[#27] check (#59)

* [#27] check

* check - tests

* review fixes

src/controllers/GameController.ts

@@ -36,7 +36,7 @@ class GameController {
 
             if (isLegalMove) {
                 this.playSound(this.activeSquare, square);
-                this.gameEngine.movePiece(this.activeSquare, square);
+                this.gameEngine.movePiece(this.activeSquare, square, false);
                 this.boardView.render(this.gameEngine.board);
                 this.changePlayer();
             }

src/services/game-logic/Board.ts

@@ -11,8 +11,8 @@ import { Queen } from './pieces/Queen';
 class Board {
     public static BOARD_SIZE = 8;
 
-    private state: Array<Array<Piece | null>>;
     private movesHistory: [Piece, Square][] = [];
+    public state: Array<Array<Piece | null>>;
 
     constructor() {
         this.state = new Array(Board.BOARD_SIZE);
@@ -27,9 +27,17 @@ class Board {
         return this.state[square.row][square.column];
     }
 
-    public movePiece(location: Square, destination: Square): void {
+    public checkAllSquares = (callback: any) => {
+        this.state.forEach((row) => {
+            row.forEach((square) => {
+                callback(square);
+            });
+        });
+    };
+
+    public movePiece(location: Square, destination: Square, potentialMove: boolean): void {
         const piece = this.getPiece(location);
-        if (piece) this.movesHistory.push([piece, destination]);
+        if (!potentialMove && piece) this.movesHistory.push([piece, destination]);
 
         this.state[location.row][location.column]?.move(destination);
         this.state[destination.row][destination.column] = this.state[location.row][location.column];

src/services/game-logic/GameEngine.ts

@@ -1,6 +1,7 @@
-import { PieceNames, Constants } from '../../enums';
+import { PieceNames, Constants, Colors } from '../../enums';
 import { Square } from '../../models/Square';
 import { Board } from './Board';
+import { King } from './pieces/King';
 import { Piece } from './pieces/Piece';
 
 class GameEngine {
@@ -12,13 +13,61 @@ class GameEngine {
 
     getLegalMoves = (square: Square): Square[] => {
         const piece = this.board.getPiece(square);
-        let legalMoves = piece?.getPossibleMoves(this.board).filter(this.isOnBoard) ?? [];
+        let legalMoves = piece?.getPossibleMoves(this.board) ?? [];
         if (piece?.name === PieceNames.KING) {
             legalMoves = legalMoves.filter(
                 (move) => !this.isCastling(move, piece) || this.isCastlingLegal(move, piece)
             );
         }
-        return legalMoves.filter((destination) => !this.isOccupiedBySameColor(destination, piece));
+        return legalMoves
+            .filter((destination) => !this.isOccupiedBySameColor(destination, piece))
+            .filter((move) => this.moveNotResultWithCheck(move, piece, square));
+    };
+
+    moveNotResultWithCheck(move: Square, piece: Piece | null, square: Square): boolean {
+        const potentialMove = new Square(move.row, move.column);
+        const potentialPiece = this.board.getPiece(potentialMove);
+
+        this.movePiece(square, potentialMove, true);
+        piece!.hasMoved = true;
+        const isMovePossible = !this.isCheck(piece);
+
+        this.movePiece(potentialMove, square, true);
+        piece!.hasMoved = false;
+
+        if (potentialPiece)
+            this.board.state[potentialPiece.position.row][potentialPiece.position.column] = potentialPiece;
+
+        return isMovePossible;
+    }
+
+    private isCheck(piece: Piece | null): boolean {
+        const color = piece?.color === Colors.BLACK ? Colors.WHITE : Colors.BLACK;
+        let currentPlayerKing = this.getKingForCheck(piece)?.position;
+        const isChecked = this.isKingUnderCheck(color, currentPlayerKing);
+        return isChecked;
+    }
+
+    isKingUnderCheck(color: Colors, piecePosition: Square | undefined): boolean {
+        let checked = false;
+        this.board.checkAllSquares((square: Piece) => {
+            if (square && square.color === color) {
+                checked = square
+                    .getPossibleMoves(this.board)
+                    .some((move) => move.row === piecePosition?.row && move.column === piecePosition.column);
+            }
+        });
+        return checked;
+    }
+
+    getKingForCheck = (piece: Piece | null): King | null => {
+        let king = null;
+        this.board.checkAllSquares((square: Piece) => {
+            if (square && square?.color === piece?.color && square.name === PieceNames.KING) {
+                king = square;
+            }
+        });
+        return king;
     };
 
     public runSpecialRoutines(location: Square, destination: Square): void {
@@ -31,11 +80,11 @@ class GameEngine {
         }
     }
 
