element-ready-check-iframe-child.html

<!DOCTYPE html>
<title>Element ready check for child of iframe</title>
<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="../trusted-click.js"></script>
<div id="log"></div>
<iframe><!-- script inserts child here --></iframe>
<script>
    promise_test(async (t) => {
        document.onfullscreenerror = t.unreached_func("fullscreenerror event");
        const div = document.createElement("div");
        document.querySelector("iframe").appendChild(div);

        await Promise.all([
            trusted_request(div, document.body),
            fullScreenChange(),
        ]);

        assert_equals(document.fullscreenElement, div);
    }, "Element ready check for child of iframe");
</script>

chromium/third_party/blink/web_tests/external/wpt/fullscreen/api/element-ready-check-iframe-child.html