From 43a97878ce14b72f0981164f87f2e35e14151312 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 11:22:09 +0200
Subject: Adding upstream version 110.0.1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 ...ss-origin-traversal-does-not-fire-navigate.html | 25 ++++++
 ...sdocument-crossorigin-sameorigindomain.sub.html | 41 +++++++++
 .../click-crossdocument-crossorigin.html           | 30 +++++++
 .../click-crossdocument-sameorigin.html            | 29 +++++++
 ...edocument-crossorigin-sameorigindomain.sub.html | 41 +++++++++
 .../click-samedocument-crossorigin.html            | 39 +++++++++
 .../click-samedocument-sameorigin.html             | 27 ++++++
 ...sdocument-crossorigin-sameorigindomain.sub.html | 34 ++++++++
 .../location-crossdocument-crossorigin.html        | 23 ++++++
 .../location-crossdocument-sameorigin.html         | 26 ++++++
 ...edocument-crossorigin-sameorigindomain.sub.html | 34 ++++++++
 .../location-samedocument-crossorigin.html         | 32 ++++++++
 .../location-samedocument-sameorigin.html          | 26 ++++++
 ...sdocument-crossorigin-sameorigindomain.sub.html | 35 ++++++++
 .../open-crossdocument-crossorigin.html            | 24 ++++++
 .../open-crossdocument-sameorigin.html             | 26 ++++++
 ...edocument-crossorigin-sameorigindomain.sub.html | 35 ++++++++
 .../open-samedocument-crossorigin.html             | 33 ++++++++
 .../cross-window/open-samedocument-sameorigin.html | 26 ++++++
 .../resources/cross-origin-iframe-helper.html      | 28 +++++++
 .../resources/document-domain-setter.sub.html      |  3 +
 ...sdocument-crossorigin-sameorigindomain.sub.html | 41 +++++++++
 .../submit-crossdocument-crossorigin.html          | 30 +++++++
 .../submit-crossdocument-sameorigin.html           | 27 ++++++
 ...edocument-crossorigin-sameorigindomain.sub.html | 41 +++++++++
 .../submit-samedocument-crossorigin.html           | 39 +++++++++
 .../submit-samedocument-sameorigin.html            | 27 ++++++
 .../navigate-event/event-constructor.html          | 96 ++++++++++++++++++++++
 .../navigate-event/intercept-after-dispatch.html   | 16 ++++
 .../navigate-event/intercept-and-navigate.html     | 27 ++++++
 .../navigate-event/intercept-canceled-event.html   | 17 ++++
 .../intercept-cross-document-same-origin.html      | 21 +++++
 .../navigate-event/intercept-cross-origin.html     | 18 ++++
 .../navigate-event/intercept-detach-multiple.html  | 18 ++++
 .../navigate-event/intercept-detach.html           | 17 ++++
 .../intercept-handler-null-or-undefined.html       | 21 +++++
 .../intercept-handler-returns-non-promise.html     | 18 ++++
 .../navigate-event/intercept-handler-throws.html   | 26 ++++++
 .../intercept-history-pushState.html               | 23 ++++++
 .../intercept-history-replaceState.html            | 23 ++++++
 .../intercept-multiple-times-reject.html           | 38 +++++++++
 .../navigate-event/intercept-multiple-times.html   | 41 +++++++++
 .../navigate-event/intercept-navigation-back.html  | 19 +++++
 .../intercept-on-synthetic-event.html              | 17 ++++
 .../navigate-event/intercept-popstate.html         | 26 ++++++
 .../navigate-event/intercept-reject.html           | 29 +++++++
 .../navigate-event/intercept-resolve.html          | 20 +++++
 .../intercept-same-document-history-back.html      | 40 +++++++++
 .../navigate-anchor-cross-origin.html              | 24 ++++++
 .../navigate-anchor-download-userInitiated.html    | 29 +++++++
 .../navigate-event/navigate-anchor-download.html   | 34 ++++++++
 .../navigate-event/navigate-anchor-fragment.html   | 25 ++++++
 ...navigate-anchor-same-origin-cross-document.html | 25 ++++++
 .../navigate-anchor-userInitiated.html             | 29 +++++++
 .../navigate-anchor-with-target.html               | 31 +++++++
 ...navigate-destination-getState-back-forward.html | 26 ++++++
 .../navigate-destination-getState-navigate.html    | 23 ++++++
 .../navigate-destination-getState-reload.html      | 25 ++++++
 .../navigate-event/navigate-form-get.html          | 27 ++++++
 .../navigate-event/navigate-form-reload.html       | 28 +++++++
 .../navigate-event/navigate-form-traverse.html     | 44 ++++++++++
 .../navigate-form-userInitiated.html               | 30 +++++++
 .../navigate-event/navigate-form-with-target.html  | 29 +++++++
 .../navigate-event/navigate-form.html              | 25 ++++++
 .../navigate-history-back-after-fragment.html      | 31 +++++++
 .../navigate-history-back-after-pushState.html     | 31 +++++++
 .../navigate-history-back-cross-document.html      | 32 ++++++++
 .../navigate-event/navigate-history-go-0.html      | 27 ++++++
 .../navigate-event/navigate-history-pushState.html | 29 +++++++
 .../navigate-history-replaceState.html             | 29 +++++++
 .../navigate-event/navigate-iframe-location.html   | 30 +++++++
 .../navigate-event/navigate-location.html          | 23 ++++++
 .../navigate-event/navigate-meta-refresh.html      | 27 ++++++
 .../navigate-navigation-back-cross-document.html   | 32 ++++++++
 .../navigate-navigation-back-same-document.html    | 32 ++++++++
 .../navigate-navigation-navigate.html              | 22 +++++
 .../navigate-event/navigate-to-javascript.html     | 18 ++++
 .../navigate-event/navigate-to-srcdoc.html         | 34 ++++++++
 .../navigate-event/navigate-window-open-self.html  | 23 ++++++
 .../navigate-event/navigate-window-open.html       | 30 +++++++
 .../navigatesuccess-cross-document.html            | 14 ++++
 .../navigatesuccess-same-document.html             | 10 +++
 .../navigate-event/resources/meta-refresh.html     |  4 +
 .../navigatesuccess-cross-document-helper.html     |  6 ++
 .../resources/opener-postMessage-onload.html       |  6 ++
 .../signal-abort-detach-in-onnavigate.html         | 21 +++++
 .../navigate-event/signal-abort-intercept.html     | 18 ++++
 .../signal-abort-preventDefault.html               | 19 +++++
 .../signal-abort-window-stop-after-intercept.html  | 40 +++++++++
 .../signal-abort-window-stop-in-onnavigate.html    | 24 ++++++
 .../navigate-event/signal-abort-window-stop.html   | 23 ++++++
 91 files changed, 2482 insertions(+)
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-origin-traversal-does-not-fire-navigate.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-crossorigin-sameorigindomain.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-crossorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-sameorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-crossorigin-sameorigindomain.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-crossorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-sameorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-crossorigin-sameorigindomain.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-crossorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-sameorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-crossorigin-sameorigindomain.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-crossorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-sameorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-crossorigin-sameorigindomain.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-crossorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-sameorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-crossorigin-sameorigindomain.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-crossorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-sameorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/resources/cross-origin-iframe-helper.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/resources/document-domain-setter.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-crossorigin-sameorigindomain.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-crossorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-sameorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-crossorigin-sameorigindomain.sub.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-crossorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-sameorigin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/event-constructor.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-after-dispatch.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-and-navigate.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-canceled-event.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-cross-document-same-origin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-cross-origin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-detach-multiple.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-detach.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-null-or-undefined.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-returns-non-promise.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-throws.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-history-pushState.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-history-replaceState.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-multiple-times-reject.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-multiple-times.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-navigation-back.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-on-synthetic-event.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-popstate.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-reject.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-resolve.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/intercept-same-document-history-back.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-cross-origin.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-download-userInitiated.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-download.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-fragment.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-same-origin-cross-document.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-userInitiated.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-with-target.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-back-forward.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-navigate.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-reload.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-form-get.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-form-reload.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-form-traverse.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-form-userInitiated.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-form-with-target.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-form.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-after-fragment.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-after-pushState.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-cross-document.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-history-go-0.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-history-pushState.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-history-replaceState.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-iframe-location.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-location.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-meta-refresh.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-back-cross-document.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-back-same-document.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-navigate.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-to-javascript.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-to-srcdoc.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-window-open-self.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigate-window-open.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigatesuccess-cross-document.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/navigatesuccess-same-document.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/resources/meta-refresh.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/resources/navigatesuccess-cross-document-helper.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/resources/opener-postMessage-onload.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/signal-abort-detach-in-onnavigate.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/signal-abort-intercept.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/signal-abort-preventDefault.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop-after-intercept.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop-in-onnavigate.html
 create mode 100644 testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop.html

(limited to 'testing/web-platform/tests/navigation-api/navigate-event')

diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-origin-traversal-does-not-fire-navigate.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-origin-traversal-does-not-fire-navigate.html
new file mode 100644
index 0000000000..36491be22c
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-origin-traversal-does-not-fire-navigate.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../navigation-methods/return-value/resources/helpers.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script>
+promise_test(async t => {
+  // Open a cross-origin window.
+  let w = window.open(get_host_info().HTTP_REMOTE_ORIGIN + "/navigation-api/navigate-event/resources/opener-postMessage-onload.html");
+  await new Promise(resolve => window.onmessage = resolve);
+
+  // Navigate the opened window to this origin.
+  w.location = get_host_info().ORIGIN + "/navigation-api/navigate-event/resources/opener-postMessage-onload.html";
+  await new Promise(resolve => window.onmessage = resolve);
+  assert_equals(w.navigation.entries().length, 1);
+  assert_equals(w.navigation.currentEntry.index, 0);
+
+  // Go back. This should not fire a navigate event, because the traversal is
+  // cross-origin. Note that history.back() must be used instead of
+  // navigation.back() because navigation.back() can never go cross-origin.
+  w.navigation.onnavigate = t.unreached_func("navigate should not fire");
+  w.history.back();
+  await new Promise(resolve => window.onmessage = resolve);
+}, "A cross-origin traversal does not fire the navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-crossorigin-sameorigindomain.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-crossorigin-sameorigindomain.sub.html
new file mode 100644
index 0000000000..676672a230
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-crossorigin-sameorigindomain.sub.html
@@ -0,0 +1,41 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<script>
+document.domain = "{{host}}";
+async_test(t => {
+  const url = new URL("resources/document-domain-setter.sub.html", location.href);
+  url.hostname = "{{domains[www1]}}";
+  const iframe = document.createElement("iframe");
+  iframe.name = "windowname";
+  iframe.src = url;
+  document.body.append(iframe);
+
+  url.search = "?foo";
+  const link = document.createElement("a");
+  link.href = url;
+  link.target = iframe.name;
+  document.body.append(link);
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_false(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, link.href, "destination.url");
+      assert_false(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    link.click();
+  });
+}, "clicking on an <a> element that navigates cross-document targeting a same-origin-domain (but cross-origin) window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-crossorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-crossorigin.html
new file mode 100644
index 0000000000..2f40238912
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-crossorigin.html
@@ -0,0 +1,30 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+
+<script>
+async_test(t => {
+  const url = new URL("resources/cross-origin-iframe-helper.html", location.href);
+  url.hostname = get_host_info().REMOTE_HOST;
+  const iframe = document.createElement("iframe");
+  iframe.src = url;
+  iframe.name = "windowname";
+  document.body.append(iframe);
+
+  url.search = "?postMessage-top-when-done";
+  const link = document.createElement("a");
+  link.href = url;
+  link.target = iframe.name;
+  document.body.append(link);
+
+  window.onmessage = t.step_func_done(e => {
+    // If we hit onnavigate in the target window, we'll get a different message, and fail.
