Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

11 files changed, 1384 insertions, 0 deletions

diff --git a/testing/web-platform/tests/fetch/api/headers/header-setcookie.any.js b/testing/web-platform/tests/fetch/api/headers/header-setcookie.any.js
new file mode 100644
index 0000000000..cafb780c2c
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/header-setcookie.any.js
@@ -0,0 +1,266 @@
+// META: title=Headers set-cookie special cases
+// META: global=window,worker
+
+const headerList = [
+  ["set-cookie", "foo=bar"],
+  ["Set-Cookie", "fizz=buzz; domain=example.com"],
+];
+
+const setCookie2HeaderList = [
+  ["set-cookie2", "foo2=bar2"],
+  ["Set-Cookie2", "fizz2=buzz2; domain=example2.com"],
+];
+
+function assert_nested_array_equals(actual, expected) {
+  assert_equals(actual.length, expected.length, "Array length is not equal");
+  for (let i = 0; i < expected.length; i++) {
+    assert_array_equals(actual[i], expected[i]);
+  }
+}
+
+test(function () {
+  const headers = new Headers(headerList);
+  assert_equals(
+    headers.get("set-cookie"),
+    "foo=bar, fizz=buzz; domain=example.com",
+  );
+}, "Headers.prototype.get combines set-cookie headers in order");
+
+test(function () {
+  const headers = new Headers(headerList);
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "foo=bar"],
+    ["set-cookie", "fizz=buzz; domain=example.com"],
+  ]);
+}, "Headers iterator does not combine set-cookie headers");
+
+test(function () {
+  const headers = new Headers(setCookie2HeaderList);
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie2", "foo2=bar2, fizz2=buzz2; domain=example2.com"],
+  ]);
+}, "Headers iterator does not special case set-cookie2 headers");
+
+test(function () {
+  const headers = new Headers([...headerList, ...setCookie2HeaderList]);
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "foo=bar"],
+    ["set-cookie", "fizz=buzz; domain=example.com"],
+    ["set-cookie2", "foo2=bar2, fizz2=buzz2; domain=example2.com"],
+  ]);
+}, "Headers iterator does not combine set-cookie & set-cookie2 headers");
+
+test(function () {
+  // Values are in non alphabetic order, and the iterator should yield in the
+  // headers in the exact order of the input.
+  const headers = new Headers([
+    ["set-cookie", "z=z"],
+    ["set-cookie", "a=a"],
+    ["set-cookie", "n=n"],
+  ]);
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "z=z"],
+    ["set-cookie", "a=a"],
+    ["set-cookie", "n=n"],
+  ]);
+}, "Headers iterator preserves set-cookie ordering");
+
+test(
+  function () {
+    const headers = new Headers([
+      ["xylophone-header", "1"],
+      ["best-header", "2"],
+      ["set-cookie", "3"],
+      ["a-cool-header", "4"],
+      ["set-cookie", "5"],
+      ["a-cool-header", "6"],
+      ["best-header", "7"],
+    ]);
+    const list = [...headers];
+    assert_nested_array_equals(list, [
+      ["a-cool-header", "4, 6"],
+      ["best-header", "2, 7"],
+      ["set-cookie", "3"],
+      ["set-cookie", "5"],
+      ["xylophone-header", "1"],
+    ]);
+  },
+  "Headers iterator preserves per header ordering, but sorts keys alphabetically",
+);
+
+test(
+  function () {
+    const headers = new Headers([
+      ["xylophone-header", "7"],
+      ["best-header", "6"],
+      ["set-cookie", "5"],
+      ["a-cool-header", "4"],
+      ["set-cookie", "3"],
+      ["a-cool-header", "2"],
+      ["best-header", "1"],
+    ]);
+    const list = [...headers];
+    assert_nested_array_equals(list, [
+      ["a-cool-header", "4, 2"],
+      ["best-header", "6, 1"],
+      ["set-cookie", "5"],
+      ["set-cookie", "3"],
+      ["xylophone-header", "7"],
+    ]);
+  },
+  "Headers iterator preserves per header ordering, but sorts keys alphabetically (and ignores value ordering)",
+);
+
+test(function () {
+  const headers = new Headers([["fizz", "buzz"], ["X-Header", "test"]]);
+  const iterator = headers[Symbol.iterator]();
+  assert_array_equals(iterator.next().value, ["fizz", "buzz"]);
+  headers.append("Set-Cookie", "a=b");
+  assert_array_equals(iterator.next().value, ["set-cookie", "a=b"]);
+  headers.append("Accept", "text/html");
+  assert_array_equals(iterator.next().value, ["set-cookie", "a=b"]);
+  assert_array_equals(iterator.next().value, ["x-header", "test"]);
+  headers.append("set-cookie", "c=d");
+  assert_array_equals(iterator.next().value, ["x-header", "test"]);
+  assert_true(iterator.next().done);
+}, "Headers iterator is correctly updated with set-cookie changes");
+
+test(function () {
+  const headers = new Headers([
+    ["set-cookie", "a"],
+    ["set-cookie", "b"],
+    ["set-cookie", "c"]
+  ]);
+  const iterator = headers[Symbol.iterator]();
+  assert_array_equals(iterator.next().value, ["set-cookie", "a"]);
+  headers.delete("set-cookie");
+  headers.append("set-cookie", "d");
+  headers.append("set-cookie", "e");
+  headers.append("set-cookie", "f");
+  assert_array_equals(iterator.next().value, ["set-cookie", "e"]);
+  assert_array_equals(iterator.next().value, ["set-cookie", "f"]);
+  assert_true(iterator.next().done);
+}, "Headers iterator is correctly updated with set-cookie changes #2");
+
+test(function () {
+  const headers = new Headers(headerList);
+  assert_true(headers.has("sEt-cOoKiE"));
+}, "Headers.prototype.has works for set-cookie");
+
+test(function () {
+  const headers = new Headers(setCookie2HeaderList);
+  headers.append("set-Cookie", "foo=bar");
+  headers.append("sEt-cOoKiE", "fizz=buzz");
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "foo=bar"],
+    ["set-cookie", "fizz=buzz"],
+    ["set-cookie2", "foo2=bar2, fizz2=buzz2; domain=example2.com"],
+  ]);
+}, "Headers.prototype.append works for set-cookie");
+
+test(function () {
+  const headers = new Headers(headerList);
+  headers.set("set-cookie", "foo2=bar2");
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "foo2=bar2"],
+  ]);
+}, "Headers.prototype.set works for set-cookie");
+
+test(function () {
+  const headers = new Headers(headerList);
+  headers.delete("set-Cookie");
+  const list = [...headers];
+  assert_nested_array_equals(list, []);
+}, "Headers.prototype.delete works for set-cookie");
