fix!: correct hash increment in make_move

1 files changed, 13 insertions, 9 deletions

diff --git a/src/board/mod.rs b/src/board/mod.rs
index 84d77fb..8dbf476 100644
--- a/src/board/mod.rs
+++ b/src/board/mod.rs
@@ -503,7 +503,7 @@ impl Board {
         let mut captured_piece = match self.piece_by_square(mov.target) {
             Some(target_piece) => {
                 self.pieces[target_piece as usize] ^= move_target_bb;
-                self.hash ^= self.zobrist_seed[(target_piece as usize) * 12 + mov.target as usize];
+                self.hash ^= self.zobrist_seed[(target_piece as usize) * 64 + mov.target as usize];
                 Some(target_piece)
             },
             None => None,
@@ -516,7 +516,7 @@ impl Board {
             captured_piece = match self.piece_by_square(captured_square) {
                 Some(pawn_type) => {
                     self.pieces[pawn_type as usize] ^= captured_square.to_bitboard();
-                    self.hash ^= self.zobrist_seed[pawn_type as usize* 12 + captured_square as usize];
+                    self.hash ^= self.zobrist_seed[pawn_type as usize* 64 + captured_square as usize];
                     Some(pawn_type)
                 },
                 None => panic!("Pawn captured by En Passant was not found"),
@@ -529,11 +529,11 @@ impl Board {
                 let source_id = source_piece as usize;
                 self.pieces[source_id] ^= move_source_bb;
                 self.occupancy            ^= move_source_bb;
-                self.hash                 ^= self.zobrist_seed[source_id * 12 + mov.source as usize];
+                self.hash                 ^= self.zobrist_seed[source_id * 64 + mov.source as usize];
 
                 self.pieces[source_id] |= move_target_bb;
                 self.occupancy            |= move_target_bb;
-                self.hash                 ^= self.zobrist_seed[source_id * 12 + mov.target as usize];
+                self.hash                 ^= self.zobrist_seed[source_id * 64 + mov.target as usize];
                 PieceType::from(source_piece)
             },
             None => {
@@ -561,11 +561,11 @@ impl Board {
                     let rook_id = rook_type as usize;
                     self.pieces[rook_id] ^= rook_source_bb;
                     self.occupancy         ^= rook_source_bb;
-                    self.hash              ^= self.zobrist_seed[rook_id * 12 + rook_source_square as usize];
+                    self.hash              ^= self.zobrist_seed[rook_id * 64 + rook_source_square as usize];
 
                     self.pieces[rook_id] |= rook_target_bb;
                     self.occupancy         |= rook_target_bb;
-                    self.hash              ^= self.zobrist_seed[rook_id * 12 + rook_target_square as usize];
+                    self.hash              ^= self.zobrist_seed[rook_id * 64 + rook_target_square as usize];
                 },
                 None => panic!("Rook was not found when castling"),
             }
@@ -838,13 +838,17 @@ mod tests {
         let black_move = Move { source: Square::F7, target: Square::F5, kind: MoveKind::Quiet };
         println!("\n{:?}", black_move);
 
-        match board.make_move(black_move).unwrap() {
+        match board.make_move(black_move) {
             Some(..) => panic!("No piece should be captured"),
             None => {},
         };
 
         board.print();
 
+        let hash = board.hash;
+        board.update_zobrist_hash();
+        assert_eq!(hash, board.hash, "Hash should be correctly updated after move");
+
         assert!(board.pieces[PieceType::PawnBlack as usize] & Square::F7.to_bitboard() == 0);
         assert!(board.pieces[PieceType::PawnBlack as usize] & Square::F5.to_bitboard() > 0);
         assert!(board.ply == 1);
@@ -852,7 +856,7 @@ mod tests {
         let white_move = Move { source: Square::D2, target: Square::A5, kind: MoveKind::Capture };
         println!("\n{:?}", white_move);
 
-        match board.make_move(white_move).unwrap() {
+        match board.make_move(white_move) {
             Some(captured) => assert!(captured == PieceType::PawnBlack),
             None => panic!("A piece should be captured"),
         };
@@ -876,7 +880,7 @@ mod tests {
 
         board.print();
 
-        let captured_piece = board.make_move(mov).unwrap();
+        let captured_piece = board.make_move(mov);
         board.print();
 
         board.unmake_move(mov, captured_piece, None, board.castling_rights, initial_board.hash);