+    assert_equals(e.data, "DONE");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => link.click());
+}, "clicking on an <a> element that navigates cross-document targeting a cross-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-sameorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-sameorigin.html
new file mode 100644
index 0000000000..41c3ca71ee
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-crossdocument-sameorigin.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<a id="link" href="/common/blank.html?foo" target="windowname">Click me</a>
+<iframe id="i" name="windowname" src="/common/blank.html"></iframe>
+
+<script>
+async_test(t => {
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_false(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, link.href, "destination.url");
+      assert_false(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    link.click();
+  });
+}, "clicking on an <a> element that navigates cross-document targeting a same-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-crossorigin-sameorigindomain.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-crossorigin-sameorigindomain.sub.html
new file mode 100644
index 0000000000..a467ecf9d7
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-crossorigin-sameorigindomain.sub.html
@@ -0,0 +1,41 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<script>
+document.domain = "{{host}}";
+async_test(t => {
+  const url = new URL("resources/document-domain-setter.sub.html", location.href);
+  url.hostname = "{{domains[www1]}}";
+  const iframe = document.createElement("iframe");
+  iframe.name = "windowname";
+  iframe.src = url;
+  document.body.append(iframe);
+
+  url.hash = "#foo";
+  const link = document.createElement("a");
+  link.href = url;
+  link.target = iframe.name;
+  document.body.append(link);
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_true(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, link.href, "destination.url");
+      assert_true(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    link.click();
+  });
+}, "clicking on an <a> element that navigates same-document targeting a same-origin-domain (but cross-origin) window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-crossorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-crossorigin.html
new file mode 100644
index 0000000000..b9fa97f6d5
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-crossorigin.html
@@ -0,0 +1,39 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+
+<script>
+async_test(t => {
+  const url = new URL("resources/cross-origin-iframe-helper.html", location.href);
+  url.hostname = get_host_info().REMOTE_HOST;
+  const iframe = document.createElement("iframe")
+  iframe.src = url;
+  iframe.name = "windowname";
+  document.body.append(iframe);
+
+  url.hash = "#foo";
+  const link = document.createElement("a");
+  link.href = url;
+  link.target = iframe.name;
+  document.body.append(link);
+
+  window.onmessage = t.step_func_done(e => {
+    assert_equals(e.data.navigationType, "push", "navigationType");
+    assert_true(e.data.cancelable, "cancelable");
+    assert_true(e.data.canIntercept, "canIntercept");
+    assert_false(e.data.userInitiated, "userInitiated");
+    assert_true(e.data.hashChange, "hashChange");
+    assert_equals(e.data.formData, null, "formData");
+    assert_equals(e.data.destination.url, link.href, "destination.url");
+    assert_true(e.data.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.data.destination.key, null, "destination.key");
+    assert_equals(e.data.destination.id, null, "destination.id");
+    assert_equals(e.data.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => link.click());
+}, "clicking on an <a> element that navigates same-document targeting a cross-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-sameorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-sameorigin.html
new file mode 100644
index 0000000000..566bea3dc7
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/click-samedocument-sameorigin.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<a id="link" href="/common/blank.html#foo" target="windowname">Click me</a>
+<iframe id="i" name="windowname" src="/common/blank.html"></iframe>
+
+<script>
+async_test(t => {
+  i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push", "navigationType");
+    assert_true(e.cancelable, "cancelable");
+    assert_true(e.canIntercept, "canIntercept");
+    assert_false(e.userInitiated, "userInitiated");
+    assert_true(e.hashChange, "hashChange");
+    assert_equals(e.formData, null, "formData");
+    assert_equals(e.destination.url, link.href, "destination.url");
+    assert_true(e.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.destination.key, null, "destination.key");
+    assert_equals(e.destination.id, null, "destination.id");
+    assert_equals(e.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => link.click());
+}, "clicking on an <a> element that navigates same-document targeting a same-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-crossorigin-sameorigindomain.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-crossorigin-sameorigindomain.sub.html
new file mode 100644
index 0000000000..77a5873c08
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-crossorigin-sameorigindomain.sub.html
@@ -0,0 +1,34 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<script>
+document.domain = "{{host}}";
+async_test(t => {
+  const url = new URL("resources/document-domain-setter.sub.html", location.href);
+  url.hostname = "{{domains[www1]}}";
+  const iframe = document.createElement("iframe");
+  iframe.src = url;
+  document.body.append(iframe);
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_false(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, iframe.src + "?foo", "destination.url");
+      assert_false(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    iframe.contentWindow.location.href = url + "?foo";
+  });
+}, "using location.href to navigate cross-document targeting a same-origin-domain (but cross-origin) window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-crossorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-crossorigin.html
new file mode 100644
index 0000000000..79df86fdc9
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-crossorigin.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+
+<script>
+async_test(t => {
+  const iframeURL = new URL("resources/cross-origin-iframe-helper.html", location.href);
+  iframeURL.hostname = get_host_info().REMOTE_HOST;
+  const iframe = document.createElement("iframe");
+  iframe.src = iframeURL;
+  document.body.append(iframe);
+
+  window.onmessage = t.step_func_done(e => {
+    // If we hit onnavigate in the target window, we'll get a different message, and fail.
+    assert_equals(e.data, "DONE");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => iframe.contentWindow.location.href = iframeURL + "?postMessage-top-when-done");
+}, "using location.href to navigate cross-document targeting a cross-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-sameorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-sameorigin.html
new file mode 100644
index 0000000000..41ac1b0375
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-crossdocument-sameorigin.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<iframe id="i" src="/common/blank.html"></iframe>
+
+<script>
+async_test(t => {
+  i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push", "navigationType");
+    assert_true(e.cancelable, "cancelable");
+    assert_true(e.canIntercept, "canIntercept");
+    assert_false(e.userInitiated, "userInitiated");
+    assert_false(e.hashChange, "hashChange");
+    assert_equals(e.formData, null, "formData");
+    assert_equals(e.destination.url, i.src + "?foo", "destination.url");
+    assert_false(e.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.destination.key, null, "destination.key");
+    assert_equals(e.destination.id, null, "destination.id");
+    assert_equals(e.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => i.contentWindow.location.href = "/common/blank.html?foo");
+}, "using location.href to navigate cross-document targeting a same-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-crossorigin-sameorigindomain.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-crossorigin-sameorigindomain.sub.html
new file mode 100644
index 0000000000..1eda74e982
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-crossorigin-sameorigindomain.sub.html
@@ -0,0 +1,34 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<script>
+document.domain = "{{host}}";
+async_test(t => {
+  const url = new URL("resources/document-domain-setter.sub.html", location.href);
+  url.hostname = "{{domains[www1]}}";
+  const iframe = document.createElement("iframe");
+  iframe.src = url;
+  document.body.append(iframe);
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_true(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, iframe.src + "#foo", "destination.url");
+      assert_true(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    iframe.contentWindow.location.href = url + "#foo";
+  });
+}, "using location.href to navigate same-document targeting a same-origin-domain (but cross-origin) window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-crossorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-crossorigin.html
new file mode 100644
index 0000000000..5679236a7d
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-crossorigin.html
@@ -0,0 +1,32 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+
+<script>
+async_test(t => {
+  const iframeURL = new URL("resources/cross-origin-iframe-helper.html", location.href);
+  iframeURL.hostname = get_host_info().REMOTE_HOST;
+  const iframe = document.createElement("iframe")
+  iframe.src = iframeURL;
+  document.body.append(iframe);
+
+  window.onmessage = t.step_func_done(e => {
+    assert_equals(e.data.navigationType, "push", "navigationType");
+    assert_true(e.data.cancelable, "cancelable");
+    assert_true(e.data.canIntercept, "canIntercept");
+    assert_false(e.data.userInitiated, "userInitiated");
+    assert_true(e.data.hashChange, "hashChange");
+    assert_equals(e.data.formData, null, "formData");
+    assert_equals(e.data.destination.url, iframe.src + "#foo", "destination.url");
+    assert_true(e.data.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.data.destination.key, null, "destination.key");
+    assert_equals(e.data.destination.id, null, "destination.id");
+    assert_equals(e.data.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => iframe.contentWindow.location.href = iframeURL + "#foo");
+}, "using location.href to navigate same-document targeting a cross-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-sameorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-sameorigin.html
new file mode 100644
index 0000000000..a7e4181c3a
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/location-samedocument-sameorigin.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<iframe id="i" src="/common/blank.html"></iframe>
+
+<script>
+async_test(t => {
+  i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push", "navigationType");
+    assert_true(e.cancelable, "cancelable");
+    assert_true(e.canIntercept, "canIntercept");
+    assert_false(e.userInitiated, "userInitiated");
+    assert_true(e.hashChange, "hashChange");
+    assert_equals(e.formData, null, "formData");
+    assert_equals(e.destination.url, i.src + "#foo", "destination.url");
+    assert_true(e.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.destination.key, null, "destination.key");
+    assert_equals(e.destination.id, null, "destination.id");
+    assert_equals(e.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => i.contentWindow.location.href = "/common/blank.html#foo");
+}, "using location.href to navigate same-document targeting a same-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-crossorigin-sameorigindomain.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-crossorigin-sameorigindomain.sub.html
new file mode 100644
index 0000000000..ea9ea479c3
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-crossorigin-sameorigindomain.sub.html
@@ -0,0 +1,35 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<script>
+document.domain = "{{host}}";
+async_test(t => {
+  const url = new URL("resources/document-domain-setter.sub.html", location.href);
+  url.hostname = "{{domains[www1]}}";
+  const iframe = document.createElement("iframe");
+  iframe.name = "windowname";
+  iframe.src = url;
+  document.body.append(iframe);
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_false(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, url + "?foo", "destination.url");
+      assert_false(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    window.open(url + "?foo", iframe.name);
+  });
+}, "using window.open() to navigate cross-document targeting a same-origin-domain (but cross-origin) window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-crossorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-crossorigin.html
new file mode 100644
index 0000000000..73ede89cbf
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-crossorigin.html
@@ -0,0 +1,24 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+
+<script>
+async_test(t => {
+  const iframeURL = new URL("resources/cross-origin-iframe-helper.html", location.href);
+  iframeURL.hostname = get_host_info().REMOTE_HOST;
+  const iframe = document.createElement("iframe");
+  iframe.src = iframeURL;
+  iframe.name = "windowname";
+  document.body.append(iframe);
+
+  window.onmessage = t.step_func_done(e => {
+    // If we hit onnavigate in the target window, we'll get a different message, and fail.