+
+test(function () {
+  const headers = new Headers();
+  assert_array_equals(headers.getSetCookie(), []);
+}, "Headers.prototype.getSetCookie with no headers present");
+
+test(function () {
+  const headers = new Headers([headerList[0]]);
+  assert_array_equals(headers.getSetCookie(), ["foo=bar"]);
+}, "Headers.prototype.getSetCookie with one header");
+
+test(function () {
+  const headers = new Headers({ "Set-Cookie": "foo=bar" });
+  assert_array_equals(headers.getSetCookie(), ["foo=bar"]);
+}, "Headers.prototype.getSetCookie with one header created from an object");
+
+test(function () {
+  const headers = new Headers(headerList);
+  assert_array_equals(headers.getSetCookie(), [
+    "foo=bar",
+    "fizz=buzz; domain=example.com",
+  ]);
+}, "Headers.prototype.getSetCookie with multiple headers");
+
+test(function () {
+  const headers = new Headers([["set-cookie", ""]]);
+  assert_array_equals(headers.getSetCookie(), [""]);
+}, "Headers.prototype.getSetCookie with an empty header");
+
+test(function () {
+  const headers = new Headers([["set-cookie", "x"], ["set-cookie", "x"]]);
+  assert_array_equals(headers.getSetCookie(), ["x", "x"]);
+}, "Headers.prototype.getSetCookie with two equal headers");
+
+test(function () {
+  const headers = new Headers([
+    ["set-cookie2", "x"],
+    ["set-cookie", "y"],
+    ["set-cookie2", "z"],
+  ]);
+  assert_array_equals(headers.getSetCookie(), ["y"]);
+}, "Headers.prototype.getSetCookie ignores set-cookie2 headers");
+
+test(function () {
+  // Values are in non alphabetic order, and the iterator should yield in the
+  // headers in the exact order of the input.
+  const headers = new Headers([
+    ["set-cookie", "z=z"],
+    ["set-cookie", "a=a"],
+    ["set-cookie", "n=n"],
+  ]);
+  assert_array_equals(headers.getSetCookie(), ["z=z", "a=a", "n=n"]);
+}, "Headers.prototype.getSetCookie preserves header ordering");
+
+test(function () {
+  const headers = new Headers({"Set-Cookie": "  a=b\n"});
+  headers.append("set-cookie", "\n\rc=d  ");
+  assert_nested_array_equals([...headers], [
+    ["set-cookie", "a=b"],
+    ["set-cookie", "c=d"]
+  ]);
+  headers.set("set-cookie", "\te=f ");
+  assert_nested_array_equals([...headers], [["set-cookie", "e=f"]]);
+}, "Adding Set-Cookie headers normalizes their value");
+
+test(function () {
+  assert_throws_js(TypeError, () => {
+    new Headers({"set-cookie": "\0"});
+  });
+
+  const headers = new Headers();
+  assert_throws_js(TypeError, () => {
+    headers.append("Set-Cookie", "a\nb");
+  });
+  assert_throws_js(TypeError, () => {
+    headers.set("Set-Cookie", "a\rb");
+  });
+}, "Adding invalid Set-Cookie headers throws");
+
+test(function () {
+  const response = new Response();
+  response.headers.append("Set-Cookie", "foo=bar");
+  assert_array_equals(response.headers.getSetCookie(), []);
+  response.headers.append("sEt-cOokIe", "bar=baz");
+  assert_array_equals(response.headers.getSetCookie(), []);
+}, "Set-Cookie is a forbidden response header");
diff --git a/testing/web-platform/tests/fetch/api/headers/header-values-normalize.any.js b/testing/web-platform/tests/fetch/api/headers/header-values-normalize.any.js
new file mode 100644
index 0000000000..5710554ada
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/header-values-normalize.any.js
@@ -0,0 +1,72 @@
+// META: title=Header value normalizing test
+// META: global=window,worker
+// META: timeout=long
+
+"use strict";
+
+for(let i = 0; i < 0x21; i++) {
+  let fail = false,
+      strip = false
+
+  // REMOVE 0x0B/0x0C exception once https://github.com/web-platform-tests/wpt/issues/8372 is fixed
+  if(i === 0x0B || i === 0x0C)
+    continue
+
+  if(i === 0) {
+    fail = true
+  }
+
+  if(i === 0x09 || i === 0x0A || i === 0x0D || i === 0x20) {
+    strip = true
+  }
+
+  let url = "../resources/inspect-headers.py?headers=val1|val2|val3",
+      val = String.fromCharCode(i),
+      expectedVal = strip ? "" : val,
+      val1 = val,
+      expectedVal1 = expectedVal,
+      val2 = "x" + val,
+      expectedVal2 = "x" + expectedVal,
+      val3 = val + "x",
+      expectedVal3 = expectedVal + "x"
+
+  // XMLHttpRequest is not available in service workers
+  if (!self.GLOBAL.isWorker()) {
+    async_test((t) => {
+      let xhr = new XMLHttpRequest()
+      xhr.open("POST", url)
+      if(fail) {
+          assert_throws_dom("SyntaxError", () => xhr.setRequestHeader("val1", val1))
+          assert_throws_dom("SyntaxError", () => xhr.setRequestHeader("val2", val2))
+          assert_throws_dom("SyntaxError", () => xhr.setRequestHeader("val3", val3))
+          t.done()
+      } else {
+        xhr.setRequestHeader("val1", val1)
+        xhr.setRequestHeader("val2", val2)
+        xhr.setRequestHeader("val3", val3)
+        xhr.onload = t.step_func_done(() => {
+          assert_equals(xhr.getResponseHeader("x-request-val1"), expectedVal1)
+          assert_equals(xhr.getResponseHeader("x-request-val2"), expectedVal2)
+          assert_equals(xhr.getResponseHeader("x-request-val3"), expectedVal3)
+        })
+        xhr.send()
+      }
+    }, "XMLHttpRequest with value " + encodeURI(val))
+  }
+
+  promise_test((t) => {
+    if(fail) {
+      return Promise.all([
+        promise_rejects_js(t, TypeError, fetch(url, { headers: {"val1": val1} })),
+        promise_rejects_js(t, TypeError, fetch(url, { headers: {"val2": val2} })),
+        promise_rejects_js(t, TypeError, fetch(url, { headers: {"val3": val3} }))
+      ])
+    } else {
+      return fetch(url, { headers: {"val1": val1, "val2": val2, "val3": val3} }).then((res) => {
+        assert_equals(res.headers.get("x-request-val1"), expectedVal1)
+        assert_equals(res.headers.get("x-request-val2"), expectedVal2)
+        assert_equals(res.headers.get("x-request-val3"), expectedVal3)
+      })
+    }
+  }, "fetch() with value " + encodeURI(val))
+}
diff --git a/testing/web-platform/tests/fetch/api/headers/header-values.any.js b/testing/web-platform/tests/fetch/api/headers/header-values.any.js
new file mode 100644
index 0000000000..bb7570c5a3
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/header-values.any.js
