update_hover_after_layout_change_at_begin_frame.html

<!DOCTYPE html>
<script src='../../resources/gesture-util.js'></script>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>

<style>
#blue {
    background-color: rgb(0, 0, 255);
    position: absolute;
    left: 75px;
    top: 75px;
    height: 100px;
    width: 100px;
}
#blue:hover {
    background-color: rgb(255, 255, 0);
}
</style>
<div id="blue"></div>
<script>
var x = 100;
var y = 100;
var blue = document.getElementById('blue');

window.onload = async () => {
  promise_test(async () => {
    await mouseMoveTo(x, y);
    await raf();
    assert_true(blue.matches(':hover'), "Hover on the element blue");
    // Move the element blue away from the mouse cursor.
    blue.style.top = y + 500 + 'px';
    // Force a layout change.
    assert_equals(blue.offsetTop, 600, "Check that the blue element is moved by 600px");
    assert_true(blue.matches(':hover'), "The hover state is not yet updated");
    await raf();
    assert_false(blue.matches(':hover'), "The hover state is updated after the begin frame");
  }, 'The hover state is updated at the begin frame after the layout changes.');

}
</script>

chromium/third_party/blink/web_tests/fast/events/update_hover_after_layout_change_at_begin_frame.html