navigation-api/precommit-handler/precommitHandler-traversal-commit-new-navigation-before-commit.html

<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../navigation-methods/return-value/resources/helpers.js"></script>
<body>
<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));

  await navigation.navigate("#1").finished;

  let navigateerror_called = false;
  navigation.onnavigateerror = t.step_func(() => {
    navigateerror_called = true;
    assert_equals(location.hash, "#1");
  });

  // Go back and wait for the navigate event to fire. This traversal will be deferred.
  let promises_should_not_commit = assertBothRejectDOM(t, navigation.back(), "AbortError");
  navigation.addEventListener("navigate", e => e.intercept({ precommitHandler: () => new Promise(r => t.step_timeout(r, 1000)) }), { once: "true" });
  await new Promise(resolve => navigation.addEventListener("navigate", resolve, { once: "true" }));

  // While the traversal is deferred, start a new navigation and commit immediately.
  navigation.addEventListener("navigate", e => e.intercept(), { once: "true" });
  let promises_fulfilled = navigation.navigate("#2");

  await promises_should_not_commit;
  await assertBothFulfill(t, promises_fulfilled, navigation.currentEntry);

  assert_equals(location.hash, "#2");
  assert_true(navigateerror_called);
}, "Cancel a precommitHandler traversal before commit by starting a new navigation");
</script>
</body>