first-contentful-canvas.html

Enable keyboard shortcuts

This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /paint-timing/with-first-paint/first-contentful-canvas.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<head>

<title>Performance Paint Timing Test: FCP due to canvas</title>

</head>

<body>

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<canvas id="canvas" width="200" height="200" ></canvas>

<script>

setup({"hide_test_state": true});

async_test(function (t) {

    assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");

    const canvas = document.getElementById("canvas");

    const context = canvas.getContext("2d");

    context.beginPath();

    context.moveTo(0,0);

    context.lineTo(300,150);

    context.stroke();

    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 canvas render.");

</script>

</body>

</html>