendChild(referenceDoc.documentElement.cloneNode(true));
+  iframe.contentWindow.setupRangeTests();
+  iframe.contentWindow.testRangeInput = testRanges[i];
+  iframe.contentWindow.run();
+}
+
+function myDeleteContents(range) {
+  // "If the context object's start and end are the same, abort this method."
+  if (range.startContainer == range.endContainer
+  && range.startOffset == range.endOffset) {
+    return;
+  }
+
+  // "Let original start node, original start offset, original end node, and
+  // original end offset be the context object's start and end nodes and
+  // offsets, respectively."
+  var originalStartNode = range.startContainer;
+  var originalStartOffset = range.startOffset;
+  var originalEndNode = range.endContainer;
+  var originalEndOffset = range.endOffset;
+
+  // "If original start node and original end node are the same, and they are
+  // a Text, ProcessingInstruction, or Comment node, replace data with node
+  // original start node, offset original start offset, count original end
+  // offset minus original start offset, and data the empty string, and then
+  // terminate these steps"
+  if (originalStartNode == originalEndNode
+  && (range.startContainer.nodeType == Node.TEXT_NODE
+  || range.startContainer.nodeType == Node.PROCESSING_INSTRUCTION_NODE
+  || range.startContainer.nodeType == Node.COMMENT_NODE)) {
+    originalStartNode.deleteData(originalStartOffset, originalEndOffset - originalStartOffset);
+    return;
+  }
+
+  // "Let nodes to remove be a list of all the Nodes that are contained in
+  // the context object, in tree order, omitting any Node whose parent is
+  // also contained in the context object."
+  //
+  // We rely on the fact that the contained nodes must lie in tree order
+  // between the start node, and the end node's last descendant (inclusive).
+  var nodesToRemove = [];
+  var stop = nextNodeDescendants(range.endContainer);
+  for (var node = range.startContainer; node != stop; node = nextNode(node)) {
+    if (isContained(node, range)
+    && !(node.parentNode && isContained(node.parentNode, range))) {
+      nodesToRemove.push(node);
+    }
+  }
+
+  // "If original start node is an ancestor container of original end node,
+  // set new node to original start node and new offset to original start
+  // offset."
+  var newNode;
+  var newOffset;
+  if (originalStartNode == originalEndNode
+  || originalEndNode.compareDocumentPosition(originalStartNode) & Node.DOCUMENT_POSITION_CONTAINS) {
+    newNode = originalStartNode;
+    newOffset = originalStartOffset;
+  // "Otherwise:"
+  } else {
+    // "Let reference node equal original start node."
+    var referenceNode = originalStartNode;
+
+    // "While reference node's parent is not null and is not an ancestor
+    // container of original end node, set reference node to its parent."
+    while (referenceNode.parentNode
+    && referenceNode.parentNode != originalEndNode
+    && !(originalEndNode.compareDocumentPosition(referenceNode.parentNode) & Node.DOCUMENT_POSITION_CONTAINS)) {
+      referenceNode = referenceNode.parentNode;
+    }
+
+    // "Set new node to the parent of reference node, and new offset to one
+    // plus the index of reference node."
+    newNode = referenceNode.parentNode;
+    newOffset = 1 + indexOf(referenceNode);
+  }
+
+  // "If original start node is a Text, ProcessingInstruction, or Comment node,
+  // replace data with node original start node, offset original start offset,
+  // count original start node's length minus original start offset, data the
+  // empty start"
+  if (originalStartNode.nodeType == Node.TEXT_NODE
+  || originalStartNode.nodeType == Node.PROCESSING_INSTRUCTION_NODE
+  || originalStartNode.nodeType == Node.COMMENT_NODE) {
+    originalStartNode.deleteData(originalStartOffset, nodeLength(originalStartNode) - originalStartOffset);
+  }
+
+  // "For each node in nodes to remove, in order, remove node from its
+  // parent."
+  for (var i = 0; i < nodesToRemove.length; i++) {
+    nodesToRemove[i].parentNode.removeChild(nodesToRemove[i]);
+  }
+
+  // "If original end node is a Text, ProcessingInstruction, or Comment node,
+  // replace data with node original end node, offset 0, count original end
+  // offset, and data the empty string."
+  if (originalEndNode.nodeType == Node.TEXT_NODE
+  || originalEndNode.nodeType == Node.PROCESSING_INSTRUCTION_NODE
+  || originalEndNode.nodeType == Node.COMMENT_NODE) {
+    originalEndNode.deleteData(0, originalEndOffset);
+  }
+
+  // "Set the context object's start and end to (new node, new offset)."
+  range.setStart(newNode, newOffset);
+  range.setEnd(newNode, newOffset);
+}
+
+function testDeleteContents(i) {
+  restoreIframe(actualIframe, i);
+  restoreIframe(expectedIframe, i);
+
+  var actualRange = actualIframe.contentWindow.testRange;
+  var expectedRange = expectedIframe.contentWindow.testRange;
+  var actualRoots, expectedRoots;
+
+  domTests[i].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual deleteContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated deleteContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+
+    // Just to be pedantic, we'll test not only that the tree we're
+    // modifying is the same in expected vs. actual, but also that all the
+    // nodes originally in it were the same.  Typically some nodes will
+    // become detached when the algorithm is run, but they still exist and
+    // references can still be kept to them, so they should also remain the
+    // same.
+    //
+    // We initialize the list to all nodes, and later on remove all the
+    // ones which still have parents, since the parents will presumably be
+    // tested for isEqualNode() and checking the children would be
+    // redundant.
+    var actualAllNodes = [];
+    var node = furthestAncestor(actualRange.startContainer);
+    do {
+      actualAllNodes.push(node);
+    } while (node = nextNode(node));
+
+    var expectedAllNodes = [];
+    var node = furthestAncestor(expectedRange.startContainer);
+    do {
+      expectedAllNodes.push(node);
+    } while (node = nextNode(node));
+
+    actualRange.deleteContents();
+    myDeleteContents(expectedRange);
+
+    actualRoots = [];
+    for (var j = 0; j < actualAllNodes.length; j++) {
+      if (!actualAllNodes[j].parentNode) {
+        actualRoots.push(actualAllNodes[j]);
+      }
+    }
+
+    expectedRoots = [];
+    for (var j = 0; j < expectedAllNodes.length; j++) {
+      if (!expectedAllNodes[j].parentNode) {
+        expectedRoots.push(expectedAllNodes[j]);
+      }
+    }
+
+    for (var j = 0; j < actualRoots.length; j++) {
+      if (!actualRoots[j].isEqualNode(expectedRoots[j])) {
+        var msg = j ? "detached node #" + j : "tree root";
+        msg = "Actual and expected mismatch for " + msg + ".  ";
+
+        // Find the specific error
+        var actual = actualRoots[j];
+        var expected = expectedRoots[j];
+
+        while (actual && expected) {
+          assert_equals(actual.nodeType, expected.nodeType,
+            msg + "First difference: differing nodeType");
+          assert_equals(actual.nodeName, expected.nodeName,
+            msg + "First difference: differing nodeName");
+          assert_equals(actual.nodeValue, expected.nodeValue,
+            msg + 'First difference: differing nodeValue (nodeName = "' + actual.nodeName + '")');
+          assert_equals(actual.childNodes.length, expected.childNodes.length,
+            msg + 'First difference: differing number of children (nodeName = "' + actual.nodeName + '")');
+          actual = nextNode(actual);
+          expected = nextNode(expected);
+        }
+
+        assert_unreached("DOMs were not equal but we couldn't figure out why");
+      }
+
+      if (j == 0) {
+        // Clearly something is wrong if the node lists are different
+        // lengths.  We want to report this only after we've already
+        // checked the main tree for equality, though, so it doesn't
+        // mask more interesting errors.
+        assert_equals(actualRoots.length, expectedRoots.length,
+          "Actual and expected DOMs were broken up into a different number of pieces by deleteContents() (this probably means you created or detached nodes when you weren't supposed to)");
+      }
+    }
+  });
+  domTests[i].done();
+
+  positionTests[i].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual deleteContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated deleteContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+    assert_true(actualRoots[0].isEqualNode(expectedRoots[0]),
+      "The resulting DOMs were not equal, so comparing positions makes no sense");
+
+    assert_equals(actualRange.startContainer, actualRange.endContainer,
+      "startContainer and endContainer must always be the same after deleteContents()");
+    assert_equals(actualRange.startOffset, actualRange.endOffset,
+      "startOffset and endOffset must always be the same after deleteContents()");
+    assert_equals(expectedRange.startContainer, expectedRange.endContainer,
+      "Test bug!  Expected startContainer and endContainer must always be the same after deleteContents()");
+    assert_equals(expectedRange.startOffset, expectedRange.endOffset,
+      "Test bug!  Expected startOffset and endOffset must always be the same after deleteContents()");
+
+    assert_equals(actualRange.startOffset, expectedRange.startOffset,
+      "Unexpected startOffset after deleteContents()");
+    // How do we decide that the two nodes are equal, since they're in
+    // different trees?  Since the DOMs are the same, it's enough to check
+    // that the index in the parent is the same all the way up the tree.
+    // But we can first cheat by just checking they're actually equal.
+    assert_true(actualRange.startContainer.isEqualNode(expectedRange.startContainer),
+      "Unexpected startContainer after deleteContents(), expected " +
+      expectedRange.startContainer.nodeName.toLowerCase() + " but got " +
+      actualRange.startContainer.nodeName.toLowerCase());
+    var currentActual = actualRange.startContainer;
+    var currentExpected = expectedRange.startContainer;
+    var actual = "";
+    var expected = "";
+    while (currentActual && currentExpected) {
+      actual = indexOf(currentActual) + "-" + actual;
+      expected = indexOf(currentExpected) + "-" + expected;
+
+      currentActual = currentActual.parentNode;
+      currentExpected = currentExpected.parentNode;
+    }
+    actual = actual.substr(0, actual.length - 1);
+    expected = expected.substr(0, expected.length - 1);
+    assert_equals(actual, expected,
+      "startContainer superficially looks right but is actually the wrong node if you trace back its index in all its ancestors (I'm surprised this actually happened");
+  });
+  positionTests[i].done();
+}
+
+// First test a detached Range, synchronously
+test(function() {
+  var range = document.createRange();
+  range.detach();
+  range.deleteContents();
+}, "Detached Range");
+
+var iStart = 0;
+var iStop = testRanges.length;
+
+if (/subtest=[0-9]+/.test(location.search)) {
+  var matches = /subtest=([0-9]+)/.exec(location.search);
+  iStart = Number(matches[1]);
+  iStop = Number(matches[1]) + 1;
+}
+
+var domTests = [];
+var positionTests = [];
+
+for (var i = iStart; i < iStop; i++) {
+  domTests[i] = async_test("Resulting DOM for range " + i + " " + testRanges[i]);
+  positionTests[i] = async_test("Resulting cursor position for range " + i + " " + testRanges[i]);
+}
+
+var referenceDoc = document.implementation.createHTMLDocument("");
+referenceDoc.removeChild(referenceDoc.documentElement);
+
+actualIframe.onload = function() {
+  expectedIframe.onload = function() {
+    for (var i = iStart; i < iStop; i++) {
+      testDeleteContents(i);
+    }
+  }
+  expectedIframe.src = "Range-test-iframe.html";
+  referenceDoc.appendChild(actualIframe.contentDocument.documentElement.cloneNode(true));
+}
+actualIframe.src = "Range-test-iframe.html";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-detach.html b/testing/web-platform/tests/dom/ranges/Range-detach.html
new file mode 100644
index 0000000000..ac35d71369
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-detach.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<title>Range.detach</title>
+<link rel="author" title="Ms2ger" href="mailto:ms2ger@gmail.com">
+<meta name=timeout content=long>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+test(function() {
+  var r = document.createRange();
+  r.detach()
+  r.detach()
+})
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-extractContents.html b/testing/web-platform/tests/dom/ranges/Range-extractContents.html
new file mode 100644
index 0000000000..88f8fa55f8
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-extractContents.html
@@ -0,0 +1,252 @@
+<!doctype html>
+<title>Range.extractContents() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<p>To debug test failures, add a query parameter "subtest" with the test id (like
+"?subtest=5").  Only that test will be run.  Then you can look at the resulting
+iframe in the DOM.
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+testDiv.parentNode.removeChild(testDiv);
+
+var actualIframe = document.createElement("iframe");
+actualIframe.style.display = "none";
+document.body.appendChild(actualIframe);
+
+var expectedIframe = document.createElement("iframe");
+expectedIframe.style.display = "none";
+document.body.appendChild(expectedIframe);
+
+function restoreIframe(iframe, i) {
+  // Most of this function is designed to work around the fact that Opera
+  // doesn't let you add a doctype to a document that no longer has one, in
+  // any way I can figure out.  I eventually compromised on something that
+  // will still let Opera pass most tests that don't actually involve
+  // doctypes.
+  while (iframe.contentDocument.firstChild
+  && iframe.contentDocument.firstChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+    iframe.contentDocument.removeChild(iframe.contentDocument.firstChild);
+  }
+
+  while (iframe.contentDocument.lastChild
+  && iframe.contentDocument.lastChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+    iframe.contentDocument.removeChild(iframe.contentDocument.lastChild);
+  }
+
+  if (!iframe.contentDocument.firstChild) {
+    // This will throw an exception in Opera if we reach here, which is why
+    // I try to avoid it.  It will never happen in a browser that obeys the
+    // spec, so it's really just insurance.  I don't think it actually gets
+    // hit by anything.
+    iframe.contentDocument.appendChild(iframe.contentDocument.implementation.createDocumentType("html", "", ""));
+  }
+  iframe.contentDocument.appendChild(referenceDoc.documentElement.cloneNode(true));
+  iframe.contentWindow.setupRangeTests();
+  iframe.contentWindow.testRangeInput = testRanges[i];
+  iframe.contentWindow.run();
+}
+
+function testExtractContents(i) {
+  restoreIframe(actualIframe, i);
+  restoreIframe(expectedIframe, i);
+
+  var actualRange = actualIframe.contentWindow.testRange;
+  var expectedRange = expectedIframe.contentWindow.testRange;
+  var actualFrag, expectedFrag;
+  var actualRoots, expectedRoots;
+
+  domTests[i].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual extractContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated extractContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+
+    // Just to be pedantic, we'll test not only that the tree we're
+    // modifying is the same in expected vs. actual, but also that all the
+    // nodes originally in it were the same.  Typically some nodes will
+    // become detached when the algorithm is run, but they still exist and
+    // references can still be kept to them, so they should also remain the
+    // same.
+    //
+    // We initialize the list to all nodes, and later on remove all the
+    // ones which still have parents, since the parents will presumably be
+    // tested for isEqualNode() and checking the children would be
+    // redundant.
+    var actualAllNodes = [];
+    var node = furthestAncestor(actualRange.startContainer);
+    do {
+      actualAllNodes.push(node);
+    } while (node = nextNode(node));
+
+    var expectedAllNodes = [];
+    var node = furthestAncestor(expectedRange.startContainer);
+    do {
+      expectedAllNodes.push(node);
+    } while (node = nextNode(node));
+
+    expectedFrag = myExtractContents(expectedRange);
+    if (typeof expectedFrag == "string") {
+      assert_throws_dom(
+        expectedFrag,
+        actualIframe.contentWindow.DOMException,
+        function() {
+          actualRange.extractContents();
+        }
+      );
+    } else {
+      actualFrag = actualRange.extractContents();
+    }
+
+    actualRoots = [];
+    for (var j = 0; j < actualAllNodes.length; j++) {
+      if (!actualAllNodes[j].parentNode) {
+        actualRoots.push(actualAllNodes[j]);
+      }
+    }
+
+    expectedRoots = [];
+    for (var j = 0; j < expectedAllNodes.length; j++) {
+      if (!expectedAllNodes[j].parentNode) {
+        expectedRoots.push(expectedAllNodes[j]);
+      }
+    }
+
+    for (var j = 0; j < actualRoots.length; j++) {
+      assertNodesEqual(actualRoots[j], expectedRoots[j], j ? "detached node #" + j : "tree root");
+
+      if (j == 0) {
+        // Clearly something is wrong if the node lists are different
+        // lengths.  We want to report this only after we've already
+        // checked the main tree for equality, though, so it doesn't
+        // mask more interesting errors.
+        assert_equals(actualRoots.length, expectedRoots.length,
+          "Actual and expected DOMs were broken up into a different number of pieces by extractContents() (this probably means you created or detached nodes when you weren't supposed to)");
+      }
+    }
+  });
+  domTests[i].done();
+
+  positionTests[i].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual extractContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated extractContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+
+    assert_true(actualRoots[0].isEqualNode(expectedRoots[0]),
+      "The resulting DOMs were not equal, so comparing positions makes no sense");
+
+    if (typeof expectedFrag == "string") {
+      // It's no longer true that, e.g., startContainer and endContainer
+      // must always be the same
+      return;
+    }
+    assert_equals(actualRange.startContainer, actualRange.endContainer,
+      "startContainer and endContainer must always be the same after extractContents()");
+    assert_equals(actualRange.startOffset, actualRange.endOffset,
+      "startOffset and endOffset must always be the same after extractContents()");
+    assert_equals(expectedRange.startContainer, expectedRange.endContainer,
+      "Test bug!  Expected startContainer and endContainer must always be the same after extractContents()");
+    assert_equals(expectedRange.startOffset, expectedRange.endOffset,
+      "Test bug!  Expected startOffset and endOffset must always be the same after extractContents()");
+
+    assert_equals(actualRange.startOffset, expectedRange.startOffset,
+      "Unexpected startOffset after extractContents()");
+    // How do we decide that the two nodes are equal, since they're in
+    // different trees?  Since the DOMs are the same, it's enough to check
+    // that the index in the parent is the same all the way up the tree.
+    // But we can first cheat by just checking they're actually equal.
+    assert_true(actualRange.startContainer.isEqualNode(expectedRange.startContainer),
+      "Unexpected startContainer after extractContents(), expected " +
+      expectedRange.startContainer.nodeName.toLowerCase() + " but got " +
+      actualRange.startContainer.nodeName.toLowerCase());
+    var currentActual = actualRange.startContainer;
+    var currentExpected = expectedRange.startContainer;
+    var actual = "";
+    var expected = "";
+    while (currentActual && currentExpected) {
+      actual = indexOf(currentActual) + "-" + actual;
+      expected = indexOf(currentExpected) + "-" + expected;
+
+      currentActual = currentActual.parentNode;
+      currentExpected = currentExpected.parentNode;
+    }
+    actual = actual.substr(0, actual.length - 1);
+    expected = expected.substr(0, expected.length - 1);
+    assert_equals(actual, expected,
+      "startContainer superficially looks right but is actually the wrong node if you trace back its index in all its ancestors (I'm surprised this actually happened");
+  });
+  positionTests[i].done();
+
+  fragTests[i].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual extractContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated extractContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+
+    if (typeof expectedFrag == "string") {
+      // Comparing makes no sense
+      return;
+    }
+    assertNodesEqual(actualFrag, expectedFrag,
+      "returned fragment");
+  });
+  fragTests[i].done();
+}
+
+// First test a detached Range, synchronously
+test(function() {
+  var range = document.createRange();
+  range.detach();
+  assert_array_equals(range.extractContents().childNodes, []);
+}, "Detached Range");
+
+var iStart = 0;
+var iStop = testRanges.length;
+
+if (/subtest=[0-9]+/.test(location.search)) {
+  var matches = /subtest=([0-9]+)/.exec(location.search);
+  iStart = Number(matches[1]);
+  iStop = Number(matches[1]) + 1;
+}
+
+var domTests = [];
+var positionTests = [];
+var fragTests = [];
+
+for (var i = iStart; i < iStop; i++) {
+  domTests[i] = async_test("Resulting DOM for range " + i + " " + testRanges[i]);
+  positionTests[i] = async_test("Resulting cursor position for range " + i + " " + testRanges[i]);
+  fragTests[i] = async_test("Returned fragment for range " + i + " " + testRanges[i]);
+}
+
+var referenceDoc = document.implementation.createHTMLDocument("");
+referenceDoc.removeChild(referenceDoc.documentElement);
+
+actualIframe.onload = function() {
+  expectedIframe.onload = function() {
+    for (var i = iStart; i < iStop; i++) {
+      testExtractContents(i);
+    }
+  }
+  expectedIframe.src = "Range-test-iframe.html";
+  referenceDoc.appendChild(actualIframe.contentDocument.documentElement.cloneNode(true));
+}
+actualIframe.src = "Range-test-iframe.html";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-insertNode.html b/testing/web-platform/tests/dom/ranges/Range-insertNode.html
new file mode 100644
index 0000000000..b0a9d43f98
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-insertNode.html
@@ -0,0 +1,286 @@
+<!doctype html>
+<title>Range.insertNode() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<p>To debug test failures, add a query parameter "subtest" with the test id (like
+"?subtest=5,16").  Only that test will be run.  Then you can look at the resulting
+iframes in the DOM.
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+testDiv.parentNode.removeChild(testDiv);
+
+function restoreIframe(iframe, i, j) {
+    // Most of this function is designed to work around the fact that Opera
+    // doesn't let you add a doctype to a document that no longer has one, in
+    // any way I can figure out.  I eventually compromised on something that
+    // will still let Opera pass most tests that don't actually involve
+    // doctypes.
+    while (iframe.contentDocument.firstChild
+    && iframe.contentDocument.firstChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+        iframe.contentDocument.removeChild(iframe.contentDocument.firstChild);
+    }
+
+    while (iframe.contentDocument.lastChild
+    && iframe.contentDocument.lastChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+        iframe.contentDocument.removeChild(iframe.contentDocument.lastChild);
+    }
+
+    if (!iframe.contentDocument.firstChild) {
+        // This will throw an exception in Opera if we reach here, which is why
+        // I try to avoid it.  It will never happen in a browser that obeys the
+        // spec, so it's really just insurance.  I don't think it actually gets
+        // hit by anything.
+        iframe.contentDocument.appendChild(iframe.contentDocument.implementation.createDocumentType("html", "", ""));
+    }
+    iframe.contentDocument.appendChild(referenceDoc.documentElement.cloneNode(true));
+    iframe.contentWindow.setupRangeTests();
+    iframe.contentWindow.testRangeInput = testRangesShort[i];
+    iframe.contentWindow.testNodeInput = testNodesShort[j];
+    iframe.contentWindow.run();
+}
+
+function testInsertNode(i, j) {
+    var actualRange;
+    var expectedRange;
+    var actualNode;
+    var expectedNode;
+    var actualRoots = [];
+    var expectedRoots = [];
+
+    var detached = false;
+
+    domTests[i][j].step(function() {
+        restoreIframe(actualIframe, i, j);
+        restoreIframe(expectedIframe, i, j);
+
+        actualRange = actualIframe.contentWindow.testRange;
+        expectedRange = expectedIframe.contentWindow.testRange;
+        actualNode = actualIframe.contentWindow.testNode;
+        expectedNode = expectedIframe.contentWindow.testNode;
+
+        try {
+            actualRange.collapsed;
+        } catch (e) {
+            detached = true;
+        }
+
+        assert_equals(actualIframe.contentWindow.unexpectedException, null,
+            "Unexpected exception thrown when setting up Range for actual insertNode()");
+        assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+            "Unexpected exception thrown when setting up Range for simulated insertNode()");
+        assert_equals(typeof actualRange, "object",
+            "typeof Range produced in actual iframe");
+        assert_not_equals(actualRange, null,
+            "Range produced in actual iframe was null");
+        assert_equals(typeof expectedRange, "object",
+            "typeof Range produced in expected iframe");
+        assert_not_equals(expectedRange, null,
+            "Range produced in expected iframe was null");
+        assert_equals(typeof actualNode, "object",
+            "typeof Node produced in actual iframe");
+        assert_not_equals(actualNode, null,
+            "Node produced in actual iframe was null");
+        assert_equals(typeof expectedNode, "object",
+            "typeof Node produced in expected iframe");
+        assert_not_equals(expectedNode, null,
+            "Node produced in expected iframe was null");
+
+        // We want to test that the trees containing the ranges are equal, and
+        // also the trees containing the moved nodes.  These might not be the
+        // same, if we're inserting a node from a detached tree or a different
+        // document.
+        //
+        // Detached ranges are always in the contentDocument.
+        if (detached) {
+            actualRoots.push(actualIframe.contentDocument);
+            expectedRoots.push(expectedIframe.contentDocument);
+        } else {
+            actualRoots.push(furthestAncestor(actualRange.startContainer));
+            expectedRoots.push(furthestAncestor(expectedRange.startContainer));
+        }
+
+        if (furthestAncestor(actualNode) != actualRoots[0]) {
+            actualRoots.push(furthestAncestor(actualNode));
+        }
+        if (furthestAncestor(expectedNode) != expectedRoots[0]) {
+            expectedRoots.push(furthestAncestor(expectedNode));
+        }
+
+        assert_equals(actualRoots.length, expectedRoots.length,
+            "Either the actual node and actual range are in the same tree but the expected are in different trees, or vice versa");
+
+        // This doctype stuff is to work around the fact that Opera 11.00 will
+        // move around doctypes within a document, even to totally invalid
+        // positions, but it won't allow a new doctype to be added to a
+        // document in any way I can figure out.  So if we try moving a doctype
+        // to some invalid place, in Opera it will actually succeed, and then
+        // restoreIframe() will remove the doctype along with the root element,
+        // and then nothing can re-add the doctype.  So instead, we catch it
+        // during the test itself and move it back to the right place while we
+        // still can.
+        //
+        // I spent *way* too much time debugging and working around this bug.
+        var actualDoctype = actualIframe.contentDocument.doctype;
+        var expectedDoctype = expectedIframe.contentDocument.doctype;
+
+        var result;
+        try {
+            result = myInsertNode(expectedRange, expectedNode);
+        } catch (e) {
+            if (expectedDoctype != expectedIframe.contentDocument.firstChild) {
+                expectedIframe.contentDocument.insertBefore(expectedDoctype, expectedIframe.contentDocument.firstChild);
+            }
+            throw e;
+        }
+        if (typeof result == "string") {
+            assert_throws_dom(result, actualIframe.contentWindow.DOMException, function() {
+                try {
+                    actualRange.insertNode(actualNode);
+                } catch (e) {
+                    if (expectedDoctype != expectedIframe.contentDocument.firstChild) {
+                        expectedIframe.contentDocument.insertBefore(expectedDoctype, expectedIframe.contentDocument.firstChild);
+                    }
+                    if (actualDoctype != actualIframe.contentDocument.firstChild) {
+                        actualIframe.contentDocument.insertBefore(actualDoctype, actualIframe.contentDocument.firstChild);
+                    }
+                    throw e;
+                }
+            }, "A " + result + " DOMException must be thrown in this case");
+            // Don't return, we still need to test DOM equality
+        } else {
+            try {
+                actualRange.insertNode(actualNode);
+            } catch (e) {
+                if (expectedDoctype != expectedIframe.contentDocument.firstChild) {
+                    expectedIframe.contentDocument.insertBefore(expectedDoctype, expectedIframe.contentDocument.firstChild);
+                }
+                if (actualDoctype != actualIframe.contentDocument.firstChild) {
+                    actualIframe.contentDocument.insertBefore(actualDoctype, actualIframe.contentDocument.firstChild);
+                }
+                throw e;
+            }
+        }
+
+        for (var k = 0; k < actualRoots.length; k++) {
+            assertNodesEqual(actualRoots[k], expectedRoots[k], k ? "moved node's tree root" : "range's tree root");
+        }
+    });
+    domTests[i][j].done();
+
+    positionTests[i][j].step(function() {
+        assert_equals(actualIframe.contentWindow.unexpectedException, null,
+            "Unexpected exception thrown when setting up Range for actual insertNode()");
+        assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+            "Unexpected exception thrown when setting up Range for simulated insertNode()");
+        assert_equals(typeof actualRange, "object",
+            "typeof Range produced in actual iframe");
+        assert_not_equals(actualRange, null,
+            "Range produced in actual iframe was null");
+        assert_equals(typeof expectedRange, "object",
+            "typeof Range produced in expected iframe");
+        assert_not_equals(expectedRange, null,
+            "Range produced in expected iframe was null");
+        assert_equals(typeof actualNode, "object",
+            "typeof Node produced in actual iframe");
+        assert_not_equals(actualNode, null,
+            "Node produced in actual iframe was null");
+        assert_equals(typeof expectedNode, "object",
+            "typeof Node produced in expected iframe");
+        assert_not_equals(expectedNode, null,
+            "Node produced in expected iframe was null");
+
+        for (var k = 0; k < actualRoots.length; k++) {
+            assertNodesEqual(actualRoots[k], expectedRoots[k], k ? "moved node's tree root" : "range's tree root");
+        }
+
+        if (detached) {
+            // No further tests we can do
+            return;
+        }
+
+        assert_equals(actualRange.startOffset, expectedRange.startOffset,
+            "Unexpected startOffset after insertNode()");
+        assert_equals(actualRange.endOffset, expectedRange.endOffset,
+            "Unexpected endOffset after insertNode()");
+        // How do we decide that the two nodes are equal, since they're in
+        // different trees?  Since the DOMs are the same, it's enough to check
+        // that the index in the parent is the same all the way up the tree.
