<body>
<script>
// This tests that an <input type="week"> created in a template document (e.g. one without a frame)
// is identical to one created in the main document.
let template = document.createElement('template');
template.innerHTML = '<input type="week" value="1982-W25">';
document.body.appendChild(template.content.cloneNode(true));
</script>
</body>