+    assert_equals(e.data, "DONE");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => window.open(iframeURL + "?postMessage-top-when-done", "windowname"));
+}, "using window.open() to navigate cross-document targeting a cross-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-sameorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-sameorigin.html
new file mode 100644
index 0000000000..478483e238
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-crossdocument-sameorigin.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<iframe id="i" name="windowname" src="/common/blank.html"></iframe>
+
+<script>
+async_test(t => {
+  i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push", "navigationType");
+    assert_true(e.cancelable, "cancelable");
+    assert_true(e.canIntercept, "canIntercept");
+    assert_false(e.userInitiated, "userInitiated");
+    assert_false(e.hashChange, "hashChange");
+    assert_equals(e.formData, null, "formData");
+    assert_equals(e.destination.url, i.src + "?foo", "destination.url");
+    assert_false(e.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.destination.key, null, "destination.key");
+    assert_equals(e.destination.id, null, "destination.id");
+    assert_equals(e.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => window.open("/common/blank.html?foo", "windowname"));
+}, "using window.open() to navigate cross-document targeting a same-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-crossorigin-sameorigindomain.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-crossorigin-sameorigindomain.sub.html
new file mode 100644
index 0000000000..324adb32a4
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-crossorigin-sameorigindomain.sub.html
@@ -0,0 +1,35 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<script>
+document.domain = "{{host}}";
+async_test(t => {
+  const url = new URL("resources/document-domain-setter.sub.html", location.href);
+  url.hostname = "{{domains[www1]}}";
+  const iframe = document.createElement("iframe");
+  iframe.name = "windowname";
+  iframe.src = url;
+  document.body.append(iframe);
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_true(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, url + "#foo", "destination.url");
+      assert_true(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    window.open(url + "#foo", iframe.name);
+  });
+}, "using window.open() to navigate same-document targeting a same-origin-domain (but cross-origin) window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-crossorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-crossorigin.html
new file mode 100644
index 0000000000..23dceb0420
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-crossorigin.html
@@ -0,0 +1,33 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+
+<script>
+async_test(t => {
+  const iframeURL = new URL("resources/cross-origin-iframe-helper.html", location.href);
+  iframeURL.hostname = get_host_info().REMOTE_HOST;
+  const iframe = document.createElement("iframe")
+  iframe.src = iframeURL;
+  iframe.name = "windowname";
+  document.body.append(iframe);
+
+  window.onmessage = t.step_func_done(e => {
+    assert_equals(e.data.navigationType, "push", "navigationType");
+    assert_true(e.data.cancelable, "cancelable");
+    assert_true(e.data.canIntercept, "canIntercept");
+    assert_false(e.data.userInitiated, "userInitiated");
+    assert_true(e.data.hashChange, "hashChange");
+    assert_equals(e.data.formData, null, "formData");
+    assert_equals(e.data.destination.url, iframe.src + "#foo", "destination.url");
+    assert_true(e.data.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.data.destination.key, null, "destination.key");
+    assert_equals(e.data.destination.id, null, "destination.id");
+    assert_equals(e.data.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => window.open(iframeURL + "#foo", "windowname"));
+}, "using window.open() to navigate same-document targeting a cross-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-sameorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-sameorigin.html
new file mode 100644
index 0000000000..9ca8531803
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/open-samedocument-sameorigin.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<iframe id="i" name="windowname" src="/common/blank.html"></iframe>
+
+<script>
+async_test(t => {
+  i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push", "navigationType");
+    assert_true(e.cancelable, "cancelable");
+    assert_true(e.canIntercept, "canIntercept");
+    assert_false(e.userInitiated, "userInitiated");
+    assert_true(e.hashChange, "hashChange");
+    assert_equals(e.formData, null, "formData");
+    assert_equals(e.destination.url, i.src + "#foo", "destination.url");
+    assert_true(e.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.destination.key, null, "destination.key");
+    assert_equals(e.destination.id, null, "destination.id");
+    assert_equals(e.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => window.open("/common/blank.html#foo", "windowname"));
+}, "using window.open() to navigate same-document targeting a same-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/resources/cross-origin-iframe-helper.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/resources/cross-origin-iframe-helper.html
new file mode 100644
index 0000000000..3393a2ecaa
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/resources/cross-origin-iframe-helper.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<script>
+navigation.onnavigate = e => {
+  const message = {
+    navigationType: e.navigationType,
+    cancelable: e.cancelable,
+    canIntercept: e.canIntercept,
+    userInitiated: e.userInitiated,
+    hashChange: e.hashChange,
+    formData: e.formData,
+    destination: {
+      url: e.destination.url,
+      sameDocument: e.destination.sameDocument,
+      key: e.destination.key,
+      id: e.destination.id,
+      index: e.destination.index
+    }
+  };
+  e.preventDefault();
+  top.postMessage(message, "*");
+};
+
+window.onload = () => {
+  if (location.href.includes("postMessage-top-when-done")) {
+    top.postMessage("DONE", "*");
+  }
+};
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/resources/document-domain-setter.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/resources/document-domain-setter.sub.html
new file mode 100644
index 0000000000..abe32ad8fb
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/resources/document-domain-setter.sub.html
@@ -0,0 +1,3 @@
+<script>
+document.domain = "{{host}}";
+</script>
\ No newline at end of file
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-crossorigin-sameorigindomain.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-crossorigin-sameorigindomain.sub.html
new file mode 100644
index 0000000000..f611034617
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-crossorigin-sameorigindomain.sub.html
@@ -0,0 +1,41 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<script>
+document.domain = "{{host}}";
+async_test(t => {
+  const url = new URL("resources/document-domain-setter.sub.html?start", location.href);
+  url.hostname = "{{domains[www1]}}";
+  const iframe = document.createElement("iframe");
+  iframe.name = "windowname";
+  iframe.src = url;
+  document.body.append(iframe);
+
+  url.search = ""; // setting to "?" actually erases it anyway
+  const form = document.createElement("form");
+  form.action = url + "?";
+  form.target = iframe.name;
+  document.body.append(form);
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_false(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, form.action, "destination.url");
+      assert_false(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    form.submit();
+  });
+}, "submitting a <form> element that navigates cross-document targeting a same-origin-domain (but cross-origin) window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-crossorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-crossorigin.html
new file mode 100644
index 0000000000..007f58b1fb
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-crossorigin.html
@@ -0,0 +1,30 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+
+<script>
+async_test(t => {
+  const url = new URL("resources/cross-origin-iframe-helper.html", location.href);
+  url.hostname = get_host_info().REMOTE_HOST;
+  const iframe = document.createElement("iframe")
+  iframe.src = url;
+  iframe.name = "windowname";
+  document.body.append(iframe);
+
+  const form = document.createElement("form");
+  form.action = url;
+  form.target = iframe.name;
+  form.innerHTML = `<input type="hidden" name="postMessage-top-when-done" value="yes">`;
+  document.body.append(form);
+
+  window.onmessage = t.step_func_done(e => {
+    // If we hit onnavigate in the target window, we'll get a different message, and fail.
+    assert_equals(e.data, "DONE");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => form.submit());
+}, "submitting a <form> element that navigates cross-document targeting a cross-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-sameorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-sameorigin.html
new file mode 100644
index 0000000000..05347335a1
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-crossdocument-sameorigin.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<form id="form" action="/common/blank.html?" target="windowname"></form>
+<iframe id="i" name="windowname" src="/common/blank.html?start"></iframe>
+
+<script>
+async_test(t => {
+  i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push", "navigationType");
+    assert_true(e.cancelable, "cancelable");
+    assert_true(e.canIntercept, "canIntercept");
+    assert_false(e.userInitiated, "userInitiated");
+    assert_false(e.hashChange, "hashChange");
+    assert_equals(e.formData, null, "formData");
+    assert_equals(e.destination.url, form.action, "destination.url");
+    assert_false(e.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.destination.key, null, "destination.key");
+    assert_equals(e.destination.id, null, "destination.id");
+    assert_equals(e.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => form.submit());
+}, "submitting a <form> element that navigates cross-document targeting a same-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-crossorigin-sameorigindomain.sub.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-crossorigin-sameorigindomain.sub.html
new file mode 100644
index 0000000000..9e64a0124d
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-crossorigin-sameorigindomain.sub.html
@@ -0,0 +1,41 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+
+<script>
+document.domain = "{{host}}";
+async_test(t => {
+  const url = new URL("resources/document-domain-setter.sub.html?", location.href);
+  url.hostname = "{{domains[www1]}}";
+  const iframe = document.createElement("iframe");
+  iframe.name = "windowname";
+  iframe.src = url;
+  document.body.append(iframe);
+
+  url.hash = "#foo";
+  const form = document.createElement("form");
+  form.action = url;
+  form.target = iframe.name;
+  document.body.append(form);
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => {
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push", "navigationType");
+      assert_true(e.cancelable, "cancelable");
+      assert_true(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_true(e.hashChange, "hashChange");
+      assert_equals(e.formData, null, "formData");
+      assert_equals(e.destination.url, form.action, "destination.url");
+      assert_true(e.destination.sameDocument, "destination.sameDocument");
+      assert_equals(e.destination.key, null, "destination.key");
+      assert_equals(e.destination.id, null, "destination.id");
+      assert_equals(e.destination.index, -1, "destination.index");
+    });
+
+    form.submit();
+  });
+}, "submitting a <form> element that navigates cross-document targeting a same-origin-domain (but cross-origin) window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-crossorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-crossorigin.html
new file mode 100644
index 0000000000..e53a1f93e7
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-crossorigin.html
@@ -0,0 +1,39 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<body>
+
+<script>
+async_test(t => {
+  const url = new URL("resources/cross-origin-iframe-helper.html?", location.href);
+  url.hostname = get_host_info().REMOTE_HOST;
+  const iframe = document.createElement("iframe")
+  iframe.src = url;
+  iframe.name = "windowname";
+  document.body.append(iframe);
+
+  url.hash = "#foo";
+  const form = document.createElement("form");
+  form.action = url;
+  form.target = iframe.name;
+  document.body.append(form);
+
+  window.onmessage = t.step_func_done(e => {
+    assert_equals(e.data.navigationType, "push", "navigationType");
+    assert_true(e.data.cancelable, "cancelable");
+    assert_true(e.data.canIntercept, "canIntercept");
+    assert_false(e.data.userInitiated, "userInitiated");
+    assert_true(e.data.hashChange, "hashChange");
+    assert_equals(e.data.formData, null, "formData");
+    assert_equals(e.data.destination.url, form.action, "destination.url");
+    assert_true(e.data.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.data.destination.key, null, "destination.key");
+    assert_equals(e.data.destination.id, null, "destination.id");
+    assert_equals(e.data.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => form.submit());
+}, "submitting a <form> element that navigates same-document targeting a cross-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-sameorigin.html b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-sameorigin.html
new file mode 100644
index 0000000000..43aa3226fc
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/cross-window/submit-samedocument-sameorigin.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<form id="form" action="/common/blank.html?#foo" target="windowname"></form>
+<iframe id="i" name="windowname" src="/common/blank.html?"></iframe>
+
+<script>
+async_test(t => {
+  i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push", "navigationType");
+    assert_true(e.cancelable, "cancelable");
+    assert_true(e.canIntercept, "canIntercept");
+    assert_false(e.userInitiated, "userInitiated");
+    assert_true(e.hashChange, "hashChange");
+    assert_equals(e.formData, null, "formData");
+    assert_equals(e.destination.url, form.action, "destination.url");
+    assert_true(e.destination.sameDocument, "destination.sameDocument");
+    assert_equals(e.destination.key, null, "destination.key");
+    assert_equals(e.destination.id, null, "destination.id");
+    assert_equals(e.destination.index, -1, "destination.index");
+  });
+
+  navigation.onnavigate = t.unreached_func("onnavigate must not fire in the source window");
+  window.onload = t.step_func(() => form.submit());
+}, "submitting a <form> element that navigates same-document targeting a same-origin window");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/event-constructor.html b/testing/web-platform/tests/navigation-api/navigate-event/event-constructor.html
new file mode 100644
index 0000000000..065884240e
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/event-constructor.html
@@ -0,0 +1,96 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+test(() => {
+  assert_throws_js(TypeError, () => {
+    new NavigateEvent("navigate");
+  });
+}, "can't bypass required members by omitting the dictionary entirely");
+
+test(() => {
+  assert_throws_js(TypeError, () => {
+    new NavigateEvent("navigate", {
+      navigationType: "push",
+      canIntercept: false,
+      userInitiated: false,
+      hashChange: false,
+      signal: (new AbortController()).signal,
+      formData: null,
+      downloadRequest: null,
+      info: null
+    });
+  });
+}, "destination is required");
+
+async_test(t => {
+  // We need to grab an NavigationDestination.
