sousa-gecko/testing/web-platform/tests/fetch/fetch-later/resources/fetch-later.html

<!DOCTYPE html>
<head>
</head>
<body>
  <script src="/resources/testharness.js"></script>
  <script src="/resources/testharnessreport.js"></script>
  <script src="/fetch/fetch-later/resources/fetch-later-helper.js"></script>
  <script>
    const PARAMS = new URL(location.href).searchParams;
    const TARGET_URL= decodeURIComponent(PARAMS.get('url')) || '';
    const BODY_TYPE = PARAMS.get('bodyType');
    const BODY_SIZE = PARAMS.get('bodySize');
    const BODY = BODY_TYPE !== null && BODY_SIZE !== null ? makeBeaconData(generatePayload(BODY_SIZE), BODY_TYPE) : null;
    const REQUEST_INIT = Object.assign({},
      PARAMS.has('activateAfter') ? {activateAfter: parseInt(PARAMS.get('activateAfter'), 10)} : null,
      PARAMS.has('method') ? {method: PARAMS.get('method')} : null,
      PARAMS.has('referrer') ? {referrer: PARAMS.get('referrer')} : null,
      BODY !== null ? {body: BODY} : null,
    );

    function postMessageBack(message) {
      if (window.opener) {
        window.opener.postMessage(message, '*');
      } else {
        parent.postMessage(message, '*');
      }
    }

    try {
      fetchLater(TARGET_URL, REQUEST_INIT);
      postMessageBack({type: FetchLaterIframeMessageType.DONE});
    } catch (e) {
      postMessageBack({
        type: FetchLaterIframeMessageType.ERROR,
        // When an error is caught, it might not be cloneable across the boundary.
        error: {name: e.name, message: e.message}
      });
    }
  </script>
</body>