speculation-rules/prerender-until-script/prerender-until-script.https.html

<!DOCTYPE html>
<title>Prerender and activate prerender-until-script action page correctly</title>
<meta name="timeout" content="long">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/utils.js"></script>
<script src="/speculation-rules/prerender/resources/utils.js"></script>
<script src="../resources/utils.js"></script>
<body>
<script>
setup(() => assertSpeculationRulesIsSupported('prerender'));

promise_test(async t => {
  /*
  Workflows:
  1. The initiator page (pus-initiator-page-template.html)
  triggers the prerender and simultaneously fetches a signal_url. This
  fetch is designed to hang on the server.

  2. The prerendered page (pus-page-template.html) is allowed to fetch an
  async script (which also hits the signal_url, but with
  isprerendering=True).

  3. When the server receives the request from the prerendered page, it
  puts a token in its stash, which in turn unblocks the initiator's
  hanging fetch.

  4. The .then() block of the initiator's fetch then runs, navigating to
  the prerendered page and causing activation.

  5. The (previously blocked) inline script on the prerendered page then
  executes, verifying that document.prerendering is false and sending the
  result back to the main test page.
  */

  const uid = token();
  const bc = new PrerenderChannel('test-channel', uid);

  const gotMessage = new Promise(resolve => {
    bc.addEventListener('message', e => {
      resolve(e.data);
    }, {
      once: true
    });
  });
  const url = `resources/pus-handler.py?type=main&uid=${uid}`;
  window.open(url, '_blank', 'noopener');

  const result = await gotMessage;
  assert_equals(result, 'prerendering state when executing JS: false');

  bc.close();
}, `when prerender-until-script action prerenders a page, the script on that page should always be executed after activation.`);
</script>