
<!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 => {
  // Wait for after the load event so that the navigation doesn't get converted
  // into a replace navigation.
  let w = window.open("resources/opener-postMessage-onload.html");
  await new Promise(resolve => window.onmessage = resolve);
  // Navigate to a url that will notify us when the navigation is complete.
  w.navigation.navigate("opener-postMessage-onload.html?1");

  await new Promise(resolve => window.onmessage = resolve);
  assert_equals(w.navigation.entries().length, 2);
  assert_equals(w.navigation.currentEntry.index, 1);
  let navigate_called = false;
  w.navigation.onnavigate = t.step_func(e => {
    navigate_called = true;
    assert_false(e.destination.sameDocument);
    assert_false(e.cancelable);
    // Should do nothing.
    e.preventDefault();
  });
  w.navigation.back();
  await new Promise(resolve => window.onmessage = resolve);
  assert_equals(w.navigation.currentEntry.index, 0);
  assert_true(navigate_called);
}, "navigation.back() cross-document cannot be cancelled with the navigate event");
</script>

