Nazım Can Altınova
fc7f4f1323
This test makes sure that the event timing entries that don't trigger a paint gets correct timing information. Differential Revision: https://phabricator.services.mozilla.com/D288420
75 lines
2.9 KiB
HTML
75 lines
2.9 KiB
HTML
<!DOCTYPE html>
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<html>
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<meta charset=utf-8 />
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<title>Event Timing: keydown entry dispatched without a repaint.</title>
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<script src=/resources/testharness.js></script>
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<script src=/resources/testharnessreport.js></script>
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<script src=/resources/testdriver.js></script>
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<script src=/resources/testdriver-actions.js></script>
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<script src=/resources/testdriver-vendor.js></script>
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<script src=resources/event-timing-test-utils.js></script>
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<div id='target' tabindex=0>key target</div>
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<script>
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// When a key is held on a static page with no pending repaints, keydown
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// timing entries must still be dispatched promptly via a posted task
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// rather than waiting indefinitely for a paint that may never come.
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// Without the fix, entries would only be flushed when some unrelated
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// activity (e.g. mouse movement) triggered a repaint, causing durations
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// inflated to the total key-hold time.
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promise_test(async t => {
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const entries = [];
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new PerformanceObserver(list => {
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for (const entry of list.getEntries()) {
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if (entry.name === 'keydown') entries.push(entry);
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}
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}).observe({type: 'event', durationThreshold: 16});
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const target = document.getElementById('target');
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target.focus();
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// Wait for any focus-related repaint and for the browser to go idle.
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// afterNextPaint() resolves from a setTimeout inside a rAF callback, so
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// the rendering pipeline may still be scheduled for one or two more
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// vsyncs at that point; the extra delay lets painting settle before
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// sending the key.
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await afterNextPaint();
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await new Promise(resolve => t.step_timeout(resolve, 100));
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// Block every keydown long enough that each entry exceeds the 16ms
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// observation threshold, without involving any DOM changes that would
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// schedule a repaint.
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target.addEventListener('keydown', () => mainThreadBusy(30));
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const keyDownHandled = new Promise(resolve => {
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let keyDownCount = 0;
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target.addEventListener('keydown', () => {
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if (++keyDownCount === 2) {
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resolve();
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}
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}, { capture: true });
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});
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await new test_driver.Actions()
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.keyDown('a')
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.keyDown('a')
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.send();
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await keyDownHandled;
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// The entry must be dispatched via a posted task, without requiring a
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// repaint. step_wait will fail if no entry arrives within the timeout.
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await t.step_wait(() => entries.length === 2,
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'keydown timing entry should be dispatched without a repaint');
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assert_equals(entries.length, 2, 'two keydown entries');
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// Duration should reflect only the processing time (~30ms), not the full
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// key-hold duration.
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assert_less_than(entries[0].duration, 60,
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'duration must not be inflated to the key-hold duration');
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assert_less_than(entries[1].duration, 60,
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'duration must not be inflated to the key-hold duration');
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}, 'keydown timing entry is dispatched without a repaint');
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</script>
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</html>
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