From 6153112c21738497047cb7a41de79cd8616682f1 Mon Sep 17 00:00:00 2001
From: nocturn9x <nocturn9x@nocturn9x.space>
Date: Sat, 13 Apr 2024 14:56:08 +0200
Subject: [PATCH] Fix promotion bugs: all test positions from the wiki are now
 passing

---
 src/Chess/board.nim | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/Chess/board.nim b/src/Chess/board.nim
index 1e55d21..cfd08dd 100644
--- a/src/Chess/board.nim
+++ b/src/Chess/board.nim
@@ -1509,7 +1509,7 @@ proc doMove(self: ChessBoard, move: Move) =
         castlingAvailable = self.position.castlingAvailable
         enPassantTarget = emptyLocation()
     # Needed to detect draw by the 50 move rule
-    if piece.kind == Pawn or move.isCapture():
+    if piece.kind == Pawn or move.isCapture() or move.isEnPassant():
         halfMoveClock = 0
     else:
         inc(halfMoveClock)
@@ -1609,7 +1609,6 @@ proc doMove(self: ChessBoard, move: Move) =
         # Make the en passant pawn disappear
         self.removePiece(move.targetSquare + piece.color.bottomSide(), attack=false)
 
-
     if move.isCapture():
         # Get rid of captured pieces
         self.removePiece(move.targetSquare, attack=false)
@@ -1618,6 +1617,7 @@ proc doMove(self: ChessBoard, move: Move) =
     if move.isPromotion():
         # Move is a pawn promotion: get rid of the pawn
         # and spawn a new piece
+        self.removePiece(move.targetSquare)
         case move.getPromotionType():
             of PromoteToBishop:
                 self.spawnPiece(move.targetSquare, Piece(kind: Bishop, color: piece.color))
@@ -1628,10 +1628,9 @@ proc doMove(self: ChessBoard, move: Move) =
             of PromoteToQueen:
                 self.spawnPiece(move.targetSquare, Piece(kind: Queen, color: piece.color))
             else:
+                # Unreachable
                 discard
     self.updateAttackedSquares()
-    # TODO: Remove this, once I figure out what the heck is wrong
-    # with updating the board representation
     self.updateBoard()