@@ -0,0 +1,63 @@
+// META: title=Header value test
+// META: global=window,worker
+// META: timeout=long
+
+"use strict";
+
+// Invalid values
+[0, 0x0A, 0x0D].forEach(val => {
+  val = "x" + String.fromCharCode(val) + "x"
+
+  // XMLHttpRequest is not available in service workers
+  if (!self.GLOBAL.isWorker()) {
+    test(() => {
+      let xhr = new XMLHttpRequest()
+      xhr.open("POST", "/")
+      assert_throws_dom("SyntaxError", () => xhr.setRequestHeader("value-test", val))
+    }, "XMLHttpRequest with value " + encodeURI(val) + " needs to throw")
+  }
+
+  promise_test(t => promise_rejects_js(t, TypeError, fetch("/", { headers: {"value-test": val} })), "fetch() with value " + encodeURI(val) + " needs to throw")
+})
+
+// Valid values
+let headerValues =[]
+for(let i = 0; i < 0x100; i++) {
+  if(i === 0 || i === 0x0A || i === 0x0D) {
+    continue
+  }
+  headerValues.push("x" + String.fromCharCode(i) + "x")
+}
+var url = "../resources/inspect-headers.py?headers="
+headerValues.forEach((_, i) => {
+  url += "val" + i + "|"
+})
+
+// XMLHttpRequest is not available in service workers
+if (!self.GLOBAL.isWorker()) {
+  async_test((t) => {
+    let xhr = new XMLHttpRequest()
+    xhr.open("POST", url)
+    headerValues.forEach((val, i) => {
+      xhr.setRequestHeader("val" + i, val)
+    })
+    xhr.onload = t.step_func_done(() => {
+      headerValues.forEach((val, i) => {
+        assert_equals(xhr.getResponseHeader("x-request-val" + i), val)
+      })
+    })
+    xhr.send()
+  }, "XMLHttpRequest with all valid values")
+}
+
+promise_test((t) => {
+  const headers = new Headers
+  headerValues.forEach((val, i) => {
+    headers.append("val" + i, val)
+  })
+  return fetch(url, { headers }).then((res) => {
+    headerValues.forEach((val, i) => {
+      assert_equals(res.headers.get("x-request-val" + i), val)
+    })
+  })
+}, "fetch() with all valid values")
diff --git a/testing/web-platform/tests/fetch/api/headers/headers-basic.any.js b/testing/web-platform/tests/fetch/api/headers/headers-basic.any.js
new file mode 100644
index 0000000000..ead1047645
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/headers-basic.any.js
@@ -0,0 +1,275 @@
+// META: title=Headers structure
+// META: global=window,worker
+
+"use strict";
+
+test(function() {
+  new Headers();
+}, "Create headers from no parameter");
+
+test(function() {
+  new Headers(undefined);
+}, "Create headers from undefined parameter");
+
+test(function() {
+  new Headers({});
+}, "Create headers from empty object");
+
+var parameters = [null, 1];
+parameters.forEach(function(parameter) {
+  test(function() {
+    assert_throws_js(TypeError, function() { new Headers(parameter) });
+  }, "Create headers with " + parameter + " should throw");
+});
+
+var headerDict = {"name1": "value1",
+                  "name2": "value2",
+                  "name3": "value3",
+                  "name4": null,
+                  "name5": undefined,
+                  "name6": 1,
+                  "Content-Type": "value4"
+};
+
+var headerSeq = [];
+for (var name in headerDict)
+  headerSeq.push([name, headerDict[name]]);
+
+test(function() {
+  var headers = new Headers(headerSeq);
+  for (name in headerDict) {
+    assert_equals(headers.get(name), String(headerDict[name]),
+      "name: " + name + " has value: " + headerDict[name]);
+  }
+  assert_equals(headers.get("length"), null, "init should be treated as a sequence, not as a dictionary");
+}, "Create headers with sequence");
+
+test(function() {
+  var headers = new Headers(headerDict);
+  for (name in headerDict) {
+    assert_equals(headers.get(name), String(headerDict[name]),
+      "name: " + name + " has value: " + headerDict[name]);
+  }
+}, "Create headers with record");
+
+test(function() {
+  var headers = new Headers(headerDict);
+  var headers2 = new Headers(headers);
+  for (name in headerDict) {
+    assert_equals(headers2.get(name), String(headerDict[name]),
+      "name: " + name + " has value: " + headerDict[name]);
+  }
+}, "Create headers with existing headers");
+
+test(function() {
+  var headers = new Headers()
+  headers[Symbol.iterator] = function *() {
+    yield ["test", "test"]
+  }
+  var headers2 = new Headers(headers)
+  assert_equals(headers2.get("test"), "test")
+}, "Create headers with existing headers with custom iterator");
+
+test(function() {
+  var headers = new Headers();
+  for (name in headerDict) {
+    headers.append(name, headerDict[name]);
+    assert_equals(headers.get(name), String(headerDict[name]),
+      "name: " + name + " has value: " + headerDict[name]);
+  }
+}, "Check append method");
+
+test(function() {
+  var headers = new Headers();
+  for (name in headerDict) {
+    headers.set(name, headerDict[name]);
+    assert_equals(headers.get(name), String(headerDict[name]),
+      "name: " + name + " has value: " + headerDict[name]);
+  }
+}, "Check set method");
+
+test(function() {
+  var headers = new Headers(headerDict);
+  for (name in headerDict)
+    assert_true(headers.has(name),"headers has name " + name);
+
+  assert_false(headers.has("nameNotInHeaders"),"headers do not have header: nameNotInHeaders");
+}, "Check has method");
+
+test(function() {
+  var headers = new Headers(headerDict);
+  for (name in headerDict) {
+    assert_true(headers.has(name),"headers have a header: " + name);
+    headers.delete(name)
+    assert_true(!headers.has(name),"headers do not have anymore a header: " + name);
+  }
+}, "Check delete method");
+
+test(function() {
+  var headers = new Headers(headerDict);
+  for (name in headerDict)
+    assert_equals(headers.get(name), String(headerDict[name]),
+      "name: " + name + " has value: " + headerDict[name]);
+
+  assert_equals(headers.get("nameNotInHeaders"), null, "header: nameNotInHeaders has no value");
+}, "Check get method");
+
+var headerEntriesDict = {"name1": "value1",
+                          "Name2": "value2",
+                          "name": "value3",
+                          "content-Type": "value4",
+                          "Content-Typ": "value5",
+                          "Content-Types": "value6"
