chromium/third_party/blink/web_tests/http/tests/devtools/service-workers/resources/wasm-cache-iframe.html

<script src="../../../resources/testharness.js"></script>
<script>
// Instantiate a WASM module and make sure it works.
async function instantiateModule(url)
{
  const module = await WebAssembly.compileStreaming(fetch(url));
  const instance = await WebAssembly.instantiate(module);
  assert_equals(instance.exports.exported_func(), 42);
}

const url_base = 'http://127.0.0.1:8000/wasm/resources/load-wasm.php?name=';

(async function loadModules() {
  // This should load without any code cache.
  await instantiateModule(url_base + 'large.wasm&cors');

  // We need to wait for the large wasm code cache to flush to disk.  We
  // approximate how long to wait by writing a very large dummy file to disk
  // and then deleting it.
  const cache = await caches.open('foo');
  await cache.put('/bar', new Response('snafu'.repeat(20 * 1024 * 1024)));
  await caches.delete('foo');

  // This should load with code cache.
  await instantiateModule(url_base + 'large.wasm&cors');

  window.top.postMessage('done', '*');
})();

</script>