loaf-congested-moment-worker.html

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This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /long-animation-frame/loaf-congested-moment-worker.html - WPT Dashboard Interop Dashboard

<!DOCTYPE HTML>

<meta charset=utf-8>

<title>Long Animation Frame Timing: congested moments in a dedicated worker</title>

<meta name="timeout" content="long">

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<body>

<h1>Long Animation Frame: worker congested moment</h1>

<div id="log"></div>

<script>

// This test exercises the Long Animation Frame extension to Web Workers: a

// worker whose event loop stays saturated past the congestion threshold emits

// a "long-animation-frame" entry. It requires

// the LongAnimationFrameWorker feature to be enabled, e.g. run with

// --enable-blink-features=LongAnimationFrameWorker.

promise_test(async (t) => {

  const worker = new Worker(

      "resources/loaf-congested-moment-worker.js");

  t.add_cleanup(() => worker.terminate());

  const message = new Promise((resolve) => {

    worker.onmessage = (e) => resolve(e.data);

});

  worker.postMessage("start");

  const entry = await message;

  assert_equals(entry.entryType, "long-animation-frame");

  assert_greater_than_equal(entry.duration, 200,

      "congested moment spans at least the threshold");

  // The blocking onmessage handler should be attributed to the worker script.

  const workerScripts = entry.scripts.filter(

      (s) => s.sourceURL &&

          s.sourceURL.includes("loaf-congested-moment-worker.js"));

  assert_greater_than_equal(workerScripts.length, 1,

      "a blocking script is attributed to the worker script");

}, "A saturated worker event loop reports a congested-moment LoAF entry");

</script>

</body>