+        // But we can first cheat by just checking they're actually equal.
+        assert_true(actualRange.startContainer.isEqualNode(expectedRange.startContainer),
+            "Unexpected startContainer after insertNode(), expected " +
+            expectedRange.startContainer.nodeName.toLowerCase() + " but got " +
+            actualRange.startContainer.nodeName.toLowerCase());
+        var currentActual = actualRange.startContainer;
+        var currentExpected = expectedRange.startContainer;
+        var actual = "";
+        var expected = "";
+        while (currentActual && currentExpected) {
+            actual = indexOf(currentActual) + "-" + actual;
+            expected = indexOf(currentExpected) + "-" + expected;
+
+            currentActual = currentActual.parentNode;
+            currentExpected = currentExpected.parentNode;
+        }
+        actual = actual.substr(0, actual.length - 1);
+        expected = expected.substr(0, expected.length - 1);
+        assert_equals(actual, expected,
+            "startContainer superficially looks right but is actually the wrong node if you trace back its index in all its ancestors (I'm surprised this actually happened");
+    });
+    positionTests[i][j].done();
+}
+
+testRanges.unshift('"detached"');
+
+var iStart = 0;
+var iStop = testRangesShort.length;
+var jStart = 0;
+var jStop = testNodesShort.length;
+
+if (/subtest=[0-9]+,[0-9]+/.test(location.search)) {
+    var matches = /subtest=([0-9]+),([0-9]+)/.exec(location.search);
+    iStart = Number(matches[1]);
+    iStop = Number(matches[1]) + 1;
+    jStart = Number(matches[2]) + 0;
+    jStop = Number(matches[2]) + 1;
+}
+
+var domTests = [];
+var positionTests = [];
+for (var i = iStart; i < iStop; i++) {
+    domTests[i] = [];
+    positionTests[i] = [];
+    for (var j = jStart; j < jStop; j++) {
+        domTests[i][j] = async_test(i + "," + j + ": resulting DOM for range " + testRangesShort[i] + ", node " + testNodesShort[j]);
+        positionTests[i][j] = async_test(i + "," + j + ": resulting range position for range " + testRangesShort[i] + ", node " + testNodesShort[j]);
+    }
+}
+
+var actualIframe = document.createElement("iframe");
+actualIframe.style.display = "none";
+document.body.appendChild(actualIframe);
+
+var expectedIframe = document.createElement("iframe");
+expectedIframe.style.display = "none";
+document.body.appendChild(expectedIframe);
+
+var referenceDoc = document.implementation.createHTMLDocument("");
+referenceDoc.removeChild(referenceDoc.documentElement);
+
+actualIframe.onload = function() {
+    expectedIframe.onload = function() {
+        for (var i = iStart; i < iStop; i++) {
+            for (var j = jStart; j < jStop; j++) {
+                testInsertNode(i, j);
+            }
+        }
+    }
+    expectedIframe.src = "Range-test-iframe.html";
+    referenceDoc.appendChild(actualIframe.contentDocument.documentElement.cloneNode(true));
+}
+actualIframe.src = "Range-test-iframe.html";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-intersectsNode-2.html b/testing/web-platform/tests/dom/ranges/Range-intersectsNode-2.html
new file mode 100644
index 0000000000..48072d98af
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-intersectsNode-2.html
@@ -0,0 +1,36 @@
+<!doctype htlml>
+<title>Range.intersectsNode</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="div"><span id="s0">s0</span><span id="s1">s1</span><span id="s2">s2</span></div>
+<script>
+// Taken from Chromium bug: http://crbug.com/822510
+test(() => {
+  const range = new Range();
+  const div = document.getElementById('div');
+  const s0 = document.getElementById('s0');
+  const s1 = document.getElementById('s1');
+  const s2 = document.getElementById('s2');
+
+  // Range encloses s0
+  range.setStart(div, 0);
+  range.setEnd(div, 1);
+  assert_true(range.intersectsNode(s0), '[s0] range.intersectsNode(s0)');
+  assert_false(range.intersectsNode(s1), '[s0] range.intersectsNode(s1)');
+  assert_false(range.intersectsNode(s2), '[s0] range.intersectsNode(s2)');
+
+  // Range encloses s1
+  range.setStart(div, 1);
+  range.setEnd(div, 2);
+  assert_false(range.intersectsNode(s0), '[s1] range.intersectsNode(s0)');
+  assert_true(range.intersectsNode(s1), '[s1] range.intersectsNode(s1)');
+  assert_false(range.intersectsNode(s2), '[s1] range.intersectsNode(s2)');
+
+  // Range encloses s2
+  range.setStart(div, 2);
+  range.setEnd(div, 3);
+  assert_false(range.intersectsNode(s0), '[s2] range.intersectsNode(s0)');
+  assert_false(range.intersectsNode(s1), '[s2] range.intersectsNode(s1)');
+  assert_true(range.intersectsNode(s2), '[s2] range.intersectsNode(s2)');
+}, 'Range.intersectsNode() simple cases');
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-intersectsNode-binding.html b/testing/web-platform/tests/dom/ranges/Range-intersectsNode-binding.html
new file mode 100644
index 0000000000..57d159b030
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-intersectsNode-binding.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<title>Range.intersectsNode</title>
+<link rel="author" title="Ms2ger" href="mailto:ms2ger@gmail.com">
+<meta name=timeout content=long>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<div id=log></div>
+<script>
+test(function() {
+  var r = document.createRange();
+  assert_throws_js(TypeError, function() { r.intersectsNode(); });
+  assert_throws_js(TypeError, function() { r.intersectsNode(null); });
+  assert_throws_js(TypeError, function() { r.intersectsNode(undefined); });
+  assert_throws_js(TypeError, function() { r.intersectsNode(42); });
+  assert_throws_js(TypeError, function() { r.intersectsNode("foo"); });
+  assert_throws_js(TypeError, function() { r.intersectsNode({}); });
+  r.detach();
+  assert_throws_js(TypeError, function() { r.intersectsNode(); });
+  assert_throws_js(TypeError, function() { r.intersectsNode(null); });
+  assert_throws_js(TypeError, function() { r.intersectsNode(undefined); });
+  assert_throws_js(TypeError, function() { r.intersectsNode(42); });
+  assert_throws_js(TypeError, function() { r.intersectsNode("foo"); });
+  assert_throws_js(TypeError, function() { r.intersectsNode({}); });
+}, "Calling intersectsNode without an argument or with an invalid argument should throw a TypeError.")
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-intersectsNode-shadow.html b/testing/web-platform/tests/dom/ranges/Range-intersectsNode-shadow.html
new file mode 100644
index 0000000000..8219ba8285
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-intersectsNode-shadow.html
@@ -0,0 +1,19 @@
+<!doctype html>
+<title>Range.intersectsNode with Shadow DOM</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="host"></div>
+<script>
+test(() => {
+  const host = document.getElementById("host");
+  host.attachShadow({ mode: "open" }).innerHTML = `<span>ABC</span>`;
+
+  const range = document.createRange();
+  range.selectNode(document.body);
+
+  assert_true(range.intersectsNode(host), "Should intersect host");
+  assert_false(range.intersectsNode(host.shadowRoot), "Should not intersect shadow root");
+  assert_false(range.intersectsNode(host.shadowRoot.firstElementChild), "Should not intersect shadow span");
+}, "Range.intersectsNode() doesn't return true for shadow children in other trees");
+</script>
+
diff --git a/testing/web-platform/tests/dom/ranges/Range-intersectsNode.html b/testing/web-platform/tests/dom/ranges/Range-intersectsNode.html
new file mode 100644
index 0000000000..97e10f6f0d
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-intersectsNode.html
@@ -0,0 +1,70 @@
+<!doctype html>
+<title>Range.intersectsNode() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+// Will be filled in on the first run for that range
+var testRangesCached = [];
+
+for (var i = 0; i < testNodes.length; i++) {
+  var node = eval(testNodes[i]);
+
+  for (var j = 0; j < testRanges.length; j++) {
+    test(function() {
+      if (testRangesCached[j] === undefined) {
+        try {
+          testRangesCached[j] = rangeFromEndpoints(eval(testRanges[i]));
+        } catch(e) {
+          testRangesCached[j] = null;
+        }
+      }
+      assert_not_equals(testRangesCached[j], null,
+        "Setting up the range failed");
+
+      var range = testRangesCached[j].cloneRange();
+
+      // "If node's root is different from the context object's root,
+      // return false and terminate these steps."
+      if (furthestAncestor(node) !== furthestAncestor(range.startContainer)) {
+        assert_equals(range.intersectsNode(node), false,
+          "Must return false if node and range have different roots");
+        return;
+      }
+
+      // "Let parent be node's parent."
+      var parent_ = node.parentNode;
+
+      // "If parent is null, return true and terminate these steps."
+      if (!parent_) {
+        assert_equals(range.intersectsNode(node), true,
+          "Must return true if node's parent is null");
+        return;
+      }
+
+      // "Let offset be node's index."
+      var offset = indexOf(node);
+
+      // "If (parent, offset) is before end and (parent, offset + 1) is
+      // after start, return true and terminate these steps."
+      if (getPosition(parent_, offset, range.endContainer, range.endOffset) === "before"
+      && getPosition(parent_, offset + 1, range.startContainer, range.startOffset) === "after") {
+        assert_equals(range.intersectsNode(node), true,
+          "Must return true if (parent, offset) is before range end and (parent, offset + 1) is after range start");
+        return;
+      }
+
+      // "Return false."
+      assert_equals(range.intersectsNode(node), false,
+        "Must return false if (parent, offset) is not before range end or (parent, offset + 1) is not after range start");
+    }, "Node " + i + " " + testNodes[i] + ", range " + j + " " + testRanges[j]);
+  }
+}
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-isPointInRange.html b/testing/web-platform/tests/dom/ranges/Range-isPointInRange.html
new file mode 100644
index 0000000000..80db97e844
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-isPointInRange.html
@@ -0,0 +1,83 @@
+<!doctype html>
+<title>Range.isPointInRange() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+var testRangesCached = [];
+test(function() {
+  for (var j = 0; j < testRanges.length; j++) {
+    test(function() {
+      testRangesCached[j] = rangeFromEndpoints(eval(testRanges[j]));
+    }, "Set up for range " + j + " " + testRanges[j]);
+  }
+  var detachedRange = document.createRange();
+  detachedRange.detach();
+  testRanges.push("detached");
+  testRangesCached.push(detachedRange);
+}, "Setup");
+
+for (var i = 0; i < testPoints.length; i++) {
+  var node = eval(testPoints[i])[0];
+  var offset = eval(testPoints[i])[1];
+
+  // isPointInRange is an unsigned long, so per WebIDL, we need to treat it
+  // as though it wrapped to an unsigned 32-bit integer.
+  var normalizedOffset = offset % Math.pow(2, 32);
+  if (normalizedOffset < 0) {
+    normalizedOffset += Math.pow(2, 32);
+  }
+
+  for (var j = 0; j < testRanges.length; j++) {
+    test(function() {
+      var range = testRangesCached[j].cloneRange();
+
+      // "If node's root is different from the context object's root,
+      // return false and terminate these steps."
+      if (furthestAncestor(node) !== furthestAncestor(range.startContainer)) {
+        assert_false(range.isPointInRange(node, offset),
+          "Must return false if node has a different root from the context object");
+        return;
+      }
+
+      // "If node is a doctype, throw an "InvalidNodeTypeError" exception
+      // and terminate these steps."
+      if (node.nodeType == Node.DOCUMENT_TYPE_NODE) {
+        assert_throws_dom("INVALID_NODE_TYPE_ERR", function() {
+          range.isPointInRange(node, offset);
+        }, "Must throw InvalidNodeTypeError if node is a doctype");
+        return;
+      }
+
+      // "If offset is greater than node's length, throw an
+      // "IndexSizeError" exception and terminate these steps."
+      if (normalizedOffset > nodeLength(node)) {
+        assert_throws_dom("INDEX_SIZE_ERR", function() {
+          range.isPointInRange(node, offset);
+        }, "Must throw IndexSizeError if offset is greater than  length");
+        return;
+      }
+
+      // "If (node, offset) is before start or after end, return false
+      // and terminate these steps."
+      if (getPosition(node, normalizedOffset, range.startContainer, range.startOffset) === "before"
+      || getPosition(node, normalizedOffset, range.endContainer, range.endOffset) === "after") {
+        assert_false(range.isPointInRange(node, offset),
+          "Must return false if point is before start or after end");
+        return;
+      }
+
+      // "Return true."
+      assert_true(range.isPointInRange(node, offset),
+        "Must return true if point is not before start, after end, or in different tree");
+    }, "Point " + i + " " + testPoints[i] + ", range " + j + " " + testRanges[j]);
+  }
+}
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-appendChild.html b/testing/web-platform/tests/dom/ranges/Range-mutations-appendChild.html
new file mode 100644
index 0000000000..5b5b5a55df
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-appendChild.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<title>Range mutation tests - appendChild</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(appendChildTests, function(params) { return params[0] + ".appendChild(" + params[1] + ")" }, testAppendChild);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-appendData.html b/testing/web-platform/tests/dom/ranges/Range-mutations-appendData.html
new file mode 100644
index 0000000000..1d4879d57c
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-appendData.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - appendData</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(appendDataTests, function(params) { return params[0] + ".appendData(" + params[1] + ")" }, testAppendData);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-dataChange.html b/testing/web-platform/tests/dom/ranges/Range-mutations-dataChange.html
new file mode 100644
index 0000000000..3683e8bb9b
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-dataChange.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - update data by IDL attributes</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(dataChangeTests, function(params) { return params[0] + "." + eval(params[1]) + " " + eval(params[2]) + ' ' + params[3] }, testDataChange);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-deleteData.html b/testing/web-platform/tests/dom/ranges/Range-mutations-deleteData.html
new file mode 100644
index 0000000000..5f2b852f5b
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-deleteData.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - deleteData</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(deleteDataTests, function(params) { return params[0] + ".deleteData(" + params[1] + ", " + params[2] + ")" }, testDeleteData);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-insertBefore.html b/testing/web-platform/tests/dom/ranges/Range-mutations-insertBefore.html
new file mode 100644
index 0000000000..c71b239547
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-insertBefore.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - insertBefore</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(insertBeforeTests, function(params) { return params[0] + ".insertBefore(" + params[1] + ", " + params[2] + ")" }, testInsertBefore);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-insertData.html b/testing/web-platform/tests/dom/ranges/Range-mutations-insertData.html
new file mode 100644
index 0000000000..fca533d503
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-insertData.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - insertData</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(insertDataTests, function(params) { return params[0] + ".insertData(" + params[1] + ", " + params[2] + ")" }, testInsertData);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-removeChild.html b/testing/web-platform/tests/dom/ranges/Range-mutations-removeChild.html
new file mode 100644
index 0000000000..a8d2381253
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-removeChild.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - removeChild</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(removeChildTests, function(params) { return params[0] + ".parentNode.removeChild(" + params[0] + ")" }, testRemoveChild);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-replaceChild.html b/testing/web-platform/tests/dom/ranges/Range-mutations-replaceChild.html
new file mode 100644
index 0000000000..a4ef0c365e
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-replaceChild.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - replaceChild</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(replaceChildTests, function(params) { return params[0] + ".replaceChild(" + params[1] + ", " + params[2] + ")" }, testReplaceChild);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-replaceData.html b/testing/web-platform/tests/dom/ranges/Range-mutations-replaceData.html
new file mode 100644
index 0000000000..55ddb146ea
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-replaceData.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - replaceData</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(replaceDataTests, function(params) { return params[0] + ".replaceData(" + params[1] + ", " + params[2] + ", " + params[3] + ")" }, testReplaceData);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations-splitText.html b/testing/web-platform/tests/dom/ranges/Range-mutations-splitText.html
new file mode 100644
index 0000000000..fbb4c8d9b6
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations-splitText.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<title>Range mutation tests - splitText</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../common.js"></script>
+<script src="Range-mutations.js"></script>
+<script>
+doTests(splitTextTests, function(params) { return params[0] + ".splitText(" + params[1] + ")" }, testSplitText);
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-mutations.js b/testing/web-platform/tests/dom/ranges/Range-mutations.js
new file mode 100644
index 0000000000..23c013ac6a
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-mutations.js
@@ -0,0 +1,921 @@
+"use strict";
+
+// These tests probably use too much abstraction and too little copy-paste.
+// Reader beware.
+//
+// TODO:
+//
+// * Lots and lots and lots more different types of ranges
+// * insertBefore() with DocumentFragments
+// * Fill out other insert/remove tests
+// * normalize() (https://www.w3.org/Bugs/Public/show_bug.cgi?id=13843)
+
+// Give a textual description of the range we're testing, for the test names.
+function describeRange(startContainer, startOffset, endContainer, endOffset) {
+  if (startContainer == endContainer && startOffset == endOffset) {
+    return "range collapsed at (" + startContainer + ", " + startOffset + ")";
+  } else if (startContainer == endContainer) {
+    return "range on " + startContainer + " from " + startOffset + " to " + endOffset;
+  } else {
+    return "range from (" + startContainer + ", " + startOffset + ") to (" + endContainer + ", " + endOffset + ")";
+  }
+}
+
+// Lists of the various types of nodes we'll want to use.  We use strings that
+// we can later eval(), so that we can produce legible test names.
+var textNodes = [
+  "paras[0].firstChild",
+  "paras[1].firstChild",
+  "foreignTextNode",
+  "xmlTextNode",
+  "detachedTextNode",
+  "detachedForeignTextNode",
+  "detachedXmlTextNode",
+];
+var commentNodes = [
+  "comment",
+  "foreignComment",
+  "xmlComment",
+  "detachedComment",
+  "detachedForeignComment",
+  "detachedXmlComment",
+];
+var characterDataNodes = textNodes.concat(commentNodes);
+
+// This function is slightly scary, but it works well enough, so . . .
+// sourceTests is an array of test data that will be altered in mysterious ways
+// before being passed off to doTest, descFn is something that takes an element
+// of sourceTests and produces the first part of a human-readable description
+// of the test, testFn is the function that doTest will call to do the actual
+// work and tell it what results to expect.
+function doTests(sourceTests, descFn, testFn) {
+  var tests = [];
+  for (var i = 0; i < sourceTests.length; i++) {
+    var params = sourceTests[i];
+    var len = params.length;
+    tests.push([
+      descFn(params) + ", with unselected " + describeRange(params[len - 4], params[len - 3], params[len - 2], params[len - 1]),
+      // The closure here ensures that the params that testFn get are the
+      // current version of params, not the version from the last
+      // iteration of this loop.  We test that none of the parameters
+      // evaluate to undefined to catch bugs in our eval'ing, like
+      // mistyping a property name.
+      function(params) { return function() {
+        var evaledParams = params.map(eval);
+        for (var i = 0; i < evaledParams.length; i++) {
+          assert_not_equals(typeof evaledParams[i], "undefined",
+            "Test bug: " + params[i] + " is undefined");
+        }
+        return testFn.apply(null, evaledParams);
+      } }(params),
+      false,
+      params[len - 4],
+      params[len - 3],
+      params[len - 2],
+      params[len - 1]
+    ]);
+    tests.push([
+      descFn(params) + ", with selected " + describeRange(params[len - 4], params[len - 3], params[len - 2], params[len - 1]),
+      function(params) { return function(selectedRange) {
+        var evaledParams = params.slice(0, len - 4).map(eval);
+        for (var i = 0; i < evaledParams.length; i++) {
+          assert_not_equals(typeof evaledParams[i], "undefined",
+            "Test bug: " + params[i] + " is undefined");
+        }
+        // Override input range with the one that was actually selected when computing the expected result.
+        evaledParams = evaledParams.concat([selectedRange.startContainer, selectedRange.startOffset, selectedRange.endContainer, selectedRange.endOffset]);
+        return testFn.apply(null, evaledParams);
+      } }(params),
+      true,
+      params[len - 4],
+      params[len - 3],
+      params[len - 2],
+      params[len - 1]
+    ]);
+  }
+  generate_tests(doTest, tests);
+}
+
+// Set up the range, call the callback function to do the DOM modification and
+// tell us what to expect.  The callback function needs to return a
+// four-element array with the expected start/end containers/offsets, and
+// receives no arguments.  useSelection tells us whether the Range should be
+// added to a Selection and the Selection tested to ensure that the mutation
+// affects user selections as well as other ranges; every test is run with this
+// both false and true, because when it's set to true WebKit and Opera fail all
+// tests' sanity checks, which is unhelpful.  The last four parameters just
+// tell us what range to build.
+function doTest(callback, useSelection, startContainer, startOffset, endContainer, endOffset) {
+  // Recreate all the test nodes in case they were altered by the last test
+  // run.
+  setupRangeTests();
+  startContainer = eval(startContainer);
+  startOffset = eval(startOffset);
+  endContainer = eval(endContainer);
+  endOffset = eval(endOffset);
+
+  var ownerDoc = startContainer.nodeType == Node.DOCUMENT_NODE
+    ? startContainer
+    : startContainer.ownerDocument;
+  var range = ownerDoc.createRange();
+  range.setStart(startContainer, startOffset);
+  range.setEnd(endContainer, endOffset);
+
+  if (useSelection) {
+    getSelection().removeAllRanges();
+    getSelection().addRange(range);
+
+    // Some browsers refuse to add a range unless it results in an actual visible selection.
+    if (!getSelection().rangeCount)
+        return;
+
+    // Override range with the one that was actually selected as it differs in some browsers.
+    range = getSelection().getRangeAt(0);
+  }
+
+  var expected = callback(range);
+
+  assert_equals(range.startContainer, expected[0],
+    "Wrong start container");
+  assert_equals(range.startOffset, expected[1],
+    "Wrong start offset");
+  assert_equals(range.endContainer, expected[2],
+    "Wrong end container");
+  assert_equals(range.endOffset, expected[3],
+    "Wrong end offset");
+}
+
+
+// Now we get to the specific tests.
+
+function testSplitText(oldNode, offset, startContainer, startOffset, endContainer, endOffset) {
+  // Save these for later
+  var originalStartOffset = startOffset;
+  var originalEndOffset = endOffset;
+  var originalLength = oldNode.length;
+
+  var newNode;
+  try {
+    newNode = oldNode.splitText(offset);
+  } catch (e) {
+    // Should only happen if offset is negative
+    return [startContainer, startOffset, endContainer, endOffset];
+  }
+
+  // First we adjust for replacing data:
+  //
+  // "Replace data with offset offset, count count, and data the empty
+  // string."
+  //
+  // That translates to offset = offset, count = originalLength - offset,
+  // data = "".  node is oldNode.
+  //
+  // "For every boundary point whose node is node, and whose offset is
+  // greater than offset but less than or equal to offset plus count, set its
+  // offset to offset."
+  if (startContainer == oldNode
+  && startOffset > offset
+  && startOffset <= originalLength) {
+    startOffset = offset;
+  }
+
+  if (endContainer == oldNode
+  && endOffset > offset
+  && endOffset <= originalLength) {
+    endOffset = offset;
+  }
+
+  // "For every boundary point whose node is node, and whose offset is
+  // greater than offset plus count, add the length of data to its offset,
+  // then subtract count from it."
+  //
+  // Can't happen: offset plus count is originalLength.
+
+  // Now we insert a node, if oldNode's parent isn't null: "For each boundary
+  // point whose node is the new parent of the affected node and whose offset
+  // is greater than the new index of the affected node, add one to the
+  // boundary point's offset."
+  if (startContainer == oldNode.parentNode
+  && startOffset > 1 + indexOf(oldNode)) {
+    startOffset++;
+  }
+
+  if (endContainer == oldNode.parentNode
+  && endOffset > 1 + indexOf(oldNode)) {
+    endOffset++;
+  }
+
+  // Finally, the splitText stuff itself:
+  //
+  // "If parent is not null, run these substeps:
+  //
+  //   * "For each range whose start node is node and start offset is greater
+  //   than offset, set its start node to new node and decrease its start
+  //   offset by offset.
+  //
+  //   * "For each range whose end node is node and end offset is greater
+  //   than offset, set its end node to new node and decrease its end offset
+  //   by offset.
+  //
+  //   * "For each range whose start node is parent and start offset is equal
+  //   to the index of node + 1, increase its start offset by one.
+  //
+  //   * "For each range whose end node is parent and end offset is equal to
+  //   the index of node + 1, increase its end offset by one."
+  if (oldNode.parentNode) {
+    if (startContainer == oldNode && originalStartOffset > offset) {
+      startContainer = newNode;
+      startOffset = originalStartOffset - offset;
+    }
+
+    if (endContainer == oldNode && originalEndOffset > offset) {
+      endContainer = newNode;
+      endOffset = originalEndOffset - offset;
+    }
+
+    if (startContainer == oldNode.parentNode
+    && startOffset == 1 + indexOf(oldNode)) {
+      startOffset++;
+    }
+
+    if (endContainer == oldNode.parentNode
+    && endOffset == 1 + indexOf(oldNode)) {
+      endOffset++;
+    }
+  }
+
+  return [startContainer, startOffset, endContainer, endOffset];
+}
+
+// The offset argument is unsigned, so per WebIDL -1 should wrap to 4294967295,
+// which is probably longer than the length, so it should throw an exception.
+// This is no different from the other cases where the offset is longer than
+// the length, and the wrapping complicates my testing slightly, so I won't
+// bother testing negative values here or in other cases.
+var splitTextTests = [];
+for (var i = 0; i < textNodes.length; i++) {
+  var node = textNodes[i];
+  splitTextTests.push([node, 376, node, 0, node, 1]);
+  splitTextTests.push([node, 0, node, 0, node, 0]);
+  splitTextTests.push([node, 1, node, 1, node, 1]);
+  splitTextTests.push([node, node + ".length", node, node + ".length", node, node + ".length"]);
+  splitTextTests.push([node, 1, node, 1, node, 3]);
+  splitTextTests.push([node, 2, node, 1, node, 3]);
+  splitTextTests.push([node, 3, node, 1, node, 3]);
+}
+
+splitTextTests.push(
+  ["paras[0].firstChild", 1, "paras[0]", 0, "paras[0]", 0],
+  ["paras[0].firstChild", 1, "paras[0]", 0, "paras[0]", 1],
+  ["paras[0].firstChild", 1, "paras[0]", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 2, "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 3, "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 2, "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 3, "paras[0]", 0, "paras[0].firstChild", 3]
+);
+
+
+function testReplaceDataAlgorithm(node, offset, count, data, callback, startContainer, startOffset, endContainer, endOffset) {
+  // Mutation works the same any time DOM Core's "replace data" algorithm is
+  // invoked.  node, offset, count, data are as in that algorithm.  The
+  // callback is what does the actual setting.  Not to be confused with
+  // testReplaceData, which tests the replaceData() method.
