chromium/third_party/blink/web_tests/external/wpt/speculation-rules/prerender/indexeddb.html

<!DOCTYPE html>
<title>Same-origin prerendering can access Indexed Database</title>
<meta name="timeout" content="long">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/utils.js"></script>
<script src="/common/dispatcher/dispatcher.js"></script>
<script src="resources/indexedb-utils.js"></script>
<script src="../resources/utils.js"></script>
<script src="resources/utils.js"></script>

<body>
<script>
setup(() => assertSpeculationRulesIsSupported());

promise_test(async t => {
  const db = await openIndexedDatabase(t);
  assert_not_equals(db, null, 'Failed to open database.');
  await addData(db, INITIATOR_KEY, INITIATOR_VALUE);

  const {exec} = await create_prerendered_page(t);

  const result = await exec(async () => {
    await import_script_to_prerendered_page("indexedb-utils.js");
    const db = await openIndexedDatabase();

    await addData(db, PRERENDER_KEY, PRERENDER_VALUE);
    const result = await readData(db, INITIATOR_KEY);
    db.close();
    return result;
  });

  assert_equals(
    result, INITIATOR_VALUE,
    'prerendering page should be able to read from Indexed DataBase');
  const initiatorReadResult = await readData(db, PRERENDER_KEY);
  assert_equals(
    initiatorReadResult, PRERENDER_VALUE,
    'prerendering page should be able to write to Indexed DataBase');
  db.close();
}, 'prerendering page should be able to access Indexed DataBase')
</script>