Content - ddcc78fbe55ec55c34faa59d25f1a2acb4e1724f - 81c2aca/paint-timing/first-contentful-bg-image.html

visit type:

Tip revision: d31a2d55e6e91358b0c30d2d5e614024a81ef81c authored by Nicolas Pena on 10 April 2018, 22:25:46 UTC
WPT-fy Intel/user-timing/ tests

Tip revision: d31a2d5

first-contentful-bg-image.html

<!DOCTYPE html>
<head>
<title>Performance Paint Timing Test: FCP due to background image</title>
</head>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="main"></div>
</body>

<footer>
<script>
async_test(function (t) {
    const body = document.getElementsByTagName('body')[0];
    body.style.backgroundImage = 'url(resources/circles.png)';
    window.onload = function() {
        function testPaintEntries() {
            const bufferedEntries = performance.getEntriesByType('paint');
            if (bufferedEntries.length < 2) {
                t.step_timeout(function() {
                    testPaintEntries();
                }, 20);
                return;
            }
            t.step(function() {
                assert_equals(bufferedEntries.length, 2, "There should be two paint timing instances.");
                assert_equals(bufferedEntries[0].entryType, "paint");
                assert_equals(bufferedEntries[0].name, "first-paint");
                assert_equals(bufferedEntries[1].entryType, "paint");
                assert_equals(bufferedEntries[1].name, "first-contentful-paint");
                t.done();
            });
        }
        t.step(function() {
            testPaintEntries();
        });
    };
}, "First contentful paint fires due to background image render.");
</script>
<footer>
</html>

Browse the archive

https://github.com/web-platform-tests/wpt