chromium/third_party/blink/web_tests/http/tests/cookie-store/cookie-store-on-http-localhost.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>Cookie Store API on http://localhost</title>
<!-- Cookie Store API should work on http://localhost, which is considered a
     secure context:
     https://html.spec.whatwg.org/multipage/webappapis.html#secure-context
     https://w3c.github.io/webappsec-secure-contexts/#is-origin-trustworthy

     This test also verifies it behaves consistently with document.cookie -->
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>

promise_test(async testCase => {
  assert_equals(await cookieStore.get('cookie-name'), null);

  await cookieStore.set('cookie-name', 'cookie-value');
  testCase.add_cleanup(async () => {
    await cookieStore.delete('cookie-name');
  });

  const cookie = await cookieStore.get('cookie-name');
  assert_equals(cookie.name, 'cookie-name');
  assert_equals(cookie.value, 'cookie-value');

  await cookieStore.delete('cookie-name');
  assert_equals(await cookieStore.get('cookie-name'), null);
}, 'cookieStore API with parameters');

promise_test(async testCase => {
  assert_equals(await cookieStore.get({name: 'cookie-name'}), null);

  await cookieStore.set({name: 'cookie-name', value: 'cookie-value'});
  testCase.add_cleanup(async () => {
    await cookieStore.delete({name: 'cookie-name', value: 'cookie-value'});
  });

  const cookie = await cookieStore.get({name: 'cookie-name'});
  assert_equals(cookie.name, 'cookie-name');
  assert_equals(cookie.value, 'cookie-value');

  await cookieStore.delete({name: 'cookie-name', value: 'cookie-value'});
  assert_equals(await cookieStore.get({name: 'cookie-name'}), null);
}, 'cookieStore API with one single object parameter.');

function documentWriteGet(cookie_name) {
  let row = document.cookie.split('; ').
    find(row => row.startsWith(`${cookie_name}=`));
  return row ? row.split('=')[1] : null;
}

function documentWriteSet(cookie_name, cookie_value) {
  document.cookie = `${cookie_name}=${cookie_value}`;
}

function documentWriteDelete(cookie_name) {
 document.cookie = `${cookie_name}=;expires=Thu, 01 Jan 1970 00:00:01 GMT`;
}

promise_test(async testCase => {
  assert_equals(documentWriteGet("cookie-name-2"), null);

  documentWriteSet('cookie-name-2', 'cookie-value');
  testCase.add_cleanup(() => {
    documentWriteDelete('cookie-name-2');
  });

  assert_equals(documentWriteGet('cookie-name-2'), 'cookie-value');

  documentWriteDelete('cookie-name-2');
  assert_equals(documentWriteGet('cookie-name-2'), null);
}, 'document.cookie');

</script>