chromium/third_party/blink/web_tests/external/wpt/html/semantics/embedded-content/media-elements/event_volumechange.html

<!doctype html>
<title>volumechange event</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="log"></div>
<script>
function volumechange_test(tagName) {
  async_test(function(t) {
    var e = document.createElement(tagName);
    assert_equals(e.volume, 1);
    e.volume = 0.5;
    assert_equals(e.volume, 0.5);
    e.onvolumechange = t.step_func(function() {
      assert_equals(e.volume, 0.5);
      e.volume = 1;
      assert_equals(e.volume, 1);
      e.onvolumechange = t.step_func(function() {
        assert_equals(e.volume, 1);
        t.done();
      });
    });
  }, "setting " + tagName + ".volume fires volumechange");

  async_test(function(t) {
    var e = document.createElement(tagName);
    assert_false(e.muted);
    e.muted = true;
    assert_true(e.muted);
    e.onvolumechange = t.step_func(function() {
      assert_true(e.muted);
      e.muted = false;
      assert_false(e.muted);
      e.onvolumechange = t.step_func(function() {
        assert_false(e.muted);
        t.done();
      });
    });
  }, "setting " + tagName + ".muted fires volumechange");

  async_test(function(t) {
    var e = document.createElement(tagName);
    e.volume = e.volume;
    e.muted = e.muted;
    e.onvolumechange = t.step_func(function() {
      assert_unreached();
    });
    var e2 = document.createElement(tagName);
    e2.muted = !e2.muted;
    e2.onvolumechange = t.step_func(function() {
      t.done();
    });
  }, "setting " + tagName + ".volume/muted to the same value does not fire volumechange");

  async_test(function(t) {
    var e = document.createElement(tagName);
    e.muted = !e.muted;
    e.volume = 1 - e.volume;
    e.muted = !e.muted;
    e.volume = 1 - e.volume;
    var volumechange_count = 0;
    e.onvolumechange = t.step_func(function() {
      volumechange_count++;
      if (volumechange_count == 4) {
        t.done();
      }
    });
  }, "setting " + tagName + ".volume/muted repeatedly fires volumechange repeatedly");
}

volumechange_test("audio");
volumechange_test("video");
</script>