speculation-rules/prerender/main-frame-navigation.https.html

<!DOCTYPE html>
<title>Test about: main frame navigation in a prerendered page</title>
<meta name="timeout" content="long">
<script src="/common/utils.js"></script>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../resources/utils.js"></script>
<script src="resources/utils.js"></script>

<body>
<script>
setup(() => assertSpeculationRulesIsSupported());

promise_test(async t => {
  const uid = token();
  const bc = new PrerenderChannel('result', uid);

  const gotMessage = new Promise(resolve => {
    bc.addEventListener('message', e => {
      resolve(e.data);
    }, {
      once: true
    });
  });

  const url = `resources/main-frame-navigation.html?uid=${uid}`;
  window.open(url, '_blank', 'noopener');

  const result = await gotMessage;

  assert_equals(result.onprerenderingchangeCalled, true,
      'prerenderingchange event should be called after activation.');
  assert_equals(result.prerenderingValueBeforeActivation, true,
      'document.prerendering should be true prior to activation.');
  assert_equals(result.prerenderingValueAfterActivation, false,
      'document.prerendering should be false after activation.');
}, 'Test document.prerendering and prerenderingchange event in the navigated ' +
   'page');
</script>