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Test Info: Warnings
- 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/fcp-only/fcp-ensure-update-the-rendering-step.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<head>
<title>
Ensure the timing is marked during the `update the rendering` step.
</title>
</head>
<style>
#main {
width: 100px;
height: 100px;
left: 0px;
position: relative;
top: 0;
background-image: url(../resources/circles.png);
opacity: 0;
}
#main.contentful {
opacity: 0.1;
}
</style>
<body>
<script src="../resources/utils.js"></script>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.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.");
let fired = false;
const main = document.getElementById('main');
let animationFrameStamps = [];
requestAnimationFrame(function frame(stamp) {
animationFrameStamps.unshift(stamp);
main.className = "contentful";
while (performance.now() - stamp <= 5) {
/* Busy-wait */
}
if(!fired)
requestAnimationFrame(frame);
});
new PerformanceObserver(t.step_func(list=>{
for (let entry of list.getEntries()) {
if (entry.name == "first-contentful-paint") {
fired = true;
assert_any(assert_approx_equals, entry.startTime, animationFrameStamps, 1, "One of the past requestAnimationFrame should have the same timestamp as paint entry");
t.done();
}
}
})).observe({type: "paint"});
}, 'The first-contentful-paint timestamp should be same as the last RAF');
</script>
</body>
</html>