fullscreen/rendering/fullscreen-pseudo-class.html

<!DOCTYPE html>
<title>:fullscreen pseudo-class</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><div></div></div>
<script>
  promise_test(async (t) => {
    t.add_cleanup(() => {
      if (document.fullscreenElement) {
        return document.exitFullscreen();
      }
    });
    const outer = document.querySelector("div");
    const inner = outer.firstChild;

    // First request fullscreen for the outer element.
    await trusted_request(outer);
    await fullScreenChange();
    assert_equals(document.fullscreenElement, outer);
    assert_true(
      outer.matches(":fullscreen"),
      "outer:fullscreen in simple fullscreen"
    );
    assert_false(
      inner.matches(":fullscreen"),
      "inner:fullscreen in simple fullscreen"
    );

    // Then request fullscreen for the inner element.
    await trusted_request(inner);
    // Although inner is the fullscreen element, both elements match the
    // selector, as both have their fullscreen flag set.
    assert_equals(document.fullscreenElement, inner);
    assert_true(
      inner.matches(":fullscreen"),
      "inner:fullscreen in nested fullscreen"
    );
    assert_true(
      outer.matches(":fullscreen"),
      "outer:fullscreen in nested fullscreen"
    );
  });
</script>