<!DOCTYPE html>
<meta charset="utf-8">
<meta name="timeout" content="long">
<title>Test that mode is set to same-origin for a main module</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/test-helpers.sub.js"></script>
<script>
// Tests a main module service worker script fetch during an update check.
// The fetch should have the mode set to 'same-origin'.
//
// The test works by registering a main module service worker. It then does an
// update. The test server responds with an updated worker script that remembers
// the http request. The updated worker reports back this request to the test
// page.
promise_test(async (t) => {
  const script = "resources/test-request-mode-worker.py";
  const scope = "resources/";

  // Register the service worker.
  await service_worker_unregister(t, scope);
  const registration = await navigator.serviceWorker.register(
      script, {scope, type: 'module'});
  await wait_for_state(t, registration.installing, 'activated');

  // Do an update.
  await registration.update();

  // Ask the new worker what the request was.
  const newWorker = registration.installing;
  const sawMessage = new Promise((resolve) => {
    navigator.serviceWorker.onmessage = (event) => {
      resolve(event.data);
    };
  });
  newWorker.postMessage('getHeaders');
  const result = await sawMessage;

  // Test the result.
  assert_equals(result['sec-fetch-mode'], 'same-origin');
  assert_equals(result['origin'], undefined);

}, 'headers of a main module script');

</script>