LayoutTests/requestidlecallback/requestidlecallback-id.html

<!DOCTYPE html><!-- webkit-test-runner [ RequestIdleCallbackEnabled=true ] -->
<html>
<body>
<script src="../resources/js-test.js"></script>
<script>

description('This tests that requestIdleCallback identifier starts from 1 in each document.');

shouldBe('requestIdleCallback(() => { })', '1');
shouldBe('requestIdleCallback(() => { })', '2');

const iframe1 = document.body.appendChild(document.createElement('iframe'));
const iframe2 = document.body.appendChild(document.createElement('iframe'));

shouldBe('iframe1.contentWindow.requestIdleCallback(() => { })', '1');
shouldBe('iframe2.contentWindow.requestIdleCallback(() => { })', '1');
shouldBe('iframe1.contentWindow.requestIdleCallback(() => { })', '2');
shouldBe('iframe1.contentWindow.requestIdleCallback(() => { })', '3');
shouldBe('iframe2.contentWindow.requestIdleCallback(() => { })', '2');

</script>
</body>
</html>