+};
+var sortedHeaderDict = {};
+var headerValues = [];
+var sortedHeaderKeys = Object.keys(headerEntriesDict).map(function(value) {
+  sortedHeaderDict[value.toLowerCase()] = headerEntriesDict[value];
+  headerValues.push(headerEntriesDict[value]);
+  return value.toLowerCase();
+}).sort();
+
+var iteratorPrototype = Object.getPrototypeOf(Object.getPrototypeOf([][Symbol.iterator]()));
+function checkIteratorProperties(iterator) {
+  var prototype = Object.getPrototypeOf(iterator);
+  assert_equals(Object.getPrototypeOf(prototype), iteratorPrototype);
+
+  var descriptor = Object.getOwnPropertyDescriptor(prototype, "next");
+  assert_true(descriptor.configurable, "configurable");
+  assert_true(descriptor.enumerable, "enumerable");
+  assert_true(descriptor.writable, "writable");
+}
+
+test(function() {
+  var headers = new Headers(headerEntriesDict);
+  var actual = headers.keys();
+  checkIteratorProperties(actual);
+
+  sortedHeaderKeys.forEach(function(key) {
+      const entry = actual.next();
+      assert_false(entry.done);
+      assert_equals(entry.value, key);
+  });
+  assert_true(actual.next().done);
+  assert_true(actual.next().done);
+
+  for (const key of headers.keys())
+      assert_true(sortedHeaderKeys.indexOf(key) != -1);
+}, "Check keys method");
+
+test(function() {
+  var headers = new Headers(headerEntriesDict);
+  var actual = headers.values();
+  checkIteratorProperties(actual);
+
+  sortedHeaderKeys.forEach(function(key) {
+      const entry = actual.next();
+      assert_false(entry.done);
+      assert_equals(entry.value, sortedHeaderDict[key]);
+  });
+  assert_true(actual.next().done);
+  assert_true(actual.next().done);
+
+  for (const value of headers.values())
+      assert_true(headerValues.indexOf(value) != -1);
+}, "Check values method");
+
+test(function() {
+  var headers = new Headers(headerEntriesDict);
+  var actual = headers.entries();
+  checkIteratorProperties(actual);
+
+  sortedHeaderKeys.forEach(function(key) {
+      const entry = actual.next();
+      assert_false(entry.done);
+      assert_equals(entry.value[0], key);
+      assert_equals(entry.value[1], sortedHeaderDict[key]);
+  });
+  assert_true(actual.next().done);
+  assert_true(actual.next().done);
+
+  for (const entry of headers.entries())
+      assert_equals(entry[1], sortedHeaderDict[entry[0]]);
+}, "Check entries method");
+
+test(function() {
+  var headers = new Headers(headerEntriesDict);
+  var actual = headers[Symbol.iterator]();
+
+  sortedHeaderKeys.forEach(function(key) {
+      const entry = actual.next();
+      assert_false(entry.done);
+      assert_equals(entry.value[0], key);
+      assert_equals(entry.value[1], sortedHeaderDict[key]);
+  });
+  assert_true(actual.next().done);
+  assert_true(actual.next().done);
+}, "Check Symbol.iterator method");
+
+test(function() {
+  var headers = new Headers(headerEntriesDict);
+  var reference = sortedHeaderKeys[Symbol.iterator]();
+  headers.forEach(function(value, key, container) {
+      assert_equals(headers, container);
+      const entry = reference.next();
+      assert_false(entry.done);
+      assert_equals(key, entry.value);
+      assert_equals(value, sortedHeaderDict[entry.value]);
+  });
+  assert_true(reference.next().done);
+}, "Check forEach method");
+
+test(() => {
+  const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0"});
+  const actualKeys = [];
+  const actualValues = [];
+  for (const [header, value] of headers) {
+    actualKeys.push(header);
+    actualValues.push(value);
+    headers.delete("foo");
+  }
+  assert_array_equals(actualKeys, ["bar", "baz"]);
+  assert_array_equals(actualValues, ["0", "1"]);
+}, "Iteration skips elements removed while iterating");
+
+test(() => {
+  const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"});
+  const actualKeys = [];
+  const actualValues = [];
+  for (const [header, value] of headers) {
+    actualKeys.push(header);
+    actualValues.push(value);
+    if (header === "baz")
+      headers.delete("bar");
+  }
+  assert_array_equals(actualKeys, ["bar", "baz", "quux"]);
+  assert_array_equals(actualValues, ["0", "1", "3"]);
+}, "Removing elements already iterated over causes an element to be skipped during iteration");
+
+test(() => {
+  const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"});
+  const actualKeys = [];
+  const actualValues = [];
+  for (const [header, value] of headers) {
+    actualKeys.push(header);
+    actualValues.push(value);
+    if (header === "baz")
+      headers.append("X-yZ", "4");
+  }
+  assert_array_equals(actualKeys, ["bar", "baz", "foo", "quux", "x-yz"]);
+  assert_array_equals(actualValues, ["0", "1", "2", "3", "4"]);
+}, "Appending a value pair during iteration causes it to be reached during iteration");
+
+test(() => {
+  const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"});
+  const actualKeys = [];
+  const actualValues = [];
+  for (const [header, value] of headers) {
+    actualKeys.push(header);
+    actualValues.push(value);
+    if (header === "baz")
+      headers.append("abc", "-1");
+  }
+  assert_array_equals(actualKeys, ["bar", "baz", "baz", "foo", "quux"]);
+  assert_array_equals(actualValues, ["0", "1", "1", "2", "3"]);
+}, "Prepending a value pair before the current element position causes it to be skipped during iteration and adds the current element a second time");
diff --git a/testing/web-platform/tests/fetch/api/headers/headers-casing.any.js b/testing/web-platform/tests/fetch/api/headers/headers-casing.any.js
new file mode 100644
index 0000000000..20b8a9d375
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/headers-casing.any.js
@@ -0,0 +1,54 @@
+// META: title=Headers case management
+// META: global=window,worker
+
+"use strict";
+
+var headerDictCase = {"UPPERCASE": "value1",
+                      "lowercase": "value2",
+                      "mixedCase": "value3",
+                      "Content-TYPE": "value4"
+                      };
+
+function checkHeadersCase(originalName, headersToCheck, expectedDict) {
+  var lowCaseName = originalName.toLowerCase();
+  var upCaseName = originalName.toUpperCase();
