long-animation-frame/loaf-basic.html

<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Long Animation Frame Timing: basic</title>
<meta name="timeout" content="long">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/utils.js"></script>

<body>
<h1>Long Animation Frame: basic</h1>
<div id="log"></div>
<script>

promise_test(async t => {
    await expect_long_frame((t, busy_wait) => busy_wait(), t);
}, 'A long busy wait is a long animation frame');

promise_test(async t => {
    await expect_long_frame((t, busy_wait) => requestAnimationFrame(busy_wait), t);
}, 'A long busy wait in a requestAnimationFrame is a long animation frame');

promise_test(async t => {
    const segment_duration = very_long_frame_duration / 2;
    const entry = await expect_long_frame(async (t, busy_wait) => {
        busy_wait(segment_duration);
        await new Promise(resolve => requestAnimationFrame(() => {
            busy_wait(segment_duration)
            resolve();
        }));
    }, t);

    assert_not_equals(entry, "timeout");
    assert_greater_than_equal(entry.renderStart - entry.startTime, segment_duration);
}, 'A long busy wait split between a task and a requestAnimationFrame is a long animation frame');

promise_test(async t => {
    const segment_duration = very_long_frame_duration / 3;
    const entry = await expect_long_frame(async (t, busy_wait) => {
        const element = document.createElement("div");
        document.body.appendChild(element);
        t.add_cleanup(() => element.remove());
        busy_wait(segment_duration);
        requestAnimationFrame(() => {
            busy_wait(segment_duration);
        });

        new ResizeObserver(() => {
            busy_wait(segment_duration);
        }).observe(element);
    }, t);

    assert_not_equals(entry, "timeout");
    assert_greater_than_equal(entry.renderStart - entry.startTime, segment_duration);
    assert_greater_than_equal(entry.styleAndLayoutStart - entry.renderStart, segment_duration);
}, 'ResizeObservers should create a long-frame and affect layoutStartTime');
</script>
</body>