chromium/third_party/blink/web_tests/external/wpt/service-workers/service-worker/fetch-request-css-cross-origin.https.html

<!DOCTYPE html>
<title>Service Worker: Cross-origin CSS files fetched via SW.</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/get-host-info.sub.js"></script>
<script src="resources/test-helpers.sub.js"></script>
<script>

function getElementColorInFrame(frame, id) {
  var element = frame.contentDocument.getElementById(id);
  var style = frame.contentWindow.getComputedStyle(element, '');
  return style['color'];
}

promise_test(async t => {
  var SCOPE =
      'resources/fetch-request-css-cross-origin';
  var SCRIPT =
      'resources/fetch-request-css-cross-origin-worker.js';
  let registration = await service_worker_unregister_and_register(
    t, SCRIPT, SCOPE);
  promise_test(async t => {
    await registration.unregister();
  }, 'cleanup global state');

  await wait_for_state(t, registration.installing, 'activated');
}, 'setup global state');

promise_test(async t => {
  const EXPECTED_COLOR = 'rgb(0, 0, 255)';
  const PAGE =
      'resources/fetch-request-css-cross-origin-mime-check-iframe.html';

  const f = await with_iframe(PAGE);
  t.add_cleanup(() => {f.remove(); });
  assert_equals(
      getElementColorInFrame(f, 'crossOriginCss'),
      EXPECTED_COLOR,
      'The color must be overridden by cross origin CSS.');
  assert_equals(
      getElementColorInFrame(f, 'crossOriginHtml'),
      EXPECTED_COLOR,
      'The color must not be overridden by cross origin non CSS file.');
  assert_equals(
      getElementColorInFrame(f, 'sameOriginCss'),
      EXPECTED_COLOR,
      'The color must be overridden by same origin CSS.');
  assert_equals(
      getElementColorInFrame(f, 'sameOriginHtml'),
      EXPECTED_COLOR,
      'The color must be overridden by same origin non CSS file.');
  assert_equals(
      getElementColorInFrame(f, 'synthetic'),
      EXPECTED_COLOR,
      'The color must be overridden by synthetic CSS.');
}, 'MIME checking of CSS resources fetched via service worker when Content-Type is not set.');

promise_test(async t => {
  const PAGE =
      'resources/fetch-request-css-cross-origin-read-contents.html';

  const f = await with_iframe(PAGE);
  t.add_cleanup(() => {f.remove(); });
  assert_throws_dom('SecurityError', f.contentWindow.DOMException, () => {
    f.contentDocument.styleSheets[0].cssRules[0].cssText;
  });
  assert_equals(
    f.contentDocument.styleSheets[1].cssRules[0].cssText,
    '#crossOriginCss { color: blue; }',
    'cross-origin CORS approved response');
  assert_equals(
    f.contentDocument.styleSheets[2].cssRules[0].cssText,
    '#sameOriginCss { color: blue; }',
    'same-origin response');
  assert_equals(
    f.contentDocument.styleSheets[3].cssRules[0].cssText,
    '#synthetic { color: blue; }',
    'service worker generated response');
  }, 'Same-origin policy for access to CSS resources fetched via service worker');

</script>