sibling-painting-first-image.html | Explore in Territory

<!DOCTYPE html>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
 <!-- This iframe will have a sibling that paints, we want to ensure it does not detect that paint. -->
<iframe id="listening-iframe" src="../resources/subframe-sending-paint.html"></iframe>
<script>
setup({"hide_test_state": true});
var entriesExpectToReceive = [
    {
        'entryType': 'paint',
        'name': 'first-paint'
    },
    {
        'entryType': 'paint',
        'name': 'first-contentful-paint'
    }
];
async_test(function (t) {
    assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");
    let paintingIframeHasDispatchedEntries = false;
    window.addEventListener('message', t.step_func(e => {
        if (!paintingIframeHasDispatchedEntries) {
            // Check paint-timing entries from the painting iframe.
            for (let i = 0; i < entriesExpectToReceive.length; i++) {
                if (entriesExpectToReceive[i].entryType == e.data.entryType &&
                    entriesExpectToReceive[i].name == e.data.name) {
                    entriesExpectToReceive.splice(i, 1);
                    break;
                }
            }
            if (entriesExpectToReceive.length == 0) {
                paintingIframeHasDispatchedEntries = true;
                // Ask the listening iframe to send its paint-timing entries.
                document.getElementById('listening-iframe').
                    contentWindow.postMessage('', '*');
            }
            return;
        }
        // Check the paint-timing entries from the listening iframe.
        assert_equals(e.data, '0');
        // Check that current frame receives first-paint but not first-contentful-paint.
        const bufferedEntries = performance.getEntriesByType('paint');
        assert_equals(bufferedEntries.length, 1);
        assert_equals(bufferedEntries[0].entryType, 'paint');
        assert_equals(bufferedEntries[0].name, 'first-paint');
        t.done();
    }));
}, 'Frame ignores paint-timing events fired from sibling frame.');
</script>
<!-- This iframe is where all of the painting occurs. -->
<iframe id="painting-iframe" src="../resources/subframe-painting.html"></iframe>
</body>
</html>
chromium/third_party/blink/web_tests/external/wpt/paint-timing/with-first-paint/sibling-painting-first-image.html