+  var expectedValue = expectedDict[originalName];
+  assert_equals(headersToCheck.get(originalName), expectedValue,
+      "name: " + originalName + " has value: " + expectedValue);
+  assert_equals(headersToCheck.get(lowCaseName), expectedValue,
+      "name: " + lowCaseName + " has value: " + expectedValue);
+  assert_equals(headersToCheck.get(upCaseName), expectedValue,
+      "name: " + upCaseName + " has value: " + expectedValue);
+}
+
+test(function() {
+  var headers = new Headers(headerDictCase);
+  for (const name in headerDictCase)
+    checkHeadersCase(name, headers, headerDictCase)
+}, "Create headers, names use characters with different case");
+
+test(function() {
+  var headers = new Headers();
+  for (const name in headerDictCase) {
+    headers.append(name, headerDictCase[name]);
+    checkHeadersCase(name, headers, headerDictCase);
+  }
+}, "Check append method, names use characters with different case");
+
+test(function() {
+  var headers = new Headers();
+  for (const name in headerDictCase) {
+    headers.set(name, headerDictCase[name]);
+    checkHeadersCase(name, headers, headerDictCase);
+  }
+}, "Check set method, names use characters with different case");
+
+test(function() {
+  var headers = new Headers();
+  for (const name in headerDictCase)
+    headers.set(name, headerDictCase[name]);
+  for (const name in headerDictCase)
+    headers.delete(name.toLowerCase());
+  for (const name in headerDictCase)
+    assert_false(headers.has(name), "header " + name + " should have been deleted");
+}, "Check delete method, names use characters with different case");
diff --git a/testing/web-platform/tests/fetch/api/headers/headers-combine.any.js b/testing/web-platform/tests/fetch/api/headers/headers-combine.any.js
new file mode 100644
index 0000000000..4f3b6d11df
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/headers-combine.any.js
@@ -0,0 +1,66 @@
+// META: title=Headers have combined (and sorted) values
+// META: global=window,worker
+
+"use strict";
+
+var headerSeqCombine = [["single", "singleValue"],
+                        ["double", "doubleValue1"],
+                        ["double", "doubleValue2"],
+                        ["triple", "tripleValue1"],
+                        ["triple", "tripleValue2"],
+                        ["triple", "tripleValue3"]
+];
+var expectedDict = {"single": "singleValue",
+                    "double": "doubleValue1, doubleValue2",
+                    "triple": "tripleValue1, tripleValue2, tripleValue3"
+};
+
+test(function() {
+  var headers = new Headers(headerSeqCombine);
+  for (const name in expectedDict)
+    assert_equals(headers.get(name), expectedDict[name]);
+}, "Create headers using same name for different values");
+
+test(function() {
+  var headers = new Headers(headerSeqCombine);
+  for (const name in expectedDict) {
+    assert_true(headers.has(name), "name: " + name + " has value(s)");
+    headers.delete(name);
+    assert_false(headers.has(name), "name: " + name + " has no value(s) anymore");
+  }
+}, "Check delete and has methods when using same name for different values");
+
+test(function() {
+  var headers = new Headers(headerSeqCombine);
+  for (const name in expectedDict) {
+    headers.set(name,"newSingleValue");
+    assert_equals(headers.get(name), "newSingleValue", "name: " + name + " has value: newSingleValue");
+  }
+}, "Check set methods when called with already used name");
+
+test(function() {
+  var headers = new Headers(headerSeqCombine);
+  for (const name in expectedDict) {
+    var value = headers.get(name);
+    headers.append(name,"newSingleValue");
+    assert_equals(headers.get(name), (value + ", " + "newSingleValue"));
+  }
+}, "Check append methods when called with already used name");
+
+test(() => {
+  const headers = new Headers([["1", "a"],["1", "b"]]);
+  for(let header of headers) {
+    assert_array_equals(header, ["1", "a, b"]);
+  }
+}, "Iterate combined values");
+
+test(() => {
+  const headers = new Headers([["2", "a"], ["1", "b"], ["2", "b"]]),
+        expected = [["1", "b"], ["2", "a, b"]];
+  let i = 0;
+  for(let header of headers) {
+    assert_array_equals(header, expected[i]);
+    i++;
+  }
+  assert_equals(i, 2);
+}, "Iterate combined values in sorted order")
diff --git a/testing/web-platform/tests/fetch/api/headers/headers-errors.any.js b/testing/web-platform/tests/fetch/api/headers/headers-errors.any.js
new file mode 100644
index 0000000000..82dadd8234
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/headers-errors.any.js
@@ -0,0 +1,96 @@
+// META: title=Headers errors
+// META: global=window,worker
+
+"use strict";
+
+test(function() {
+  assert_throws_js(TypeError, function() { new Headers([["name"]]); });
+}, "Create headers giving an array having one string as init argument");
+
+test(function() {
+  assert_throws_js(TypeError, function() { new Headers([["invalid", "invalidValue1", "invalidValue2"]]); });
+}, "Create headers giving an array having three strings as init argument");
+
+test(function() {
+  assert_throws_js(TypeError, function() { new Headers([["invalidĀ", "Value1"]]); });
+}, "Create headers giving bad header name as init argument");
+
+test(function() {
+  assert_throws_js(TypeError, function() { new Headers([["name", "invalidValueĀ"]]); });
+}, "Create headers giving bad header value as init argument");
+
+var badNames = ["invalidĀ", {}];
+var badValues = ["invalidĀ"];
+
+badNames.forEach(function(name) {
+  test(function() {
+    var headers = new Headers();
+    assert_throws_js(TypeError, function() { headers.get(name); });
+  }, "Check headers get with an invalid name " + name);
+});
+
+badNames.forEach(function(name) {
+  test(function() {
+    var headers = new Headers();
+    assert_throws_js(TypeError, function() { headers.delete(name); });
+  }, "Check headers delete with an invalid name " + name);
+});
+
+badNames.forEach(function(name) {
+  test(function() {
+    var headers = new Headers();
+    assert_throws_js(TypeError, function() { headers.has(name); });
+  }, "Check headers has with an invalid name " + name);
+});
+
+badNames.forEach(function(name) {
