drop Snapback

If 'snapback' is passed to the drop event's setAction() function, the dragged piece will return to it's source square.

HTML

<chess-board
    style="width: 400px"
    position="start"
    draggable-pieces>
</chess-board>

JavaScript

const board = document.querySelector('chess-board');

// snapback black pieces when they are dropped
board.addEventListener('drop', (e) => {
  const {piece, setAction} = e.detail;
  if (piece.search(/b/) !== -1) {
    setAction('snapback');
  }
});