Chess.js library. Determine winner and loser

Question

Using the chess.js library (see this link), I can know if a chess game is finished, by using game_over() function.

But how do I know who won and who lost?

Answer 1

in_checkmate()

Returns true or false if the side to move has been checkmated.

Combined with turn(), it gives you the winner / loser (if it's not a draw).