chromium/third_party/blink/web_tests/external/wpt/idle-detection/page-visibility.https.html

<!DOCTYPE html>
<link rel="help" href="https://github.com/samuelgoto/idle-detection">
<title>Tests the Idle Detection API</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/test-only-api.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="/page-visibility/resources/window_state_context.js"></script>
<script src="resources/idle-detection-helper.js"></script>
<script>
'use strict';

promise_setup(async t => {
  await test_driver.set_permission({ name: 'idle-detection' }, 'granted');
  if (isChromiumBased) {
    await loadChromiumResources();
  }
})

promise_test(async t => {
  let monitor;

  expect(addMonitor).andReturn(async (monitorPtr) => {
      monitor = monitorPtr;
      return {
        error: IdleDetectorError.SUCCESS,
        state: {
          idleTime: null,
          screenLocked: false
        }
      };
    });

  const controller = new AbortController();
  t.add_cleanup(() => {
    controller.abort();
  });
  const detector = new IdleDetector();
  const watcher = new EventWatcher(t, detector, ["change"]);
  const initial_state = watcher.wait_for("change");

  await detector.start({threshold: 60000, signal: controller.signal});
  await initial_state;

  assert_equals(detector.userState, "active");
  assert_false(document.hidden);

  const {minimize, restore} = window_state_context(t);

  await minimize();
  monitor.update(
          {
            idleTime: { milliseconds: 0 },
            screenLocked: false
          },
          /*is_overridden_by_devtools=*/true
        );

  // Assert that the detector works while the page is not visible.
  await watcher.wait_for("change");
  assert_equals(detector.userState, "idle");
  assert_true(document.hidden);

  await restore();
  monitor.update(
          {
            idleTime: null,
            screenLocked: false
          },
          /*is_overridden_by_devtools=*/true
        );

  await watcher.wait_for("change");
  assert_equals(detector.userState, "active");
  assert_false(document.hidden);
}, 'Page visibility.');

</script>