timingconditions.html

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This WPT test may be referenced by the following Test IDs:
- /event-timing/timingconditions.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<html>

<meta charset=utf-8 />

<title>Event Timing only times certain types of trusted event.

</title>

<meta name="timeout" content="long">

<button id='button' onmousedown='mainThreadBusy(60)'

  onfocus='mainThreadBusy(60)'>Generate a 'click' event</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/event-timing-test-utils.js></script>

<script>

  let trustedClickStart;

  function trustedClickAndBlockMain(id) {

    trustedClickStart = performance.now();

    return clickAndBlockMain(id);

  function untrustedClickAndBlockMain(id) {

    const target = document.getElementById(id);

    // Block mainthread in the callback, as dispatchEvent() is a sync call.

    target.dispatchEvent(new MouseEvent('mousedown'));

  function trustedFocusAndBlockMain(id) {

    const target = document.getElementById(id);

    trustedFocusStart = performance.now();

    // Block mainthread in the callback,  as focus() is a sync call.

    target.focus();

  promise_test(function(t) {

    assert_implements(window.PerformanceEventTiming, 'Event Timing is not supported.');

    let observedMouseDown = false;

    const observerPromise = new Promise(resolve => {

      new PerformanceObserver(t.step_func(entryList => {

        const observerCallbackTime = performance.now();

        const mouseDowns = entryList.getEntriesByName('mousedown');

        // Ignore cases in which there is no mousedown.

        if (mouseDowns.length === 0)

          return;

        assert_false(observedMouseDown, 'Got more than one callback with mousedown.');

        assert_equals(mouseDowns.length, 1,

            "Should only observe one mousedown entry. Instead, got these: " +

            JSON.stringify(mouseDowns) + ".");

        assert_equals(mouseDowns[0].name, 'mousedown',

            "The observed entry should be a mousedown");

        assert_less_than(mouseDowns[0].startTime, observerCallbackTime,

            "The startTime should be before observerCallbackTime");

        assert_greater_than(mouseDowns[0].startTime, trustedClickStart,

            "The startTime should be after trustedClickStart");

        observedMouseDown = true;

        resolve();

      })).observe({ entryTypes: ['event'] });

});

    // Untrusted event of a type event timing cares about.

    untrustedClickAndBlockMain('button');

    // Trusted event of a type event timing doesn't cares about.

    trustedFocusAndBlockMain('button');

    // Trusted event of a type event timing cares about.

    const clickPromise = trustedClickAndBlockMain('button').then(wait);

    return Promise.all([observerPromise, clickPromise]);

  }, "Event Timing only times certain types of trusted event.");

</script>

</html>