Source code

Revision control

Copy as Markdown

Other Tools

Test Info: Warnings

<!DOCTYPE html>
<meta charset=utf-8 />
<title>First Input: interactionId-tap.</title>
<button id='testButtonId'>Tap me</button>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script src=/resources/testdriver.js></script>
<script src=/resources/testdriver-vendor.js></script>
<script src=/resources/testdriver-actions.js></script>
<script src=resources/event-timing-test-utils.js></script>
let firstInputInteractionId = 0;
let eventTimingPointerDownInteractionId = 0;
let hasFirstInputEntry = false;
let hasEventTimingPointerDownEntry = false;
promise_test(async t => {
assert_implements(window.PerformanceEventTiming, 'Event Timing is not supported.');
const callback = (entryList) => {
entryList.getEntries().forEach(entry => {
switch (entry.entryType) {
case 'first-input': {
firstInputInteractionId = entry.interactionId;
hasFirstInputEntry = true;
case 'event': {
if ('pointerdown' == {
eventTimingPointerDownInteractionId = entry.interactionId;
hasEventTimingPointerDownEntry = true;
const readyToResolve = () => {
return hasFirstInputEntry && hasEventTimingPointerDownEntry;
const observerPromise = createPerformanceObserverPromise(['event', 'first-input'], callback, readyToResolve);
await interactAndObserve('tap', document.getElementById('testButtonId'), observerPromise);
assert_greater_than(firstInputInteractionId, 0, 'The first input entry should have a non-trivial interactionId');
assert_equals(firstInputInteractionId, eventTimingPointerDownInteractionId, 'The first input entry should have the same interactionId as the event timing pointerdown entry');
assert_equals(,, 'The first input entry should have the same target as the event timing pointerdown entry');
assert_not_equals(, null, 'The first input entry should have a non-null target');
}, "The interactionId of the first input entry should match the same pointerdown entry of event timing when tap.");