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_throws_js(TypeError, () => {
+      new NavigateEvent("navigate", {
+        navigationType: "push",
+        destination: e.destination,
+        canIntercept: false,
+        userInitiated: false,
+        hashChange: false,
+        formData: null,
+        downloadRequest: null,
+        info: null
+      });
+    });
+  });
+  history.pushState(1, null, "#1");
+}, "signal is required");
+
+async_test(t => {
+  // We need to grab an NavigationDestination.
+  navigation.onnavigate = t.step_func_done(e => {
+    const info = { some: "object with identity" };
+    const formData = new FormData();
+    const signal = (new AbortController()).signal;
+    const downloadRequest = "abc";
+
+    const event = new NavigateEvent("navigate", {
+      navigationType: "replace",
+      destination: e.destination,
+      canIntercept: true,
+      userInitiated: true,
+      hashChange: true,
+      signal,
+      formData,
+      downloadRequest,
+      info
+    });
+
+    assert_equals(event.navigationType, "replace");
+    assert_equals(event.destination, e.destination);
+    assert_equals(event.canIntercept, true);
+    assert_equals(event.userInitiated, true);
+    assert_equals(event.hashChange, true);
+    assert_equals(event.signal, signal);
+    assert_equals(event.formData, formData);
+    assert_equals(event.downloadRequest, downloadRequest);
+    assert_equals(event.info, info);
+  });
+  history.pushState(2, null, "#2");
+}, "all properties are reflected back");
+
+async_test(t => {
+  // We need to grab an NavigationDestination.
+  navigation.onnavigate = t.step_func_done(e => {
+    const event = new NavigateEvent("navigate", {
+      destination: e.destination,
+      signal: (new AbortController()).signal
+    });
+
+    assert_equals(event.navigationType, "push");
+    assert_equals(event.canIntercept, false);
+    assert_equals(event.userInitiated, false);
+    assert_equals(event.hashChange, false);
+    assert_equals(event.formData, null);
+    assert_equals(event.downloadRequest, null);
+    assert_equals(event.info, undefined);
+  });
+  history.pushState(3, null, "#3");
+}, "defaults are as expected");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-after-dispatch.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-after-dispatch.html
new file mode 100644
index 0000000000..abb328050d
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-after-dispatch.html
@@ -0,0 +1,16 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="/common/blank.html"></iframe>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func(e => {
+    t.step_timeout(t.step_func_done(() => {
+      assert_equals(e.eventPhase, Event.NONE);
+      assert_throws_dom("InvalidStateError", () => e.intercept());
+    }), 0);
+  });
+
+  location.href = "#1";
+}, "event.intercept() throws if used after the dispatch phase");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-and-navigate.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-and-navigate.html
new file mode 100644
index 0000000000..dfbb67b6b6
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-and-navigate.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+promise_test(async t => {
+  // Wait for after the load event so that the navigation doesn't get converted
+  // into a replace navigation.
+  await new Promise(r => window.onload = () => t.step_timeout(r, 0));
+  await navigation.navigate("#1").finished;
+
+  navigation.onnavigate = e => e.intercept();
+  navigation.oncurrententrychange = e => {
+    if (e.navigationType == "traverse") {
+      assert_equals(location.hash, "");
+      assert_equals(navigation.currentEntry.index, 0);
+      assert_equals(navigation.entries().length, 2);
+      navigation.navigate("#2");
+    }
+  };
+  let back_result = navigation.back();
+  await back_result.committed;
+  assert_equals(location.hash, "#2");
+  await promise_rejects_dom(t, "AbortError", back_result.finished);
+  assert_equals(navigation.currentEntry.index, 1);
+  assert_equals(navigation.entries().length, 2);
+}, "Using intercept() then navigate() in the ensuing currententrychange should abort the finished promise (but not the committed promise)");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-canceled-event.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-canceled-event.html
new file mode 100644
index 0000000000..d4b9633c1a
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-canceled-event.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="/common/blank.html"></iframe>
+<script>
+test(t => {
+  let assertionHappened = false;
+  navigation.onnavigate = t.step_func_done(e => {
+    e.preventDefault();
+    assert_throws_dom("InvalidStateError", () => e.intercept());
+    assertionHappened = true;
+  });
+
+  location.href = "#1";
+  assert_true(assertionHappened);
+}, "event.intercept() throws if used on a canceled event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-cross-document-same-origin.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-cross-document-same-origin.html
new file mode 100644
index 0000000000..0d610cce4f
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-cross-document-same-origin.html
@@ -0,0 +1,21 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script>
+async_test(t => {
+  let target_url = location.href + "?1";
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_false(e.hashChange);
+    e.intercept({ handler: async () => {
+      await Promise.resolve();
+      t.step_func_done(() => assert_equals(location.href, target_url));
+    }});
+  });
+
+  window.onload = t.step_func(() => location.href = target_url);
+}, "event.intercept() intercepts a same-origin cross-document navigation");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-cross-origin.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-cross-origin.html
new file mode 100644
index 0000000000..b367df546c
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-cross-origin.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_true(e.cancelable);
+    assert_false(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_throws_dom("SecurityError", () => e.intercept());
+    e.preventDefault();
+  });
+
+  window.onload = t.step_func(() => location.href = get_host_info().HTTPS_REMOTE_ORIGIN);
+}, "event.intercept() should throw if called for a cross origin navigation");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-detach-multiple.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-detach-multiple.html
new file mode 100644
index 0000000000..5b6a623284
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-detach-multiple.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="/common/blank.html"></iframe>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    let second_handler_run = false;
+    i.contentWindow.navigation.onnavigate = e => {
+      e.intercept({ handler() { i.remove(); }});
+      e.intercept({ handler() { second_handler_run = true; }});
+    };
+
+    i.contentWindow.location.href = "#1";
+    t.step_timeout(t.step_func_done(() => assert_true(second_handler_run)), 0);
+  });
+}, "event.intercept() throws if used on an event from a detached iframe");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-detach.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-detach.html
new file mode 100644
index 0000000000..b5ce45aa29
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-detach.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="/common/blank.html"></iframe>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      let iframe_constructor = i.contentWindow.DOMException;
+      i.remove();
+      assert_throws_dom("InvalidStateError", iframe_constructor, () => e.intercept());
+    });
+
+    i.contentWindow.location.href = "#1";
+  });
+}, "event.intercept() throws if used on an event from a detached iframe");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-null-or-undefined.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-null-or-undefined.html
new file mode 100644
index 0000000000..7f5bd6b19f
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-null-or-undefined.html
@@ -0,0 +1,21 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_throws_js(TypeError, () => e.intercept({ handler: null }));
+  });
+
+  location.href = "#1";
+  assert_equals(location.hash, "#1");
+}, "event.intercept() should throw if the handler is null");
+
+async_test(t => {
+  navigation.onnavigatesuccess = t.step_func_done(e => {});
+  navigation.onnavigate = e =>  e.intercept({ handler: undefined });
+
+  location.href = "#2";
+  assert_equals(location.hash, "#2");
+}, "event.intercept() should not throw if the handler is explicit undefined");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-returns-non-promise.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-returns-non-promise.html
new file mode 100644
index 0000000000..96116e9295
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-returns-non-promise.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  navigation.onnavigatesuccess = t.step_func_done(e => {
+    assert_equals(location.hash, "#1");
+    assert_equals(e.constructor, Event);
+    assert_false(e.bubbles);
+    assert_false(e.cancelable);
+  });
+  navigation.onnavigateerror = t.step_func_done(assert_unreached);
+  navigation.onnavigate = e => e.intercept({ handler() { return "123"; }});
+
+  location.href = "#1";
+  assert_equals(location.hash, "#1");
+}, "event.intercept() should resolve immediately if the handler doesn't return a promise");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-throws.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-throws.html
new file mode 100644
index 0000000000..769f675999
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-handler-throws.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  const err = new TypeError("a message");
+  let start_href = location.href;
+
+  navigation.onnavigatesuccess = t.step_func_done(assert_unreached);
+  navigation.onnavigateerror = t.step_func_done(e => {
+    assert_equals(location.hash, "#1");
+    assert_equals(e.constructor, ErrorEvent);
+    assert_true(e.error === err);
+    assert_equals(e.message, "Uncaught TypeError: a message");
+    assert_equals(e.filename, start_href);
+    assert_greater_than(e.colno, 0);
+    assert_greater_than(e.lineno, 0);
+  });
+  navigation.onnavigate = e => {
+    e.intercept({ handler() { throw err; }});
