chromium/third_party/blink/web_tests/external/wpt/webaudio/the-audio-api/the-audioworklet-interface/suspended-context-messageport.https.html

<!doctype html>
<title>Test MessagePort while AudioContext is not running</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script>
const get_node_and_message = (context) => {
  const node = new AudioWorkletNode(context, 'port-processor');
  return new Promise((resolve) => {
    node.port.onmessage = (event) => resolve({node: node, event: event});
  });
};
const ping_for_message = (node) => {
  return new Promise((resolve) => {
    node.port.onmessage = resolve;
    node.port.postMessage('ping');
  });
};
const modulePath = 'processors/port-processor.js';

promise_test(async () => {
  const realtime = new AudioContext();
  await realtime.audioWorklet.addModule(modulePath);
  await realtime.suspend();
  const currentTime = realtime.currentTime;
  let {node, event} = await get_node_and_message(realtime);
  assert_equals(event.data.timeStamp, currentTime, 'created message time');
  event = await ping_for_message(node);
  assert_equals(event.data.timeStamp, currentTime, 'pong time');
}, 'realtime suspended');

let offline;
promise_test(async () => {
  offline = new OfflineAudioContext({length: 128 + 1, sampleRate: 16384});
  await offline.audioWorklet.addModule(modulePath);
  assert_equals(offline.currentTime, 0, 'time before start');
  let {node, event} = await get_node_and_message(offline);
  assert_equals(event.data.timeStamp, 0, 'created time before start');
  event = await ping_for_message(node);
  assert_equals(event.data.timeStamp, 0, 'pong time before start');
}, 'offline before start');

promise_test(async () => {
  await offline.startRendering();
  const expected = 2 * 128 / offline.sampleRate;
  assert_equals(offline.currentTime, expected, 'time on complete');
  let {node, event} = await get_node_and_message(offline);
  assert_equals(event.data.timeStamp, expected, "created time on complete");
  event = await ping_for_message(node);
  assert_equals(event.data.timeStamp, expected, "pong time on complete");
}, 'offline on complete');
</script>