<html>
<body>
<iframe id="testframe"></iframe>
<script type="application/javascript">

  // simply passing on the message from the child to parent
  window.addEventListener("message", receiveMessage);
  function receiveMessage(event) {
    window.removeEventListener("message", receiveMessage);
    window.parent.postMessage({result: event.data.result}, '*');
  }

  const NESTED_IFRAME_NAVIGATION = `
    <html>
    <body>
      <a id="testlink" href="http://mochi.test:8888/tests/dom/security/test/general/file_same_site_cookies_iframe.sjs"></a>
      <script type="application/javascript">
        let link = document.getElementById("testlink");
        link.click();
      <\/script>
    </body>
  </html>`;
  let NESTED_BLOB_IFRAME_NAVIGATION = new Blob([NESTED_IFRAME_NAVIGATION], {type:'text/html'});

  // query the testframe and set blob URL
  let testframe = document.getElementById("testframe");
  testframe.src = window.URL.createObjectURL(NESTED_BLOB_IFRAME_NAVIGATION);
</script>
</body>
</html>
