gecko-dev/dom/media/test/fragment_play.js

function test_fragment_play(v, start, end, is, ok, finish) {
  var completed = false;
  var loadedMetadataRaised = false;
  var seekedRaised = false;
  var pausedRaised = false;

  function onLoadedMetadata() {
    var s = start == null ? 0 : start;
    var e = end == null ? v.duration : end;
    ok(
      v.currentTime == s,
      "loadedmetadata currentTime is " + v.currentTime + " != " + s
    );
    ok(
      v.mozFragmentEnd == e,
      "mozFragmentEnd (" + v.mozFragmentEnd + ") == end Time (" + e + ")"
    );
    loadedMetadataRaised = true;
    v.play();
  }

  function onSeeked() {
    if (completed) {
      return;
    }

    var s = start == null ? 0 : start;
    ok(
      v.currentTime - s < 0.1,
      "seeked currentTime is " +
        v.currentTime +
        " != " +
        s +
        " (fuzzy compare +-0.1)"
    );

    seekedRaised = true;
  }

  function onTimeUpdate() {
    if (completed) {
      return;
    }

    v._lastTimeUpdate = v.currentTime;
  }

  function onPause() {
    if (completed) {
      return;
    }

    var e = end == null ? v.duration : end;
    var a = e - 0.05;
    var b = e + 0.05;
    ok(
      v.currentTime >= a && v.currentTime <= b,
      "paused currentTime is " +
        a +
        " < " +
        v.currentTime +
        " < " +
        b +
        " ? " +
        v._lastTimeUpdate
    );
    pausedRaised = true;
    v.play();
  }

  function onEnded() {
    if (completed) {
      return;
    }

    completed = true;
    ok(loadedMetadataRaised, "loadedmetadata event");
    if (start) {
      ok(seekedRaised, "seeked event");
    }
    if (end) {
      ok(pausedRaised, "paused event: " + end + " " + v.duration);
    }
    finish();
  }

  v.addEventListener("ended", onEnded);
  v.addEventListener("loadedmetadata", onLoadedMetadata);
  v.addEventListener("seeked", onSeeked);
  v.addEventListener("pause", onPause);
  v.addEventListener("timeupdate", onTimeUpdate);
}