24 lines
1.1 KiB
JavaScript
24 lines
1.1 KiB
JavaScript
setup({"hide_test_state": true});
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async_test(t => {
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assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");
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// First observer creates a second one in the callback to ensure the entry has been dispatched
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// by the time the second observer begins observing.
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new PerformanceObserver(entries => {
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const entry_seen = entries.getEntriesByName('first-contentful-paint').length > 0;
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// Abort if we have not yet received the entry.
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if (!entry_seen)
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return;
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// Second observer requires 'buffered: true' to see the entry.
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new PerformanceObserver(t.step_func_done(list => {
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const fcp = list.getEntriesByName('first-contentful-paint');
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assert_equals(fcp.length, 1, 'Should have an fcp entry');
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const entry = fcp[0];
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assert_equals(entry.entryType, 'paint');
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})).observe({'type': 'paint', buffered: true});
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}).observe({'entryTypes': ['paint']});
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// Trigger the first contentful paint entry.
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const img = document.createElement("img");
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img.src = "../resources/circles.png";
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document.body.appendChild(img);
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}, "PerformanceObserver with buffered flag sees previous FCP entry.");
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