add_move(square) {
/* Cannot move to an occupied square. */
if (this.state.board[square])
- return false;
+ return { legal: false, message: "Square is already occupied" };
this.state.board[square] = this.state.next_player;
this.state.moves.push(square);
else
this.state.next_player = "X";
- return true;
+ return { legal: true };
}
}