+  };
+
+  location.href = "#1";
+  assert_equals(location.hash, "#1");
+}, "event.intercept() should abort if the handler throws");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-history-pushState.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-history-pushState.html
new file mode 100644
index 0000000000..aad08b742e
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-history-pushState.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  let start_length = history.length;
+  navigation.onnavigate = t.step_func(e => {
+    e.intercept({ handler: async () => {
+      await new Promise(r => t.step_timeout(r, 0));
+      t.step_timeout(t.step_func_done(() => {
+        assert_equals(location.hash, "#1");
+        assert_equals(history.state, "update");
+        assert_equals(history.length, start_length + 1);
+      }, 0));
+    }});
+  });
+
+  history.pushState("update", "", "#1");
+  assert_equals(location.hash, "#1");
+  assert_equals(history.state, "update");
+  assert_equals(history.length, start_length + 1);
+}, "event.intercept() should proceed if the given promise resolves");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-history-replaceState.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-history-replaceState.html
new file mode 100644
index 0000000000..16edec8596
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-history-replaceState.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  let start_length = history.length;
+  navigation.onnavigate = t.step_func(e => {
+    e.intercept({ handler: async () => {
+      await new Promise(r => t.step_timeout(r, 0));
+      t.step_timeout(t.step_func_done(() => {
+        assert_equals(location.hash, "#1");
+        assert_equals(history.state, "update");
+        assert_equals(history.length, start_length);
+      }, 0));
+    }});
+  });
+
+  history.replaceState("update", "", "#1");
+  assert_equals(location.hash, "#1");
+  assert_equals(history.state, "update");
+  assert_equals(history.length, start_length);
+}, "event.intercept() should proceed if the given promise resolves");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-multiple-times-reject.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-multiple-times-reject.html
new file mode 100644
index 0000000000..0b0f1f0b8e
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-multiple-times-reject.html
@@ -0,0 +1,38 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+promise_test(async t => {
+  const err = new TypeError("a message");
+  let start_href = location.href;
+
+  let onnavigateerror_called = false;
+  let caught_rejection = false;
+  navigation.onnavigatesuccess = t.step_func(assert_unreached);
+  navigation.onnavigateerror = t.step_func(e => {
+    onnavigateerror_called = true;
+    assert_equals(location.hash, "#1");
+    assert_equals(e.constructor, ErrorEvent);
+    assert_equals(e.error, err);
+    assert_equals(e.message, "Uncaught TypeError: a message");
+    assert_equals(e.filename, start_href);
+    assert_greater_than(e.colno, 0);
+    assert_greater_than(e.lineno, 0);
+  });
+  navigation.onnavigate = t.step_func(e => {
+    e.intercept();
+    e.intercept({ handler: async () => {
+      await new Promise(r => t.step_timeout(r, 1));
+      return Promise.reject(err);
+    }});
+    e.intercept({ handler: () => new Promise(resolve => t.step_timeout(resolve, 1)) });
+  });
+
+  await navigation.navigate("#1").finished.catch(t.step_func(e => {
+    caught_rejection = true;
+    assert_equals(e, err);
+  }));
+  assert_true(onnavigateerror_called);
+  assert_true(caught_rejection);
+}, "event.intercept() is called multiple times and one of the promises rejects");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-multiple-times.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-multiple-times.html
new file mode 100644
index 0000000000..6deaeeb507
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-multiple-times.html
@@ -0,0 +1,41 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+promise_test(async t => {
+  let p1_resolved = false;
+  let p2_resolved = false;
+  let p3_resolved = false;
+  navigation.onnavigate = t.step_func(e => {
+    e.intercept({ handler: async () => {
+      await Promise.resolve();
+      assert_false(p2_resolved);
+      assert_false(p3_resolved);
+      p1_resolved = true;
+    }});
+    e.intercept({ handler: async () => {
+      await new Promise(resolve => t.step_timeout(resolve, 1));
+      assert_true(p1_resolved);
+      assert_false(p3_resolved);
+      p2_resolved = true;
+    }});
+    e.intercept({ handler: async () => {
+      await new Promise(resolve => t.step_timeout(resolve, 1));
+      assert_true(p1_resolved);
+      assert_true(p2_resolved);
+      p3_resolved = true;
+    }});
+  });
+
+  let promise = navigation.navigate("#1").finished;
+  assert_equals(location.hash, "#1");
+  assert_false(p1_resolved);
+  assert_false(p2_resolved);
+  assert_false(p3_resolved);
+
+  await promise;
+  assert_true(p1_resolved);
+  assert_true(p2_resolved);
+  assert_true(p3_resolved);
+}, "navigation.navigate() returns a finished promise that awaits all promises if event.intercept() is called multiple times");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-navigation-back.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-navigation-back.html
new file mode 100644
index 0000000000..8babf2bcdc
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-navigation-back.html
@@ -0,0 +1,19 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  // Wait for after the load event so that the navigation doesn't get converted
+  // into a replace navigation.
+  window.onload = () => t.step_timeout(() => {
+    navigation.navigate("#foo").committed.then(() => {
+      assert_true(navigation.canGoBack);
+      navigation.onnavigate = t.step_func(e => e.intercept());
+      navigation.back().committed.then(t.step_func_done(() => {
+        assert_equals(navigation.entries().length, 2);
+        assert_equals(navigation.currentEntry, navigation.entries()[0]);
+      }));
+    });
+  }, 0);
+}, "event.intercept() can intercept navigation.back()");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-on-synthetic-event.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-on-synthetic-event.html
new file mode 100644
index 0000000000..3a4b54de5e
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-on-synthetic-event.html
@@ -0,0 +1,17 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  // We need to grab an NavigationDestination to construct the event.
+  navigation.onnavigate = t.step_func_done(e => {
+    const event = new NavigateEvent("navigate", {
+      destination: e.destination,
+      signal: (new AbortController()).signal
+    });
+
+    assert_throws_dom("SecurityError", () => event.intercept());
+  });
+  history.pushState(1, null, "#1");
+}, "event.intercept() throws if invoked on a synthetic event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-popstate.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-popstate.html
new file mode 100644
index 0000000000..f5f9d82be7
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-popstate.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+promise_test(async t => {
+  // Wait for after the load event so that the navigation doesn't get converted
+  // into a replace navigation.
+  await new Promise(resolve => window.onload = () => t.step_timeout(resolve, 0));
+  history.replaceState({ state: "foo"}, "", "#replace");
+
+  let onpopstate_fired = false;
+  let last_state;
+  window.onpopstate = e => {
+    onpopstate_fired = true;
+    last_state = e.state;
+  }
+  navigation.onnavigate = t.step_func(e => e.intercept());
+
+  await navigation.navigate("#").finished;
+  assert_true(navigation.canGoBack);
+
+  await navigation.back().finished;
+  assert_true(onpopstate_fired);
+  assert_not_equals(last_state, null);
+}, "event.intercept() should provide popstate with a valid state object");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-reject.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-reject.html
new file mode 100644
index 0000000000..4c5ec0163d
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-reject.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  const err = new TypeError("a message");
+  let start_href = location.href;
+
+  navigation.onnavigatesuccess = t.step_func_done(assert_unreached);
+  navigation.onnavigateerror = t.step_func_done(e => {
+    assert_equals(location.hash, "#1");
+    assert_equals(e.constructor, ErrorEvent);
+    assert_true(e.error === err);
+    assert_equals(e.message, "Uncaught TypeError: a message");
+    assert_equals(e.filename, start_href);
+    assert_greater_than(e.colno, 0);
+    assert_greater_than(e.lineno, 0);
+  });
+  navigation.onnavigate = e => {
+    e.intercept({ handler: async () => {
+      await new Promise(r => t.step_timeout(r, 0));
+      return Promise.reject(err);
+    }});
+  };
+
+  location.href = "#1";
+  assert_equals(location.hash, "#1");
+}, "event.intercept() should abort if the given promise rejects");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-resolve.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-resolve.html
new file mode 100644
index 0000000000..b60d89b5df
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-resolve.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  navigation.onnavigatesuccess = t.step_func_done(e => {
+    assert_equals(location.hash, "#1");
+    assert_equals(e.constructor, Event);
+    assert_false(e.bubbles);
+    assert_false(e.cancelable);
+  });
+  navigation.onnavigateerror = t.step_func_done(assert_unreached);
+  navigation.onnavigate = e => {
+    e.intercept({ handler: () => new Promise(resolve => t.step_timeout(resolve, 0)) });
+  };
+
+  location.href = "#1";
+  assert_equals(location.hash, "#1");
+}, "event.intercept() should proceed if the given promise resolves");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/intercept-same-document-history-back.html b/testing/web-platform/tests/navigation-api/navigate-event/intercept-same-document-history-back.html
new file mode 100644
index 0000000000..6faabe1964
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/intercept-same-document-history-back.html
@@ -0,0 +1,40 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  // Wait for after the load event so that the navigation doesn't get converted
+  // into a replace navigation.
