chromium/third_party/blink/web_tests/external/wpt/css/selectors/invalidation/media-loading-pseudo-classes-in-has.html

<!DOCTYPE html>
<meta name="timeout" content="long" />
<title>:has() invalidation with :buffering & :stalled pseudo-classes</title>
<link rel="author" title="Tim Nguyen" href="https://github.com/nt1m">
<link rel="help" href="https://drafts.csswg.org/selectors/#relational">
<link rel="help" href="https://drafts.csswg.org/selectors/#media-loading-state">

<style>
#subject:has(video:buffering) {
    background-color: blue;
}
#subject:has(video:stalled) {
    border-color: green;
}
</style>

<div id="subject">
    <video width="300" height="300" muted loop controls></video>
</div>

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
const BLUE = "rgb(0, 0, 255)";
const GREEN = "rgb(0, 128, 0)";

function assert_buffering_state(buffering) {
    if (buffering)
        assert_equals(getComputedStyle(subject).backgroundColor, BLUE);
    else
        assert_not_equals(getComputedStyle(subject).backgroundColor, BLUE);
}

function assert_stalled_state(stalled) {
    if (stalled)
        assert_equals(getComputedStyle(subject).borderColor, GREEN);
    else
        assert_not_equals(getComputedStyle(subject).borderColor, GREEN);
}

promise_test(async (t) => {
    const video = document.querySelector("video");
    assert_stalled_state(false);
    await new Promise((r) => {
        video.addEventListener("stalled", r, { once: true });
        video.src = `/media/counting.mp4?pipe=trickle(100:d1:r2)&random=${Math.random()}`;
    });
    assert_stalled_state(false);
    const promise = video.play();
    assert_stalled_state(true);
    video.src = "";
    // Wait for the video to abort trying to play
    try {
        await promise;
    } catch (err) {}
    await video.pause();
    assert_stalled_state(false);
}, "Test :has(:stalled) invalidation");

promise_test(async (t) => {
    const video = document.querySelector("video");
    assert_buffering_state(false);
    await new Promise((r) => {
        video.addEventListener("stalled", r, { once: true });
        video.src = `/media/counting.mp4?pipe=trickle(100:d1:r2)&random=${Math.random()}`;
    });
    video.currentTime = 10;
    assert_buffering_state(false);
    const promise = video.play();
    assert_buffering_state(true);
    video.src = "";
    // Wait for the video to abort trying to play
    try {
        await promise;
    } catch (err) {}
    await video.pause();
    assert_buffering_state(false);
}, "Test :has(:buffering) invalidation");
</script>