navigation-api/navigate-event/intercept-and-navigate.html

<!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>