+  window.onload = () => t.step_timeout(() => {
+    let onnavigate_calls = 0;
+    let onnavigatesuccess_calls = 0;
+    navigation.onnavigate = e => {
+      onnavigate_calls++;
+      e.intercept();
+    }
+    navigation.onnavigatesuccess = t.step_func(e => {
+      onnavigatesuccess_calls++;
+      if (onnavigatesuccess_calls == 3) {
+        assert_equals(navigation.entries().length, 3);
+        assert_equals(navigation.currentEntry.index, 1);
+        assert_equals(onnavigate_calls, 3);
+        history.back();
+      } else if (onnavigatesuccess_calls == 4) {
+        assert_equals(navigation.entries().length, 3);
+        assert_equals(navigation.currentEntry.index, 0);
+        assert_equals(onnavigate_calls, 4);
+        t.done();
+      }
+    });
+
+    navigation.navigate("?foo").finished
+      .then(t.step_func(() => navigation.navigate("?bar").finished))
+      .then(t.step_func(() => {
+        assert_equals(navigation.entries().length, 3);
+        assert_equals(navigation.currentEntry.index, 2);
+        assert_equals(onnavigate_calls, 2);
+        history.back();
+      }));
+  }, 0);
+}, "event.intercept() can intercept same-document history.back()");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-cross-origin.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-cross-origin.html
new file mode 100644
index 0000000000..d8f2e38312
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-cross-origin.html
@@ -0,0 +1,24 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<a id="a" href="https://does-not-exist/foo.html"></a>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push");
+    assert_true(e.cancelable);
+    assert_false(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_equals(e.formData, null);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(e.destination.url, "https://does-not-exist/foo.html");
+    assert_false(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    e.preventDefault();
+  });
+  a.click();
+}, "<a> cross-origin navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-download-userInitiated.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-download-userInitiated.html
new file mode 100644
index 0000000000..90a612b758
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-download-userInitiated.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<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>
+<script src="/resources/testdriver-actions.js"></script>
+<a id="a" href="?1">Click me</a>
+<script>
+async_test(t => {
+  a.download = "";
+  navigation.onnavigate = t.step_func(e => {
+    assert_equals(e.navigationType, "push");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_true(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_equals(e.downloadRequest, "");
+    assert_equals(e.formData, null);
+    assert_equals(new URL(e.destination.url).search, "?1");
+    assert_false(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    e.preventDefault();
+    t.step_timeout(t.step_func_done(() => assert_equals(location.hash, "")), 0);
+  });
+  test_driver.click(a);
+}, "<a download> click fires navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-download.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-download.html
new file mode 100644
index 0000000000..c5ca306b79
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-download.html
@@ -0,0 +1,34 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<script>
+const tests = [["a", ""], ["a", "filename"], ["area", ""], ["area", "filename"]];
+
+for (const [tag, download_attr] of tests) {
+  async_test(t => {
+    let a = document.createElement(tag);
+    a.href = "foo.html";
+    a.download = download_attr;
+    document.body.appendChild(a);
+    navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push");
+      assert_true(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_false(e.hashChange);
+      assert_equals(e.downloadRequest, download_attr);
+      assert_equals(e.formData, null);
+      assert_equals(new URL(e.destination.url).pathname,
+                    "/navigation-api/navigate-event/foo.html");
+      assert_false(e.destination.sameDocument);
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      e.preventDefault();
+    });
+    a.click();
+  }, `<${tag}> fires navigate and populates downloadRequest with '${download_attr}'`);
+}
+</script>
+</body>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-fragment.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-fragment.html
new file mode 100644
index 0000000000..b7706b7deb
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-fragment.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<a id="a" href="#1"></a>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func(e => {
+    assert_equals(e.navigationType, "push");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_true(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(e.formData, null);
+    assert_equals(new URL(e.destination.url).hash, "#1");
+    assert_true(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    e.preventDefault();
+    t.step_timeout(t.step_func_done(() => assert_equals(location.hash, "")), 0);
+  });
+  a.click();
+}, "Fragment <a> click fires navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-same-origin-cross-document.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-same-origin-cross-document.html
new file mode 100644
index 0000000000..b8e925a4db
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-same-origin-cross-document.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<a id="a" href="foo.html"></a>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_equals(e.formData, null);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(new URL(e.destination.url).pathname,
+                  "/navigation-api/navigate-event/foo.html");
+    assert_false(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    e.preventDefault();
+  });
+  a.click();
+}, "<a> cross-document (but same-origin) navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-userInitiated.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-userInitiated.html
new file mode 100644
index 0000000000..b746bbe3f0
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-userInitiated.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<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>
+<script src="/resources/testdriver-actions.js"></script>
+<a id="a" href="#1">Click me</a>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func(e => {
+    assert_equals(e.navigationType, "push");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_true(e.userInitiated);
+    assert_true(e.hashChange);
+    assert_equals(e.formData, null);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(new URL(e.destination.url).hash, "#1");
+    assert_true(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    e.preventDefault();
+    t.step_timeout(t.step_func_done(() => assert_equals(location.hash, "")), 0);
+  });
+
+  test_driver.click(a);
+}, "Fragment <a> click fires navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-with-target.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-with-target.html
new file mode 100644
index 0000000000..c2053a37b0
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-anchor-with-target.html
@@ -0,0 +1,31 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe" name="i" src="/common/blank.html"></iframe>
+<a id="a" href="foo.html" target="i"></a>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    navigation.onnavigate = t.step_func_done(() => {
+      assert_unreached("onnavigate should not have fired in source window");
+    });
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push");
+      assert_true(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_false(e.hashChange);
+      assert_equals(e.formData, null);
+      assert_equals(e.downloadRequest, null);
+      assert_equals(new URL(e.destination.url).pathname,
+                    "/navigation-api/navigate-event/foo.html");
+      assert_false(e.destination.sameDocument);
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      e.preventDefault();
+    });
+    a.click();
+  });
+}, "<a> with a target fires navigate event in target window but not source");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-back-forward.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-back-forward.html
new file mode 100644
index 0000000000..c118aa7a1f
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-back-forward.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  // Wait for after the load event so that the navigation doesn't get converted
+  // into a replace navigation.
+  window.onload = () => t.step_timeout(t.step_func_done(() => {
+    let navState = { statevar: "state" };
+    navigation.navigate("#foo", { history: "replace", state: navState });
+    let target_key = navigation.currentEntry.key;
+    let target_id = navigation.currentEntry.id;
+    navigation.navigate("#bar");
+    navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "traverse");
+      assert_not_equals(e.destination, null);
+      assert_not_equals(e.destination.getState(), undefined);
+      assert_not_equals(e.destination.getState(), e.destination.getState());
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+    });
+    navigation.back();
+  }), 0);
+}, "navigate event destination.getState() on back/forward navigation");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-navigate.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-navigate.html
new file mode 100644
index 0000000000..9c34c5753a
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-navigate.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  // Wait for after the load event so that the navigation doesn't get converted
+  // into a replace navigation.
+  window.onload = () => t.step_timeout(() => {
+    let navState = { statevar: "state" };
+    navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push");
+      assert_not_equals(e.destination, null);
+      assert_not_equals(e.destination.getState(), undefined);
+      assert_equals(e.destination.getState().statevar, "state");
+      assert_not_equals(e.destination.getState(), e.destination.getState());
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+    });
+    navigation.navigate("#foo", { state: navState });
+  }, 0);
+}, "navigate event destination.getState() should be the state given to navigate()");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-reload.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-reload.html
new file mode 100644
index 0000000000..b3afb72482
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-destination-getState-reload.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  // Wait for after the load event so that the navigation doesn't get converted
+  // into a replace navigation.
+  window.onload = () => t.step_timeout(() => {
+    let navState = { statevar: "state" };
+    navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "reload");
+      assert_not_equals(e.destination, null);
+      assert_not_equals(e.destination.getState(), undefined);
+      assert_equals(e.destination.getState().statevar, "state");
+      assert_not_equals(e.destination.getState(), e.destination.getState());
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      e.intercept();
+    });
+    navigation.updateCurrentEntry({ state: navState });
+    location.reload();
+  }, 0);
+}, "navigate event destination.getState() on location.reload()");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-get.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-get.html
new file mode 100644
index 0000000000..69a49eb08a
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-get.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<form id="form" action=""></form>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    e.preventDefault();
+
+    assert_equals(e.navigationType, "replace");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(e.destination.url, location.href + "?");
+    assert_false(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+
+    // Because it's a GET, not a POST
+    assert_equals(e.formData, null);
+  });
+  window.onload = t.step_func(() => form.submit());
+}, "<form> submission with GET method fires navigate event but with formData null");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-reload.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-reload.html
new file mode 100644
index 0000000000..f18a11ebda
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-reload.html
@@ -0,0 +1,28 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe" name="i" src="/common/blank.html"></iframe>
+<form id="form" action="/common/blank.html?1" method="post" target="i"></form>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    navigation.onnavigate = t.step_func_done(() => {
+      assert_unreached("onnavigate should not have fired in source window");
+    });
+    iframe.contentWindow.navigation.onnavigate = t.step_func(e => {
+      assert_equals(e.navigationType, "push");
+      assert_not_equals(e.formData, null);
+
+      iframe.onload = t.step_func(() => {
+        iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+          assert_equals(e.navigationType, "reload");
+          assert_equals(e.formData, null);
+        });
+
+        iframe.contentWindow.location.reload();
+      });
+    });
+    form.submit();
+  });
+}, "reloading a page created from form submission results in formData of null, not the original form data");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-traverse.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-traverse.html
new file mode 100644
index 0000000000..d673537503
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-traverse.html
@@ -0,0 +1,44 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe" name="i" src="/common/blank.html"></iframe>
+<form id="form" action="/common/blank.html?1" method="post" target="i"></form>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    navigation.onnavigate = t.step_func_done(() => {
+      assert_unreached("onnavigate should not have fired in source window");
+    });
+    iframe.contentWindow.navigation.onnavigate = t.step_func(e => {
+      assert_equals(e.navigationType, "push");
+      assert_not_equals(e.formData, null);
+
+      iframe.onload = t.step_func(() => {
+        // Avoid the replace behavior that occurs if you navigate during the load handler
+        t.step_timeout(() => {
+          iframe.contentWindow.navigation.onnavigate = t.step_func(e => {
+            assert_equals(e.navigationType, "push");
+            assert_equals(e.formData, null);
+          });
+
+          iframe.contentWindow.onhashchange = t.step_func(() => {
+            iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+              assert_equals(e.navigationType, "traverse");
+              assert_equals(e.formData, null);
+            });
+
+            // 3: go back
+            iframe.contentWindow.history.back();
+          });
+
+          // 2: navigate from /common/blank.html?1-with-form-data to /common/blank.html?1#1-with-form-data
+          iframe.contentWindow.location.hash = "#1";
+        }, 0);
+      });
+    });
+
+    // 1: submit the form, navigating from /common/blank.html to /common/blank.html?1-with-form-data
+    form.submit();
+  });
+}, "reloading a page created from form submission results in formData of null, not the original form data");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-userInitiated.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-userInitiated.html
new file mode 100644
index 0000000000..454f077396
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-userInitiated.html
@@ -0,0 +1,30 @@
+<!doctype html>
+<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>
+<script src="/resources/testdriver-actions.js"></script>
+<form id="form" method="post" action="">
+<input id="submit" type="submit" value="Submit">
+</form>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    e.preventDefault();
+
+    assert_equals(e.navigationType, "push");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_true(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(e.destination.url, location.href);
+    assert_false(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    assert_not_equals(e.formData, null);
+  });
+  window.onload = t.step_func(() => test_driver.click(submit));
+}, "<form> submission fires navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-with-target.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-with-target.html
new file mode 100644
index 0000000000..b23ab3a70c
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form-with-target.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe" name="i" src="/common/blank.html"></iframe>