+
+  // Barring any provision to the contrary, the containers and offsets must
+  // not change.
+  var expectedStartContainer = startContainer;
+  var expectedStartOffset = startOffset;
+  var expectedEndContainer = endContainer;
+  var expectedEndOffset = endOffset;
+
+  var originalParent = node.parentNode;
+  var originalData = node.data;
+
+  var exceptionThrown = false;
+  try {
+    callback();
+  } catch (e) {
+    // Should only happen if offset is greater than length
+    exceptionThrown = true;
+  }
+
+  assert_equals(node.parentNode, originalParent,
+    "Sanity check failed: changing data changed the parent");
+
+  // "User agents must run the following steps whenever they replace data of
+  // a CharacterData node, as though they were written in the specification
+  // for that algorithm after all other steps. In particular, the steps must
+  // not be executed if the algorithm threw an exception."
+  if (exceptionThrown) {
+    assert_equals(node.data, originalData,
+      "Sanity check failed: exception thrown but data changed");
+  } else {
+    assert_equals(node.data,
+      originalData.substr(0, offset) + data + originalData.substr(offset + count),
+      "Sanity check failed: data not changed as expected");
+  }
+
+  // "For every boundary point whose node is node, and whose offset is
+  // greater than offset but less than or equal to offset plus count, set
+  // its offset to offset."
+  if (!exceptionThrown
+  && startContainer == node
+  && startOffset > offset
+  && startOffset <= offset + count) {
+    expectedStartOffset = offset;
+  }
+
+  if (!exceptionThrown
+  && endContainer == node
+  && endOffset > offset
+  && endOffset <= offset + count) {
+    expectedEndOffset = offset;
+  }
+
+  // "For every boundary point whose node is node, and whose offset is
+  // greater than offset plus count, add the length of data to its offset,
+  // then subtract count from it."
+  if (!exceptionThrown
+  && startContainer == node
+  && startOffset > offset + count) {
+    expectedStartOffset += data.length - count;
+  }
+
+  if (!exceptionThrown
+  && endContainer == node
+  && endOffset > offset + count) {
+    expectedEndOffset += data.length - count;
+  }
+
+  return [expectedStartContainer, expectedStartOffset, expectedEndContainer, expectedEndOffset];
+}
+
+function testInsertData(node, offset, data, startContainer, startOffset, endContainer, endOffset) {
+  return testReplaceDataAlgorithm(node, offset, 0, data,
+    function() { node.insertData(offset, data) },
+    startContainer, startOffset, endContainer, endOffset);
+}
+
+var insertDataTests = [];
+for (var i = 0; i < characterDataNodes.length; i++) {
+  var node = characterDataNodes[i];
+  insertDataTests.push([node, 376, '"foo"', node, 0, node, 1]);
+  insertDataTests.push([node, 0, '"foo"', node, 0, node, 0]);
+  insertDataTests.push([node, 1, '"foo"', node, 1, node, 1]);
+  insertDataTests.push([node, node + ".length", '"foo"', node, node + ".length", node, node + ".length"]);
+  insertDataTests.push([node, 1, '"foo"', node, 1, node, 3]);
+  insertDataTests.push([node, 2, '"foo"', node, 1, node, 3]);
+  insertDataTests.push([node, 3, '"foo"', node, 1, node, 3]);
+
+  insertDataTests.push([node, 376, '""', node, 0, node, 1]);
+  insertDataTests.push([node, 0, '""', node, 0, node, 0]);
+  insertDataTests.push([node, 1, '""', node, 1, node, 1]);
+  insertDataTests.push([node, node + ".length", '""', node, node + ".length", node, node + ".length"]);
+  insertDataTests.push([node, 1, '""', node, 1, node, 3]);
+  insertDataTests.push([node, 2, '""', node, 1, node, 3]);
+  insertDataTests.push([node, 3, '""', node, 1, node, 3]);
+}
+
+insertDataTests.push(
+  ["paras[0].firstChild", 1, '"foo"', "paras[0]", 0, "paras[0]", 0],
+  ["paras[0].firstChild", 1, '"foo"', "paras[0]", 0, "paras[0]", 1],
+  ["paras[0].firstChild", 1, '"foo"', "paras[0]", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 2, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 3, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 2, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 3, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3]
+);
+
+
+function testAppendData(node, data, startContainer, startOffset, endContainer, endOffset) {
+  return testReplaceDataAlgorithm(node, node.length, 0, data,
+    function() { node.appendData(data) },
+    startContainer, startOffset, endContainer, endOffset);
+}
+
+var appendDataTests = [];
+for (var i = 0; i < characterDataNodes.length; i++) {
+  var node = characterDataNodes[i];
+  appendDataTests.push([node, '"foo"', node, 0, node, 1]);
+  appendDataTests.push([node, '"foo"', node, 0, node, 0]);
+  appendDataTests.push([node, '"foo"', node, 1, node, 1]);
+  appendDataTests.push([node, '"foo"', node, 0, node, node + ".length"]);
+  appendDataTests.push([node, '"foo"', node, 1, node, node + ".length"]);
+  appendDataTests.push([node, '"foo"', node, node + ".length", node, node + ".length"]);
+  appendDataTests.push([node, '"foo"', node, 1, node, 3]);
+
+  appendDataTests.push([node, '""', node, 0, node, 1]);
+  appendDataTests.push([node, '""', node, 0, node, 0]);
+  appendDataTests.push([node, '""', node, 1, node, 1]);
+  appendDataTests.push([node, '""', node, 0, node, node + ".length"]);
+  appendDataTests.push([node, '""', node, 1, node, node + ".length"]);
+  appendDataTests.push([node, '""', node, node + ".length", node, node + ".length"]);
+  appendDataTests.push([node, '""', node, 1, node, 3]);
+}
+
+appendDataTests.push(
+  ["paras[0].firstChild", '""', "paras[0]", 0, "paras[0]", 0],
+  ["paras[0].firstChild", '""', "paras[0]", 0, "paras[0]", 1],
+  ["paras[0].firstChild", '""', "paras[0]", 1, "paras[0]", 1],
+  ["paras[0].firstChild", '""', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", '""', "paras[0]", 0, "paras[0].firstChild", 3],
+
+  ["paras[0].firstChild", '"foo"', "paras[0]", 0, "paras[0]", 0],
+  ["paras[0].firstChild", '"foo"', "paras[0]", 0, "paras[0]", 1],
+  ["paras[0].firstChild", '"foo"', "paras[0]", 1, "paras[0]", 1],
+  ["paras[0].firstChild", '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", '"foo"', "paras[0]", 0, "paras[0].firstChild", 3]
+);
+
+
+function testDeleteData(node, offset, count, startContainer, startOffset, endContainer, endOffset) {
+  return testReplaceDataAlgorithm(node, offset, count, "",
+    function() { node.deleteData(offset, count) },
+    startContainer, startOffset, endContainer, endOffset);
+}
+
+var deleteDataTests = [];
+for (var i = 0; i < characterDataNodes.length; i++) {
+  var node = characterDataNodes[i];
+  deleteDataTests.push([node, 376, 2, node, 0, node, 1]);
+  deleteDataTests.push([node, 0, 2, node, 0, node, 0]);
+  deleteDataTests.push([node, 1, 2, node, 1, node, 1]);
+  deleteDataTests.push([node, node + ".length", 2, node, node + ".length", node, node + ".length"]);
+  deleteDataTests.push([node, 1, 2, node, 1, node, 3]);
+  deleteDataTests.push([node, 2, 2, node, 1, node, 3]);
+  deleteDataTests.push([node, 3, 2, node, 1, node, 3]);
+
+  deleteDataTests.push([node, 376, 0, node, 0, node, 1]);
+  deleteDataTests.push([node, 0, 0, node, 0, node, 0]);
+  deleteDataTests.push([node, 1, 0, node, 1, node, 1]);
+  deleteDataTests.push([node, node + ".length", 0, node, node + ".length", node, node + ".length"]);
+  deleteDataTests.push([node, 1, 0, node, 1, node, 3]);
+  deleteDataTests.push([node, 2, 0, node, 1, node, 3]);
+  deleteDataTests.push([node, 3, 0, node, 1, node, 3]);
+
+  deleteDataTests.push([node, 376, 631, node, 0, node, 1]);
+  deleteDataTests.push([node, 0, 631, node, 0, node, 0]);
+  deleteDataTests.push([node, 1, 631, node, 1, node, 1]);
+  deleteDataTests.push([node, node + ".length", 631, node, node + ".length", node, node + ".length"]);
+  deleteDataTests.push([node, 1, 631, node, 1, node, 3]);
+  deleteDataTests.push([node, 2, 631, node, 1, node, 3]);
+  deleteDataTests.push([node, 3, 631, node, 1, node, 3]);
+}
+
+deleteDataTests.push(
+  ["paras[0].firstChild", 1, 2, "paras[0]", 0, "paras[0]", 0],
+  ["paras[0].firstChild", 1, 2, "paras[0]", 0, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 2, "paras[0]", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 2, "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 2, 2, "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 3, 2, "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 2, "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 2, 2, "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 3, 2, "paras[0]", 0, "paras[0].firstChild", 3]
+);
+
+
+function testReplaceData(node, offset, count, data, startContainer, startOffset, endContainer, endOffset) {
+  return testReplaceDataAlgorithm(node, offset, count, data,
+    function() { node.replaceData(offset, count, data) },
+    startContainer, startOffset, endContainer, endOffset);
+}
+
+var replaceDataTests = [];
+for (var i = 0; i < characterDataNodes.length; i++) {
+  var node = characterDataNodes[i];
+  replaceDataTests.push([node, 376, 0, '"foo"', node, 0, node, 1]);
+  replaceDataTests.push([node, 0, 0, '"foo"', node, 0, node, 0]);
+  replaceDataTests.push([node, 1, 0, '"foo"', node, 1, node, 1]);
+  replaceDataTests.push([node, node + ".length", 0, '"foo"', node, node + ".length", node, node + ".length"]);
+  replaceDataTests.push([node, 1, 0, '"foo"', node, 1, node, 3]);
+  replaceDataTests.push([node, 2, 0, '"foo"', node, 1, node, 3]);
+  replaceDataTests.push([node, 3, 0, '"foo"', node, 1, node, 3]);
+
+  replaceDataTests.push([node, 376, 0, '""', node, 0, node, 1]);
+  replaceDataTests.push([node, 0, 0, '""', node, 0, node, 0]);
+  replaceDataTests.push([node, 1, 0, '""', node, 1, node, 1]);
+  replaceDataTests.push([node, node + ".length", 0, '""', node, node + ".length", node, node + ".length"]);
+  replaceDataTests.push([node, 1, 0, '""', node, 1, node, 3]);
+  replaceDataTests.push([node, 2, 0, '""', node, 1, node, 3]);
+  replaceDataTests.push([node, 3, 0, '""', node, 1, node, 3]);
+
+  replaceDataTests.push([node, 376, 1, '"foo"', node, 0, node, 1]);
+  replaceDataTests.push([node, 0, 1, '"foo"', node, 0, node, 0]);
+  replaceDataTests.push([node, 1, 1, '"foo"', node, 1, node, 1]);
+  replaceDataTests.push([node, node + ".length", 1, '"foo"', node, node + ".length", node, node + ".length"]);
+  replaceDataTests.push([node, 1, 1, '"foo"', node, 1, node, 3]);
+  replaceDataTests.push([node, 2, 1, '"foo"', node, 1, node, 3]);
+  replaceDataTests.push([node, 3, 1, '"foo"', node, 1, node, 3]);
+
+  replaceDataTests.push([node, 376, 1, '""', node, 0, node, 1]);
+  replaceDataTests.push([node, 0, 1, '""', node, 0, node, 0]);
+  replaceDataTests.push([node, 1, 1, '""', node, 1, node, 1]);
+  replaceDataTests.push([node, node + ".length", 1, '""', node, node + ".length", node, node + ".length"]);
+  replaceDataTests.push([node, 1, 1, '""', node, 1, node, 3]);
+  replaceDataTests.push([node, 2, 1, '""', node, 1, node, 3]);
+  replaceDataTests.push([node, 3, 1, '""', node, 1, node, 3]);
+
+  replaceDataTests.push([node, 376, 47, '"foo"', node, 0, node, 1]);
+  replaceDataTests.push([node, 0, 47, '"foo"', node, 0, node, 0]);
+  replaceDataTests.push([node, 1, 47, '"foo"', node, 1, node, 1]);
+  replaceDataTests.push([node, node + ".length", 47, '"foo"', node, node + ".length", node, node + ".length"]);
+  replaceDataTests.push([node, 1, 47, '"foo"', node, 1, node, 3]);
+  replaceDataTests.push([node, 2, 47, '"foo"', node, 1, node, 3]);
+  replaceDataTests.push([node, 3, 47, '"foo"', node, 1, node, 3]);
+
+  replaceDataTests.push([node, 376, 47, '""', node, 0, node, 1]);
+  replaceDataTests.push([node, 0, 47, '""', node, 0, node, 0]);
+  replaceDataTests.push([node, 1, 47, '""', node, 1, node, 1]);
+  replaceDataTests.push([node, node + ".length", 47, '""', node, node + ".length", node, node + ".length"]);
+  replaceDataTests.push([node, 1, 47, '""', node, 1, node, 3]);
+  replaceDataTests.push([node, 2, 47, '""', node, 1, node, 3]);
+  replaceDataTests.push([node, 3, 47, '""', node, 1, node, 3]);
+}
+
+replaceDataTests.push(
+  ["paras[0].firstChild", 1, 0, '"foo"', "paras[0]", 0, "paras[0]", 0],
+  ["paras[0].firstChild", 1, 0, '"foo"', "paras[0]", 0, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 0, '"foo"', "paras[0]", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 0, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 2, 0, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 3, 0, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 0, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 2, 0, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 3, 0, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+
+  ["paras[0].firstChild", 1, 1, '"foo"', "paras[0]", 0, "paras[0]", 0],
+  ["paras[0].firstChild", 1, 1, '"foo"', "paras[0]", 0, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 1, '"foo"', "paras[0]", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 1, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 2, 1, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 3, 1, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 1, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 2, 1, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 3, 1, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+
+  ["paras[0].firstChild", 1, 47, '"foo"', "paras[0]", 0, "paras[0]", 0],
+  ["paras[0].firstChild", 1, 47, '"foo"', "paras[0]", 0, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 47, '"foo"', "paras[0]", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 47, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 2, 47, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 3, 47, '"foo"', "paras[0].firstChild", 1, "paras[0]", 1],
+  ["paras[0].firstChild", 1, 47, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 2, 47, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3],
+  ["paras[0].firstChild", 3, 47, '"foo"', "paras[0]", 0, "paras[0].firstChild", 3]
+);
+
+
+// There are lots of ways to set data, so we pass a callback that does the
+// actual setting.
+function testDataChange(node, attr, op, rval, startContainer, startOffset, endContainer, endOffset) {
+  return testReplaceDataAlgorithm(node, 0, node.length, op == "=" ? rval : node[attr] + rval,
+    function() {
+      if (op == "=") {
+        node[attr] = rval;
+      } else if (op == "+=") {
+        node[attr] += rval;
+      } else {
+        throw "Unknown op " + op;
+      }
+    },
+    startContainer, startOffset, endContainer, endOffset);
+}
+
+var dataChangeTests = [];
+var dataChangeTestAttrs = ["data", "textContent", "nodeValue"];
+for (var i = 0; i < characterDataNodes.length; i++) {
+  var node = characterDataNodes[i];
+  var dataChangeTestRanges = [
+    [node, 0, node, 0],
+    [node, 0, node, 1],
+    [node, 1, node, 1],
+    [node, 0, node, node + ".length"],
+    [node, 1, node, node + ".length"],
+    [node, node + ".length", node, node + ".length"],
+  ];
+
+  for (var j = 0; j < dataChangeTestRanges.length; j++) {
+    for (var k = 0; k < dataChangeTestAttrs.length; k++) {
+      dataChangeTests.push([
+        node,
+        '"' + dataChangeTestAttrs[k] + '"',
+        '"="',
+        '""',
+      ].concat(dataChangeTestRanges[j]));
+
+      dataChangeTests.push([
+        node,
+        '"' + dataChangeTestAttrs[k] + '"',
+        '"="',
+        '"foo"',
+      ].concat(dataChangeTestRanges[j]));
+
+      dataChangeTests.push([
+        node,
+        '"' + dataChangeTestAttrs[k] + '"',
+        '"="',
+        node + "." + dataChangeTestAttrs[k],
+      ].concat(dataChangeTestRanges[j]));
+
+      dataChangeTests.push([
+        node,
+        '"' + dataChangeTestAttrs[k] + '"',
+        '"+="',
+        '""',
+      ].concat(dataChangeTestRanges[j]));
+
+      dataChangeTests.push([
+        node,
+        '"' + dataChangeTestAttrs[k] + '"',
+        '"+="',
+        '"foo"',
+      ].concat(dataChangeTestRanges[j]));
+
+      dataChangeTests.push([
+        node,
+        '"' + dataChangeTestAttrs[k] + '"',
+        '"+="',
+        node + "." + dataChangeTestAttrs[k]
+      ].concat(dataChangeTestRanges[j]));
+    }
+  }
+}
+
+
+// Now we test node insertions and deletions, as opposed to just data changes.
+// To avoid loads of repetition, we define modifyForRemove() and
+// modifyForInsert().
+
+// If we were to remove removedNode from its parent, what would the boundary
+// point [node, offset] become?  Returns [new node, new offset].  Must be
+// called BEFORE the node is actually removed, so its parent is not null.  (If
+// the parent is null, it will do nothing.)
+function modifyForRemove(removedNode, point) {
+  var oldParent = removedNode.parentNode;
+  var oldIndex = indexOf(removedNode);
+  if (!oldParent) {
+    return point;
+  }
+
+  // "For each boundary point whose node is removed node or a descendant of
+  // it, set the boundary point to (old parent, old index)."
+  if (point[0] == removedNode || isDescendant(point[0], removedNode)) {
+    return [oldParent, oldIndex];
+  }
+
+  // "For each boundary point whose node is old parent and whose offset is
+  // greater than old index, subtract one from its offset."
+  if (point[0] == oldParent && point[1] > oldIndex) {
+    return [point[0], point[1] - 1];
+  }
+
+  return point;
+}
+
+// Update the given boundary point [node, offset] to account for the fact that
+// insertedNode was just inserted into its current position.  This must be
+// called AFTER insertedNode was already inserted.
+function modifyForInsert(insertedNode, point) {
+  // "For each boundary point whose node is the new parent of the affected
+  // node and whose offset is greater than the new index of the affected
+  // node, add one to the boundary point's offset."
+  if (point[0] == insertedNode.parentNode && point[1] > indexOf(insertedNode)) {
+    return [point[0], point[1] + 1];
+  }
+
+  return point;
+}
+
+
+function testInsertBefore(newParent, affectedNode, refNode, startContainer, startOffset, endContainer, endOffset) {
+  var expectedStart = [startContainer, startOffset];
+  var expectedEnd = [endContainer, endOffset];
+
+  expectedStart = modifyForRemove(affectedNode, expectedStart);
+  expectedEnd = modifyForRemove(affectedNode, expectedEnd);
+
+  try {
+    newParent.insertBefore(affectedNode, refNode);
+  } catch (e) {
+    // For our purposes, assume that DOM Core is true -- i.e., ignore
+    // mutation events and similar.
+    return [startContainer, startOffset, endContainer, endOffset];
+  }
+
+  expectedStart = modifyForInsert(affectedNode, expectedStart);
+  expectedEnd = modifyForInsert(affectedNode, expectedEnd);
+
+  return expectedStart.concat(expectedEnd);
+}
+
+var insertBeforeTests = [
+  // Moving a node to its current position
+  ["testDiv", "paras[0]", "paras[1]", "paras[0]", 0, "paras[0]", 0],
+  ["testDiv", "paras[0]", "paras[1]", "paras[0]", 0, "paras[0]", 1],
+  ["testDiv", "paras[0]", "paras[1]", "paras[0]", 1, "paras[0]", 1],
+  ["testDiv", "paras[0]", "paras[1]", "testDiv", 0, "testDiv", 2],
+  ["testDiv", "paras[0]", "paras[1]", "testDiv", 1, "testDiv", 1],
+  ["testDiv", "paras[0]", "paras[1]", "testDiv", 1, "testDiv", 2],
+  ["testDiv", "paras[0]", "paras[1]", "testDiv", 2, "testDiv", 2],
+
+  // Stuff that actually moves something.  Note that paras[0] and paras[1]
+  // are both children of testDiv.
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 0],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "paras[0]", 1, "paras[0]", 1],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "testDiv", 0, "testDiv", 1],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "testDiv", 0, "testDiv", 2],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "testDiv", 1, "testDiv", 1],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "testDiv", 1, "testDiv", 2],
+  ["paras[0]", "paras[1]", "null", "paras[0]", 0, "paras[0]", 0],
+  ["paras[0]", "paras[1]", "null", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "paras[1]", "null", "paras[0]", 1, "paras[0]", 1],
+  ["paras[0]", "paras[1]", "null", "testDiv", 0, "testDiv", 1],
+  ["paras[0]", "paras[1]", "null", "testDiv", 0, "testDiv", 2],
+  ["paras[0]", "paras[1]", "null", "testDiv", 1, "testDiv", 1],
+  ["paras[0]", "paras[1]", "null", "testDiv", 1, "testDiv", 2],
+  ["foreignDoc", "detachedComment", "foreignDoc.documentElement", "foreignDoc", 0, "foreignDoc", 0],
+  ["foreignDoc", "detachedComment", "foreignDoc.documentElement", "foreignDoc", 0, "foreignDoc", 1],
+  ["foreignDoc", "detachedComment", "foreignDoc.documentElement", "foreignDoc", 0, "foreignDoc", 2],
+  ["foreignDoc", "detachedComment", "foreignDoc.documentElement", "foreignDoc", 1, "foreignDoc", 1],
+  ["foreignDoc", "detachedComment", "foreignDoc.doctype", "foreignDoc", 0, "foreignDoc", 0],
+  ["foreignDoc", "detachedComment", "foreignDoc.doctype", "foreignDoc", 0, "foreignDoc", 1],
+  ["foreignDoc", "detachedComment", "foreignDoc.doctype", "foreignDoc", 0, "foreignDoc", 2],
+  ["foreignDoc", "detachedComment", "foreignDoc.doctype", "foreignDoc", 1, "foreignDoc", 1],
+  ["foreignDoc", "detachedComment", "null", "foreignDoc", 0, "foreignDoc", 1],
+  ["paras[0]", "xmlTextNode", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 0],
+  ["paras[0]", "xmlTextNode", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "xmlTextNode", "paras[0].firstChild", "paras[0]", 1, "paras[0]", 1],
+
+  // Stuff that throws exceptions
+  ["paras[0]", "paras[0]", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "testDiv", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "document", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "foreignDoc", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "document.doctype", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+];
+
+
+function testReplaceChild(newParent, newChild, oldChild, startContainer, startOffset, endContainer, endOffset) {
+  var expectedStart = [startContainer, startOffset];
+  var expectedEnd = [endContainer, endOffset];
+
+  expectedStart = modifyForRemove(oldChild, expectedStart);
+  expectedEnd = modifyForRemove(oldChild, expectedEnd);
+
+  if (newChild != oldChild) {
+    // Don't do this twice, if they're the same!
+    expectedStart = modifyForRemove(newChild, expectedStart);
+    expectedEnd = modifyForRemove(newChild, expectedEnd);
+  }
+
+  try {
+    newParent.replaceChild(newChild, oldChild);
+  } catch (e) {
+    return [startContainer, startOffset, endContainer, endOffset];
+  }
+
+  expectedStart = modifyForInsert(newChild, expectedStart);
+  expectedEnd = modifyForInsert(newChild, expectedEnd);
+
+  return expectedStart.concat(expectedEnd);
+}
+
+var replaceChildTests = [
+  // Moving a node to its current position.  Doesn't match most browsers'
+  // behavior, but we probably want to keep the spec the same anyway:
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=647603
+  ["testDiv", "paras[0]", "paras[0]", "paras[0]", 0, "paras[0]", 0],
+  ["testDiv", "paras[0]", "paras[0]", "paras[0]", 0, "paras[0]", 1],
+  ["testDiv", "paras[0]", "paras[0]", "paras[0]", 1, "paras[0]", 1],
+  ["testDiv", "paras[0]", "paras[0]", "testDiv", 0, "testDiv", 2],
+  ["testDiv", "paras[0]", "paras[0]", "testDiv", 1, "testDiv", 1],
+  ["testDiv", "paras[0]", "paras[0]", "testDiv", 1, "testDiv", 2],
+  ["testDiv", "paras[0]", "paras[0]", "testDiv", 2, "testDiv", 2],
+
+  // Stuff that actually moves something.
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 0],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "paras[0]", 1, "paras[0]", 1],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "testDiv", 0, "testDiv", 1],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "testDiv", 0, "testDiv", 2],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "testDiv", 1, "testDiv", 1],
+  ["paras[0]", "paras[1]", "paras[0].firstChild", "testDiv", 1, "testDiv", 2],
+  ["foreignDoc", "detachedComment", "foreignDoc.documentElement", "foreignDoc", 0, "foreignDoc", 0],
+  ["foreignDoc", "detachedComment", "foreignDoc.documentElement", "foreignDoc", 0, "foreignDoc", 1],
+  ["foreignDoc", "detachedComment", "foreignDoc.documentElement", "foreignDoc", 0, "foreignDoc", 2],
+  ["foreignDoc", "detachedComment", "foreignDoc.documentElement", "foreignDoc", 1, "foreignDoc", 1],
+  ["foreignDoc", "detachedComment", "foreignDoc.doctype", "foreignDoc", 0, "foreignDoc", 0],
+  ["foreignDoc", "detachedComment", "foreignDoc.doctype", "foreignDoc", 0, "foreignDoc", 1],
+  ["foreignDoc", "detachedComment", "foreignDoc.doctype", "foreignDoc", 0, "foreignDoc", 2],
+  ["foreignDoc", "detachedComment", "foreignDoc.doctype", "foreignDoc", 1, "foreignDoc", 1],
+  ["paras[0]", "xmlTextNode", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 0],
+  ["paras[0]", "xmlTextNode", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "xmlTextNode", "paras[0].firstChild", "paras[0]", 1, "paras[0]", 1],
+
+  // Stuff that throws exceptions
+  ["paras[0]", "paras[0]", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "testDiv", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "document", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "foreignDoc", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "document.doctype", "paras[0].firstChild", "paras[0]", 0, "paras[0]", 1],
+];
+
+
+function testAppendChild(newParent, affectedNode, startContainer, startOffset, endContainer, endOffset) {
+  var expectedStart = [startContainer, startOffset];
+  var expectedEnd = [endContainer, endOffset];
+
+  expectedStart = modifyForRemove(affectedNode, expectedStart);
+  expectedEnd = modifyForRemove(affectedNode, expectedEnd);
+
+  try {
+    newParent.appendChild(affectedNode);
+  } catch (e) {
+    return [startContainer, startOffset, endContainer, endOffset];
+  }
+
+  // These two lines will actually never do anything, if you think about it,
+  // but let's leave them in so correctness is more obvious.