+  test(function() {
+    var headers = new Headers();
+    assert_throws_js(TypeError, function() { headers.set(name, "Value1"); });
+  }, "Check headers set with an invalid name " + name);
+});
+
+badValues.forEach(function(value) {
+  test(function() {
+    var headers = new Headers();
+    assert_throws_js(TypeError, function() { headers.set("name", value); });
+  }, "Check headers set with an invalid value " + value);
+});
+
+badNames.forEach(function(name) {
+  test(function() {
+    var headers = new Headers();
+    assert_throws_js(TypeError, function() { headers.append("invalidĀ", "Value1"); });
+  }, "Check headers append with an invalid name " + name);
+});
+
+badValues.forEach(function(value) {
+  test(function() {
+    var headers = new Headers();
+    assert_throws_js(TypeError, function() { headers.append("name", value); });
+  }, "Check headers append with an invalid value " + value);
+});
+
+test(function() {
+  var headers = new Headers([["name", "value"]]);
+  assert_throws_js(TypeError, function() { headers.forEach(); });
+  assert_throws_js(TypeError, function() { headers.forEach(undefined); });
+  assert_throws_js(TypeError, function() { headers.forEach(1); });
+}, "Headers forEach throws if argument is not callable");
+
+test(function() {
+  var headers = new Headers([["name1", "value1"], ["name2", "value2"], ["name3", "value3"]]);
+  var counter = 0;
+  try {
+      headers.forEach(function(value, name) {
+          counter++;
+          if (name == "name2")
+                throw "error";
+      });
+  } catch (e) {
+      assert_equals(counter, 2);
+      assert_equals(e, "error");
+      return;
+  }
+  assert_unreached();
+}, "Headers forEach loop should stop if callback is throwing exception");
diff --git a/testing/web-platform/tests/fetch/api/headers/headers-no-cors.any.js b/testing/web-platform/tests/fetch/api/headers/headers-no-cors.any.js
new file mode 100644
index 0000000000..60dbb9ef67
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/headers-no-cors.any.js
@@ -0,0 +1,59 @@
+// META: global=window,worker
+
+"use strict";
+
+promise_test(() => fetch("../cors/resources/not-cors-safelisted.json").then(res => res.json().then(runTests)), "Loading data…");
+
+const longValue = "s".repeat(127);
+
+[
+  {
+    "headers": ["accept", "accept-language", "content-language"],
+    "values": [longValue, "", longValue]
+  },
+  {
+    "headers": ["accept", "accept-language", "content-language"],
+    "values": ["", longValue]
+  },
+  {
+    "headers": ["content-type"],
+    "values": ["text/plain;" + "s".repeat(116), "text/plain"]
+  }
+].forEach(testItem => {
+  testItem.headers.forEach(header => {
+    test(() => {
+      const noCorsHeaders = new Request("about:blank", { mode: "no-cors" }).headers;
+      testItem.values.forEach((value) => {
+        noCorsHeaders.append(header, value);
+        assert_equals(noCorsHeaders.get(header), testItem.values[0], '1');
+      });
+      noCorsHeaders.set(header, testItem.values.join(", "));
+      assert_equals(noCorsHeaders.get(header), testItem.values[0], '2');
+      noCorsHeaders.delete(header);
+      assert_false(noCorsHeaders.has(header));
+    }, "\"no-cors\" Headers object cannot have " + header + " set to " + testItem.values.join(", "));
+  });
+});
+
+function runTests(testArray) {
+  testArray = testArray.concat([
+    ["dpr", "2"],
+    ["rtt", "1.0"],
+    ["downlink", "-1.0"],
+    ["ect", "6g"],
+    ["save-data", "on"],
+    ["viewport-width", "100"],
+    ["width", "100"],
+    ["unknown", "doesitmatter"]
+  ]);
+  testArray.forEach(testItem => {
+    const [headerName, headerValue] = testItem;
+    test(() => {
+      const noCorsHeaders = new Request("about:blank", { mode: "no-cors" }).headers;
+      noCorsHeaders.append(headerName, headerValue);
+      assert_false(noCorsHeaders.has(headerName));
+      noCorsHeaders.set(headerName, headerValue);
+      assert_false(noCorsHeaders.has(headerName));
+    }, "\"no-cors\" Headers object cannot have " + headerName + "/" + headerValue + " as header");
+  });
+}
diff --git a/testing/web-platform/tests/fetch/api/headers/headers-normalize.any.js b/testing/web-platform/tests/fetch/api/headers/headers-normalize.any.js
new file mode 100644
index 0000000000..68cf5b85f3
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/headers-normalize.any.js
@@ -0,0 +1,56 @@
+// META: title=Headers normalize values
+// META: global=window,worker
+
+"use strict";
+
+const expectations = {
+  "name1": [" space ", "space"],
+  "name2": ["\ttab\t", "tab"],
+  "name3": [" spaceAndTab\t", "spaceAndTab"],
+  "name4": ["\r\n newLine", "newLine"], //obs-fold cases
+  "name5": ["newLine\r\n ", "newLine"],
+  "name6": ["\r\n\tnewLine", "newLine"],
+  "name7": ["\t\f\tnewLine\n", "\f\tnewLine"],
+  "name8": ["newLine\xa0", "newLine\xa0"], // \xa0 == non breaking space
+};
+
+test(function () {
+  const headerDict = Object.fromEntries(
+    Object.entries(expectations).map(([name, [actual]]) => [name, actual]),
+  );
+  var headers = new Headers(headerDict);
+  for (const name in expectations) {
+    const expected = expectations[name][1];
+    assert_equals(
+      headers.get(name),
+      expected,
+      "name: " + name + " has normalized value: " + expected,
+    );
+  }
+}, "Create headers with not normalized values");
+
+test(function () {
+  var headers = new Headers();
+  for (const name in expectations) {
+    headers.append(name, expectations[name][0]);
+    const expected = expectations[name][1];
+    assert_equals(
+      headers.get(name),
+      expected,
+      "name: " + name + " has value: " + expected,
+    );
+  }
+}, "Check append method with not normalized values");
+
+test(function () {
+  var headers = new Headers();
+  for (const name in expectations) {
+    headers.set(name, expectations[name][0]);
+    const expected = expectations[name][1];
+    assert_equals(
+      headers.get(name),
+      expected,
+      "name: " + name + " has value: " + expected,
+    );
+  }
+}, "Check set method with not normalized values");
