<!DOCTYPE html>
<meta charset="utf-8">
<title>Relevant page used as a test helper</title>

<script>
// promise-job-incumbent will end up posting a message to here. We need to signal back the "source".

window.onmessage = e => {
  const testId = e.data;
  const sourceURL = e.source.document.URL;

  window.dispatchEvent(new CustomEvent("messagereceived", { detail: [testId, sourceURL] }));
};
</script>