<!DOCTYPE html>
<title>Regression test to ensure detaching a ScrollTimeline shouldn't crash</title>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>

<script src="resources/animation-worklet-tests.js"></script>

<style>
#scroller {
  overflow: auto;
  height: 100px;
  width: 100px;
}

#contents {
  height: 1000px;
  width: 100%;
}
</style>

<script id="simple_animate" type="text/worklet">
registerAnimator("test_animator", class {
  animate(currentTime, effect) {}
});
</script>

<div id="box"></div>
<div id="scroller">
  <div id="contents"></div>
</div>

<script>
// This is a regression test for the crash seen when http://crrev.com/ddd9f0ee
// landed. The root of the crash was assuming a WeakMember from a static object
// would still be alive during a USING_PRE_FINALIZER method, which is not true.
async_test(t => {
  runInAnimationWorklet(
   document.getElementById('simple_animate').textContent
  ).then(_ => {
    const box = document.getElementById('box');
    const effect = new KeyframeEffect(box, null);

    let scroller = document.getElementById('scroller');
    let timeline = new ScrollTimeline({
      scrollSource: scroller,
      timeRange: 1000,
      orientation: 'block'
    });
    // Creating the animation will cause the scroller to be registered as being
    // used in an attached ScrollTimeline.
    let animation = new WorkletAnimation('test_animator', effect, timeline, {});

    // Now free up everything at once.
    scroller.remove();
    animation.cancel();
    scroller = undefined;
    timeline = undefined;
    animation = undefined;

    requestAnimationFrame(t.step_func_done(() => {
      // Force GC - this shouldn't crash.
      gc();
    }));
  });
}, 'Disposing of an attached ScrollTimeline should not crash');
</script>