diff --git a/testing/web-platform/tests/fetch/api/headers/headers-record.any.js b/testing/web-platform/tests/fetch/api/headers/headers-record.any.js
new file mode 100644
index 0000000000..fa853914f4
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/headers-record.any.js
@@ -0,0 +1,357 @@
+// META: global=window,worker
+
+"use strict";
+
+var log = [];
+function clearLog() {
+  log = [];
+}
+function addLogEntry(name, args) {
+  log.push([ name, ...args ]);
+}
+
+var loggingHandler = {
+};
+
+setup(function() {
+  for (let prop of Object.getOwnPropertyNames(Reflect)) {
+    loggingHandler[prop] = function(...args) {
+      addLogEntry(prop, args);
+      return Reflect[prop](...args);
+    }
+  }
+});
+
+test(function() {
+  var h = new Headers();
+  assert_equals([...h].length, 0);
+}, "Passing nothing to Headers constructor");
+
+test(function() {
+  var h = new Headers(undefined);
+  assert_equals([...h].length, 0);
+}, "Passing undefined to Headers constructor");
+
+test(function() {
+  assert_throws_js(TypeError, function() {
+    var h = new Headers(null);
+  });
+}, "Passing null to Headers constructor");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = { a: "b" };
+  var proxy = new Proxy(record, loggingHandler);
+  var h = new Headers(proxy);
+
+  assert_equals(log.length, 4);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", record, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", record]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", record, "a"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[3], ["get", record, "a", proxy]);
+
+  // Check the results.
+  assert_equals([...h].length, 1);
+  assert_array_equals([...h.keys()], ["a"]);
+  assert_true(h.has("a"));
+  assert_equals(h.get("a"), "b");
+}, "Basic operation with one property");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var recordProto = { c: "d" };
+  var record = Object.create(recordProto, { a: { value: "b", enumerable: true } });
+  var proxy = new Proxy(record, loggingHandler);
+  var h = new Headers(proxy);
+
+  assert_equals(log.length, 4);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", record, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", record]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", record, "a"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[3], ["get", record, "a", proxy]);
+
+  // Check the results.
+  assert_equals([...h].length, 1);
+  assert_array_equals([...h.keys()], ["a"]);
+  assert_true(h.has("a"));
+  assert_equals(h.get("a"), "b");
+}, "Basic operation with one property and a proto");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = { a: "b", c: "d" };
+  var proxy = new Proxy(record, loggingHandler);
+  var h = new Headers(proxy);
+
+  assert_equals(log.length, 6);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", record, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", record]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", record, "a"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[3], ["get", record, "a", proxy]);
+  // Then the second [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[4], ["getOwnPropertyDescriptor", record, "c"]);
+  // Then the second [[Get]] from step 5.2.
+  assert_array_equals(log[5], ["get", record, "c", proxy]);
+
+  // Check the results.
+  assert_equals([...h].length, 2);
+  assert_array_equals([...h.keys()], ["a", "c"]);
+  assert_true(h.has("a"));
+  assert_equals(h.get("a"), "b");
+  assert_true(h.has("c"));
+  assert_equals(h.get("c"), "d");
+}, "Correct operation ordering with two properties");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = { a: "b", "\uFFFF": "d" };
+  var proxy = new Proxy(record, loggingHandler);
+  assert_throws_js(TypeError, function() {
+    var h = new Headers(proxy);
+  });
+
+  assert_equals(log.length, 5);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", record, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", record]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", record, "a"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[3], ["get", record, "a", proxy]);
+  // Then the second [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[4], ["getOwnPropertyDescriptor", record, "\uFFFF"]);
+  // The second [[Get]] never happens, because we convert the invalid name to a
+  // ByteString first and throw.
+}, "Correct operation ordering with two properties one of which has an invalid name");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = { a: "\uFFFF", c: "d" }
+  var proxy = new Proxy(record, loggingHandler);
+  assert_throws_js(TypeError, function() {
+    var h = new Headers(proxy);
+  });
+
+  assert_equals(log.length, 4);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", record, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", record]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", record, "a"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[3], ["get", record, "a", proxy]);
+  // Nothing else after this, because converting the result of that [[Get]] to a
+  // ByteString throws.
+}, "Correct operation ordering with two properties one of which has an invalid value");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = {};
+  Object.defineProperty(record, "a", { value: "b", enumerable: false });
+  Object.defineProperty(record, "c", { value: "d", enumerable: true });
+  Object.defineProperty(record, "e", { value: "f", enumerable: false });
+  var proxy = new Proxy(record, loggingHandler);
+  var h = new Headers(proxy);
+
+  assert_equals(log.length, 6);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", record, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", record]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", record, "a"]);
+  // No [[Get]] because not enumerable
+  // Then the second [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[3], ["getOwnPropertyDescriptor", record, "c"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[4], ["get", record, "c", proxy]);
+  // Then the third [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[5], ["getOwnPropertyDescriptor", record, "e"]);
+  // No [[Get]] because not enumerable
+
+  // Check the results.