+  expectedStart = modifyForInsert(affectedNode, expectedStart);
+  expectedEnd = modifyForInsert(affectedNode, expectedEnd);
+
+  return expectedStart.concat(expectedEnd);
+}
+
+var appendChildTests = [
+  // Moving a node to its current position
+  ["testDiv", "testDiv.lastChild", "testDiv.lastChild", 0, "testDiv.lastChild", 0],
+  ["testDiv", "testDiv.lastChild", "testDiv.lastChild", 0, "testDiv.lastChild", 1],
+  ["testDiv", "testDiv.lastChild", "testDiv.lastChild", 1, "testDiv.lastChild", 1],
+  ["testDiv", "testDiv.lastChild", "testDiv", "testDiv.childNodes.length - 2", "testDiv", "testDiv.childNodes.length"],
+  ["testDiv", "testDiv.lastChild", "testDiv", "testDiv.childNodes.length - 2", "testDiv", "testDiv.childNodes.length - 1"],
+  ["testDiv", "testDiv.lastChild", "testDiv", "testDiv.childNodes.length - 1", "testDiv", "testDiv.childNodes.length"],
+  ["testDiv", "testDiv.lastChild", "testDiv", "testDiv.childNodes.length - 1", "testDiv", "testDiv.childNodes.length - 1"],
+  ["testDiv", "testDiv.lastChild", "testDiv", "testDiv.childNodes.length", "testDiv", "testDiv.childNodes.length"],
+  ["detachedDiv", "detachedDiv.lastChild", "detachedDiv.lastChild", 0, "detachedDiv.lastChild", 0],
+  ["detachedDiv", "detachedDiv.lastChild", "detachedDiv.lastChild", 0, "detachedDiv.lastChild", 1],
+  ["detachedDiv", "detachedDiv.lastChild", "detachedDiv.lastChild", 1, "detachedDiv.lastChild", 1],
+  ["detachedDiv", "detachedDiv.lastChild", "detachedDiv", "detachedDiv.childNodes.length - 2", "detachedDiv", "detachedDiv.childNodes.length"],
+  ["detachedDiv", "detachedDiv.lastChild", "detachedDiv", "detachedDiv.childNodes.length - 2", "detachedDiv", "detachedDiv.childNodes.length - 1"],
+  ["detachedDiv", "detachedDiv.lastChild", "detachedDiv", "detachedDiv.childNodes.length - 1", "detachedDiv", "detachedDiv.childNodes.length"],
+  ["detachedDiv", "detachedDiv.lastChild", "detachedDiv", "detachedDiv.childNodes.length - 1", "detachedDiv", "detachedDiv.childNodes.length - 1"],
+  ["detachedDiv", "detachedDiv.lastChild", "detachedDiv", "detachedDiv.childNodes.length", "detachedDiv", "detachedDiv.childNodes.length"],
+
+  // Stuff that actually moves something
+  ["paras[0]", "paras[1]", "paras[0]", 0, "paras[0]", 0],
+  ["paras[0]", "paras[1]", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "paras[1]", "paras[0]", 1, "paras[0]", 1],
+  ["paras[0]", "paras[1]", "testDiv", 0, "testDiv", 1],
+  ["paras[0]", "paras[1]", "testDiv", 0, "testDiv", 2],
+  ["paras[0]", "paras[1]", "testDiv", 1, "testDiv", 1],
+  ["paras[0]", "paras[1]", "testDiv", 1, "testDiv", 2],
+  ["foreignDoc", "detachedComment", "foreignDoc", "foreignDoc.childNodes.length - 1", "foreignDoc", "foreignDoc.childNodes.length"],
+  ["foreignDoc", "detachedComment", "foreignDoc", "foreignDoc.childNodes.length - 1", "foreignDoc", "foreignDoc.childNodes.length - 1"],
+  ["foreignDoc", "detachedComment", "foreignDoc", "foreignDoc.childNodes.length", "foreignDoc", "foreignDoc.childNodes.length"],
+  ["foreignDoc", "detachedComment", "detachedComment", 0, "detachedComment", 5],
+  ["paras[0]", "xmlTextNode", "paras[0]", 0, "paras[0]", 0],
+  ["paras[0]", "xmlTextNode", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "xmlTextNode", "paras[0]", 1, "paras[0]", 1],
+
+  // Stuff that throws exceptions
+  ["paras[0]", "paras[0]", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "testDiv", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "document", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "foreignDoc", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "document.doctype", "paras[0]", 0, "paras[0]", 1],
+];
+
+
+function testRemoveChild(affectedNode, startContainer, startOffset, endContainer, endOffset) {
+  var expectedStart = [startContainer, startOffset];
+  var expectedEnd = [endContainer, endOffset];
+
+  expectedStart = modifyForRemove(affectedNode, expectedStart);
+  expectedEnd = modifyForRemove(affectedNode, expectedEnd);
+
+  // We don't test cases where the parent is wrong, so this should never
+  // throw an exception.
+  affectedNode.parentNode.removeChild(affectedNode);
+
+  return expectedStart.concat(expectedEnd);
+}
+
+var removeChildTests = [
+  ["paras[0]", "paras[0]", 0, "paras[0]", 0],
+  ["paras[0]", "paras[0]", 0, "paras[0]", 1],
+  ["paras[0]", "paras[0]", 1, "paras[0]", 1],
+  ["paras[0]", "testDiv", 0, "testDiv", 0],
+  ["paras[0]", "testDiv", 0, "testDiv", 1],
+  ["paras[0]", "testDiv", 1, "testDiv", 1],
+  ["paras[0]", "testDiv", 0, "testDiv", 2],
+  ["paras[0]", "testDiv", 1, "testDiv", 2],
+  ["paras[0]", "testDiv", 2, "testDiv", 2],
+
+  ["foreignDoc.documentElement", "foreignDoc", 0, "foreignDoc", "foreignDoc.childNodes.length"],
+];
diff --git a/testing/web-platform/tests/dom/ranges/Range-selectNode.html b/testing/web-platform/tests/dom/ranges/Range-selectNode.html
new file mode 100644
index 0000000000..fe9b1f7860
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-selectNode.html
@@ -0,0 +1,99 @@
+<!doctype html>
+<title>Range.selectNode() and .selectNodeContents() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+function testSelectNode(range, node) {
+    try {
+        range.collapsed;
+    } catch (e) {
+        // Range is detached
+        assert_throws_dom("INVALID_STATE_ERR", function () {
+            range.selectNode(node);
+        }, "selectNode() on a detached node must throw INVALID_STATE_ERR");
+        assert_throws_dom("INVALID_STATE_ERR", function () {
+            range.selectNodeContents(node);
+        }, "selectNodeContents() on a detached node must throw INVALID_STATE_ERR");
+        return;
+    }
+
+    if (!node.parentNode) {
+        assert_throws_dom("INVALID_NODE_TYPE_ERR", function() {
+            range.selectNode(node);
+        }, "selectNode() on a node with no parent must throw INVALID_NODE_TYPE_ERR");
+    } else {
+        var index = 0;
+        while (node.parentNode.childNodes[index] != node) {
+            index++;
+        }
+
+        range.selectNode(node);
+        assert_equals(range.startContainer, node.parentNode,
+            "After selectNode(), startContainer must equal parent node");
+        assert_equals(range.endContainer, node.parentNode,
+            "After selectNode(), endContainer must equal parent node");
+        assert_equals(range.startOffset, index,
+            "After selectNode(), startOffset must be index of node in parent (" + index + ")");
+        assert_equals(range.endOffset, index + 1,
+            "After selectNode(), endOffset must be one plus index of node in parent (" + (index + 1) + ")");
+    }
+
+    if (node.nodeType == Node.DOCUMENT_TYPE_NODE) {
+        assert_throws_dom("INVALID_NODE_TYPE_ERR", function () {
+            range.selectNodeContents(node);
+        }, "selectNodeContents() on a doctype must throw INVALID_NODE_TYPE_ERR");
+    } else {
+        range.selectNodeContents(node);
+        assert_equals(range.startContainer, node,
+            "After selectNodeContents(), startContainer must equal node");
+        assert_equals(range.endContainer, node,
+            "After selectNodeContents(), endContainer must equal node");
+        assert_equals(range.startOffset, 0,
+            "After selectNodeContents(), startOffset must equal 0");
+        var len = nodeLength(node);
+        assert_equals(range.endOffset, len,
+            "After selectNodeContents(), endOffset must equal node length (" + len + ")");
+    }
+}
+
+var range = document.createRange();
+var foreignRange = foreignDoc.createRange();
+var xmlRange = xmlDoc.createRange();
+var detachedRange = document.createRange();
+detachedRange.detach();
+var tests = [];
+function testTree(root, marker) {
+    if (root.nodeType == Node.ELEMENT_NODE && root.id == "log") {
+        // This is being modified during the tests, so let's not test it.
+        return;
+    }
+    tests.push([marker + ": " + root.nodeName.toLowerCase() + " node, current doc's range, type " + root.nodeType, range, root]);
+    tests.push([marker + ": " + root.nodeName.toLowerCase() + " node, foreign doc's range, type " + root.nodeType, foreignRange, root]);
+    tests.push([marker + ": " + root.nodeName.toLowerCase() + " node, XML doc's range, type " + root.nodeType, xmlRange, root]);
+    tests.push([marker + ": " + root.nodeName.toLowerCase() + " node, detached range, type " + root.nodeType, detachedRange, root]);
+    for (var i = 0; i < root.childNodes.length; i++) {
+        testTree(root.childNodes[i], marker + "[" + i + "]");
+    }
+}
+testTree(document, "current doc");
+testTree(foreignDoc, "foreign doc");
+testTree(detachedDiv, "detached div in current doc");
+
+var otherTests = ["xmlDoc", "xmlElement", "detachedTextNode",
+"foreignTextNode", "xmlTextNode", "processingInstruction", "comment",
+"foreignComment", "xmlComment", "docfrag", "foreignDocfrag", "xmlDocfrag"];
+
+for (var i = 0; i < otherTests.length; i++) {
+    testTree(window[otherTests[i]], otherTests[i]);
+}
+
+generate_tests(testSelectNode, tests);
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-set.html b/testing/web-platform/tests/dom/ranges/Range-set.html
new file mode 100644
index 0000000000..694fc60749
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-set.html
@@ -0,0 +1,221 @@
+<!doctype html>
+<title>Range setting tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+function testSetStart(range, node, offset) {
+  if (node.nodeType == Node.DOCUMENT_TYPE_NODE) {
+    assert_throws_dom("INVALID_NODE_TYPE_ERR", function() {
+      range.setStart(node, offset);
+    }, "setStart() to a doctype must throw INVALID_NODE_TYPE_ERR");
+    return;
+  }
+
+  if (offset < 0 || offset > nodeLength(node)) {
+    assert_throws_dom("INDEX_SIZE_ERR", function() {
+      range.setStart(node, offset);
+    }, "setStart() to a too-large offset must throw INDEX_SIZE_ERR");
+    return;
+  }
+
+  var newRange = range.cloneRange();
+  newRange.setStart(node, offset);
+
+  assert_equals(newRange.startContainer, node,
+    "setStart() must change startContainer to the new node");
+  assert_equals(newRange.startOffset, offset,
+    "setStart() must change startOffset to the new offset");
+
+  // FIXME: I'm assuming comparePoint() is correct, but the tests for that
+  // will depend on setStart()/setEnd().
+  if (furthestAncestor(node) != furthestAncestor(range.startContainer)
+  || range.comparePoint(node, offset) > 0) {
+    assert_equals(newRange.endContainer, node,
+      "setStart(node, offset) where node is after current end or in different document must set the end node to node too");
+    assert_equals(newRange.endOffset, offset,
+      "setStart(node, offset) where node is after current end or in different document must set the end offset to offset too");
+  } else {
+    assert_equals(newRange.endContainer, range.endContainer,
+      "setStart() must not change the end node if the new start is before the old end");
+    assert_equals(newRange.endOffset, range.endOffset,
+      "setStart() must not change the end offset if the new start is before the old end");
+  }
+}
+
+function testSetEnd(range, node, offset) {
+  if (node.nodeType == Node.DOCUMENT_TYPE_NODE) {
+    assert_throws_dom("INVALID_NODE_TYPE_ERR", function() {
+      range.setEnd(node, offset);
+    }, "setEnd() to a doctype must throw INVALID_NODE_TYPE_ERR");
+    return;
+  }
+
+  if (offset < 0 || offset > nodeLength(node)) {
+    assert_throws_dom("INDEX_SIZE_ERR", function() {
+      range.setEnd(node, offset);
+    }, "setEnd() to a too-large offset must throw INDEX_SIZE_ERR");
+    return;
+  }
+
+  var newRange = range.cloneRange();
+  newRange.setEnd(node, offset);
+
+  // FIXME: I'm assuming comparePoint() is correct, but the tests for that
+  // will depend on setStart()/setEnd().
+  if (furthestAncestor(node) != furthestAncestor(range.startContainer)
+  || range.comparePoint(node, offset) < 0) {
+    assert_equals(newRange.startContainer, node,
+      "setEnd(node, offset) where node is before current start or in different document must set the end node to node too");
+    assert_equals(newRange.startOffset, offset,
+      "setEnd(node, offset) where node is before current start or in different document must set the end offset to offset too");
+  } else {
+    assert_equals(newRange.startContainer, range.startContainer,
+      "setEnd() must not change the start node if the new end is after the old start");
+    assert_equals(newRange.startOffset, range.startOffset,
+      "setEnd() must not change the start offset if the new end is after the old start");
+  }
+
+  assert_equals(newRange.endContainer, node,
+    "setEnd() must change endContainer to the new node");
+  assert_equals(newRange.endOffset, offset,
+    "setEnd() must change endOffset to the new offset");
+}
+
+function testSetStartBefore(range, node) {
+  var parent = node.parentNode;
+  if (parent === null) {
+    assert_throws_dom("INVALID_NODE_TYPE_ERR", function () {
+      range.setStartBefore(node);
+    }, "setStartBefore() to a node with null parent must throw INVALID_NODE_TYPE_ERR");
+    return;
+  }
+
+  var idx = 0;
+  while (node.parentNode.childNodes[idx] != node) {
+    idx++;
+  }
+
+  testSetStart(range, node.parentNode, idx);
+}
+
+function testSetStartAfter(range, node) {
+  var parent = node.parentNode;
+  if (parent === null) {
+    assert_throws_dom("INVALID_NODE_TYPE_ERR", function () {
+      range.setStartAfter(node);
+    }, "setStartAfter() to a node with null parent must throw INVALID_NODE_TYPE_ERR");
+    return;
+  }
+
+  var idx = 0;
+  while (node.parentNode.childNodes[idx] != node) {
+    idx++;
+  }
+
+  testSetStart(range, node.parentNode, idx + 1);
+}
+
+function testSetEndBefore(range, node) {
+  var parent = node.parentNode;
+  if (parent === null) {
+    assert_throws_dom("INVALID_NODE_TYPE_ERR", function () {
+      range.setEndBefore(node);
+    }, "setEndBefore() to a node with null parent must throw INVALID_NODE_TYPE_ERR");
+    return;
+  }
+
+  var idx = 0;
+  while (node.parentNode.childNodes[idx] != node) {
+    idx++;
+  }
+
+  testSetEnd(range, node.parentNode, idx);
+}
+
+function testSetEndAfter(range, node) {
+  var parent = node.parentNode;
+  if (parent === null) {
+    assert_throws_dom("INVALID_NODE_TYPE_ERR", function () {
+      range.setEndAfter(node);
+    }, "setEndAfter() to a node with null parent must throw INVALID_NODE_TYPE_ERR");
+    return;
+  }
+
+  var idx = 0;
+  while (node.parentNode.childNodes[idx] != node) {
+    idx++;
+  }
+
+  testSetEnd(range, node.parentNode, idx + 1);
+}
+
+
+var startTests = [];
+var endTests = [];
+var startBeforeTests = [];
+var startAfterTests = [];
+var endBeforeTests = [];
+var endAfterTests = [];
+
+// Don't want to eval() each point a bazillion times
+var testPointsCached = testPoints.map(eval);
+var testNodesCached = testNodesShort.map(eval);
+
+for (var i = 0; i < testRangesShort.length; i++) {
+  var endpoints = eval(testRangesShort[i]);
+  var range;
+  test(function() {
+    range = ownerDocument(endpoints[0]).createRange();
+    range.setStart(endpoints[0], endpoints[1]);
+    range.setEnd(endpoints[2], endpoints[3]);
+  }, "Set up range " + i + " " + testRangesShort[i]);
+
+  for (var j = 0; j < testPoints.length; j++) {
+    startTests.push(["setStart() with range " + i + " " + testRangesShort[i] + ", point " + j + " " + testPoints[j],
+      range,
+      testPointsCached[j][0],
+      testPointsCached[j][1]
+    ]);
+    endTests.push(["setEnd() with range " + i + " " + testRangesShort[i] + ", point " + j + " " + testPoints[j],
+      range,
+      testPointsCached[j][0],
+      testPointsCached[j][1]
+    ]);
+  }
+
+  for (var j = 0; j < testNodesShort.length; j++) {
+    startBeforeTests.push(["setStartBefore() with range " + i + " " + testRangesShort[i] + ", node " + j + " " + testNodesShort[j],
+      range,
+      testNodesCached[j]
+    ]);
+    startAfterTests.push(["setStartAfter() with range " + i + " " + testRangesShort[i] + ", node " + j + " " + testNodesShort[j],
+      range,
+      testNodesCached[j]
+    ]);
+    endBeforeTests.push(["setEndBefore() with range " + i + " " + testRangesShort[i] + ", node " + j + " " + testNodesShort[j],
+      range,
+      testNodesCached[j]
+    ]);
+    endAfterTests.push(["setEndAfter() with range " + i + " " + testRangesShort[i] + ", node " + j + " " + testNodesShort[j],
+      range,
+      testNodesCached[j]
+    ]);
+  }
+}
+
+generate_tests(testSetStart, startTests);
+generate_tests(testSetEnd, endTests);
+generate_tests(testSetStartBefore, startBeforeTests);
+generate_tests(testSetStartAfter, startAfterTests);
+generate_tests(testSetEndBefore, endBeforeTests);
+generate_tests(testSetEndAfter, endAfterTests);
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-stringifier.html b/testing/web-platform/tests/dom/ranges/Range-stringifier.html
new file mode 100644
index 0000000000..330c7421ea
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-stringifier.html
@@ -0,0 +1,44 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Range stringifier</title>
+<link rel="author" title="KiChjang" href="mailto:kungfukeith11@gmail.com">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id=test>Test div</div>
+<div id=another>Another div</div>
+<div id=last>Last div</div>
+<div id=log></div>
+<script>
+test(function() {
+  var r = new Range();
+  var testDiv = document.getElementById("test");
+  test(function() {
+    r.selectNodeContents(testDiv);
+    assert_equals(r.collapsed, false);
+    assert_equals(r.toString(), testDiv.textContent);
+  }, "Node contents of a single div");
+
+  var textNode = testDiv.childNodes[0];
+  test(function() {
+    r.setStart(textNode, 5);
+    r.setEnd(textNode, 7);
+    assert_equals(r.collapsed, false);
+    assert_equals(r.toString(), "di");
+  }, "Text node with offsets");
+
+  var anotherDiv = document.getElementById("another");
+  test(function() {
+    r.setStart(testDiv, 0);
+    r.setEnd(anotherDiv, 0);
+    assert_equals(r.toString(), "Test div\n");
+  }, "Two nodes, each with a text node");
+
+  var lastDiv = document.getElementById("last");
+  var lastText = lastDiv.childNodes[0];
+  test(function() {
+    r.setStart(textNode, 5);
+    r.setEnd(lastText, 4);
+    assert_equals(r.toString(), "div\nAnother div\nLast");
+  }, "Three nodes with start offset and end offset on text nodes");
+});
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-surroundContents.html b/testing/web-platform/tests/dom/ranges/Range-surroundContents.html
new file mode 100644
index 0000000000..c9d47fcbad
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-surroundContents.html
@@ -0,0 +1,324 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Range.surroundContents() tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<p>To debug test failures, add a query parameter "subtest" with the test id (like
+"?subtest=5,16").  Only that test will be run.  Then you can look at the resulting
+iframes in the DOM.
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+testDiv.parentNode.removeChild(testDiv);
+
+function mySurroundContents(range, newParent) {
+  try {
+    // "If a non-Text node is partially contained in the context object,
+    // throw a "InvalidStateError" exception and terminate these steps."
+    var node = range.commonAncestorContainer;
+    var stop = nextNodeDescendants(node);
+    for (; node != stop; node = nextNode(node)) {
+      if (node.nodeType != Node.TEXT_NODE
+      && isPartiallyContained(node, range)) {
+        return "INVALID_STATE_ERR";
+      }
+    }
+
+    // "If newParent is a Document, DocumentType, or DocumentFragment node,
+    // throw an "InvalidNodeTypeError" exception and terminate these
+    // steps."
+    if (newParent.nodeType == Node.DOCUMENT_NODE
+    || newParent.nodeType == Node.DOCUMENT_TYPE_NODE
+    || newParent.nodeType == Node.DOCUMENT_FRAGMENT_NODE) {
+      return "INVALID_NODE_TYPE_ERR";
+    }
+
+    // "Call extractContents() on the context object, and let fragment be
+    // the result."
+    var fragment = myExtractContents(range);
+    if (typeof fragment == "string") {
+      return fragment;
+    }
+
+    // "While newParent has children, remove its first child."
+    while (newParent.childNodes.length) {
+      newParent.removeChild(newParent.firstChild);
+    }
+
+    // "Call insertNode(newParent) on the context object."
+    var ret = myInsertNode(range, newParent);
+    if (typeof ret == "string") {
+      return ret;
+    }
+
+    // "Call appendChild(fragment) on newParent."
+    newParent.appendChild(fragment);
+
+    // "Call selectNode(newParent) on the context object."
+    //
+    // We just reimplement this in-place.
+    if (!newParent.parentNode) {
+      return "INVALID_NODE_TYPE_ERR";
+    }
+    var index = indexOf(newParent);
+    range.setStart(newParent.parentNode, index);
+    range.setEnd(newParent.parentNode, index + 1);
+  } catch (e) {
+    return getDomExceptionName(e);
+  }
+}
+
+function restoreIframe(iframe, i, j) {
+  // Most of this function is designed to work around the fact that Opera
+  // doesn't let you add a doctype to a document that no longer has one, in
+  // any way I can figure out.  I eventually compromised on something that
+  // will still let Opera pass most tests that don't actually involve
+  // doctypes.
+  while (iframe.contentDocument.firstChild
+  && iframe.contentDocument.firstChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+    iframe.contentDocument.removeChild(iframe.contentDocument.firstChild);
+  }
+
+  while (iframe.contentDocument.lastChild
+  && iframe.contentDocument.lastChild.nodeType != Node.DOCUMENT_TYPE_NODE) {
+    iframe.contentDocument.removeChild(iframe.contentDocument.lastChild);
+  }
+
+  if (!iframe.contentDocument.firstChild) {
+    // This will throw an exception in Opera if we reach here, which is why
+    // I try to avoid it.  It will never happen in a browser that obeys the
+    // spec, so it's really just insurance.  I don't think it actually gets
+    // hit by anything.
+    iframe.contentDocument.appendChild(iframe.contentDocument.implementation.createDocumentType("html", "", ""));
+  }
+  iframe.contentDocument.appendChild(referenceDoc.documentElement.cloneNode(true));
+  iframe.contentWindow.setupRangeTests();
+  iframe.contentWindow.testRangeInput = testRangesShort[i];
+  iframe.contentWindow.testNodeInput = testNodesShort[j];
+  iframe.contentWindow.run();
+}
+
+function testSurroundContents(i, j) {
+  var actualRange;
+  var expectedRange;
+  var actualNode;
+  var expectedNode;
+  var actualRoots = [];
+  var expectedRoots = [];
+
+  domTests[i][j].step(function() {
+    restoreIframe(actualIframe, i, j);
+    restoreIframe(expectedIframe, i, j);
+
+    actualRange = actualIframe.contentWindow.testRange;
+    expectedRange = expectedIframe.contentWindow.testRange;
+    actualNode = actualIframe.contentWindow.testNode;
+    expectedNode = expectedIframe.contentWindow.testNode;
+
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual surroundContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated surroundContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_not_equals(actualRange, null,
+      "Range produced in actual iframe was null");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+    assert_not_equals(expectedRange, null,
+      "Range produced in expected iframe was null");
+    assert_equals(typeof actualNode, "object",
+      "typeof Node produced in actual iframe");
+    assert_not_equals(actualNode, null,
+      "Node produced in actual iframe was null");
+    assert_equals(typeof expectedNode, "object",
+      "typeof Node produced in expected iframe");
+    assert_not_equals(expectedNode, null,
+      "Node produced in expected iframe was null");
+
+    // We want to test that the trees containing the ranges are equal, and
+    // also the trees containing the moved nodes.  These might not be the
+    // same, if we're inserting a node from a detached tree or a different
+    // document.
+    actualRoots.push(furthestAncestor(actualRange.startContainer));
+    expectedRoots.push(furthestAncestor(expectedRange.startContainer));
+
+    if (furthestAncestor(actualNode) != actualRoots[0]) {
+      actualRoots.push(furthestAncestor(actualNode));
+    }
+    if (furthestAncestor(expectedNode) != expectedRoots[0]) {
+      expectedRoots.push(furthestAncestor(expectedNode));
+    }
+
+    assert_equals(actualRoots.length, expectedRoots.length,
+      "Either the actual node and actual range are in the same tree but the expected are in different trees, or vice versa");
+
+    // This doctype stuff is to work around the fact that Opera 11.00 will
+    // move around doctypes within a document, even to totally invalid
+    // positions, but it won't allow a new doctype to be added to a
+    // document in any way I can figure out.  So if we try moving a doctype
+    // to some invalid place, in Opera it will actually succeed, and then
+    // restoreIframe() will remove the doctype along with the root element,
+    // and then nothing can re-add the doctype.  So instead, we catch it
+    // during the test itself and move it back to the right place while we
+    // still can.
+    //
+    // I spent *way* too much time debugging and working around this bug.
+    var actualDoctype = actualIframe.contentDocument.doctype;
+    var expectedDoctype = expectedIframe.contentDocument.doctype;
+
+    var result;
+    try {
+      result = mySurroundContents(expectedRange, expectedNode);
+    } catch (e) {
+      if (expectedDoctype != expectedIframe.contentDocument.firstChild) {
+        expectedIframe.contentDocument.insertBefore(expectedDoctype, expectedIframe.contentDocument.firstChild);
+      }
+      throw e;
+    }
+    if (typeof result == "string") {
+      assert_throws_dom(result, actualIframe.contentWindow.DOMException, function() {
+        try {
+          actualRange.surroundContents(actualNode);
+        } catch (e) {
+          if (expectedDoctype != expectedIframe.contentDocument.firstChild) {
+            expectedIframe.contentDocument.insertBefore(expectedDoctype, expectedIframe.contentDocument.firstChild);
+          }
+          if (actualDoctype != actualIframe.contentDocument.firstChild) {
+            actualIframe.contentDocument.insertBefore(actualDoctype, actualIframe.contentDocument.firstChild);
+          }
+          throw e;
+        }
+      }, "A " + result + " must be thrown in this case");
+      // Don't return, we still need to test DOM equality
+    } else {
+      try {
+        actualRange.surroundContents(actualNode);
+      } catch (e) {
+        if (expectedDoctype != expectedIframe.contentDocument.firstChild) {
+          expectedIframe.contentDocument.insertBefore(expectedDoctype, expectedIframe.contentDocument.firstChild);
+        }
+        if (actualDoctype != actualIframe.contentDocument.firstChild) {
+          actualIframe.contentDocument.insertBefore(actualDoctype, actualIframe.contentDocument.firstChild);
+        }
+        throw e;
+      }
+    }
+
+    for (var k = 0; k < actualRoots.length; k++) {
+      assertNodesEqual(actualRoots[k], expectedRoots[k], k ? "moved node's tree root" : "range's tree root");
+    }
+  });
+  domTests[i][j].done();
+
+  positionTests[i][j].step(function() {
+    assert_equals(actualIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for actual surroundContents()");
+    assert_equals(expectedIframe.contentWindow.unexpectedException, null,
+      "Unexpected exception thrown when setting up Range for simulated surroundContents()");
+    assert_equals(typeof actualRange, "object",
+      "typeof Range produced in actual iframe");
+    assert_not_equals(actualRange, null,
+      "Range produced in actual iframe was null");
+    assert_equals(typeof expectedRange, "object",
+      "typeof Range produced in expected iframe");
+    assert_not_equals(expectedRange, null,
+      "Range produced in expected iframe was null");
+    assert_equals(typeof actualNode, "object",
+      "typeof Node produced in actual iframe");
+    assert_not_equals(actualNode, null,
+      "Node produced in actual iframe was null");
+    assert_equals(typeof expectedNode, "object",
+      "typeof Node produced in expected iframe");
+    assert_not_equals(expectedNode, null,
+      "Node produced in expected iframe was null");
+
+    for (var k = 0; k < actualRoots.length; k++) {
+      assertNodesEqual(actualRoots[k], expectedRoots[k], k ? "moved node's tree root" : "range's tree root");
+    }
+
+    assert_equals(actualRange.startOffset, expectedRange.startOffset,
+      "Unexpected startOffset after surroundContents()");
+    assert_equals(actualRange.endOffset, expectedRange.endOffset,
+      "Unexpected endOffset after surroundContents()");
+    // How do we decide that the two nodes are equal, since they're in
+    // different trees?  Since the DOMs are the same, it's enough to check
+    // that the index in the parent is the same all the way up the tree.
