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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:
- /container-timing/tentative/containertiming-observe-no-paint.html - WPT Dashboard Interop Dashboard
<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Container Timing: if no paint happens, observer is not called</title>
<body>
<style>
body {
margin: 0;
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/container-timing/resources/container-timing-helpers.js"></script>
<script src="/element-timing/resources/element-timing-helpers.js"></script>
<script>
async_test(function (t) {
assert_implements(window.PerformanceContainerTiming, "PerformanceContainerTiming is not implemented");
const observer = new PerformanceObserver(
function(entryList) {
assert_unreached("No entry is expected with nothing to paint");
}
);
observer.observe({entryTypes: ['container']});
t.step_timeout(() => {
t.done();
}, 2000);
// Add the image during onload to be sure that the observer is registered
// in time.
window.onload = () => {
const div = document.createElement('div');
div.setAttribute('containertiming', 'div_ct');
document.body.appendChild(div);
beforeRender = performance.now();
};
}, 'Container timing did not report paints when there was nothing to paint.');
</script>
</body>