+  assert_equals([...h].length, 1);
+  assert_array_equals([...h.keys()], ["c"]);
+  assert_true(h.has("c"));
+  assert_equals(h.get("c"), "d");
+}, "Correct operation ordering with non-enumerable properties");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = {a: "b", c: "d", e: "f"};
+  var lyingHandler = {
+    getOwnPropertyDescriptor: function(target, name) {
+      if (name == "a" || name == "e") {
+        return undefined;
+      }
+      return Reflect.getOwnPropertyDescriptor(target, name);
+    }
+  };
+  var lyingProxy = new Proxy(record, lyingHandler);
+  var proxy = new Proxy(lyingProxy, loggingHandler);
+  var h = new Headers(proxy);
+
+  assert_equals(log.length, 6);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", lyingProxy, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", lyingProxy]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", lyingProxy, "a"]);
+  // No [[Get]] because no descriptor
+  // Then the second [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[3], ["getOwnPropertyDescriptor", lyingProxy, "c"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[4], ["get", lyingProxy, "c", proxy]);
+  // Then the third [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[5], ["getOwnPropertyDescriptor", lyingProxy, "e"]);
+  // No [[Get]] because no descriptor
+
+  // Check the results.
+  assert_equals([...h].length, 1);
+  assert_array_equals([...h.keys()], ["c"]);
+  assert_true(h.has("c"));
+  assert_equals(h.get("c"), "d");
+}, "Correct operation ordering with undefined descriptors");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = {a: "b", c: "d"};
+  var lyingHandler = {
+    ownKeys: function() {
+      return [ "a", "c", "a", "c" ];
+    },
+  };
+  var lyingProxy = new Proxy(record, lyingHandler);
+  var proxy = new Proxy(lyingProxy, loggingHandler);
+
+  // Returning duplicate keys from ownKeys() throws a TypeError.
+  assert_throws_js(TypeError,
+                   function() { var h = new Headers(proxy); });
+
+  assert_equals(log.length, 2);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", lyingProxy, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", lyingProxy]);
+}, "Correct operation ordering with repeated keys");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = {
+    a: "b",
+    [Symbol.toStringTag]: {
+      // Make sure the ToString conversion of the value happens
+      // after the ToString conversion of the key.
+      toString: function () { addLogEntry("toString", [this]); return "nope"; }
+    },
+    c: "d" };
+  var proxy = new Proxy(record, loggingHandler);
+  assert_throws_js(TypeError,
+                   function() { var h = new Headers(proxy); });
+
+  assert_equals(log.length, 7);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", record, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", record]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", record, "a"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[3], ["get", record, "a", proxy]);
+  // Then the second [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[4], ["getOwnPropertyDescriptor", record, "c"]);
+  // Then the second [[Get]] from step 5.2.
+  assert_array_equals(log[5], ["get", record, "c", proxy]);
+  // Then the third [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[6], ["getOwnPropertyDescriptor", record,
+                               Symbol.toStringTag]);
+  // Then we throw an exception converting the Symbol to a string, before we do
+  // the third [[Get]].
+}, "Basic operation with Symbol keys");
+
+test(function() {
+  this.add_cleanup(clearLog);
+  var record = {
+    a: {
+      toString: function() { addLogEntry("toString", [this]); return "b"; }
+    },
+    [Symbol.toStringTag]: {
+      toString: function () { addLogEntry("toString", [this]); return "nope"; }
+    },
+    c: {
+      toString: function() { addLogEntry("toString", [this]); return "d"; }
+    }
+  };
+  // Now make that Symbol-named property not enumerable.
+  Object.defineProperty(record, Symbol.toStringTag, { enumerable: false });
+  assert_array_equals(Reflect.ownKeys(record),
+                      ["a", "c", Symbol.toStringTag]);
+
+  var proxy = new Proxy(record, loggingHandler);
+  var h = new Headers(proxy);
+
+  assert_equals(log.length, 9);
+  // The first thing is the [[Get]] of Symbol.iterator to figure out whether
+  // we're a sequence, during overload resolution.
+  assert_array_equals(log[0], ["get", record, Symbol.iterator, proxy]);
+  // Then we have the [[OwnPropertyKeys]] from
+  // https://webidl.spec.whatwg.org/#es-to-record step 4.
+  assert_array_equals(log[1], ["ownKeys", record]);
+  // Then the [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[2], ["getOwnPropertyDescriptor", record, "a"]);
+  // Then the [[Get]] from step 5.2.
+  assert_array_equals(log[3], ["get", record, "a", proxy]);
+  // Then the ToString on the value.
+  assert_array_equals(log[4], ["toString", record.a]);
+  // Then the second [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[5], ["getOwnPropertyDescriptor", record, "c"]);
+  // Then the second [[Get]] from step 5.2.
+  assert_array_equals(log[6], ["get", record, "c", proxy]);
+  // Then the ToString on the value.
+  assert_array_equals(log[7], ["toString", record.c]);
+  // Then the third [[GetOwnProperty]] from step 5.1.
+  assert_array_equals(log[8], ["getOwnPropertyDescriptor", record,
+                               Symbol.toStringTag]);
+  // No [[Get]] because not enumerable.
+
+  // Check the results.
+  assert_equals([...h].length, 2);
+  assert_array_equals([...h.keys()], ["a", "c"]);
+  assert_true(h.has("a"));
+  assert_equals(h.get("a"), "b");
+  assert_true(h.has("c"));
+  assert_equals(h.get("c"), "d");
+}, "Operation with non-enumerable Symbol keys");
diff --git a/testing/web-platform/tests/fetch/api/headers/headers-structure.any.js b/testing/web-platform/tests/fetch/api/headers/headers-structure.any.js
new file mode 100644
index 0000000000..d826bcab2a
--- /dev/null
+++ b/testing/web-platform/tests/fetch/api/headers/headers-structure.any.js
@@ -0,0 +1,20 @@
+// META: title=Headers basic
+// META: global=window,worker
+
+"use strict";
+
+var headers = new Headers();
+var methods = ["append",
+                "delete",
+                "get",
+                "has",
+                "set",
+                //Headers is iterable
+                "entries",
+                "keys",
+                "values"
+                ];
+for (var idx in methods)
+  test(function() {
+    assert_true(methods[idx] in headers, "headers has " + methods[idx] + " method");
+  }, "Headers has " + methods[idx] + " method");