<!DOCTYPE html>
<html>
<head>
<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/battery-status-helpers.js"></script>
</head>
<body>
<script>
battery_status_test(async (t, mockBatteryMonitor) => {
  mockBatteryMonitor.setBatteryStatus(false, 10, 20, 0.5);
  const battery = await navigator.getBattery();

  mockBatteryMonitor.verifyBatteryStatus(battery);

  const fail = () => { throw new Error('unexpected levelchange event'); };
  battery.addEventListener('levelchange', fail);

  const {minimize, restore} = window_state_context(t);
  await minimize();
  mockBatteryMonitor.setBatteryStatus(false, 10, 20, 0.55);
  battery.removeEventListener('levelchange', fail);

  const change =
      new Promise(resolve => battery.addEventListener('levelchange', resolve));
  await restore();
  mockBatteryMonitor.setBatteryStatus(false, 10, 20, 0.6);
  await change;

  mockBatteryMonitor.verifyBatteryStatus(battery);
}, 'battery status events only fire on visible pages');
</script>
</body>
</html>