+    // But we can first cheat by just checking they're actually equal.
+    assert_true(actualRange.startContainer.isEqualNode(expectedRange.startContainer),
+      "Unexpected startContainer after surroundContents(), expected " +
+      expectedRange.startContainer.nodeName.toLowerCase() + " but got " +
+      actualRange.startContainer.nodeName.toLowerCase());
+    var currentActual = actualRange.startContainer;
+    var currentExpected = expectedRange.startContainer;
+    var actual = "";
+    var expected = "";
+    while (currentActual && currentExpected) {
+      actual = indexOf(currentActual) + "-" + actual;
+      expected = indexOf(currentExpected) + "-" + expected;
+
+      currentActual = currentActual.parentNode;
+      currentExpected = currentExpected.parentNode;
+    }
+    actual = actual.substr(0, actual.length - 1);
+    expected = expected.substr(0, expected.length - 1);
+    assert_equals(actual, expected,
+      "startContainer superficially looks right but is actually the wrong node if you trace back its index in all its ancestors (I'm surprised this actually happened");
+  });
+  positionTests[i][j].done();
+}
+
+var iStart = 0;
+var iStop = testRangesShort.length;
+var jStart = 0;
+var jStop = testNodesShort.length;
+
+if (/subtest=[0-9]+,[0-9]+/.test(location.search)) {
+  var matches = /subtest=([0-9]+),([0-9]+)/.exec(location.search);
+  iStart = Number(matches[1]);
+  iStop = Number(matches[1]) + 1;
+  jStart = Number(matches[2]) + 0;
+  jStop = Number(matches[2]) + 1;
+}
+
+var domTests = [];
+var positionTests = [];
+for (var i = iStart; i < iStop; i++) {
+  domTests[i] = [];
+  positionTests[i] = [];
+  for (var j = jStart; j < jStop; j++) {
+    domTests[i][j] = async_test(i + "," + j + ": resulting DOM for range " + testRangesShort[i] + ", node " + testNodesShort[j]);
+    positionTests[i][j] = async_test(i + "," + j + ": resulting range position for range " + testRangesShort[i] + ", node " + testNodesShort[j]);
+  }
+}
+
+var actualIframe = document.createElement("iframe");
+actualIframe.style.display = "none";
+actualIframe.id = "actual";
+document.body.appendChild(actualIframe);
+
+var expectedIframe = document.createElement("iframe");
+expectedIframe.style.display = "none";
+expectedIframe.id = "expected";
+document.body.appendChild(expectedIframe);
+
+var referenceDoc = document.implementation.createHTMLDocument("");
+referenceDoc.removeChild(referenceDoc.documentElement);
+
+actualIframe.onload = function() {
+  expectedIframe.onload = function() {
+    for (var i = iStart; i < iStop; i++) {
+      for (var j = jStart; j < jStop; j++) {
+        testSurroundContents(i, j);
+      }
+    }
+  }
+  expectedIframe.src = "Range-test-iframe.html";
+  referenceDoc.appendChild(actualIframe.contentDocument.documentElement.cloneNode(true));
+}
+actualIframe.src = "Range-test-iframe.html";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/Range-test-iframe.html b/testing/web-platform/tests/dom/ranges/Range-test-iframe.html
new file mode 100644
index 0000000000..f354ff758f
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/Range-test-iframe.html
@@ -0,0 +1,56 @@
+<!doctype html>
+<title>Range test iframe</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<body onload=run()>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+// This script only exists because we want to evaluate the range endpoints
+// in each iframe using that iframe's local variables set up by common.js.  It
+// just creates the range and does nothing else.  The data is returned via
+// window.testRange, and if an exception is thrown, it's put in
+// window.unexpectedException.
+window.unexpectedException = null;
+
+function run() {
+  try {
+    window.unexpectedException = null;
+
+    if (typeof window.testNodeInput != "undefined") {
+      window.testNode = eval(window.testNodeInput);
+    }
+
+    var rangeEndpoints;
+    if (typeof window.testRangeInput == "undefined") {
+      // Use the hash (old way of doing things, bad because it requires
+      // navigation)
+      if (location.hash == "") {
+        return;
+      }
+      rangeEndpoints = eval(location.hash.substr(1));
+    } else {
+      // Get the variable directly off the window, faster and can be done
+      // synchronously
+      rangeEndpoints = eval(window.testRangeInput);
+    }
+
+    var range;
+    if (rangeEndpoints == "detached") {
+      range = document.createRange();
+      range.detach();
+    } else {
+      range = ownerDocument(rangeEndpoints[0]).createRange();
+      range.setStart(rangeEndpoints[0], rangeEndpoints[1]);
+      range.setEnd(rangeEndpoints[2], rangeEndpoints[3]);
+    }
+
+    window.testRange = range;
+  } catch(e) {
+    window.unexpectedException = e;
+  }
+}
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/ranges/StaticRange-constructor.html b/testing/web-platform/tests/dom/ranges/StaticRange-constructor.html
new file mode 100644
index 0000000000..6aae93f49b
--- /dev/null
+++ b/testing/web-platform/tests/dom/ranges/StaticRange-constructor.html
@@ -0,0 +1,200 @@
+<!doctype html>
+<title>StaticRange constructor test</title>
+<link rel='author' title='Sanket Joshi' href='mailto:sajos@microsoft.com'>
+<div id='log'></div>
+<script src='/resources/testharness.js'></script>
+<script src='/resources/testharnessreport.js'></script>
+<div id='testDiv'>abc<span>def</span>ghi</div>
+<script>
+'use strict';
+
+const testDiv = document.getElementById('testDiv');
+const testTextNode = testDiv.firstChild;
+const testPINode = document.createProcessingInstruction('foo', 'abc');
+const testCommentNode =  document.createComment('abc');
+document.body.append(testPINode, testCommentNode);
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testDiv, startOffset: 1, endContainer: testDiv, endOffset: 2});
+    assert_equals(staticRange.startContainer, testDiv, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 1, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testDiv, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 2, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with Element container');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testTextNode, startOffset: 1, endContainer: testTextNode, endOffset: 2});
+    assert_equals(staticRange.startContainer, testTextNode, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 1, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testTextNode, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 2, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with Text container');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testDiv, startOffset: 0, endContainer: testTextNode, endOffset: 1});
+    assert_equals(staticRange.startContainer, testDiv, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 0, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testTextNode, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 1, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with Element startContainer and Text endContainer');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testTextNode, startOffset: 0, endContainer: testDiv, endOffset: 3});
+    assert_equals(staticRange.startContainer, testTextNode, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 0, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testDiv, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 3, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with Text startContainer and Element endContainer');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testPINode, startOffset: 1, endContainer: testPINode, endOffset: 2});
+    assert_equals(staticRange.startContainer, testPINode, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 1, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testPINode, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 2, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with ProcessingInstruction container');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testCommentNode, startOffset: 1, endContainer: testCommentNode, endOffset: 2});
+    assert_equals(staticRange.startContainer, testCommentNode, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 1, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testCommentNode, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 2, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with Comment container');
+
+test(function() {
+    const xmlDoc = new DOMParser().parseFromString('<xml></xml>', 'application/xml');
+    const testCDATASection = xmlDoc.createCDATASection('abc');
+    const staticRange = new StaticRange({startContainer: testCDATASection, startOffset: 1, endContainer: testCDATASection, endOffset: 2});
+    assert_equals(staticRange.startContainer, testCDATASection, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 1, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testCDATASection, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 2, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with CDATASection container');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: document, startOffset: 0, endContainer: document, endOffset: 1});
+    assert_equals(staticRange.startContainer, document, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 0, 'valid startOffset');
+    assert_equals(staticRange.endContainer, document, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 1, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with Document container');
+
+test(function() {
+    const testDocFrag = document.createDocumentFragment();
+    testDocFrag.append('a','b','c');
+    const staticRange = new StaticRange({startContainer: testDocFrag, startOffset: 0, endContainer: testDocFrag, endOffset: 1});
+    assert_equals(staticRange.startContainer, testDocFrag, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 0, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testDocFrag, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 1, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with DocumentFragment container');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testDiv, startOffset: 0, endContainer: testDiv, endOffset: 0});
+    assert_equals(staticRange.startContainer, testDiv, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 0, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testDiv, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 0, 'valid endOffset');
+    assert_true(staticRange.collapsed, 'collapsed');
+}, 'Construct collapsed static range');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testDiv, startOffset: 1, endContainer: document.body, endOffset: 0});
+    assert_equals(staticRange.startContainer, testDiv, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 1, 'valid startOffset');
+    assert_equals(staticRange.endContainer, document.body, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 0, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct inverted static range');
+
+test(function() {
+    const staticRange = new StaticRange({startContainer: testDiv, startOffset: 0, endContainer: testDiv, endOffset: 15});
+    assert_equals(staticRange.startContainer, testDiv, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 0, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testDiv, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 15, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with offset greater than length');
+
+test(function() {
+    const testNode = document.createTextNode('abc');
+    const staticRange = new StaticRange({startContainer: testNode, startOffset: 1, endContainer: testNode, endOffset: 2});
+    assert_equals(staticRange.startContainer, testNode, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 1, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testNode, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 2, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with standalone Node container');
+
+test(function() {
+    const testRoot = document.createElement('div');
+    testRoot.append('a','b');
+    const staticRange = new StaticRange({startContainer: testDiv, startOffset: 1, endContainer: testRoot, endOffset: 2});
+    assert_equals(staticRange.startContainer, testDiv, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 1, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testRoot, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 2, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with endpoints in disconnected trees');
+
+test(function() {
+    const testDocNode = document.implementation.createDocument('about:blank', 'html', null);
+    const staticRange = new StaticRange({startContainer: document, startOffset: 0, endContainer: testDocNode.documentElement, endOffset: 0});
+    assert_equals(staticRange.startContainer, document, 'valid startContainer');
+    assert_equals(staticRange.startOffset, 0, 'valid startOffset');
+    assert_equals(staticRange.endContainer, testDocNode.documentElement, 'valid endContainer');
+    assert_equals(staticRange.endOffset, 0, 'valid endOffset');
+    assert_false(staticRange.collapsed, 'not collapsed');
+}, 'Construct static range with endpoints in disconnected documents');
+
+test(function() {
+    assert_throws_dom('INVALID_NODE_TYPE_ERR', function() {
+        const staticRange = new StaticRange({startContainer: document.doctype, startOffset: 0, endContainer: document.doctype, endOffset: 0});
+    }, 'throw a InvalidNodeTypeError when a DocumentType is passed as a startContainer or endContainer');
+
+    assert_throws_dom('INVALID_NODE_TYPE_ERR', function() {
+        const testAttrNode = testDiv.getAttributeNode('id');
+        const staticRange = new StaticRange({startContainer: testAttrNode, startOffset: 0, endContainer: testAttrNode, endOffset: 0});
+    }, 'throw a InvalidNodeTypeError when a Attr is passed as a startContainer or endContainer');
+}, 'Throw on DocumentType or Attr container');
+
+test(function () {
+    assert_throws_js(TypeError, function () {
+        const staticRange = new StaticRange();
+    }, 'throw a TypeError when no argument is passed');
+
+    assert_throws_js(TypeError, function () {
+        const staticRange = new StaticRange({startOffset: 0, endContainer: testDiv, endOffset: 0});
+    }, 'throw a TypeError when a startContainer is not passed');
+
+    assert_throws_js(TypeError, function () {
+        const staticRange = new StaticRange({startContainer: testDiv, endContainer: testDiv, endOffset: 0});
+    }, 'throw a TypeError when a startOffset is not passed');
+
+    assert_throws_js(TypeError, function () {
+        const staticRange = new StaticRange({startContainer: testDiv, startOffset: 0, endOffset: 0});
+    }, 'throw a TypeError when an endContainer is not passed');
+
+    assert_throws_js(TypeError, function () {
+        const staticRange = new StaticRange({startContainer: testDiv, startOffset: 0, endContainer: testDiv});
+    }, 'throw a TypeError when an endOffset is not passed');
+
+    assert_throws_js(TypeError, function () {
+        const staticRange = new StaticRange({startContainer: null, startOffset: 0, endContainer: testDiv, endOffset: 0});
+    }, 'throw a TypeError when a null startContainer is passed');
+
+    assert_throws_js(TypeError, function () {
+        const staticRange = new StaticRange({startContainer: testDiv, startOffset: 0, endContainer: null, endOffset: 0});
+    }, 'throw a TypeError when a null endContainer is passed');
+}, 'Throw on missing or invalid arguments');
+</script>
diff --git a/testing/web-platform/tests/dom/slot-recalc-ref.html b/testing/web-platform/tests/dom/slot-recalc-ref.html
new file mode 100644
index 0000000000..521eedb42a
--- /dev/null
+++ b/testing/web-platform/tests/dom/slot-recalc-ref.html
@@ -0,0 +1,5 @@
+<!DOCTYPE html>
+<div>
+  <p>there should be more text below this</p>
+  <p>PASS if this text is visible</p>
+</div>
diff --git a/testing/web-platform/tests/dom/slot-recalc.html b/testing/web-platform/tests/dom/slot-recalc.html
new file mode 100644
index 0000000000..5124336ad2
--- /dev/null
+++ b/testing/web-platform/tests/dom/slot-recalc.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="author" title="Joey Arhar" href="mailto:jarhar@chromium.org">
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1184357">
+
+<link rel="match" href="/dom/slot-recalc-ref.html">
+
+<body>
+<script>
+const host = document.createElement('div');
+document.body.appendChild(host);
+const root = host.attachShadow({mode: 'open'});
+
+const slot = document.createElement('slot');
+slot.innerHTML = `<p>there should be more text below this</p>`;
+root.appendChild(slot);
+
+onload = () => {
+  const shouldBeVisible = document.createElement('p');
+  shouldBeVisible.textContent = 'PASS if this text is visible';
+  slot.appendChild(shouldBeVisible);
+};
+</script>
diff --git a/testing/web-platform/tests/dom/svg-insert-crash.html b/testing/web-platform/tests/dom/svg-insert-crash.html
new file mode 100644
index 0000000000..80eec1fba7
--- /dev/null
+++ b/testing/web-platform/tests/dom/svg-insert-crash.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<link rel="author" href="mailto:masonf@chromium.org">
+<link rel="help" href="https://crbug.com/1029262">
+<meta name="assert" content="The renderer should not crash.">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<svg>
+  <!-- Note that the SVG in the data URL below is intentionally malformed: -->
+ <feImage xlink:href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg'><rect"/>
+</svg>
+
+<script>
+async_test(t => {
+  window.onload = t.step_func_done();
+}, 'The renderer should not crash.');
+</script>
diff --git a/testing/web-platform/tests/dom/traversal/NodeFilter-constants.html b/testing/web-platform/tests/dom/traversal/NodeFilter-constants.html
new file mode 100644
index 0000000000..1ce4736cc6
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/NodeFilter-constants.html
@@ -0,0 +1,34 @@
+<!doctype html>
+<title>NodeFilter constants</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../constants.js"></script>
+<div id="log"></div>
+<script>
+var objects;
+setup(function() {
+  objects = [
+    [NodeFilter, "NodeFilter interface object"],
+  ]
+})
+testConstants(objects, [
+  ["FILTER_ACCEPT", 1],
+  ["FILTER_REJECT", 2],
+  ["FILTER_SKIP", 3]
+], "acceptNode")
+testConstants(objects, [
+  ["SHOW_ALL", 0xFFFFFFFF],
+  ["SHOW_ELEMENT", 0x1],
+  ["SHOW_ATTRIBUTE", 0x2],
+  ["SHOW_TEXT", 0x4],
+  ["SHOW_CDATA_SECTION", 0x8],
+  ["SHOW_ENTITY_REFERENCE", 0x10],
+  ["SHOW_ENTITY", 0x20],
+  ["SHOW_PROCESSING_INSTRUCTION", 0x40],
+  ["SHOW_COMMENT", 0x80],
+  ["SHOW_DOCUMENT", 0x100],
+  ["SHOW_DOCUMENT_TYPE", 0x200],
+  ["SHOW_DOCUMENT_FRAGMENT", 0x400],
+  ["SHOW_NOTATION", 0x800]
+], "whatToShow")
+</script>
diff --git a/testing/web-platform/tests/dom/traversal/NodeIterator-removal.html b/testing/web-platform/tests/dom/traversal/NodeIterator-removal.html
new file mode 100644
index 0000000000..b5fc69541a
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/NodeIterator-removal.html
@@ -0,0 +1,100 @@
+<!doctype html>
+<title>NodeIterator removal tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+for (var i = 0; i < testNodes.length; i++) {
+  var node = eval(testNodes[i]);
+  if (!node.parentNode) {
+    // Nothing to test
+    continue;
+  }
+  test(function() {
+    var iters = [];
+    var descs = [];
+    var expectedReferenceNodes = [];
+    var expectedPointers = [];
+
+    for (var j = 0; j < testNodes.length; j++) {
+      var root = eval(testNodes[j]);
+      // Add all distinct iterators with this root, calling nextNode()
+      // repeatedly until it winds up with the same iterator.
+      for (var k = 0; ; k++) {
+        var iter = document.createNodeIterator(root);
+        for (var l = 0; l < k; l++) {
+          iter.nextNode();
+        }
+        if (k && iter.referenceNode == iters[iters.length - 1].referenceNode
+            && iter.pointerBeforeReferenceNode
+               == iters[iters.length - 1].pointerBeforeReferenceNode) {
+          break;
+        } else {
+          iters.push(iter);
+          descs.push("document.createNodeIterator(" + testNodes[j]
+            + ") advanced " + k + " times");
+          expectedReferenceNodes.push(iter.referenceNode);
+          expectedPointers.push(iter.pointerBeforeReferenceNode);
+
+          var idx = iters.length - 1;
+
+          // "If the node is root or is not an inclusive ancestor of the
+          // referenceNode attribute value, terminate these steps."
+          //
+          // We also have to rule out the case where node is an ancestor of
+          // root, which is implicitly handled by the spec since such a node
+          // was not part of the iterator collection to start with.
+          if (isInclusiveAncestor(node, root)
+              || !isInclusiveAncestor(node, iter.referenceNode)) {
+            continue;
+          }
+
+          // "If the pointerBeforeReferenceNode attribute value is false, set
+          // the referenceNode attribute to the first node preceding the node
+          // that is being removed, and terminate these steps."
+          if (!iter.pointerBeforeReferenceNode) {
+            expectedReferenceNodes[idx] = previousNode(node);
+            continue;
+          }
+
+          // "If there is a node following the last inclusive descendant of the
+          // node that is being removed, set the referenceNode attribute to the
+          // first such node, and terminate these steps."
+          var next = nextNodeDescendants(node);
+          if (next) {
+            expectedReferenceNodes[idx] = next;
+            continue;
+          }
+
+          // "Set the referenceNode attribute to the first node preceding the
+          // node that is being removed and set the pointerBeforeReferenceNode
+          // attribute to false."
+          expectedReferenceNodes[idx] = previousNode(node);
+          expectedPointers[idx] = false;
+        }
+      }
+    }
+
+    var oldParent = node.parentNode;
+    var oldSibling = node.nextSibling;
+    oldParent.removeChild(node);
+
+    for (var j = 0; j < iters.length; j++) {
+      var iter = iters[j];
+      assert_equals(iter.referenceNode, expectedReferenceNodes[j],
+                    ".referenceNode of " + descs[j]);
+      assert_equals(iter.pointerBeforeReferenceNode, expectedPointers[j],
+                    ".pointerBeforeReferenceNode of " + descs[j]);
+    }
+
+    oldParent.insertBefore(node, oldSibling);
+  }, "Test removing node " + testNodes[i]);
+}
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/traversal/NodeIterator.html b/testing/web-platform/tests/dom/traversal/NodeIterator.html
new file mode 100644
index 0000000000..fb81676cc5
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/NodeIterator.html
@@ -0,0 +1,215 @@
+<!doctype html>
+<title>NodeIterator tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+function check_iter(iter, root, whatToShowValue) {
+    whatToShowValue = whatToShowValue === undefined ? 0xFFFFFFFF : whatToShowValue;
+
+    assert_equals(iter.toString(), '[object NodeIterator]', 'toString');
+    assert_equals(iter.root, root, 'root');
+    assert_equals(iter.whatToShow, whatToShowValue, 'whatToShow');
+    assert_equals(iter.filter, null, 'filter');
+    assert_equals(iter.referenceNode, root, 'referenceNode');
+    assert_equals(iter.pointerBeforeReferenceNode, true, 'pointerBeforeReferenceNode');
+    assert_readonly(iter, 'root');
+    assert_readonly(iter, 'whatToShow');
+    assert_readonly(iter, 'filter');
+    assert_readonly(iter, 'referenceNode');
+    assert_readonly(iter, 'pointerBeforeReferenceNode');
+}
+
+test(function() {
+  var iter = document.createNodeIterator(document);
+  iter.detach();
+  iter.detach();
+}, "detach() should be a no-op");
+
+test(function() {
+  var iter = document.createNodeIterator(document);
+  check_iter(iter, document);
+}, "createNodeIterator() parameter defaults");
+
+test(function() {
+  var iter = document.createNodeIterator(document, null, null);
+  check_iter(iter, document, 0);
+}, "createNodeIterator() with null as arguments");
+
+test(function() {
+  var iter = document.createNodeIterator(document, undefined, undefined);
+  check_iter(iter, document);
+}, "createNodeIterator() with undefined as arguments");
+
+test(function() {
+  var err = {name: "failed"};
+  var iter = document.createNodeIterator(document, NodeFilter.SHOW_ALL,
+                                         function() { throw err; });
+  assert_throws_exactly(err, function() { iter.nextNode() });
+}, "Propagate exception from filter function");
+
+test(function() {
+  var depth = 0;
+  var iter = document.createNodeIterator(document, NodeFilter.SHOW_ALL,
+    function() {
+      if (iter.referenceNode != document && depth == 0) {
+        depth++;
+        iter.nextNode();
+      }
+      return NodeFilter.FILTER_ACCEPT;
+    });
+  iter.nextNode();
+  iter.nextNode();
+  assert_throws_dom("InvalidStateError", function() { iter.nextNode() });
+  depth--;
+  assert_throws_dom("InvalidStateError", function() { iter.previousNode() });
+}, "Recursive filters need to throw");
+
+function testIterator(root, whatToShow, filter) {
+  var iter = document.createNodeIterator(root, whatToShow, filter);
+
+  assert_equals(iter.root, root, ".root");
+  assert_equals(iter.referenceNode, root, "Initial .referenceNode");
+  assert_equals(iter.pointerBeforeReferenceNode, true,
+                ".pointerBeforeReferenceNode");
+  assert_equals(iter.whatToShow, whatToShow, ".whatToShow");
+  assert_equals(iter.filter, filter, ".filter");
+
+  var expectedReferenceNode = root;
+  var expectedBeforeNode = true;
+  // "Let node be the value of the referenceNode attribute."
+  var node = root;
+  // "Let before node be the value of the pointerBeforeReferenceNode
+  // attribute."
+  var beforeNode = true;
+  var i = 1;
+  // Each loop iteration runs nextNode() once.
+  while (node) {
+    do {
+      if (!beforeNode) {
+        // "If before node is false, let node be the first node following node
+        // in the iterator collection. If there is no such node return null."
+        node = nextNode(node);
+        if (!isInclusiveDescendant(node, root)) {
+          node = null;
+          break;
+        }
+      } else {
+        // "If before node is true, set it to false."
+        beforeNode = false;
+      }
+      // "Filter node and let result be the return value.
+      //
+      // "If result is FILTER_ACCEPT, go to the next step in the overall set of
+      // steps.
+      //
+      // "Otherwise, run these substeps again."
+      if (!((1 << (node.nodeType - 1)) & whatToShow)
+          || (filter && filter(node) != NodeFilter.FILTER_ACCEPT)) {
+        continue;
+      }
+
+      // "Set the referenceNode attribute to node, set the
+      // pointerBeforeReferenceNode attribute to before node, and return node."
+      expectedReferenceNode = node;
+      expectedBeforeNode = beforeNode;
+
+      break;
+    } while (true);
+
+    assert_equals(iter.nextNode(), node, ".nextNode() " + i + " time(s)");
+    assert_equals(iter.referenceNode, expectedReferenceNode,
+                  ".referenceNode after nextNode() " + i + " time(s)");
+    assert_equals(iter.pointerBeforeReferenceNode, expectedBeforeNode,
+             ".pointerBeforeReferenceNode after nextNode() " + i + " time(s)");
+
+    i++;
+  }
+
+  // Same but for previousNode() (mostly copy-pasted, oh well)
+  var iter = document.createNodeIterator(root, whatToShow, filter);
+
+  var expectedReferenceNode = root;
+  var expectedBeforeNode = true;
+  // "Let node be the value of the referenceNode attribute."
+  var node = root;
+  // "Let before node be the value of the pointerBeforeReferenceNode
+  // attribute."
+  var beforeNode = true;
+  var i = 1;
+  // Each loop iteration runs previousNode() once.
+  while (node) {
+    do {
+      if (beforeNode) {
+        // "If before node is true, let node be the first node preceding node
+        // in the iterator collection. If there is no such node return null."
+        node = previousNode(node);
+        if (!isInclusiveDescendant(node, root)) {
+          node = null;
+          break;
+        }
+      } else {
+        // "If before node is false, set it to true."
+        beforeNode = true;
+      }
+      // "Filter node and let result be the return value.
+      //
+      // "If result is FILTER_ACCEPT, go to the next step in the overall set of
+      // steps.
+      //
+      // "Otherwise, run these substeps again."
+      if (!((1 << (node.nodeType - 1)) & whatToShow)
+          || (filter && filter(node) != NodeFilter.FILTER_ACCEPT)) {
+        continue;
+      }
+
+      // "Set the referenceNode attribute to node, set the
+      // pointerBeforeReferenceNode attribute to before node, and return node."
