<!DOCTYPE html>
<html>
<head>
<style>

body {
    margin: 0;
}

body > div {
    position: absolute;
    width: 0;
    height: 500px;

    /* box-shadow should not be accounted for to specify the clipping bounds */
    box-shadow: 100px 100px 0px blue;
    overflow-x: hidden;
}

#container-with-width {
    width: 300px;
    background-color: red;
}

#container-with-width:hover {
    background-color: green;
}

#clipped-child {
    width: 100px;
    height: 100%;
}

</style>
</head>
<body>
    <div id="container-with-width"></div>
    <div id="container-without-width">
        <div id="clipped-child"></div>
    </div>
<script>

if (window.testRunner)
    testRunner.dumpAsText();

const result = document.body.appendChild(document.createElement("span"));
const hitTestElement = document.elementFromPoint(50, 50);
const pass = hitTestElement.id == "container-with-width";
result.textContent = `${pass ? "PASS" : "FAIL"}: target element is #${hitTestElement.id}`;

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