first-contentful-paint.html

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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-paint.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<head>

<title>Performance Paint Timing Test: FP followed by FCP</title>

</head>

<body>

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

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

<div id="main"></div>

<div id="image"></div>

<script>

setup({"hide_test_state": true});

async_test(function (t) {

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

    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";

    document.getElementById("main").appendChild(div);

    function testPaintEntries() {

      const bufferedEntries = performance.getEntriesByType('paint');

      if (bufferedEntries.length < 1) {

        t.step_timeout(function() {

          testPaintEntries();

        }, 20);

        return;

      t.step(function() {

        assert_equals(bufferedEntries.length, 1, "FP only.");

        assert_equals(bufferedEntries[0].entryType, "paint");

        assert_equals(bufferedEntries[0].name, "first-paint");

});

      const img = document.createElement("IMG");

      img.src = "../resources/circles.png";

      img.onload = function() {

        function secondTestPaintEntries() {

          const moreBufferedEntries = performance.getEntriesByType('paint');

          if (moreBufferedEntries.length < 2) {

            t.step_timeout(function() {

              secondTestPaintEntries();

            }, 20);

            return;

          t.step(function() {

            assert_equals(moreBufferedEntries.length, 2, "FP and FCP.");

            assert_equals(moreBufferedEntries[0].entryType, "paint");

            assert_equals(moreBufferedEntries[0].name, "first-paint");

            const fpEntriesGotByName =

                performance.getEntriesByName('first-paint');

            assert_equals(fpEntriesGotByName.length, 1);

            assert_equals(moreBufferedEntries[0], fpEntriesGotByName[0]);

            assert_equals(moreBufferedEntries[1].entryType, "paint");

            assert_equals(moreBufferedEntries[1].name, "first-contentful-paint");

            const fcpEntriesGotByName =

                performance.getEntriesByName('first-contentful-paint');

            assert_equals(fcpEntriesGotByName.length, 1);

            assert_equals(moreBufferedEntries[1], fcpEntriesGotByName[0]);

            t.done();

});

        t.step(function() {

          secondTestPaintEntries();

});

};

      document.getElementById('image').appendChild(img);

    t.step(function() {

      testPaintEntries();

});

}, "First Paint triggered by non-contentful paint. Image load triggers First Contentful Paint.");

</script>

</body>

</html>