high-priority-input-keyboard.html | Explore in Territory

<!doctype html>
<title>Blink Scheduler Prioritize Input - Keyboard</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/utils.js"></script>

<h1>Test Page</h1>
<textarea id="text" autofocus></textarea>

<script>
'use strict';

window.onload = () => {
  promise_test(async t => {
    const taskCountDuringInputEvent = await new Promise(async resolve => {
      let taskCount = 0;
      function blockingTask() {
        ++taskCount;
        spin(50);
      }

      document.getElementById('text').addEventListener('keypress', () => {
        resolve(taskCount);
      });

      await requestAnimationFramePromise();
      await scheduler.yield();

      const controller = new TaskController({priority: "user-blocking"});
      t.add_cleanup(() => controller.abort());

      for (let i = 0; i < 50; i++) {
        const p = scheduler.postTask(blockingTask, {signal: controller.signal});
        ignoreUnhandledRejection(p);
        const id = setTimeout(blockingTask, 0);
        t.add_cleanup(() => clearTimeout(id));
      }

      window.eventSender.keyDownAsync('A');
    });

    // There's some lag in posting the task from the compositor thread, so the
    // first input event won't happen immediately.
    assert_less_than_equal(taskCountDuringInputEvent, 10);
  }, 'Test that keyboard input is prioritized');
};

</script>

chromium/third_party/blink/web_tests/wpt_internal/scheduler/integration_tests/high-priority-input-keyboard.html