Please select a part of the text in this textarea, and then drag-and-drop the selected text to a different section of the textarea. It is expected that "deleteByDrag" events will have no data (data == null), but it is expected that "insertFromDrop" events populate the data attribute with the text that was dropped / inserted. If you see "insertFromDrop" events having the data that was dragged and dropped, then the test passes. See https://www.w3.org/TR/input-events-1/#overview