+      expectedReferenceNode = node;
+      expectedBeforeNode = beforeNode;
+
+      break;
+    } while (true);
+
+    assert_equals(iter.previousNode(), node, ".previousNode() " + i + " time(s)");
+    assert_equals(iter.referenceNode, expectedReferenceNode,
+                  ".referenceNode after previousNode() " + i + " time(s)");
+    assert_equals(iter.pointerBeforeReferenceNode, expectedBeforeNode,
+         ".pointerBeforeReferenceNode after previousNode() " + i + " time(s)");
+
+    i++;
+  }
+}
+
+var whatToShows = [
+  "0",
+  "0xFFFFFFFF",
+  "NodeFilter.SHOW_ELEMENT",
+  "NodeFilter.SHOW_ATTRIBUTE",
+  "NodeFilter.SHOW_ELEMENT | NodeFilter.SHOW_DOCUMENT",
+];
+
+var callbacks = [
+  "null",
+  "(function(node) { return true })",
+  "(function(node) { return false })",
+  "(function(node) { return node.nodeName[0] == '#' })",
+];
+
+for (var i = 0; i < testNodes.length; i++) {
+  for (var j = 0; j < whatToShows.length; j++) {
+    for (var k = 0; k < callbacks.length; k++) {
+      test(() => {
+        testIterator(eval(testNodes[i]), eval(whatToShows[j]), eval(callbacks[k]));
+      }, "document.createNodeIterator(" + testNodes[i] + ", " + whatToShows[j] + ", " + callbacks[k] + ")");
+    }
+  }
+}
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter-cross-realm-null-browsing-context.html b/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter-cross-realm-null-browsing-context.html
new file mode 100644
index 0000000000..f8e71bcdf5
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter-cross-realm-null-browsing-context.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>TreeWalker: NodeFilter from detached iframe doesn't get called</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+<div></div>
+
+<script>
+const t = async_test();
+
+const iframe = document.createElement("iframe");
+iframe.src = "support/TreeWalker-acceptNode-filter-cross-realm-null-browsing-context-subframe.html";
+iframe.onload = t.step_func_done(() => {
+    const nodeIterator = iframe.contentWindow.createNodeIterator();
+    iframe.remove();
+
+    assert_equals(iframe.contentWindow, null);
+
+    let errorWasThrown = false;
+    try { nodeIterator.nextNode(); }
+    catch { errorWasThrown = true; }
+
+    assert_true(errorWasThrown);
+    assert_false(nodeIterator.dummyFilterCalled);
+});
+
+document.body.append(iframe);
+</script>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter-cross-realm.html b/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter-cross-realm.html
new file mode 100644
index 0000000000..da91cf6cb2
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter-cross-realm.html
@@ -0,0 +1,60 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>TreeWalker: cross-realm NodeFilter throws TypeError of its associated Realm</title>
+<link rel="help" href="https://webidl.spec.whatwg.org/#ref-for-prepare-to-run-script">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<iframe name="nodeFilterGlobalObject" src="support/empty-document.html"></iframe>
+
+<div id="treeWalkerRoot">
+    <div class="firstChild"></div>
+</div>
+
+<script>
+test_onload(() => {
+    const nodeFilter = new nodeFilterGlobalObject.Object;
+
+    const walker = document.createTreeWalker(treeWalkerRoot, NodeFilter.SHOW_ELEMENT, nodeFilter);
+    assert_throws_js(nodeFilterGlobalObject.TypeError, () => { walker.firstChild(); });
+}, "NodeFilter is cross-realm plain object without 'acceptNode' property");
+
+test_onload(() => {
+    const nodeFilter = new nodeFilterGlobalObject.Object;
+    nodeFilter.acceptNode = {};
+
+    const walker = document.createTreeWalker(treeWalkerRoot, NodeFilter.SHOW_ELEMENT, nodeFilter);
+    assert_throws_js(nodeFilterGlobalObject.TypeError, () => { walker.firstChild(); });
+}, "NodeFilter is cross-realm plain object with non-callable 'acceptNode' property");
+
+test_onload(() => {
+    const { proxy, revoke } = Proxy.revocable(() => {}, {});
+    revoke();
+
+    const nodeFilter = new nodeFilterGlobalObject.Object;
+    nodeFilter.acceptNode = proxy;
+
+    const walker = document.createTreeWalker(treeWalkerRoot, NodeFilter.SHOW_ELEMENT, nodeFilter);
+    assert_throws_js(nodeFilterGlobalObject.TypeError, () => { walker.firstChild(); });
+}, "NodeFilter is cross-realm plain object with revoked Proxy as 'acceptNode' property");
+
+test_onload(() => {
+    const { proxy, revoke } = nodeFilterGlobalObject.Proxy.revocable({}, {});
+    revoke();
+
+    const walker = document.createTreeWalker(treeWalkerRoot, NodeFilter.SHOW_ELEMENT, proxy);
+    assert_throws_js(nodeFilterGlobalObject.TypeError, () => { walker.firstChild(); });
+}, "NodeFilter is cross-realm non-callable revoked Proxy");
+
+test_onload(() => {
+    const { proxy, revoke } = nodeFilterGlobalObject.Proxy.revocable(() => {}, {});
+    revoke();
+
+    const walker = document.createTreeWalker(treeWalkerRoot, NodeFilter.SHOW_ELEMENT, proxy);
+    assert_throws_js(nodeFilterGlobalObject.TypeError, () => { walker.firstChild(); });
+}, "NodeFilter is cross-realm callable revoked Proxy");
+
+function test_onload(fn, desc) {
+    async_test(t => { window.addEventListener("load", t.step_func_done(fn)); }, desc);
+}
+</script>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter.html b/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter.html
new file mode 100644
index 0000000000..282dc9d142
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-acceptNode-filter.html
@@ -0,0 +1,195 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from chromium/source/src/third_party/WebKit/LayoutTests/fast/dom/TreeWalker/script-tests/acceptNode-filter.js
+-->
+<head>
+<title>TreeWalker: acceptNode-filter</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<link rel="help" href="https://dom.spec.whatwg.org/#callbackdef-nodefilter">
+<div id=log></div>
+</head>
+<body>
+<p>Test JS objects as NodeFilters</p>
+<script>
+var testElement;
+setup(function() {
+    testElement = document.createElement("div");
+    testElement.id = 'root';
+    //testElement.innerHTML='<div id="A1"><div id="B1"></div><div id="B2"></div></div>';
+
+    // XXX for Servo, build the tree without using innerHTML
+    var a1 = document.createElement("div");
+    a1.id = "A1";
+    var b1 = document.createElement("div");
+    b1.id = "B1";
+    var b2 = document.createElement("div");
+    b2.id = "B2";
+    testElement.appendChild(a1);
+    a1.appendChild(b1);
+    a1.appendChild(b2);
+});
+
+test(function()
+{
+    function filter(node)
+    {
+        if (node.id == "B1")
+            return NodeFilter.FILTER_SKIP;
+        return NodeFilter.FILTER_ACCEPT;
+    }
+
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, filter);
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.currentNode, { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B2' });
+    assert_node(walker.currentNode, { type: Element, id: 'B2' });
+}, 'Testing with raw function filter');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, {
+        acceptNode : function(node) {
+            if (node.id == "B1")
+                return NodeFilter.FILTER_SKIP;
+            return NodeFilter.FILTER_ACCEPT;
+        }
+    });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.currentNode, { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B2' });
+    assert_node(walker.currentNode, { type: Element, id: 'B2' });
+}, 'Testing with object filter');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, null);
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.currentNode, { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B1' });
+    assert_node(walker.currentNode, { type: Element, id: 'B1' });
+}, 'Testing with null filter');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, undefined);
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.currentNode, { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B1' });
+    assert_node(walker.currentNode, { type: Element, id: 'B1' });
+}, 'Testing with undefined filter');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, {});
+    assert_throws_js(TypeError, function () { walker.firstChild(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_throws_js(TypeError, function () { walker.nextNode(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+}, 'Testing with object lacking acceptNode property');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, { acceptNode: "foo" });
+    assert_throws_js(TypeError, function () { walker.firstChild(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_throws_js(TypeError, function () { walker.nextNode(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+}, 'Testing with object with non-function acceptNode property');
+
+test(function(t)
+{
+    var filter = function() { return NodeFilter.FILTER_ACCEPT; };
+    filter.acceptNode = t.unreached_func("`acceptNode` method should not be called on functions");
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, filter);
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B1' });
+}, 'Testing with function having acceptNode function');
+
+test(function()
+{
+    var test_error = { name: "test" };
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT,
+                                           function(node) {
+                                               throw test_error;
+                                           });
+    assert_throws_exactly(test_error, function () { walker.firstChild(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_throws_exactly(test_error, function () { walker.nextNode(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+}, 'Testing with filter function that throws');
+
+test(function() {
+    var testError = { name: "test" };
+    var filter = {
+        get acceptNode() {
+            throw testError;
+        },
+    };
+
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, filter);
+    assert_throws_exactly(testError, function() { walker.firstChild(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_throws_exactly(testError, function() { walker.nextNode(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+}, "rethrows errors when getting `acceptNode`");
+
+test(function() {
+    var calls = 0;
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, {
+        get acceptNode() {
+            calls++;
+            return function() {
+                return NodeFilter.FILTER_ACCEPT;
+            };
+        },
+    });
+
+    assert_equals(calls, 0);
+    walker.nextNode();
+    walker.nextNode();
+    assert_equals(calls, 2);
+}, "performs `Get` on every traverse");
+
+test(function()
+{
+    var test_error = { name: "test" };
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT,
+                                           {
+                                               acceptNode : function(node) {
+                                                   throw test_error;
+                                               }
+                                           });
+    assert_throws_exactly(test_error, function () { walker.firstChild(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_throws_exactly(test_error, function () { walker.nextNode(); });
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+}, 'Testing with filter object that throws');
+
+test(() =>
+{
+    let thisValue, nodeArgID;
+    const filter = {
+        acceptNode(node) {
+            thisValue = this;
+            nodeArgID = node.id;
+            return NodeFilter.FILTER_ACCEPT;
+        },
+    };
+
+    const walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, filter);
+    walker.nextNode();
+
+    assert_equals(thisValue, filter);
+    assert_equals(nodeArgID, 'A1');
+}, 'Testing with filter object: this value and `node` argument');
+
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-basic.html b/testing/web-platform/tests/dom/traversal/TreeWalker-basic.html
new file mode 100644
index 0000000000..bd8b112840
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-basic.html
@@ -0,0 +1,154 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from chromium/source/src/third_party/WebKit/LayoutTests/fast/dom/TreeWalker/TreeWalker-basic.html
+-->
+<head>
+<title>TreeWalker: Basic test</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<div id=log></div>
+</head>
+<body>
+<p>This test checks the basic functionality of TreeWalker.</p>
+<script>
+function createSampleDOM()
+{
+    // Tree structure:
+    //             #a
+    //             |
+    //        +----+----+
+    //        |         |
+    //       "b"        #c
+    //                  |
+    //             +----+----+
+    //             |         |
+    //            #d      <!--j-->
+    //             |
+    //        +----+----+
+    //        |    |    |
+    //       "e"  #f   "i"
+    //             |
+    //          +--+--+
+    //          |     |
+    //         "g" <!--h-->
+    var div = document.createElement('div');
+    div.id = 'a';
+    // div.innerHTML = 'b<div id="c"><div id="d">e<span id="f">g<!--h--></span>i</div><!--j--></div>';
+
+    div.appendChild(document.createTextNode("b"));
+
+    var c = document.createElement("div");
+    c.id = 'c';
+    div.appendChild(c);
+
+    var d = document.createElement("div");
+    d.id = 'd';
+    c.appendChild(d);
+
+    var e = document.createTextNode("e");
+    d.appendChild(e);
+
+    var f = document.createElement("span");
+    f.id = 'f';
+    d.appendChild(f);
+
+    var g = document.createTextNode("g");
+    f.appendChild(g);
+
+    var h = document.createComment("h");
+    f.appendChild(h);
+
+    var i = document.createTextNode("i");
+    d.appendChild(i);
+
+    var j = document.createComment("j");
+    c.appendChild(j);
+
+    return div;
+}
+
+function check_walker(walker, root, whatToShowValue)
+{
+    whatToShowValue = whatToShowValue === undefined ? 0xFFFFFFFF : whatToShowValue;
+
+    assert_equals(walker.toString(), '[object TreeWalker]', 'toString');
+    assert_equals(walker.root, root, 'root');
+    assert_equals(walker.whatToShow, whatToShowValue, 'whatToShow');
+    assert_equals(walker.filter, null, 'filter');
+    assert_equals(walker.currentNode, root, 'currentNode');
+    assert_readonly(walker, 'root');
+    assert_readonly(walker, 'whatToShow');
+    assert_readonly(walker, 'filter');
+}
+
+test(function ()
+{
+    var root = createSampleDOM();
+    var walker = document.createTreeWalker(root);
+    check_walker(walker, root);
+}, 'Construct a TreeWalker by document.createTreeWalker(root).');
+
+test(function ()
+{
+    var root = createSampleDOM();
+    var walker = document.createTreeWalker(root, null, null);
+    check_walker(walker, root, 0);
+}, 'Construct a TreeWalker by document.createTreeWalker(root, null, null).');
+
+test(function ()
+{
+    var root = createSampleDOM();
+    var walker = document.createTreeWalker(root, undefined, undefined);
+    check_walker(walker, root);
+}, 'Construct a TreeWalker by document.createTreeWalker(root, undefined, undefined).');
+
+test(function ()
+{
+    assert_throws_js(TypeError, function () { document.createTreeWalker(); });
+    assert_throws_js(TypeError, function () { document.createTreeWalker(null); });
+    assert_throws_js(TypeError, function () { document.createTreeWalker(undefined); });
+    assert_throws_js(TypeError, function () { document.createTreeWalker(new Object()); });
+    assert_throws_js(TypeError, function () { document.createTreeWalker(1); });
+}, 'Give an invalid root node to document.createTreeWalker().');
+
+test(function ()
+{
+    var root = createSampleDOM();
+    var walker = document.createTreeWalker(root);
+    var f = root.lastChild.firstChild.childNodes[1];  // An element node: div#f.
+
+    assert_node(walker.currentNode, { type: Element, id: 'a' });
+    assert_equals(walker.parentNode(), null);
+    assert_node(walker.currentNode, { type: Element, id: 'a' });
+    assert_node(walker.firstChild(), { type: Text, nodeValue: 'b' });
+    assert_node(walker.currentNode, { type: Text, nodeValue: 'b' });
+    assert_node(walker.nextSibling(), { type: Element, id: 'c' });
+    assert_node(walker.currentNode, { type: Element, id: 'c' });
+    assert_node(walker.lastChild(), { type: Comment, nodeValue: 'j' });
+    assert_node(walker.currentNode, { type: Comment, nodeValue: 'j' });
+    assert_node(walker.previousSibling(), { type: Element, id: 'd' });
+    assert_node(walker.currentNode, { type: Element, id: 'd' });
+    assert_node(walker.nextNode(), { type: Text, nodeValue: 'e' });
+    assert_node(walker.currentNode, { type: Text, nodeValue: 'e' });
+    assert_node(walker.parentNode(), { type: Element, id: 'd' });
+    assert_node(walker.currentNode, { type: Element, id: 'd' });
+    assert_node(walker.previousNode(), { type: Element, id: 'c' });
+    assert_node(walker.currentNode, { type: Element, id: 'c' });
+    assert_equals(walker.nextSibling(), null);
+    assert_node(walker.currentNode, { type: Element, id: 'c' });
+    walker.currentNode = f;
+    assert_equals(walker.currentNode, f);
+}, 'Walk over nodes.');
+
+test(function() {
+    var treeWalker = document.createTreeWalker(document.body, 42, null);
+    assert_equals(treeWalker.root, document.body);
+    assert_equals(treeWalker.currentNode, document.body);
+    assert_equals(treeWalker.whatToShow, 42);
+    assert_equals(treeWalker.filter, null);
+}, "Optional arguments to createTreeWalker should be optional (3 passed, null).");
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-currentNode.html b/testing/web-platform/tests/dom/traversal/TreeWalker-currentNode.html
new file mode 100644
index 0000000000..f795abe0d2
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-currentNode.html
@@ -0,0 +1,73 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from chromium/source/src/third_party/WebKit/LayoutTests/fast/dom/TreeWalker/resources/TreeWalker-currentNode.js
+-->
+<head>
+<title>TreeWalker: currentNode</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<div id=log></div>
+</head>
+<body>
+<div id='parent'>
+<div id='subTree'><p>Lorem ipsum <span>dolor <b>sit</b> amet</span>, consectetur <i>adipisicing</i> elit, sed do eiusmod <tt>tempor <b><i>incididunt ut</i> labore</b> et dolore magna</tt> aliqua.</p></div>
+</div>
+<p>Test TreeWalker currentNode functionality</p>
+<script>
+// var subTree = document.createElement('div');
+// subTree.innerHTML = "<p>Lorem ipsum <span>dolor <b>sit</b> amet</span>, consectetur <i>adipisicing</i> elit, sed do eiusmod <tt>tempor <b><i>incididunt ut</i> labore</b> et dolore magna</tt> aliqua.</p>"
+// document.body.appendChild(subTree);
+var subTree = document.getElementById("subTree");
+
+var all = function(node) { return true; }
+
+test(function()
+{
+    var w = document.createTreeWalker(subTree, NodeFilter.SHOW_ELEMENT, all);
+    assert_node(w.currentNode, { type: Element, id: 'subTree' });
+    assert_equals(w.parentNode(), null);
+    assert_node(w.currentNode, { type: Element, id: 'subTree' });
+}, "Test that TreeWalker.parent() doesn't set the currentNode to a node not under the root.");
+
+test(function()
+{
+    var w = document.createTreeWalker(subTree,
+                                      NodeFilter.SHOW_ELEMENT
+                                      | NodeFilter.SHOW_COMMENT,
+                                      all);
+    w.currentNode = document.documentElement;
+    assert_equals(w.parentNode(), null);
+    assert_equals(w.currentNode, document.documentElement);
+    w.currentNode = document.documentElement;
+    assert_equals(w.nextNode(), document.documentElement.firstChild);
+    assert_equals(w.currentNode, document.documentElement.firstChild);
+    w.currentNode = document.documentElement;
+    assert_equals(w.previousNode(), null);
+    assert_equals(w.currentNode, document.documentElement);
+    w.currentNode = document.documentElement;
+    assert_equals(w.firstChild(), document.documentElement.firstChild);
+    assert_equals(w.currentNode, document.documentElement.firstChild);
+    w.currentNode = document.documentElement;
+    assert_equals(w.lastChild(), document.documentElement.lastChild);
+    assert_equals(w.currentNode, document.documentElement.lastChild);
+    w.currentNode = document.documentElement;
+    assert_equals(w.nextSibling(), null);
+    assert_equals(w.currentNode, document.documentElement);
+    w.currentNode = document.documentElement;
+    assert_equals(w.previousSibling(), null);
+    assert_equals(w.currentNode, document.documentElement);
+}, "Test that we handle setting the currentNode to arbitrary nodes not under the root element.");
+
+test(function()
+{
+    var w = document.createTreeWalker(subTree, NodeFilter.SHOW_ELEMENT, all);
+    w.currentNode = subTree.previousSibling;
+    assert_equals(w.nextNode(), subTree);
+    w.currentNode = document.getElementById("parent");
+    assert_equals(w.firstChild(), subTree);
+}, "Test how we handle the case when the traversed to node is within the root, but the currentElement is not.");
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-previousNodeLastChildReject.html b/testing/web-platform/tests/dom/traversal/TreeWalker-previousNodeLastChildReject.html
new file mode 100644
index 0000000000..e24ca06e20
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-previousNodeLastChildReject.html
@@ -0,0 +1,87 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from chromium/source/src/third_party/WebKit/LayoutTests/fast/dom/TreeWalker/script-tests/previousNodeLastChildReject.js
+-->
+<head>
+<title>TreeWalker: previousNodeLastChildReject</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<div id=log></div>
+</head>
+<body>
+<p>Test that previousNode properly respects the filter.</p>
+<script>
+var testElement;
+setup(function() {
+    testElement = document.createElement("div");
+    testElement.id = 'root';
+    // testElement.innerHTML='<div id="A1"><div id="B1"><div id="C1"></div><div id="C2"><div id="D1"></div><div id="D2"></div></div></div><div id="B2"><div id="C3"></div><div id="C4"></div></div></div>';
+    // testElement.innerHTML='
+    // <div id="A1">
+    //   <div id="B1">
+    //     <div id="C1">
+    //     </div>
+    //     <div id="C2">
+    //       <div id="D1">
+    //       </div>
+    //       <div id="D2">
+    //       </div>
+    //     </div>
+    //   </div>
+    //   <div id="B2">
+    //     <div id="C3">
+    //     </div>
+    //     <div id="C4">
+    //     </div>
+    //   </div>
+    // </div>';
+
+    // XXX for Servo, build the tree without using innerHTML
+    var a1 = document.createElement("div"); a1.id = "A1";
+    var b1 = document.createElement("div"); b1.id = "B1";
+    var b2 = document.createElement("div"); b2.id = "B2";
+    var c1 = document.createElement("div"); c1.id = "C1";
+    var c2 = document.createElement("div"); c2.id = "C2";
+    var c3 = document.createElement("div"); c3.id = "C3";
+    var c4 = document.createElement("div"); c4.id = "C4";
+    var d1 = document.createElement("div"); d1.id = "D1";
+    var d2 = document.createElement("div"); d2.id = "D2";
+
+    testElement.appendChild(a1);
+    a1.appendChild(b1);
+    a1.appendChild(b2);
+    b1.appendChild(c1);
+    b1.appendChild(c2);
+    b2.appendChild(c3);
+    b2.appendChild(c4);
+    c2.appendChild(d1);
+    c2.appendChild(d2);
+});
+
+test(function()
+{
+    function filter(node)
+    {
+        if (node.id == "C2")
+            return NodeFilter.FILTER_REJECT;
+        return NodeFilter.FILTER_ACCEPT;
+    }
+
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, filter);
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.currentNode, { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B1' });
+    assert_node(walker.currentNode, { type: Element, id: 'B1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'C1' });
+    assert_node(walker.currentNode, { type: Element, id: 'C1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B2' });
+    assert_node(walker.currentNode, { type: Element, id: 'B2' });
+    assert_node(walker.previousNode(), { type: Element, id: 'C1' });
+    assert_node(walker.currentNode, { type: Element, id: 'C1' });
+}, 'Test that previousNode properly respects the filter.');
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-previousSiblingLastChildSkip.html b/testing/web-platform/tests/dom/traversal/TreeWalker-previousSiblingLastChildSkip.html
new file mode 100644
index 0000000000..5e28aa5142
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-previousSiblingLastChildSkip.html
@@ -0,0 +1,91 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from chromium/source/src/third_party/WebKit/LayoutTests/fast/dom/TreeWalker/script-tests/previousSiblingLastChildSkip.js
+-->
+<head>
+<title>TreeWalker: previousSiblingLastChildSkip</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<div id=log></div>
+</head>
+<body>
+<p>Test that previousSibling properly respects the filter.</p>
+<script>
+var testElement;
+setup(function() {
+    testElement = document.createElement("div");
+    testElement.id = 'root';
+    // testElement.innerHTML='<div id="A1"><div id="B1"><div id="C1"></div><div id="C2"><div id="D1"></div><div id="D2"></div></div></div><div id="B2"><div id="C3"></div><div id="C4"></div></div></div>';
+    // testElement.innerHTML='
+    // <div id="A1">
+    //   <div id="B1">
+    //     <div id="C1">
+    //     </div>
+    //     <div id="C2">
+    //       <div id="D1">
+    //       </div>
+    //       <div id="D2">
+    //       </div>
+    //     </div>
+    //   </div>
+    //   <div id="B2">
+    //     <div id="C3">
+    //     </div>
+    //     <div id="C4">
+    //     </div>
+    //   </div>
+    // </div>';
+
+    // XXX for Servo, build the tree without using innerHTML
+    var a1 = document.createElement("div"); a1.id = "A1";
+    var b1 = document.createElement("div"); b1.id = "B1";
+    var b2 = document.createElement("div"); b2.id = "B2";
+    var c1 = document.createElement("div"); c1.id = "C1";
+    var c2 = document.createElement("div"); c2.id = "C2";
+    var c3 = document.createElement("div"); c3.id = "C3";
+    var c4 = document.createElement("div"); c4.id = "C4";
+    var d1 = document.createElement("div"); d1.id = "D1";
+    var d2 = document.createElement("div"); d2.id = "D2";
+
+    testElement.appendChild(a1);
+    a1.appendChild(b1);
+    a1.appendChild(b2);
+    b1.appendChild(c1);
+    b1.appendChild(c2);
+    b2.appendChild(c3);
+    b2.appendChild(c4);
+    c2.appendChild(d1);
+    c2.appendChild(d2);
+});
+
+test(function()
+{
+    function filter(node)
+    {
+        if (node.id == "B1")
+            return NodeFilter.FILTER_SKIP;
+        return NodeFilter.FILTER_ACCEPT;
+    }
+
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, filter);
+    assert_node(walker.currentNode, { type: Element, id: 'root' });
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.currentNode, { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'C1' });
+    assert_node(walker.currentNode, { type: Element, id: 'C1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'C2' });
+    assert_node(walker.currentNode, { type: Element, id: 'C2' });
+    assert_node(walker.nextNode(), { type: Element, id: 'D1' });
+    assert_node(walker.currentNode, { type: Element, id: 'D1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'D2' });
+    assert_node(walker.currentNode, { type: Element, id: 'D2' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B2' });
+    assert_node(walker.currentNode, { type: Element, id: 'B2' });
+    assert_node(walker.previousSibling(), { type: Element, id: 'C2' });
+    assert_node(walker.currentNode, { type: Element, id: 'C2' });
+}, 'Test that previousSibling properly respects the filter.');
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-reject.html b/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-reject.html
new file mode 100644
index 0000000000..d6c96adc11
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-reject.html
@@ -0,0 +1,109 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from chromium/source/src/third_party/WebKit/LayoutTests/fast/dom/TreeWalker/script-tests/traversal-reject.js
+-->
+<head>
+<title>TreeWalker: traversal-reject</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<div id=log></div>
+</head>
+<body>
+<p>Test TreeWalker with rejection</p>
+<script>
+var testElement;
+setup(function() {
+    testElement = document.createElement("div");
+    testElement.id = 'root';
+    //testElement.innerHTML='<div id="A1">  <div id="B1">  <div id="C1"></div>  </div>  <div id="B2"></div><div id="B3"></div>  </div>';
+    // <div id="A1">
+    //   <div id="B1">
+    //     <div id="C1"></div>
+    //   </div>
+    //   <div id="B2"></div>
+    //   <div id="B3"></div>
+    // </div>
+
+
+    // XXX for Servo, build the tree without using innerHTML
+    var a1 = document.createElement("div"); a1.id = "A1";
+    var b1 = document.createElement("div"); b1.id = "B1";
+    var b2 = document.createElement("div"); b2.id = "B2";
+    var b3 = document.createElement("div"); b3.id = "B3";
+    var c1 = document.createElement("div"); c1.id = "C1";
+
+    testElement.appendChild(a1);
+    a1.appendChild(b1);
+    a1.appendChild(b2);
+    a1.appendChild(b3);
+    b1.appendChild(c1);
+});
+
+var rejectB1Filter = {
+  acceptNode: function(node) {
+    if (node.id == 'B1')
+      return NodeFilter.FILTER_REJECT;
+
+    return NodeFilter.FILTER_ACCEPT;
+  }
+}
+
+var skipB2Filter = {
+  acceptNode: function(node) {
+    if (node.id == 'B2')
+      return NodeFilter.FILTER_SKIP;
+
+    return NodeFilter.FILTER_ACCEPT;
+  }
+}
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, rejectB1Filter);
+    assert_node(walker.nextNode(), { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B2' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B3' });
