<!doctype html>
<head>
<title>Test effect of selectAudioOutput() on audiooutput devices from enumerateDevices()</title>
<link rel="help" href="https://w3c.github.io/mediacapture-output/#dom-mediadevices-selectaudiooutput">
</head>
<body>
  <p class="instructions">If prompted, <strong>please allow</strong> access to
    an audio output device.</p>
</body>
<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>
<script>
'use strict';

promise_test(async () => {
  const devices = await navigator.mediaDevices.enumerateDevices();
  const outputDevices = devices.filter(info => info.kind == "audiooutput");
  assert_equals(outputDevices.length, 0, "number of audiooutput devices.");
}, "enumerateDevices() returns no audiooutput devices before permission grant");

let selected;

promise_test(async t => {
  await test_driver.bless('transient activation for selectAudioOutput()');
  selected = await navigator.mediaDevices.selectAudioOutput();
  assert_true(selected instanceof MediaDeviceInfo,
              "resolves with a MediaDeviceInfo.");
  assert_equals(selected.kind, "audiooutput", "selected.kind");
  assert_greater_than(selected.deviceId.length, 0, "selected.deviceId.length");
  assert_greater_than(selected.groupId.length, 0, "selected.groupId.length");
  assert_not_equals(selected.label, undefined, "selected.label");
}, "selectAudioOutput()");

promise_test(async () => {
  // "Once a device is exposed after a call to selectAudioOutput, it MUST be
  // listed by enumerateDevices() for the current browsing context."
  const devices = await navigator.mediaDevices.enumerateDevices();
  const outputDevices = devices.filter(info => info.kind == "audiooutput");
  assert_equals(outputDevices.length, 1, "number of audiooutput devices.");
  assert_not_equals(selected, undefined);
  const [info] = outputDevices;
  assert_equals(info.deviceId, selected.deviceId, "deviceId exposed");
  assert_equals(info.groupId, selected.groupId, "groupId exposed");
  assert_equals(info.label, selected.label, "label exposed");
}, "enumerateDevices() after selectAudioOutput()");
</script>
