paint-timing/basetest.html

<!DOCTYPE html>
<head>
<title>Performance Paint Timing Test</title>
</head>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/utils.js"></script>
<div id="main"></div>

<script>
setup({"hide_test_state": true});
async_test(function(t) {
    assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");
    t.step(function() {
        const bufferedEntries = performance.getEntriesByType('paint');
        assert_equals(bufferedEntries.length, 0, "No paint entries yet");
    });
    const div = document.createElement("div");
    div.style.width = "100px";
    div.style.height = "100px";
    div.style.backgroundColor = "red";
    div.style.color = "blue";
    div.innerHTML = "test"
    document.getElementById("main").appendChild(div);
    assertPaintTimingEntries(t, 20);
}, "Basic test to check existence of FP and FCP.");
</script>
</body>
</html>