+<form id="form" method="post" action="foo.html" target="i"></form>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    navigation.onnavigate = t.unreached_func("onnavigate should not have fired in source window");
+
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push");
+      assert_true(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_false(e.hashChange);
+      assert_equals(e.downloadRequest, null);
+      assert_equals(new URL(e.destination.url).pathname,
+                    "/navigation-api/navigate-event/foo.html");
+      assert_false(e.destination.sameDocument);
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      assert_not_equals(e.formData, null);
+    });
+    form.submit();
+  });
+}, "<form> submission with a target fires navigate event in target window but not source");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-form.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form.html
new file mode 100644
index 0000000000..b537a9b58f
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-form.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<form id="form" method="post" action=""></form>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    e.preventDefault();
+
+    assert_equals(e.navigationType, "replace");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(e.destination.url, location.href);
+    assert_false(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    assert_not_equals(e.formData, null);
+  });
+  window.onload = t.step_func(() => form.submit());
+}, "<form> submission fires navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-after-fragment.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-after-fragment.html
new file mode 100644
index 0000000000..976754f28a
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-after-fragment.html
@@ -0,0 +1,31 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  window.onload = () => t.step_timeout(() => {
+    let start_length = history.length;
+    let target_key = navigation.currentEntry.key;
+    let target_id = navigation.currentEntry.id;
+    location.hash = "#1";
+    assert_equals(history.length, start_length + 1);
+
+    navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "traverse");
+      assert_false(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_true(e.hashChange);
+      assert_equals(e.downloadRequest, null);
+      assert_equals(new URL(e.destination.url).hash, "");
+      assert_true(e.destination.sameDocument);
+      assert_equals(e.destination.key, target_key);
+      assert_equals(e.destination.id, target_id);
+        assert_equals(e.destination.index, 0);
+      assert_equals(e.formData, null);
+    });
+
+    history.back();
+  }, 0);
+}, "history.back() fires the navigate event and sets hashChange when reversing a fragment navigation");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-after-pushState.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-after-pushState.html
new file mode 100644
index 0000000000..4d870fb2ae
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-after-pushState.html
@@ -0,0 +1,31 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  window.onload = () => t.step_timeout(() => {
+    let start_length = history.length;
+    let target_key = navigation.currentEntry.key;
+    let target_id = navigation.currentEntry.id;
+    history.pushState(1, "", "pushState.html");
+    assert_equals(history.length, start_length + 1);
+
+    navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "traverse");
+      assert_false(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_false(e.hashChange);
+      assert_equals(e.downloadRequest, null);
+      assert_equals(new URL(e.destination.url).hash, "");
+      assert_true(e.destination.sameDocument);
+      assert_equals(e.destination.key, target_key);
+      assert_equals(e.destination.id, target_id);
+      assert_equals(e.destination.index, 0);
+      assert_equals(e.formData, null);
+    });
+
+    history.back();
+  }, 0);
+}, "history.back() fires the navigate event when reversing a pushState()");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-cross-document.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-cross-document.html
new file mode 100644
index 0000000000..cd7be6e9ad
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-back-cross-document.html
@@ -0,0 +1,32 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="/common/blank.html"></iframe>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    let target_key = i.contentWindow.navigation.currentEntry.key;
+    let target_id = i.contentWindow.navigation.currentEntry.id;
+    i.contentWindow.navigation.navigate("?foo");
+    i.onload = t.step_func(() => {
+      i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+        assert_equals(e.navigationType, "traverse");
+        assert_false(e.cancelable);
+        assert_false(e.canIntercept);
+        assert_false(e.userInitiated);
+        assert_false(e.hashChange);
+        assert_equals(e.downloadRequest, null);
+        assert_equals(new URL(e.destination.url).pathname, "/common/blank.html");
+        assert_false(e.destination.sameDocument);
+        assert_equals(e.destination.key, target_key);
+        assert_equals(e.destination.id, target_id);
+        assert_equals(e.destination.index, 0);
+        assert_equals(e.formData, null);
+        assert_equals(e.info, undefined);
+      });
+      assert_true(i.contentWindow.navigation.canGoBack);
+      i.contentWindow.history.back();
+    })
+  });
+}, "navigate event for history.back() - cross-document");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-go-0.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-go-0.html
new file mode 100644
index 0000000000..96d98cf44c
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-go-0.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="/common/blank.html"></iframe>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "reload");
+      assert_true(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_false(e.hashChange);
+      assert_equals(e.downloadRequest, null);
+      assert_equals(new URL(e.destination.url).pathname, "/common/blank.html");
+      assert_false(e.destination.sameDocument);
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      assert_equals(e.formData, null);
+      e.preventDefault();
+    });
+
+    i.contentWindow.history.go(0);
+  });
+}, "history.go(0) fires the navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-pushState.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-pushState.html
new file mode 100644
index 0000000000..2f8c81c709
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-pushState.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  let start_length = history.length;
+  navigation.onnavigate = t.step_func(e => {
+    assert_equals(e.navigationType, "push");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(new URL(e.destination.url).hash, "#1");
+    assert_true(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    assert_equals(e.formData, null);
+    e.preventDefault();
+    t.step_timeout(t.step_func_done(() => {
+      assert_equals(location.hash, "");
+      assert_equals(history.state, null);
+      assert_equals(history.length, start_length);
+    }), 0);
+  });
+  history.pushState(1, null, "#1");
+}, "history.pushState() fires the navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-replaceState.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-replaceState.html
new file mode 100644
index 0000000000..d8417fbfd3
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-history-replaceState.html
@@ -0,0 +1,29 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  let start_length = history.length;
+  navigation.onnavigate = t.step_func(e => {
+    assert_equals(e.navigationType, "replace");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_false(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(new URL(e.destination.url).hash, "#1");
+    assert_true(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    assert_equals(e.formData, null);
+    e.preventDefault();
+    t.step_timeout(t.step_func_done(() => {
+      assert_equals(location.hash, "");
+      assert_equals(history.state, null);
+      assert_equals(history.length, start_length);
+    }), 0);
+  });
+  history.replaceState(1, null, "#1");
+}, "history.replaceState() fires the navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-iframe-location.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-iframe-location.html
new file mode 100644
index 0000000000..059b995011
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-iframe-location.html
@@ -0,0 +1,30 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe" src="/common/blank.html"></iframe>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    navigation.onnavigate = t.step_func_done(() => {
+      assert_unreached("onnavigate should not have fired in source window");
+    });
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push");
+      assert_true(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_true(e.hashChange);
+      assert_equals(e.downloadRequest, null);
+      assert_equals(new URL(e.destination.url).hash, "#1");
+      assert_true(e.destination.sameDocument);
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      assert_equals(e.formData, null);
+      e.preventDefault();
+      t.step_timeout(t.step_func_done(() => assert_equals(location.hash, "")), 0);
+    });
+    iframe.contentWindow.location.hash = "#1";
+  });
+}, "location API on another window fires navigate event in the target window only");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-location.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-location.html
new file mode 100644
index 0000000000..c5aa0be97a
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-location.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<form id="form" action=""></form>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "replace");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_true(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(new URL(e.destination.url).hash, "#1");
+    assert_true(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    assert_equals(e.formData, null);
+  });
+  location.href = "#1";
+}, "location API fires navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-meta-refresh.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-meta-refresh.html
new file mode 100644
index 0000000000..1f8ed30685
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-meta-refresh.html
@@ -0,0 +1,27 @@
+<!doctype html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="resources/meta-refresh.html"></iframe>
+</head>
+<script>
+async_test(t => {
+  i.onload = t.step_func(() => {
+    i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "reload");
+      assert_true(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_false(e.hashChange);
+      assert_equals(e.downloadRequest, null);
+      assert_equals(e.destination.url, i.contentWindow.location.href);
+      assert_false(e.destination.sameDocument);
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      assert_equals(e.formData, null);
+      e.preventDefault();
+    });
+  });
+}, "<meta> refresh fires navigate event");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-back-cross-document.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-back-cross-document.html
new file mode 100644
index 0000000000..214644066e
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-back-cross-document.html
@@ -0,0 +1,32 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="/common/blank.html"></iframe>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    let target_key = i.contentWindow.navigation.currentEntry.key;
+    let target_id = i.contentWindow.navigation.currentEntry.id;
+    i.contentWindow.navigation.navigate("?foo");
+    i.onload = t.step_func(() => {
+      i.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+        assert_equals(e.navigationType, "traverse");
+        assert_false(e.cancelable);
+        assert_false(e.canIntercept);
+        assert_false(e.userInitiated);
+        assert_false(e.hashChange);
+        assert_equals(e.downloadRequest, null);
+        assert_equals(new URL(e.destination.url).pathname, "/common/blank.html");
+        assert_false(e.destination.sameDocument);
+        assert_equals(e.destination.key, target_key);
+        assert_equals(e.destination.id, target_id);
+        assert_equals(e.destination.index, 0);
+        assert_equals(e.formData, null);
+        assert_equals(e.info, "hi");
+      });
+      assert_true(i.contentWindow.navigation.canGoBack);
+      i.contentWindow.navigation.back({ info: "hi" });
+    })
+  });
+}, "navigate event for navigation.back() - cross-document");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-back-same-document.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-back-same-document.html
new file mode 100644
index 0000000000..8753e6b1c8
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-back-same-document.html
@@ -0,0 +1,32 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  // Wait for after the load event so that the navigation doesn't get converted
+  // into a replace navigation.
+  window.onload = () => t.step_timeout(() => {
+    let target_key = navigation.currentEntry.key;
+    let target_id = navigation.currentEntry.id;
+    navigation.navigate("#foo").committed.then(t.step_func(() => {
+      navigation.onnavigate = t.step_func_done(e => {
+        assert_equals(e.navigationType, "traverse");
+        assert_false(e.cancelable);
+        assert_true(e.canIntercept);
+        assert_false(e.userInitiated);
+        assert_true(e.hashChange);
+        assert_equals(e.downloadRequest, null);
+        assert_equals(new URL(e.destination.url).hash, "");
+        assert_true(e.destination.sameDocument);
+        assert_equals(e.destination.key, target_key);
+        assert_equals(e.destination.id, target_id);
+        assert_equals(e.destination.index, 0);
+        assert_equals(e.formData, null);
+        assert_equals(e.info, "hi");
+      });
+      assert_true(navigation.canGoBack);
+      navigation.back({ info: "hi" });
+    }));
+  }, 0);
+}, "navigate event for navigation.back() - same-document");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-navigate.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-navigate.html
new file mode 100644
index 0000000000..76f98c7236
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-navigation-navigate.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "replace");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_true(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(new URL(e.destination.url).hash, "#foo");
+    assert_true(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    assert_equals(e.formData, null);
+  });
+  navigation.navigate("#foo");
+}, "navigate event for navigation.navigate()");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-to-javascript.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-to-javascript.html
new file mode 100644
index 0000000000..78f490d87b
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-to-javascript.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe" name="i" src="/common/blank.html"></iframe>
+
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    navigation.onnavigate = t.unreached_func("onnavigate should not have fired in source window");
+
+    iframe.contentWindow.navigation.onnavigate = t.unreached_func("onnavigate should not have fired in iframe window");
+
+    iframe.contentWindow.location.href = "javascript:'foo'";
+
+    iframe.onload = () => t.done();
+  });
+}, "navigate event does not fire for javascript: URL navigations");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-to-srcdoc.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-to-srcdoc.html
new file mode 100644
index 0000000000..26ad135b6a
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-to-srcdoc.html
@@ -0,0 +1,34 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe" name="i" src="/common/blank.html"></iframe>
+
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    navigation.onnavigate = t.unreached_func("onnavigate should not have fired in source window");
+
+    iframe.contentWindow.navigation.onnavigate = t.step_func(e => {
+      assert_equals(e.navigationType, "push");
+      assert_true(e.cancelable, "cancelable");
+      assert_false(e.canIntercept, "canIntercept");
+      assert_false(e.userInitiated, "userInitiated");
+      assert_false(e.hashChange, "hashChange");
+      assert_equals(e.downloadRequest, null);
+      assert_equals(e.destination.url, "about:srcdoc");
+      assert_false(e.destination.sameDocument);
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      assert_equals(e.formData, null);
+      e.preventDefault();
+
+      // Make sure it doesn't navigate anyway.