+}, 'Testing nextNode');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, rejectB1Filter);
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.firstChild(), { type: Element, id: 'B2' });
+}, 'Testing firstChild');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, skipB2Filter);
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.firstChild(), { type: Element, id: 'B1' });
+    assert_node(walker.nextSibling(), { type: Element, id: 'B3' });
+}, 'Testing nextSibling');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, rejectB1Filter);
+    walker.currentNode = testElement.querySelectorAll('#C1')[0];
+    assert_node(walker.parentNode(), { type: Element, id: 'A1' });
+}, 'Testing parentNode');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, skipB2Filter);
+    walker.currentNode = testElement.querySelectorAll('#B3')[0];
+    assert_node(walker.previousSibling(), { type: Element, id: 'B1' });
+}, 'Testing previousSibling');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, rejectB1Filter);
+    walker.currentNode = testElement.querySelectorAll('#B3')[0];
+    assert_node(walker.previousNode(), { type: Element, id: 'B2' });
+    assert_node(walker.previousNode(), { type: Element, id: 'A1' });
+}, 'Testing previousNode');
+
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-skip-most.html b/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-skip-most.html
new file mode 100644
index 0000000000..b6eafd4596
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-skip-most.html
@@ -0,0 +1,66 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from chromium/source/src/third_party/WebKit/LayoutTests/fast/dom/TreeWalker/script-tests/traversal-skip-most.js
+-->
+<head>
+<title>TreeWalker: traversal-skip-most</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<div id=log></div>
+</head>
+<body>
+<p>Test TreeWalker with skipping</p>
+<script>
+var testElement;
+setup(function() {
+    testElement = document.createElement("div");
+    testElement.id = 'root';
+    // testElement.innerHTML='<div id="A1"><div id="B1" class="keep"></div><div id="B2">this text matters</div><div id="B3" class="keep"></div></div>';
+    // <div id="A1">
+    //   <div id="B1" class="keep"></div>
+    //   <div id="B2">this text matters</div>
+    //   <div id="B3" class="keep"></div>
+    // </div>
+
+
+    // XXX for Servo, build the tree without using innerHTML
+    var a1 = document.createElement("div"); a1.id = "A1";
+    var b1 = document.createElement("div"); b1.id = "B1"; b1.className = "keep";
+    var b2 = document.createElement("div"); b2.id = "B2";
+    var b3 = document.createElement("div"); b3.id = "B3"; b3.className = "keep";
+
+    testElement.appendChild(a1);
+    a1.appendChild(b1);
+    a1.appendChild(b2)
+        .appendChild(document.createTextNode("this text matters"));
+    a1.appendChild(b3);
+});
+
+var filter = {
+  acceptNode: function(node) {
+    if (node.className == 'keep')
+      return NodeFilter.FILTER_ACCEPT;
+
+    return NodeFilter.FILTER_SKIP;
+  }
+}
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, filter);
+    assert_node(walker.firstChild(), { type: Element, id: 'B1' });
+    assert_node(walker.nextSibling(), { type: Element, id: 'B3' });
+}, 'Testing nextSibling');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, filter);
+    walker.currentNode = testElement.querySelectorAll('#B3')[0];
+    assert_node(walker.previousSibling(), { type: Element, id: 'B1' });
+}, 'Testing previousSibling');
+
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-skip.html b/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-skip.html
new file mode 100644
index 0000000000..6bbebe667e
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-traversal-skip.html
@@ -0,0 +1,111 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from chromium/source/src/third_party/WebKit/LayoutTests/fast/dom/TreeWalker/script-tests/traversal-skip.js
+-->
+<head>
+<title>TreeWalker: traversal-skip</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<div id=log></div>
+</head>
+<body>
+<p>Test TreeWalker with skipping</p>
+<script>
+var testElement;
+setup(function() {
+    testElement = document.createElement("div");
+    testElement.id = 'root';
+    // testElement.innerHTML='<div id="A1">  <div id="B1">  <div id="C1"></div>  </div>  <div id="B2"></div><div id="B3"></div>  </div>';
+    // <div id="A1">
+    //   <div id="B1">
+    //     <div id="C1"></div>
+    //   </div>
+    //   <div id="B2"></div>
+    //   <div id="B3"></div>
+    // </div>
+
+
+    // XXX for Servo, build the tree without using innerHTML
+    var a1 = document.createElement("div"); a1.id = "A1";
+    var b1 = document.createElement("div"); b1.id = "B1";
+    var b2 = document.createElement("div"); b2.id = "B2";
+    var b3 = document.createElement("div"); b3.id = "B3";
+    var c1 = document.createElement("div"); c1.id = "C1";
+
+    testElement.appendChild(a1);
+    a1.appendChild(b1);
+    a1.appendChild(b2);
+    a1.appendChild(b3);
+    b1.appendChild(c1);
+});
+
+var skipB1Filter = {
+  acceptNode: function(node) {
+    if (node.id == 'B1')
+      return NodeFilter.FILTER_SKIP;
+
+    return NodeFilter.FILTER_ACCEPT;
+  }
+}
+
+var skipB2Filter = {
+  acceptNode: function(node) {
+    if (node.id == 'B2')
+      return NodeFilter.FILTER_SKIP;
+
+    return NodeFilter.FILTER_ACCEPT;
+  }
+}
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, skipB1Filter);
+    assert_node(walker.nextNode(), { type: Element, id: 'A1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'C1' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B2' });
+    assert_node(walker.nextNode(), { type: Element, id: 'B3' });
+}, 'Testing nextNode');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, skipB1Filter);
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.firstChild(), { type: Element, id: 'C1' });
+}, 'Testing firstChild');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, skipB2Filter);
+    assert_node(walker.firstChild(), { type: Element, id: 'A1' });
+    assert_node(walker.firstChild(), { type: Element, id: 'B1' });
+    assert_node(walker.nextSibling(), { type: Element, id: 'B3' });
+}, 'Testing nextSibling');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, skipB1Filter);
+    walker.currentNode = testElement.querySelectorAll('#C1')[0];
+    assert_node(walker.parentNode(), { type: Element, id: 'A1' });
+}, 'Testing parentNode');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, skipB2Filter);
+    walker.currentNode = testElement.querySelectorAll('#B3')[0];
+    assert_node(walker.previousSibling(), { type: Element, id: 'B1' });
+}, 'Testing previousSibling');
+
+test(function()
+{
+    var walker = document.createTreeWalker(testElement, NodeFilter.SHOW_ELEMENT, skipB1Filter);
+    walker.currentNode = testElement.querySelectorAll('#B3')[0];
+    assert_node(walker.previousNode(), { type: Element, id: 'B2' });
+    assert_node(walker.previousNode(), { type: Element, id: 'C1' });
+    assert_node(walker.previousNode(), { type: Element, id: 'A1' });
+}, 'Testing previousNode');
+
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker-walking-outside-a-tree.html b/testing/web-platform/tests/dom/traversal/TreeWalker-walking-outside-a-tree.html
new file mode 100644
index 0000000000..b99e33e01f
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker-walking-outside-a-tree.html
@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<html>
+<!--
+Test adapted from https://github.com/operasoftware/presto-testo/blob/master/core/standards/acid3/individual/006a.html
+-->
+<head>
+<title>TreeWalker: walking-outside-a-tree</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="support/assert-node.js"></script>
+<div id=log></div>
+</head>
+<body>
+<p>[Acid3 - Test 006a] walking outside a tree</p>
+<script>
+test(function () {
+    // test 6: walking outside a tree
+    var doc = document.createElement("div");
+    var head = document.createElement('head');
+    var title = document.createElement('title');
+    var body = document.createElement('body');
+    var p = document.createElement('p');
+    doc.appendChild(head);
+    head.appendChild(title);
+    doc.appendChild(body);
+    body.appendChild(p);
+
+    var w = document.createTreeWalker(body, 0xFFFFFFFF, null);
+    doc.removeChild(body);
+    assert_equals(w.lastChild(), p, "TreeWalker failed after removing the current node from the tree");
+    doc.appendChild(p);
+    assert_equals(w.previousNode(), title, "failed to handle regrafting correctly");
+    p.appendChild(body);
+    assert_equals(w.nextNode(), p, "couldn't retrace steps");
+    assert_equals(w.nextNode(), body, "couldn't step back into root");
+    assert_equals(w.previousNode(), null, "root didn't retake its rootish position");
+}, "walking outside a tree");
+</script>
+</body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/TreeWalker.html b/testing/web-platform/tests/dom/traversal/TreeWalker.html
new file mode 100644
index 0000000000..093c781447
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/TreeWalker.html
@@ -0,0 +1,324 @@
+<!doctype html>
+<title>TreeWalker tests</title>
+<link rel="author" title="Aryeh Gregor" href=ayg@aryeh.name>
+<meta name=timeout content=long>
+<div id=log></div>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=../common.js></script>
+<script>
+"use strict";
+
+// TODO .previousNode, .nextNode
+
+test(function() {
+  var depth = 0;
+  var walker = document.createTreeWalker(document, NodeFilter.SHOW_ALL,
+    function() {
+      if (depth == 0) {
+        depth++;
+        walker.firstChild();
+      }
+      return NodeFilter.FILTER_ACCEPT;
+    });
+  walker.currentNode = document.body;
+  assert_throws_dom("InvalidStateError", function() { walker.parentNode() });
+  depth--;
+  assert_throws_dom("InvalidStateError", function() { walker.firstChild() });
+  depth--;
+  assert_throws_dom("InvalidStateError", function() { walker.lastChild() });
+  depth--;
+  assert_throws_dom("InvalidStateError", function() { walker.previousSibling() });
+  depth--;
+  assert_throws_dom("InvalidStateError", function() { walker.nextSibling() });
+  depth--;
+  assert_throws_dom("InvalidStateError", function() { walker.previousNode() });
+  depth--;
+  assert_throws_dom("InvalidStateError", function() { walker.nextNode() });
+}, "Recursive filters need to throw");
+
+function filterNode(node, whatToShow, filter) {
+    // "If active flag is set throw an "InvalidStateError"."
+    // Ignore active flag for these tests, we aren't calling recursively
+    // TODO Test me
+
+    // "Let n be node's nodeType attribute value minus 1."
+    var n = node.nodeType - 1;
+
+    // "If the nth bit (where 0 is the least significant bit) of whatToShow is
+    // not set, return FILTER_SKIP."
+    if (!(whatToShow & (1 << n))) {
+        return NodeFilter.FILTER_SKIP;
+    }
+
+    // "If filter is null, return FILTER_ACCEPT."
+    if (!filter) {
+        return NodeFilter.FILTER_ACCEPT;
+    }
+
+    // "Set the active flag."
+    //
+    // "Let result be the return value of invoking filter."
+    //
+    // "Unset the active flag."
+    //
+    // "If an exception was thrown, re-throw the exception."
+    // TODO Test me
+    //
+    // "Return result."
+    return filter(node);
+}
+
+function testTraverseChildren(type, walker, root, whatToShow, filter) {
+    // TODO We don't test .currentNode other than the root
+    walker.currentNode = root;
+    assert_equals(walker.currentNode, root, "Setting .currentNode");
+
+    var expectedReturn = null;
+    var expectedCurrentNode = root;
+
+    // "To traverse children of type type, run these steps:
+    //
+    // "Let node be the value of the currentNode attribute."
+    var node = walker.currentNode;
+
+    // "Set node to node's first child if type is first, and node's last child
+    // if type is last."
+    node = type == "first" ? node.firstChild : node.lastChild;
+
+    // "Main: While node is not null, run these substeps:"
+    while (node) {
+        // "Filter node and let result be the return value."
+        var result = filterNode(node, whatToShow, filter);
+
+        // "If result is FILTER_ACCEPT, then set the currentNode attribute to
+        // node and return node."
+        if (result == NodeFilter.FILTER_ACCEPT) {
+            expectedCurrentNode = expectedReturn = node;
+            break;
+        }
+
+        // "If result is FILTER_SKIP, run these subsubsteps:"
+        if (result == NodeFilter.FILTER_SKIP) {
+            // "Let child be node's first child if type is first, and node's
+            // last child if type is last."
+            var child = type == "first" ? node.firstChild : node.lastChild;
+
+            // "If child is not null, set node to child and goto Main."
+            if (child) {
+                node = child;
+                continue;
+            }
+        }
+
+        // "While node is not null, run these subsubsteps:"
+        while (node) {
+            // "Let sibling be node's next sibling if type is first, and node's
+            // previous sibling if type is last."
+            var sibling = type == "first" ? node.nextSibling
+                : node.previousSibling;
+
+            // "If sibling is not null, set node to sibling and goto Main."
+            if (sibling) {
+                node = sibling;
+                break;
+            }
+
+            // "Let parent be node's parent."
+            var parent = node.parentNode;
+
+            // "If parent is null, parent is root, or parent is currentNode
+            // attribute's value, return null."
+            if (!parent || parent == root || parent == walker.currentNode) {
+                expectedReturn = node = null;
+                break;
+            } else {
+            // "Otherwise, set node to parent."
+                node = parent;
+            }
+        }
+    }
+
+    if (type == "first") {
+        assert_equals(walker.firstChild(), expectedReturn, ".firstChild()");
+        assert_equals(walker.currentNode, expectedCurrentNode,
+            ".currentNode after .firstChild()");
+    } else {
+        assert_equals(walker.lastChild(), expectedReturn, ".lastChild()");
+        assert_equals(walker.currentNode, expectedCurrentNode,
+        ".currentNode after .lastChild()");
+    }
+}
+
+function testTraverseSiblings(type, walker, root, whatToShow, filter) {
+    // TODO We don't test .currentNode other than the root's first or last child
+    if (!root.firstChild) {
+        // Nothing much to test
+
+        walker.currentNode = root;
+        assert_equals(walker.currentNode, root, "Setting .currentNode");
+
+        if (type == "next") {
+            assert_equals(walker.nextSibling(), null, ".nextSibling()");
+            assert_equals(walker.currentNode, root,
+                ".currentNode after .nextSibling()")
+        } else {
+            assert_equals(walker.previousSibling(), null, ".previousSibling()");
+            assert_equals(walker.currentNode, root,
+                ".currentNode after .previousSibling()")
+        }
+        return;
+    }
+
+    if (type == "next") {
+        walker.currentNode = root.firstChild;
+        assert_equals(walker.currentNode, root.firstChild,
+            "Setting .currentNode");
+    } else {
+        walker.currentNode = root.lastChild;
+        assert_equals(walker.currentNode, root.lastChild,
+            "Setting .currentNode");
+    }
+
+    var expectedReturn = null;
+    var expectedCurrentNode = type == "next" ? root.firstChild : root.lastChild;
+
+    // "To traverse siblings of type type run these steps:"
+    (function() {
+        // "Let node be the value of the currentNode attribute."
+        var node = type == "next" ? root.firstChild : root.lastChild;
+
+        // "If node is root, return null.
+        //
+        // "Run these substeps:
+        do {
+            // "Let sibling be node's next sibling if type is next, and node's
+            // previous sibling if type is previous."
+            var sibling = type == "next" ? node.nextSibling :
+                node.previousSibling;
+
+            // "While sibling is not null, run these subsubsteps:"
+            while (sibling) {
+                // "Set node to sibling."
+                node = sibling;
+
+                // "Filter node and let result be the return value."
+                var result = filterNode(node, whatToShow, filter);
+
+                // "If result is FILTER_ACCEPT, then set the currentNode
+                // attribute to node and return node."
+                if (result == NodeFilter.FILTER_ACCEPT) {
+                    expectedCurrentNode = expectedReturn = node;
+                    return;
+                }
+
+                // "Set sibling to node's first child if type is next, and
+                // node's last child if type is previous."
+                sibling = type == "next" ? node.firstChild : node.lastChild;
+
+                // "If result is FILTER_REJECT or sibling is null, then set
+                // sibling to node's next sibling if type is next, and node's
+                // previous sibling if type is previous."
+                if (result == NodeFilter.FILTER_REJECT || !sibling) {
+                    sibling = type == "next" ? node.nextSibling :
+                        node.previousSibling;
+                }
+            }
+
+            // "Set node to its parent."
+            node = node.parentNode;
+
+            // "If node is null or is root, return null.
+            if (!node || node == root) {
+                return;
+            }
+            // "Filter node and if the return value is FILTER_ACCEPT, then
+            // return null."
+            if (filterNode(node, whatToShow, filter)) {
+                return;
+            }
+
+            // "Run these substeps again."
+        } while (true);
+    })();
+
+    if (type == "next") {
+        assert_equals(walker.nextSibling(), expectedReturn, ".nextSibling()");
+        assert_equals(walker.currentNode, expectedCurrentNode,
+            ".currentNode after .nextSibling()");
+    } else {
+        assert_equals(walker.previousSibling(), expectedReturn, ".previousSibling()");
+        assert_equals(walker.currentNode, expectedCurrentNode,
+            ".currentNode after .previousSibling()");
+    }
+}
+
+function testWalker(root, whatToShow, filter) {
+    var walker = document.createTreeWalker(root, whatToShow, filter);
+
+    assert_equals(walker.root, root, ".root");
+    assert_equals(walker.whatToShow, whatToShow, ".whatToShow");
+    assert_equals(walker.filter, filter, ".filter");
+    assert_equals(walker.currentNode, root, ".currentNode");
+
+    var expectedReturn = null;
+    var expectedCurrentNode = walker.currentNode;
+    // "The parentNode() method must run these steps:"
+    //
+    // "Let node be the value of the currentNode attribute."
+    var node = walker.currentNode;
+
+    // "While node is not null and is not root, run these substeps:"
+    while (node && node != root) {
+        // "Let node be node's parent."
+        node = node.parentNode;
+
+        // "If node is not null and filtering node returns FILTER_ACCEPT, then
+        // set the currentNode attribute to node, return node."
+        if (node && filterNode(node, whatToShow, filter) ==
+        NodeFilter.FILTER_ACCEPT) {
+            expectedCurrentNode = expectedReturn = node;
+        }
+    }
+    assert_equals(walker.parentNode(), expectedReturn, ".parentNode()");
+    assert_equals(walker.currentNode, expectedCurrentNode,
+        ".currentNode after .parentNode()");
+
+    testTraverseChildren("first", walker, root, whatToShow, filter);
+    testTraverseChildren("last", walker, root, whatToShow, filter);
+
+    testTraverseSiblings("next", walker, root, whatToShow, filter);
+    testTraverseSiblings("previous", walker, root, whatToShow, filter);
+}
+
+var whatToShows = [
+    "0",
+    "0xFFFFFFFF",
+    "NodeFilter.SHOW_ELEMENT",
+    "NodeFilter.SHOW_ATTRIBUTE",
+    "NodeFilter.SHOW_ELEMENT | NodeFilter.SHOW_DOCUMENT",
+];
+
+var callbacks = [
+    "null",
+    "(function(node) { return true })",
+    "(function(node) { return false })",
+    "(function(node) { return node.nodeName[0] == '#' })",
+];
+
+var tests = [];
+for (var i = 0; i < testNodes.length; i++) {
+    for (var j = 0; j < whatToShows.length; j++) {
+        for (var k = 0; k < callbacks.length; k++) {
+            tests.push([
+                "document.createTreeWalker(" + testNodes[i] +
+                    ", " + whatToShows[j] + ", " + callbacks[k] + ")",
+                eval(testNodes[i]), eval(whatToShows[j]), eval(callbacks[k])
+            ]);
+        }
+    }
+}
+generate_tests(testWalker, tests);
+
+testDiv.style.display = "none";
+</script>
diff --git a/testing/web-platform/tests/dom/traversal/support/TreeWalker-acceptNode-filter-cross-realm-null-browsing-context-subframe.html b/testing/web-platform/tests/dom/traversal/support/TreeWalker-acceptNode-filter-cross-realm-null-browsing-context-subframe.html
new file mode 100644
index 0000000000..f5e393d0f0
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/support/TreeWalker-acceptNode-filter-cross-realm-null-browsing-context-subframe.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+
+<script>
+function createNodeIterator() {
+    function filter() {
+        nodeIterator.dummyFilterCalled = true;
+        return true;
+    }
+    const nodeIterator = parent.document.createNodeIterator(parent.document.body, NodeFilter.SHOW_ELEMENT, filter);
+    nodeIterator.dummyFilterCalled = false;
+    return nodeIterator;
+}
+</script>
diff --git a/testing/web-platform/tests/dom/traversal/support/assert-node.js b/testing/web-platform/tests/dom/traversal/support/assert-node.js
new file mode 100644
index 0000000000..0d5d8ad74f
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/support/assert-node.js
@@ -0,0 +1,10 @@
+// |expected| should be an object indicating the expected type of node.
+function assert_node(actual, expected)
+{
+    assert_true(actual instanceof expected.type,
+                'Node type mismatch: actual = ' + actual.nodeType + ', expected = ' + expected.nodeType);
+    if (typeof(expected.id) !== 'undefined')
+        assert_equals(actual.id, expected.id);
+    if (typeof(expected.nodeValue) !== 'undefined')
+        assert_equals(actual.nodeValue, expected.nodeValue);
+}
diff --git a/testing/web-platform/tests/dom/traversal/support/empty-document.html b/testing/web-platform/tests/dom/traversal/support/empty-document.html
new file mode 100644
index 0000000000..b9cd130a07
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/support/empty-document.html
@@ -0,0 +1,3 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<body>
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/001.xml b/testing/web-platform/tests/dom/traversal/unfinished/001.xml
new file mode 100644
index 0000000000..08bce72fcf
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/001.xml
@@ -0,0 +1,53 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Basics</title>
+  <script type="text/javascript"> <![CDATA[
+    function doTest() {
+      var iterator = document.createNodeIterator(document, NodeFilter.SHOW_ALL, null, false);
+      var expected = new Array(9, // document
+                               1, // html
+                               3, 1, // head
+                               3, 1, 3, // title
+                               3, 1, 3, 4, // script and CDATA block
+                               3, 3, 1, // body
+                               3, 1, 3, // pre
+                               3, // </body>
+                               3, 8, // <!-- -->
+                               3, 7, // <? ?>,
+                               3, 4, 3); // CDATA
+      var found = new Array();
+
+      // walk document
+      var node;
+      while (node = iterator.nextNode())
+        found.push(node.nodeType);
+
+      // check results
+      var errors = 0;
+      var s = '';
+      var length = (found.length > expected.length) ? found.length : expected.length;
+      s += 'EXPECTED  FOUND\n';
+      for (var i = 0; i < length; i += 1) {
+        s += '  ' + (expected[i] ? expected[i] : '-') +
+      '         ' + (found[i] ? found[i] : '-');
+        if (found[i] != expected[i]) {
+          s += '      MISMATCH';
+          errors += 1;
+        }
+        s += '\n';
+      }
+      var p = document.getElementsByTagNameNS('http://www.w3.org/1999/xhtml', 'pre')[0];
+      if (errors)
+        p.firstChild.data = 'FAIL: ' + errors + ' errors found:\n\n' + s;
+      else
+        p.firstChild.data = 'PASS';
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script failed to run.</pre>
+ </body>
+ <!-- some more nodes to test this: -->
+ <?test node?>
+ <![CDATA[]]>
+</html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/002.xml b/testing/web-platform/tests/dom/traversal/unfinished/002.xml
new file mode 100644
index 0000000000..bf3489688c
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/002.xml
@@ -0,0 +1,54 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Basics Backwards</title>
+  <script type="text/javascript"> <![CDATA[
+    function doTest() {
+      var iterator = document.createNodeIterator(document, NodeFilter.SHOW_ALL, null, false);
+      var expected = new Array(9, // document
+                               1, // html
+                               3, 1, // head
+                               3, 1, 3, // title
+                               3, 1, 3, 4, // script and CDATA block
+                               3, 3, 1, // body
+                               3, 1, 3, // pre
+                               3, // </body>
+                               3, 8, // <!-- -->
+                               3, 7, // <? ?>,
+                               3, 4, 3); // CDATA
+      var found = new Array();
+
+      // walk document
+      var node;
+      while (node = iterator.nextNode());
+      while (node = iterator.previousNode())
+        found.unshift(node.nodeType);
+
+      // check results
+      var errors = 0;
+      var s = '';
+      var length = (found.length > expected.length) ? found.length : expected.length;
+      s += 'EXPECTED  FOUND\n';
+      for (var i = 0; i < length; i += 1) {
+        s += '  ' + (expected[i] ? expected[i] : '-') +
+      '         ' + (found[i] ? found[i] : '-');
+        if (found[i] != expected[i]) {
+          s += '      MISMATCH';
+          errors += 1;
+        }
+        s += '\n';
+      }
+      var p = document.getElementsByTagNameNS('http://www.w3.org/1999/xhtml', 'pre')[0];
+      if (errors)
+        p.firstChild.data = 'FAIL: ' + errors + ' errors found:\n\n' + s;
+      else
+        p.firstChild.data = 'PASS';
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script failed to run.</pre>
+ </body>
+ <!-- some more nodes to test this: -->
+ <?test node?>
+ <![CDATA[]]>
+</html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/003.xml b/testing/web-platform/tests/dom/traversal/unfinished/003.xml
new file mode 100644
index 0000000000..268e6bb4d7
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/003.xml
@@ -0,0 +1,58 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Removal of nodes that should have no effect</title>
+  <!--
+   This tests these cases that should have no effect:
+    1. Remove a node unrelated to the reference node
+    2. Remove an ancestor of the root node
+    3. Remove the root node itself
+    4. Remove descendant of reference node
+  -->
+  <script type="text/javascript"> <![CDATA[
+    var errors = 0;
+    var log = '';
+    function doTest() {
+      var iterator = document.createNodeIterator(document.getElementById('root'), NodeFilter.SHOW_ALL, null, false);
+      var root = document.getElementById('root');
+      var A = document.getElementById('A');
+      var B = document.getElementById('B');
+      var C = document.getElementById('C');
+      var D = document.getElementById('D');
+      var E = document.getElementById('E');
+      check(iterator.nextNode(), root);
+      remove(document.getElementById('X'));
+      check(iterator.nextNode(), A);
+      remove(document.getElementById('Y'));
+      check(iterator.nextNode(), B);
+      remove(root);
+      check(iterator.nextNode(), C);
+      remove(E);
+      check(iterator.nextNode(), D);
+      if (errors)
+        document.getElementById('result').firstChild.data = 'FAIL: ' + errors + ' errors:\n' + log;
+      else
+        document.getElementById('result').firstChild.data = 'PASS';
+    }
+    function check(a, b) {
+      if (!a) {
+        errors += 1;
+        log += 'Found null but expected ' + b + ' (' + b.id + ').\n';
+      } else if (a != b) {
+        errors += 1;
+        log += 'Found ' + a + ' (' + a.id + ') but expected ' + b + ' (' + b.id + ').\n';
+      }
+    }
+    function remove(a) {
+      if (!a) {
+        errors += 1;
+        log += 'Tried removing null node.\n';
+      } else
+      a.parentNode.removeChild(a);
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script did not complete.</pre>
+  <p><span id="X"></span><span id="Y"><span id="root"><span id="A"><span id="B"><span id="C"><span id="D"><span id="E"></span></span></span></span></span></span></span></p>
+ </body>
+</html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/004.xml b/testing/web-platform/tests/dom/traversal/unfinished/004.xml
new file mode 100644
index 0000000000..618978f021
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/004.xml
@@ -0,0 +1,49 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Removal of the Reference Node</title>
+  <script type="text/javascript"> <![CDATA[
+    var errors = 0;
+    var log = '';
+    function doTest() {
