chromium/third_party/blink/renderer/core/testing/data/editable_elements.html

<!DOCTYPE html>
<body>
    <input>
    <input>
    <input>
    <input type="number">
    <p contenteditable="true">blabla</p>
    <button></button>
    <script>
    document.querySelector('input').focus();
    </script>
</body>