<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<!-- Put this page in a sandbox to give it an opaque origin -->

<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));

  location.hash = "#1";
  await new Promise(resolve => window.onhashchange = resolve);
  location.hash = "#2";
  await new Promise(resolve => window.onhashchange = resolve);
  history.back();
  await new Promise(resolve => window.onhashchange = resolve);

  assert_equals(location.hash, "#1");

  assert_equals(navigation.currentEntry, null);
  assert_equals(navigation.entries().length, 0);
  assert_false(navigation.canGoBack);
  assert_false(navigation.canGoForward);
}, "navigation.currentEntry/entries()/canGoBack/canGoForward in an opaque origin iframe");
</script>
