chromium/third_party/blink/web_tests/wpt_internal/webmidi/implicit-open.https.html

<!DOCTYPE html>
<html>
<head>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
</head>
<body>
<script type="module">
import {MockMIDIService} from './resources/mock-midiservice.js';
import {checkStateTransition} from './resources/state-check-utils.js';

const mock = new MockMIDIService();

async function checkAccess(access) {
  const inputPort = access.inputs.values().next().value;
  const outputPort = access.outputs.values().next().value;

  await checkStateTransition({
    port: inputPort,
    access,
    method: "setonmidimessage",
    initialconnection: "closed",
    finalconnection: "open",
  });

  // Reset event handlers so close() does not cause check failures.
  inputPort.onstatechange = null;
  access.onstatechange = null;
  await inputPort.close();

  await checkStateTransition({
    port: inputPort,
    access,
    method: "addeventlistener",
    initialconnection: "closed",
    finalconnection: "open",
  });

  await checkStateTransition({
    port: outputPort,
    access,
    method: "send",
    initialconnection: "closed",
    finalconnection: "open",
  });
}

promise_test(async _ => {
  await test_driver.set_permission({name: 'midi', sysex: true}, 'granted');
  const access = await navigator.requestMIDIAccess();
  await checkAccess(access);
}, 'MIDIPort implicit open');
</script>
</body>
</html>