LayoutTests/editing/deleting/smart-delete-003.html

<script>
if (window.layoutTestController)
     layoutTestController.dumpEditingCallbacks();
</script>
<p>This tests deleting a selection created with a word granularity.  To run it manually, double click on 'bar' and hit delete.  You should see 'foo bar'.</p>
<div id="div" contenteditable="true">foo bar baz</div>

<script>
if (window.layoutTestController) {
    var div = document.getElementById("div");
    var sel = window.getSelection();
    
    sel.setPosition(div, 0);
    sel.modify("move", "forward", "word");
    sel.modify("move", "forward", "word");
    sel.modify("extend", "backward", "word");
    layoutTestController.execCommand("DeleteBackward");
}
</script>