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

<!DOCTYPE html>
<html>
<body>
This text won't be selected because it isn't editable.
<div id='target' contenteditable="true">16-char header. This text is initially selected. 16-char footer.</div>
This text won't be selected because it isn't editable.
<script>
    function select() {
        var text = document.getElementById('target').firstChild;
        var range = document.createRange();
        range.setStart(text, 16);
        range.setEnd(text, 48);
        window.getSelection().addRange(range);
    }
    window.onload = select;
</script>
</body>
</html>