Commit b5bd016f authored by Nazım Can Altınova's avatar Nazım Can Altınova Committed by canaltinova@gmail.com
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Bug 1967220 - Add a WPT test case for PerformancePaintTiming toJSON r=sefeng

This test case makes sure that we properly serialize the paintTime and
presentationTime attributes that are from PaintTimingMixin.

Differential Revision: https://phabricator.services.mozilla.com/D250018
parent d98fdd85
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<!DOCTYPE html>
<head>
<title>Performance Paint Timing: Check that paintTime/presentationTime are serialized properly with toJSON</title>
</head>
<body>
<script src="resources/utils.js"></script>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
  setup({"hide_test_state": true});
  promise_test(async t => {
    assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");
    assert_implements("paintTime" in window.PerformancePaintTiming.prototype, "Paint Timing doesn't expose `paintTime`");
    await new Promise(r => window.addEventListener('load', r));
    await assertNoFirstContentfulPaint(t);
    const img = document.createElement('img');
    img.src = 'resources/circles.png';
    document.body.append(img);
    const reference_time = performance.now();
    const performance_entry_promise = new Promise(resolve => {
        new PerformanceObserver(entries => {
            const [entry] = entries.getEntriesByName("first-contentful-paint");
            if (entry)
                resolve(entry);
        }).observe({type: "paint"});
    });
    const entry = await performance_entry_promise;
    assert_greater_than(entry.paintTime, reference_time);
    if ("presentationTime" in entry && entry.presentationTime !== null) {
      assert_greater_than(entry.presentationTime, entry.paintTime);
      assert_equals(entry.presentationTime, entry.startTime);
    } else {
      assert_equals(entry.paintTime, entry.startTime);
    }

    const json = entry.toJSON();
    assert_equals(typeof json, 'object');
    // Check that basic PerformanceEntry attributes are serialized.
    assert_equals(json.name, entry.name,
            'PerformanceEventTiming "name" attribute does not match its toJSON value');
    // Check that the PaintTimingMixin attributes are serialized.
    assert_equals(json.paintTime, entry.paintTime,
      'PerformanceEventTiming "paintTime" attribute does not match its toJSON value');
    assert_equals(json.presentationTime, entry.presentationTime,
      'PerformanceEventTiming "presentationTime" attribute does not match its toJSON value');
    if ("presentationTime" in entry && entry.presentationTime !== null) {
      assert_greater_than(json.presentationTime, json.paintTime);
      assert_equals(json.presentationTime, json.startTime);
    } else {
      assert_equals(json.paintTime, json.startTime);
    }

}, "Paint timing entries should serialize paintTime and presentationTime with toJSON");
</script>
</body>
</html>