+      iframe.onload = t.unreached_func("Must not load the srcdoc document");
+      t.step_timeout(() => t.done(), 10);
+    });
+
+    iframe.srcdoc = "srcdoc contents";
+  });
+}, "navigate event fires appropriately (and can be canceled) for adding the srcdoc attribute");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-window-open-self.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-window-open-self.html
new file mode 100644
index 0000000000..274c8bc4d5
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-window-open-self.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  navigation.onnavigate = t.step_func_done(e => {
+    assert_equals(e.navigationType, "push");
+    assert_true(e.cancelable);
+    assert_true(e.canIntercept);
+    assert_false(e.userInitiated);
+    assert_true(e.hashChange);
+    assert_equals(e.downloadRequest, null);
+    assert_equals(new URL(e.destination.url).hash, "#1");
+    assert_true(e.destination.sameDocument);
+    assert_equals(e.destination.key, null);
+    assert_equals(e.destination.id, null);
+    assert_equals(e.destination.index, -1);
+    assert_equals(e.formData, null);
+    e.preventDefault();
+  });
+  window.onload = t.step_func(() => window.open("#1", "_self"));
+}, "window.open() fires navigate event when targeting self");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigate-window-open.html b/testing/web-platform/tests/navigation-api/navigate-event/navigate-window-open.html
new file mode 100644
index 0000000000..afc998271f
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigate-window-open.html
@@ -0,0 +1,30 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="iframe" name="i" src="/common/blank.html"></iframe>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    navigation.onnavigate = t.step_func_done(() => {
+      assert_unreached("onnavigate should not have fired in source window");
+    });
+    iframe.contentWindow.navigation.onnavigate = t.step_func_done(e => {
+      assert_equals(e.navigationType, "push");
+      assert_true(e.cancelable);
+      assert_true(e.canIntercept);
+      assert_false(e.userInitiated);
+      assert_true(e.hashChange);
+      assert_equals(e.downloadRequest, null);
+      assert_equals(new URL(e.destination.url).hash, "#1");
+      assert_true(e.destination.sameDocument);
+      assert_equals(e.destination.key, null);
+      assert_equals(e.destination.id, null);
+      assert_equals(e.destination.index, -1);
+      assert_equals(e.formData, null);
+      e.preventDefault();
+    });
+
+    window.open("/common/blank.html#1", "i");
+  });
+}, "window.open() fires navigate event in target window but not source");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigatesuccess-cross-document.html b/testing/web-platform/tests/navigation-api/navigate-event/navigatesuccess-cross-document.html
new file mode 100644
index 0000000000..1d528c1f5f
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigatesuccess-cross-document.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="resources/navigatesuccess-cross-document-helper.html"></iframe>
+<script>
+async_test(t => {
+  // The iframe will post a message if it receives a navigatesuccess.
+  window.onmessage = t.unreached_func("navigatesuccess received");
+  window.onload = t.step_func(() => {
+    i.contentWindow.location.search = "?1";
+    i.onload = t.step_func_done(() => assert_equals(i.contentWindow.location.search, "?1"));
+  });
+}, "navigatesuccess does not fire for a cross-document navigation");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/navigatesuccess-same-document.html b/testing/web-platform/tests/navigation-api/navigate-event/navigatesuccess-same-document.html
new file mode 100644
index 0000000000..6007170ec1
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/navigatesuccess-same-document.html
@@ -0,0 +1,10 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<a id="a" href="#1"></a>
+<script>
+async_test(t => {
+  navigation.onnavigatesuccess = t.step_func_done(() => assert_equals(location.hash, "#1"));
+  a.click();
+}, "navigatesuccess fires for a same-document navigation");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/resources/meta-refresh.html b/testing/web-platform/tests/navigation-api/navigate-event/resources/meta-refresh.html
new file mode 100644
index 0000000000..fd453e663f
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/resources/meta-refresh.html
@@ -0,0 +1,4 @@
+<head>
+<meta http-equiv="refresh" content="0"></meta>
+</head>
+<body></body>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/resources/navigatesuccess-cross-document-helper.html b/testing/web-platform/tests/navigation-api/navigate-event/resources/navigatesuccess-cross-document-helper.html
new file mode 100644
index 0000000000..aabc5015a9
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/resources/navigatesuccess-cross-document-helper.html
@@ -0,0 +1,6 @@
+<!doctype html>
+<head>
+<script>
+navigation.onnavigatesuccess = () => top.postMessage("navigatesuccess received");
+</script>
+</head>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/resources/opener-postMessage-onload.html b/testing/web-platform/tests/navigation-api/navigate-event/resources/opener-postMessage-onload.html
new file mode 100644
index 0000000000..97e1d82058
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/resources/opener-postMessage-onload.html
@@ -0,0 +1,6 @@
+<!doctype html>
+<head>
+<script>
+window.onload = () => opener.postMessage("onload", "*");
+</script>
+</head>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-detach-in-onnavigate.html b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-detach-in-onnavigate.html
new file mode 100644
index 0000000000..467ea88899
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-detach-in-onnavigate.html
@@ -0,0 +1,21 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<iframe id="i" src="/common/blank.html"></iframe>
+<script>
+promise_test(async t => {
+  await new Promise(resolve => i.onload = resolve);
+  let iframe_constructor = i.contentWindow.DOMException;
+  let iframe_typeerror = i.contentWindow.TypeError;
+  let abort_signal;
+  let onabort_called = false;
+  i.contentWindow.navigation.onnavigate = t.step_func(e => {
+    abort_signal = e.signal;
+    abort_signal.onabort = () => onabort_called = true;
+    i.remove();
+  });
+  await promise_rejects_dom(t, 'AbortError', iframe_constructor, i.contentWindow.navigation.navigate("#1").committed);
+  assert_true(abort_signal.aborted);
+  assert_true(onabort_called);
+}, "window detach inside a navigate event signals event.signal");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-intercept.html b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-intercept.html
new file mode 100644
index 0000000000..1e92d8e445
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-intercept.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+promise_test(async t => {
+  let abort_signal;
+  let onabort_called = false;
+  navigation.onnavigate = t.step_func(e => {
+    abort_signal = e.signal;
+    abort_signal.onabort = () => onabort_called = true;
+    e.intercept();
+  });
+
+  await navigation.navigate("?1").finished;
+  assert_false(abort_signal.aborted);
+  assert_false(onabort_called);
+}, "event.intercept() does not signal event.signal");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-preventDefault.html b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-preventDefault.html
new file mode 100644
index 0000000000..60fed90ce6
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-preventDefault.html
@@ -0,0 +1,19 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+promise_test(async t => {
+  let abort_signal;
+  let events = [];
+  navigation.onnavigateerror = () => events.push("onnavigateerror");
+  navigation.onnavigate = t.step_func(e => {
+    abort_signal = e.signal;
+    abort_signal.onabort = () => events.push("onabort");
+    e.preventDefault();
+  });
+
+  await promise_rejects_dom(t, 'AbortError', navigation.navigate("?1").committed);
+  assert_true(abort_signal.aborted);
+  assert_array_equals(events, ["onabort", "onnavigateerror"]);
+}, "event.preventDefault() signals event.signal");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop-after-intercept.html b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop-after-intercept.html
new file mode 100644
index 0000000000..51ba7753a8
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop-after-intercept.html
@@ -0,0 +1,40 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    let start_url = location.href;
+    let abort_signal;
+    let onabort_called = false;
+    let navigateErrorException;
+    navigation.onnavigateerror = t.step_func(e => {
+      assert_equals(e.constructor, ErrorEvent);
+      navigateErrorException = e.error;
+      assert_equals(e.filename, start_url);
+      assert_greater_than(e.lineno, 0);
+      assert_greater_than(e.colno, 0);
+    });
+    navigation.onnavigatesuccess = t.unreached_func("onnavigatesuccess");
+    navigation.onnavigate = t.step_func(e => {
+      abort_signal = e.signal;
+      abort_signal.onabort = () => onabort_called = true;
+      e.intercept({ handler: () => new Promise(resolve => t.step_timeout(resolve, 0)) });
+    });
+    let result = navigation.navigate("?1");
+    window.stop();
+    assert_true(abort_signal.aborted);
+    assert_true(onabort_called);
+
+    result.committed.then(() => {
+      return promise_rejects_dom(t, 'AbortError', result.finished);
+    }).then(() => {
+      return result.finished.catch(e => assert_equals(e, navigateErrorException));
+    }).then(() => {
+      // Complete the test asynchronously to ensure that onnavigatesuccess
+      // didn't fire on a microtask.
+      t.step_timeout(t.step_func_done(() => {}), 5);
+    });
+  });
+}, "window.stop() cancels the navigate event's intercept() and signals event.signal");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop-in-onnavigate.html b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop-in-onnavigate.html
new file mode 100644
index 0000000000..1b406c42d3
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop-in-onnavigate.html
@@ -0,0 +1,24 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  window.onload = t.step_func_done(() => {
+    let abort_signal;
+    let onabort_called = false;
+    let canceled_in_second_handler = false;
+    navigation.addEventListener("navigate", t.step_func(e => {
+      abort_signal = e.signal;
+      abort_signal.onabort = () => onabort_called = true;
+      window.stop();
+    }));
+    navigation.addEventListener("navigate", t.step_func(e => {
+      canceled_in_second_handler = e.defaultPrevented;
+    }));
+    navigation.navigate("?1");
+    assert_true(abort_signal.aborted);
+    assert_true(onabort_called);
+    assert_true(canceled_in_second_handler);
+  });
+}, "window.stop() signals event.signal inside a navigate event handler");
+</script>
diff --git a/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop.html b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop.html
new file mode 100644
index 0000000000..43e005e8b4
--- /dev/null
+++ b/testing/web-platform/tests/navigation-api/navigate-event/signal-abort-window-stop.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async_test(t => {
+  window.onload = t.step_func(() => {
+    let abort_signal;
+    let onabort_called = false;
+    navigation.onnavigatesuccess = t.unreached_func("onnavigatesuccess");
+    navigation.onnavigate = t.step_func(e => {
+      abort_signal = e.signal;
+      abort_signal.onabort = () => onabort_called = true;
+    });
+    navigation.navigate("?1");
+    window.stop();
+    assert_true(abort_signal.aborted);
+    assert_true(onabort_called);
+    // Complete the test asynchronously to ensure that onnavigatesuccess
+    // didn't fire on a microtask.
+    t.step_timeout(t.step_func_done(() => {}), 0);
+  });
+}, "window.stop() signals event.signal");
+</script>
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