chromium/third_party/blink/web_tests/external/wpt/navigation-api/navigate-event/navigation-back-same-document-preventDefault.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>
<script>
promise_test(async t => {
  let start_length = navigation.entries().length;
  let start_index = navigation.currentEntry.index;

  // 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("#").finished;
  assert_equals(navigation.entries().length, start_length + 1);
  assert_equals(navigation.currentEntry.index, start_index + 1);

  navigation.onnavigate = e => e.preventDefault();

  navigation.onnavigateerror = t.step_func(e => {
    assert_equals(e.constructor, ErrorEvent);
    assert_equals(e.filename, location.href);
    navigateerror_called = true;
  });
  await assertBothRejectDOM(t, navigation.back(), "AbortError");
  assert_equals(navigation.currentEntry.index, start_index + 1);
  assert_true(navigateerror_called);
}, "navigation.back() same-document preventDefault");
</script>