+      var iterator = document.createNodeIterator(document.getElementById('root'), NodeFilter.SHOW_ALL, null, false);
+      var root = document.getElementById('root');
+      var A = document.getElementById('A');
+      var AA = document.getElementById('AA');
+      var B = document.getElementById('B');
+      var C = document.getElementById('C');
+      check(iterator.nextNode(), root);
+      check(iterator.nextNode(), A);
+      check(iterator.nextNode(), AA);
+      check(iterator.nextNode(), B);
+      remove(B);
+      check(iterator.previousNode(), AA);
+      remove(AA);
+      check(iterator.nextNode(), C);
+      if (errors)
+        document.getElementById('result').firstChild.data = 'FAIL: ' + errors + ' errors:\n' + log;
+      else
+        document.getElementById('result').firstChild.data = 'PASS';
+    }
+    function check(a, b) {
+      if (!a) {
+        errors += 1;
+        log += 'Found null but expected ' + b + ' (' + b.id + ').\n';
+      } else if (a != b) {
+        errors += 1;
+        log += 'Found ' + a + ' (' + a.id + ') but expected ' + b + ' (' + b.id + ').\n';
+      }
+    }
+    function remove(a) {
+      if (!a) {
+        errors += 1;
+        log += 'Tried removing null node.\n';
+      } else
+      a.parentNode.removeChild(a);
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script did not complete.</pre>
+  <p><span id="root"><span id="A"><span id="AA"></span></span><span id="B"></span><span id="C"><span id="CC"></span></span></span></p>
+ </body>
+</html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/005.xml b/testing/web-platform/tests/dom/traversal/unfinished/005.xml
new file mode 100644
index 0000000000..643e2f1cd4
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/005.xml
@@ -0,0 +1,57 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Removal of the Reference Node (deep check)</title>
+  <script type="text/javascript"> <![CDATA[
+    var errors = 0;
+    var log = '';
+    function doTest() {
+      var iterator = document.createNodeIterator(document.getElementById('root'), NodeFilter.SHOW_ALL, null, false);
+      var root = document.getElementById('root');
+      var A = document.getElementById('A');
+      var AA = document.getElementById('AA');
+      var B = document.getElementById('B');
+      var C = document.getElementById('C');
+      check(iterator.nextNode(), root);
+      check(iterator.nextNode(), A);
+      check(iterator.nextNode(), AA);
+      check(iterator.nextNode(), B);
+      remove(B);
+      var X = addChildTo(AA);
+      check(iterator.nextNode(), X);
+      check(iterator.previousNode(), X);
+      remove(X);
+      var Y = addChildTo(AA);
+      check(iterator.previousNode(), Y);
+      if (errors)
+        document.getElementById('result').firstChild.data = 'FAIL: ' + errors + ' errors:\n' + log;
+      else
+        document.getElementById('result').firstChild.data = 'PASS';
+    }
+    function check(a, b) {
+      if (!a) {
+        errors += 1;
+        log += 'Found null but expected ' + b + ' (' + b.id + ').\n';
+      } else if (a != b) {
+        errors += 1;
+        log += 'Found ' + a + ' (' + a.id + ') but expected ' + b + ' (' + b.id + ').\n';
+      }
+    }
+    function remove(a) {
+      if (!a) {
+        errors += 1;
+        log += 'Tried removing null node.\n';
+      } else
+      a.parentNode.removeChild(a);
+    }
+    function addChildTo(a) {
+      var x = document.createElementNS('http://www.w3.org/1999/xhtml', 'span');
+      a.appendChild(x);
+      return x;
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script did not complete.</pre>
+  <p><span id="root"><span id="A"><span id="AA"></span></span><span id="B"></span><span id="C"><span id="CC"></span></span></span></p>
+ </body>
+</html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/006.xml b/testing/web-platform/tests/dom/traversal/unfinished/006.xml
new file mode 100644
index 0000000000..c2302af836
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/006.xml
@@ -0,0 +1,47 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Removal of an ancestor of the Reference Node (forwards)</title>
+  <script type="text/javascript"> <![CDATA[
+    var errors = 0;
+    var log = '';
+    function doTest() {
+      var iterator = document.createNodeIterator(document.getElementById('root'), NodeFilter.SHOW_ALL, null, false);
+      var root = document.getElementById('root');
+      var A = document.getElementById('A');
+      var B = document.getElementById('B');
+      var BB = document.getElementById('BB');
+      var C = document.getElementById('C');
+      check(iterator.nextNode(), root);
+      check(iterator.nextNode(), A);
+      check(iterator.nextNode(), B);
+      check(iterator.nextNode(), BB);
+      remove(B);
+      check(iterator.previousNode(), A);
+      if (errors)
+        document.getElementById('result').firstChild.data = 'FAIL: ' + errors + ' errors:\n' + log;
+      else
+        document.getElementById('result').firstChild.data = 'PASS';
+    }
+    function check(a, b) {
+      if (!a) {
+        errors += 1;
+        log += 'Found null but expected ' + b + ' (' + b.id + ').\n';
+      } else if (a != b) {
+        errors += 1;
+        log += 'Found ' + a + ' (' + a.id + ') but expected ' + b + ' (' + b.id + ').\n';
+      }
+    }
+    function remove(a) {
+      if (!a) {
+        errors += 1;
+        log += 'Tried removing null node.\n';
+      } else
+      a.parentNode.removeChild(a);
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script did not complete.</pre>
+  <p><span id="root"><span id="A"></span><span id="B"><span id="BB"></span></span><span id="C"></span></span></p>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/007.xml b/testing/web-platform/tests/dom/traversal/unfinished/007.xml
new file mode 100644
index 0000000000..98b212e4e5
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/007.xml
@@ -0,0 +1,54 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Removal of an ancestor of the Reference Node (forwards) (deep check)</title>
+  <script type="text/javascript"> <![CDATA[
+    var errors = 0;
+    var log = '';
+    function doTest() {
+      var iterator = document.createNodeIterator(document.getElementById('root'), NodeFilter.SHOW_ALL, null, false);
+      var root = document.getElementById('root');
+      var A = document.getElementById('A');
+      var B = document.getElementById('B');
+      var BB = document.getElementById('BB');
+      var C = document.getElementById('C');
+      check(iterator.nextNode(), root);
+      check(iterator.nextNode(), A);
+      check(iterator.nextNode(), B);
+      check(iterator.nextNode(), BB);
+      remove(B);
+      var X = addChildTo(A);
+      check(iterator.nextNode(), X);
+      if (errors)
+        document.getElementById('result').firstChild.data = 'FAIL: ' + errors + ' errors:\n' + log;
+      else
+        document.getElementById('result').firstChild.data = 'PASS';
+    }
+    function check(a, b) {
+      if (!a) {
+        errors += 1;
+        log += 'Found null but expected ' + b + ' (' + b.id + ').\n';
+      } else if (a != b) {
+        errors += 1;
+        log += 'Found ' + a + ' (' + a.id + ') but expected ' + b + ' (' + b.id + ').\n';
+      }
+    }
+    function remove(a) {
+      if (!a) {
+        errors += 1;
+        log += 'Tried removing null node.\n';
+      } else
+      a.parentNode.removeChild(a);
+    }
+    function addChildTo(a) {
+      var x = document.createElementNS('http://www.w3.org/1999/xhtml', 'span');
+      x.id = 'X';
+      a.appendChild(x);
+      return x;
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script did not complete.</pre>
+  <p><span id="root"><span id="A"></span><span id="B"><span id="BB"></span></span><span id="C"></span></span></p>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/008.xml b/testing/web-platform/tests/dom/traversal/unfinished/008.xml
new file mode 100644
index 0000000000..41d7008ae4
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/008.xml
@@ -0,0 +1,48 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Removal of an ancestor of the Reference Node (backwards)</title>
+  <script type="text/javascript"> <![CDATA[
+    var errors = 0;
+    var log = '';
+    function doTest() {
+      var iterator = document.createNodeIterator(document.getElementById('root'), NodeFilter.SHOW_ALL, null, false);
+      var root = document.getElementById('root');
+      var A = document.getElementById('A');
+      var B = document.getElementById('B');
+      var BB = document.getElementById('BB');
+      var C = document.getElementById('C');
+      check(iterator.nextNode(), root);
+      check(iterator.nextNode(), A);
+      check(iterator.nextNode(), B);
+      check(iterator.nextNode(), BB);
+      check(iterator.previousNode(), BB);
+      remove(B);
+      check(iterator.nextNode(), C);
+      if (errors)
+        document.getElementById('result').firstChild.data = 'FAIL: ' + errors + ' errors:\n' + log;
+      else
+        document.getElementById('result').firstChild.data = 'PASS';
+    }
+    function check(a, b) {
+      if (!a) {
+        errors += 1;
+        log += 'Found null but expected ' + b + ' (' + b.id + ').\n';
+      } else if (a != b) {
+        errors += 1;
+        log += 'Found ' + a + ' (' + a.id + ') but expected ' + b + ' (' + b.id + ').\n';
+      }
+    }
+    function remove(a) {
+      if (!a) {
+        errors += 1;
+        log += 'Tried removing null node.\n';
+      } else
+      a.parentNode.removeChild(a);
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script did not complete.</pre>
+  <p><span id="root"><span id="A"></span><span id="B"><span id="BB"></span></span><span id="C"></span></span></p>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/009.xml b/testing/web-platform/tests/dom/traversal/unfinished/009.xml
new file mode 100644
index 0000000000..c3006ecbd6
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/009.xml
@@ -0,0 +1,55 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Removal of an ancestor of the Reference Node (backwards) (deep check)</title>
+  <script type="text/javascript"> <![CDATA[
+    var errors = 0;
+    var log = '';
+    function doTest() {
+      var iterator = document.createNodeIterator(document.getElementById('root'), NodeFilter.SHOW_ALL, null, false);
+      var root = document.getElementById('root');
+      var A = document.getElementById('A');
+      var B = document.getElementById('B');
+      var BB = document.getElementById('BB');
+      var C = document.getElementById('C');
+      check(iterator.nextNode(), root);
+      check(iterator.nextNode(), A);
+      check(iterator.nextNode(), B);
+      check(iterator.nextNode(), BB);
+      check(iterator.previousNode(), BB);
+      remove(B);
+      var X = addChildTo(A);
+      check(iterator.previousNode(), X);
+      if (errors)
+        document.getElementById('result').firstChild.data = 'FAIL: ' + errors + ' errors:\n' + log;
+      else
+        document.getElementById('result').firstChild.data = 'PASS';
+    }
+    function check(a, b) {
+      if (!a) {
+        errors += 1;
+        log += 'Found null but expected ' + b + ' (' + b.id + ').\n';
+      } else if (a != b) {
+        errors += 1;
+        log += 'Found ' + a + ' (' + a.id + ') but expected ' + b + ' (' + b.id + ').\n';
+      }
+    }
+    function remove(a) {
+      if (!a) {
+        errors += 1;
+        log += 'Tried removing null node.\n';
+      } else
+      a.parentNode.removeChild(a);
+    }
+    function addChildTo(a) {
+      var x = document.createElementNS('http://www.w3.org/1999/xhtml', 'span');
+      x.id = 'X';
+      a.appendChild(x);
+      return x;
+    }
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script did not complete.</pre>
+  <p><span id="root"><span id="A"></span><span id="B"><span id="BB"></span></span><span id="C"></span></span></p>
+ </body>
+</html>
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/010.xml b/testing/web-platform/tests/dom/traversal/unfinished/010.xml
new file mode 100644
index 0000000000..63263a5fd7
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/010.xml
@@ -0,0 +1,64 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>DOM Traversal: NodeIterator: Filters</title>
+  <script type="text/javascript"> <![CDATA[
+    function doTest() {
+      var iterator = document.createNodeIterator(document, NodeFilter.SHOW_ALL, testFilter, false);
+      // skips text nodes and body element
+      var expected = new Array(9, // document
+                               1, // html
+                               1, // head
+                               1, // title
+                               1, 4, // script and CDATA block
+                               // body (skipped)
+                               1, // pre
+                               // </body>
+                               8, // <!-- -->
+                               // PI skipped
+                               4); // CDATA
+      var found = new Array();
+
+      // walk document
+      var node;
+      while (node = iterator.nextNode())
+        found.push(node.nodeType);
+
+      // check results
+      var errors = 0;
+      var s = '';
+      var length = (found.length > expected.length) ? found.length : expected.length;
+      s += 'EXPECTED  FOUND\n';
+      for (var i = 0; i < length; i += 1) {
+        s += '  ' + (expected[i] ? expected[i] : '-') +
+      '         ' + (found[i] ? found[i] : '-');
+        if (found[i] != expected[i]) {
+          s += '      MISMATCH';
+          errors += 1;
+        }
+        s += '\n';
+      }
+      var p = document.getElementsByTagNameNS('http://www.w3.org/1999/xhtml', 'pre')[0];
+      if (errors)
+        p.firstChild.data = 'FAIL: ' + errors + ' errors found:\n\n' + s;
+      else
+        p.firstChild.data = 'PASS';
+    }
+
+    function testFilter(n) {
+      if (n.nodeType == 3) {
+        return NodeFilter.FILTER_SKIP;
+      } else if (n.nodeName == 'body') {
+        return NodeFilter.FILTER_REJECT; // same as _SKIP
+      }
+      return 1; // FILTER_ACCEPT
+    }
+
+  ]]></script>
+ </head>
+ <body onload="doTest()">
+  <pre id="result">FAIL: Script failed to run.</pre>
+ </body>
+ <!-- some more nodes to test this: -->
+ <?body test?>
+ <![CDATA[]]>
+</html>
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/traversal/unfinished/TODO b/testing/web-platform/tests/dom/traversal/unfinished/TODO
new file mode 100644
index 0000000000..cecdf98b08
--- /dev/null
+++ b/testing/web-platform/tests/dom/traversal/unfinished/TODO
@@ -0,0 +1 @@
+Check what happens when a NodeFilter turns a number not in the range 1..3
+\ No newline at end of file
diff --git a/testing/web-platform/tests/dom/window-extends-event-target.html b/testing/web-platform/tests/dom/window-extends-event-target.html
new file mode 100644
index 0000000000..3b690324e5
--- /dev/null
+++ b/testing/web-platform/tests/dom/window-extends-event-target.html
@@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Window extends EventTarget</title>
+<link rel="help" href="https://github.com/jsdom/jsdom/issues/2830">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+<script>
+"use strict";
+
+test(() => {
+
+  assert_equals(window.addEventListener, EventTarget.prototype.addEventListener);
+  assert_equals(window.removeEventListener, EventTarget.prototype.removeEventListener);
+  assert_equals(window.dispatchEvent, EventTarget.prototype.dispatchEvent);
+
+}, "EventTarget methods on Window instances are inherited from the EventTarget prototype");
+
+test(() => {
+
+  const kCustom = "custom-event";
+  const customEvent = new CustomEvent(kCustom, {
+    bubbles: true
+  });
+
+  let target;
+  window.addEventListener.call(document.body, kCustom, function () {
+    target = this;
+  });
+
+  document.body.dispatchEvent(customEvent);
+
+  assert_equals(target, document.body);
+
+}, "window.addEventListener respects custom `this`");
+
+test(() => {
+
+  const kCustom = "custom-event";
+  const customEvent = new CustomEvent(kCustom, {
+    bubbles: true
+  });
+
+  let target;
+  window.addEventListener.call(null, kCustom, function () {
+    target = this;
+  });
+
+  document.body.dispatchEvent(customEvent);
+
+  assert_equals(target, window);
+
+}, "window.addEventListener treats nullish `this` as `window`");
+</script>
diff --git a/testing/web-platform/tests/dom/xslt/README.md b/testing/web-platform/tests/dom/xslt/README.md
new file mode 100644
index 0000000000..ac713ce179
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/README.md
@@ -0,0 +1,11 @@
+# XSLT
+
+This directory contains tentative tests for [XSLT](https://dom.spec.whatwg.org/#xslt).
+
+See [whatwg/dom#181](https://github.com/whatwg/dom/issues/181) for getting XSLT
+better specified.
+
+There are additional details on XSLT in HTML:
+- [Interactions with XPath and XSLT](https://html.spec.whatwg.org/multipage/infrastructure.html#interactions-with-xpath-and-xslt)
+- [Interaction of `script` elements and XSLT](https://html.spec.whatwg.org/multipage/scripting.html#scriptTagXSLT) (non-normative)
+- [Interaction of `template` elements with XSLT and XPath](https://html.spec.whatwg.org/multipage/scripting.html#template-XSLT-XPath) (non-normative)
diff --git a/testing/web-platform/tests/dom/xslt/externalScript.js b/testing/web-platform/tests/dom/xslt/externalScript.js
new file mode 100644
index 0000000000..7a2bf36225
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/externalScript.js
@@ -0,0 +1 @@
+window.externalScript = true;
diff --git a/testing/web-platform/tests/dom/xslt/functions.tentative.window.js b/testing/web-platform/tests/dom/xslt/functions.tentative.window.js
new file mode 100644
index 0000000000..81240022dc
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/functions.tentative.window.js
@@ -0,0 +1,252 @@
+const xslt_functions = [
+  "QName",
+  "abs",
+  "accumulator-after",
+  "accumulator-before",
+  "adjust-date-to-timezone",
+  "adjust-dateTime-to-timezone",
+  "adjust-time-to-timezone",
+  "analyze-string",
+  "apply",
+  "available-environment-variables",
+  "available-system-properties",
+  "avg",
+  "base-uri",
+  "boolean",
+  "ceiling",
+  "codepoint-equal",
+  "codepoints-to-string",
+  "collation-key",
+  "collection",
+  "compare",
+  "concat",
+  "contains",
+  "contains-token",
+  "copy-of",
+  "count",
+  "current",
+  "current-date",
+  "current-dateTime",
+  "current-group",
+  "current-grouping-key",
+  "current-merge-group",
+  "current-merge-key",
+  "current-output-uri",
+  "current-time",
+  "data",
+  "dateTime",
+  "day-from-date",
+  "day-from-dateTime",
+  "days-from-duration",
+  "deep-equal",
+  "default-collation",
+  "default-language",
+  "distinct-values",
+  "doc",
+  "doc-available",
+  "document",
+  "document-uri",
+  "element-available",
+  "element-with-id",
+  "empty",
+  "encode-for-uri",
+  "ends-with",
+  "environment-variable",
+  "error",
+  "escape-html-uri",
+  "exactly-one",
+  "exists",
+  "false",
+  "filter",
+  "floor",
+  "fold-left",
+  "fold-right",
+  "for-each",
+  "for-each-pair",
+  "format-date",
+  "format-dateTime",
+  "format-integer",
+  "format-number",
+  "format-time",
+  "function-arity",
+  "function-available",
+  "function-lookup",
+  "function-name",
+  "generate-id",
+  "has-children",
+  "head",
+  "hours-from-dateTime",
+  "hours-from-duration",
+  "hours-from-time",
+  "id",
+  "idref",
+  "implicit-timezone",
+  "in-scope-prefixes",
+  "index-of",
+  "innermost",
+  "insert-before",
+  "iri-to-uri",
+  "json-doc",
+  "json-to-xml",
+  "key",
+  "lang",
+  "last",
+  "load-xquery-module",
+  "local-name",
+  "local-name-from-QName",
+  "lower-case",
+  "matches",
+  "max",
+  "min",
+  "minutes-from-dateTime",
+  "minutes-from-duration",
+  "minutes-from-time",
+  "month-from-date",
+  "month-from-dateTime",
+  "months-from-duration",
+  "name",
+  "namespace-uri",
+  "namespace-uri-for-prefix",
+  "namespace-uri-from-QName",
+  "nilled",
+  "node-name",
+  "normalize-space",
+  "normalize-unicode",
+  "not",
+  "number",
+  "one-or-more",
+  "outermost",
+  "parse-ietf-date",
+  "parse-json",
+  "parse-xml",
+  "parse-xml-fragment",
+  "path",
+  "position",
+  "prefix-from-QName",
+  "put",
+  "random-number-generator",
+  "regex-group",
+  "remove",
+  "replace",
+  "resolve-QName",
+  "resolve-uri",
+  "reverse",
+  "root",
+  "round",
+  "round-half-to-even",
+  "seconds-from-dateTime",
+  "seconds-from-duration",
+  "seconds-from-time",
+  "serialize",
+  "snapshot",
+  "sort",
+  "starts-with",
+  "static-base-uri",
+  "stream-available",
+  "string",
+  "string-join",
+  "string-length",
+  "string-to-codepoints",
+  "subsequence",
+  "substring",
+  "substring-after",
+  "substring-before",
+  "sum",
+  "system-property",
+  "tail",
+  "timezone-from-date",
+  "timezone-from-dateTime",
+  "timezone-from-time",
+  "tokenize",
+  "trace",
+  "transform",
+  "translate",
+  "true",
+  "type-available",
+  "unordered",
+  "unparsed-entity-public-id",
+  "unparsed-entity-uri",
+  "unparsed-text",
+  "unparsed-text-available",
+  "unparsed-text-lines",
+  "upper-case",
+  "uri-collection",
+  "xml-to-json",
+  "year-from-date",
+  "year-from-dateTime",
+  "years-from-duration",
+  "zero-or-one",
+];
+
+const xslt1_functions = [
+  "boolean",
+  "ceiling",
+  "concat",
+  "contains",
+  "count",
+  "current",
+  "document",
+  "element-available",
+  "false",
+  "floor",
+  "format-number",
+  "function-available",
+  "generate-id",
+  "id",
+  "key",
+  "lang",
+  "last",
+  "local-name",
+  "name",
+  "namespace-uri",
+  "normalize-space",
+  "not",
+  "number",
+  "position",
+  "round",
+  "starts-with",
+  "string",
+  "string-length",
+  "substring",
+  "substring-after",
+  "substring-before",
+  "sum",
+  "system-property",
+  "translate",
+  "true",
+  "unparsed-entity-uri",
+];
+
+for (const fn of xslt_functions) {
+  test(() => {
+    const xsltSrc = `<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:output method="html" encoding="utf-8" version="5"/>
+<xsl:template match="/">
+      <xsl:choose>
+        <xsl:when test='function-available("${fn}")'>
+          <div>available</div>
+        </xsl:when>
+        <xsl:otherwise>
+          <div>unavailable</div>
+        </xsl:otherwise>
+      </xsl:choose>
+</xsl:template>
+</xsl:stylesheet>`;
+
+    const processor = new XSLTProcessor();
+    const parser = new DOMParser();
+    processor.importStylesheet(
+      parser.parseFromString(xsltSrc, "application/xml")
+    );
+    const output = processor.transformToFragment(
+      parser.parseFromString("<x/>", "application/xml"),
+      document
+    );
+
+    // Note we only expect functions defined in XSLT 1.0 to be defined.
+    assert_equals(
+      output.textContent.trim(),
+      xslt1_functions.indexOf(fn) >= 0 ? "available" : "unavailable"
+    );
+  }, fn);
+}
diff --git a/testing/web-platform/tests/dom/xslt/invalid-output-encoding-crash.html b/testing/web-platform/tests/dom/xslt/invalid-output-encoding-crash.html
new file mode 100644
index 0000000000..d84bb5b3c3
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/invalid-output-encoding-crash.html
@@ -0,0 +1,26 @@
+<body>
+
+<script id=o_xml type="text/plain">
+  <?xml version="1.0" encoding="UTF-8"?>
+</script>
+
+<script id=o_xslt type="text/plain"><?xml version="1.0" encoding="UTF-8"?>
+  <xsl:transform version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+    <xsl:output indent="no" omit-xml-declaration="no" encoding="bad-encoding" standalone="yes" />
+  </xsl:transform>
+</script>
+
+<script>
+addEventListener("load", function() {
+  const doc = new DOMParser();
+  const xml = doc.parseFromString(o_xml.textContent, "text/xml");
+  const xsl = doc.parseFromString(o_xslt.textContent, "text/xml");
+  const xsltPrs = new XSLTProcessor();
+  xsltPrs.importStylesheet(xsl);
+  xsltPrs.transformToDocument(xml);
+
+  document.body.appendChild(document.createTextNode("PASS: renderer didn't crash"));
+});
+</script>
+
+</body>
diff --git a/testing/web-platform/tests/dom/xslt/sort-ref.html b/testing/web-platform/tests/dom/xslt/sort-ref.html
new file mode 100644
index 0000000000..163002d0d0
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/sort-ref.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<link rel=author href="mailto:jarhar@chromium.org">
+<link rel=help href="https://bugs.chromium.org/p/chromium/issues/detail?id=1399858">
+
+<div>
+  <div>1</div>
+  <div>2</div>
+  <div>3</div>
+  <div>7</div>
+</div>
diff --git a/testing/web-platform/tests/dom/xslt/sort.html b/testing/web-platform/tests/dom/xslt/sort.html
new file mode 100644
index 0000000000..631c3edd6a
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/sort.html
@@ -0,0 +1,48 @@
+<!DOCTYPE html>
+<link rel=match href="sort-ref.html">
+
+<body>
+  <div id="container"></div>
+</body>
+
+<script type="text/xml" id="sampleXml">
+  <root>
+    <node id="1" />
+    <node id="7" />
+    <node id="3" />
+    <node id="2" />
+  </root>
+</script>
+
+<script type="text/xml" id="sampleXsl">
+  <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt">
+
+    <xsl:template match="/">
+      <xsl:apply-templates select="//node">
+        <xsl:sort select="@id" data-type="number" />
+      </xsl:apply-templates>
+    </xsl:template>
+
+    <xsl:template match="node">
+      <div>
+        <xsl:value-of select="@id"/>
+      </div>
+    </xsl:template>
+
+  </xsl:stylesheet>
+</script>
+
+<script>
+  let parser = new DOMParser();
+  const xslStyleSheet = parser.parseFromString(document.getElementById('sampleXsl').textContent, 'text/xml');
+
+  const xsltProcessor = new XSLTProcessor();
+  xsltProcessor.importStylesheet(xslStyleSheet);
+
+  parser = new DOMParser();
+  const xmlDoc = parser.parseFromString(document.getElementById('sampleXml').textContent, 'text/xml');
+
+  const fragment = xsltProcessor.transformToFragment(xmlDoc, document);
+
+  document.getElementById('container').appendChild(fragment);
+</script>
diff --git a/testing/web-platform/tests/dom/xslt/strip-space-crash.xml b/testing/web-platform/tests/dom/xslt/strip-space-crash.xml
new file mode 100644
index 0000000000..61a906a5e7
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/strip-space-crash.xml
@@ -0,0 +1,33 @@
+<?xml-stylesheet type="text/xsl" href="#style"?>
+<xsl:stylesheet
+    version="1.0"
+    xml:id="style"
+    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+    xmlns:exsl="http://exslt.org/common"
+    extension-element-prefixes="exsl"
+>
+    <xsl:strip-space elements="s"/>
+
+    <xsl:template match="/">
+        <xsl:variable name="space">
+            <s>
+                <xsl:text> </xsl:text>
+                <e/>
+                <xsl:text> </xsl:text>
+                <e/>
+                <xsl:text> </xsl:text>
+            </s>
+        </xsl:variable>
+        <xsl:apply-templates select="exsl:node-set($space)/s"/>
+    </xsl:template>
+
+    <xsl:template match="s">
+        <r>
+            <xsl:variable name="text-nodes" select="text()"/>
+            <xsl:apply-templates/>
+            <xsl:copy-of select="$text-nodes"/>
+        </r>
+    </xsl:template>
+
+    <xsl:template match="node()"/>
+</xsl:stylesheet>
diff --git a/testing/web-platform/tests/dom/xslt/transformToFragment-on-node-from-inactive-document-crash.html b/testing/web-platform/tests/dom/xslt/transformToFragment-on-node-from-inactive-document-crash.html
new file mode 100644
index 0000000000..38a62a0a9d
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/transformToFragment-on-node-from-inactive-document-crash.html
@@ -0,0 +1,11 @@
+<body>
+<iframe id=i></iframe>
+<script>
+var el = i.contentDocument.documentElement;
+i.remove()
+var x = new XSLTProcessor();
+var xsl =new DOMParser().parseFromString('<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"/>','application/xml');
+x.importStylesheet(xsl);
+x.transformToDocument(el);
+</script>
+</body>
diff --git a/testing/web-platform/tests/dom/xslt/transformToFragment.tentative.window.js b/testing/web-platform/tests/dom/xslt/transformToFragment.tentative.window.js
new file mode 100644
index 0000000000..7bb6a56855
--- /dev/null
+++ b/testing/web-platform/tests/dom/xslt/transformToFragment.tentative.window.js
@@ -0,0 +1,39 @@
+const cases = {
+  internal: '<script>window.internalScript = true;</script>',
+  external: '<script src="externalScript.js"></script>',
+};
+
+const loaded = new Promise(resolve => {
+  window.addEventListener('load', resolve);
+});
+
+Object.entries(cases).forEach(([k, v]) => {
+  const xsltSrc = `<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+<xsl:output method="html" encoding="utf-8" version="5"/>
+<xsl:template match="/">
+  <section>
+    ${v}
+  </section>
+</xsl:template>
+</xsl:stylesheet>`;
+
+  const processor = new XSLTProcessor();
+  const parser = new DOMParser();
+  processor.importStylesheet(
+    parser.parseFromString(xsltSrc, 'application/xml')
+  );
+  document.body.appendChild(
+    processor.transformToFragment(
+      parser.parseFromString('<x/>', 'application/xml'),
+      document
+    )
+  );
+
+  promise_test(async () => {
+    await loaded;
+    assert_true(
+      window[`${k}Script`],
+      'script element from XSLTProcessor.transformToFragment() is evaluated'
+    );
+  }, `${k} script`);
+})
author	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-04-19 01:47:29 +0000
committer	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-04-19 01:47:29 +0000
commit	0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch)
tree	a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /testing/web-platform/tests/dom
parent	Initial commit. (diff)
download	firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.tar.xz firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.zip