-    public movePiece(location: Square, destination: Square): void {
+    public movePiece(location: Square, destination: Square, potentialMove: boolean): void {
         const piece = this.board.getPiece(location);
         if (piece) {
             this.runSpecialRoutines(piece?.position, destination);
-            this.board.movePiece(location, destination);
+            this.board.movePiece(location, destination, potentialMove);
         }
     }
 
@@ -52,12 +101,14 @@ class GameEngine {
         if (destination.column - location.column === Constants.KINGSIDE_CASTLING) {
             this.board.movePiece(
                 { row: location.row, column: Constants.KINGSIDE_ROOK_COLUMN },
-                { row: location.row, column: Constants.KINGSIDE_ROOK_DESTINATION_COLUMN }
+                { row: location.row, column: Constants.KINGSIDE_ROOK_DESTINATION_COLUMN },
+                false
             );
         } else if (destination.column - location.column === Constants.QUEENSIDE_CASTLING) {
             this.board.movePiece(
                 { row: location.row, column: Constants.QUEENSIDE_ROOK_COLUMN },
-                { row: location.row, column: Constants.QUEENSIDE_ROOK_DESTINATION_COLUMN }
+                { row: location.row, column: Constants.QUEENSIDE_ROOK_DESTINATION_COLUMN },
+                false
             );
         }
     }
@@ -87,11 +138,6 @@ class GameEngine {
         return this.getLegalMoves(from).some(({ row, column }) => row === to.row && column === to.column);
     }; // might be useful for 'check'
 
-    private isOnBoard = (square: Square): boolean => {
-        // here or in knight.ts (for now knights can get outside the board)
-        return square.row >= 0 && square.row < 8 && square.column >= 0 && square.column < 8;
-    };
-
     private isOccupiedBySameColor = (square: Square, piece: Piece | null): boolean =>
         this.board.getPiece(square)?.color === piece?.color;
 }

src/services/game-logic/pieces/King.ts

@@ -17,13 +17,16 @@ class King extends Piece {
             [1, -1]
         ];
         if (!this.hasMoved) positions = [...positions, [0, 2], [0, -2]];
-        const [row, column] = positions;
 
         const possibleMoves = positions.map(([row, column]) => ({
             row: this.position.row + row,
             column: this.position.column + column
         }));
-        return possibleMoves;
+
+        const kingPossibleMovesOnBoard = possibleMoves.filter(
+            (move) => move.row >= 0 && move.row < 8 && move.column >= 0 && move.column < 8
+        );
+        return kingPossibleMovesOnBoard;
     }
 }
 

src/services/game-logic/pieces/Knight.ts

@@ -16,7 +16,8 @@ class Knight extends Piece {
             destination.push(new Square(row + possibleRowMoves[i], column + possibleColumnMoves[i]));
         }
 
-        return destination;
+        const knightPossibleMoves = destination.filter((d) => d.row >= 0 && d.row < 8 && d.column >= 0 && d.column < 8);
+        return knightPossibleMoves;
     }
 }
 

test/services/game-logic/Board.test.ts

@@ -18,3 +18,14 @@ describe('Testing Board.setup()', () => {
         });
     });
 });
+
+test(`should run function on all squares`, () => {
+    let arr = [];
+    const board = new Board();
+
+    board.checkAllSquares((square) => {
+        arr.push(square);
+    });
+
+    expect(arr.length).toBe(32);
+});

test/services/game-logic/GameEngine.test.ts

@@ -1,5 +1,10 @@
 import { Square } from '../../../src/models/Square';
 import { GameEngine } from '../../../src/services/game-logic/GameEngine';
+import { Colors } from '../../../src/enums';
+import { Board } from '../../../src/services/game-logic/Board';
+import { King } from '../../../src/services/game-logic/pieces/King';
+
+const gameEngine = new GameEngine();
 
 describe('Testing GameEngine.getLegalMoves() while playing Pawn', () => {
     test(`Pawn shall return 2 capturing moves `, () => {
@@ -16,6 +21,7 @@ describe('Testing GameEngine.getLegalMoves() while playing Pawn', () => {
         // Test
         expect(legalMoves).toEqual(expected);
     });
+
     test(`Extra En Passat move while playing white`, () => {
         // Setup
         const gameEngine = new GameEngine();
@@ -32,6 +38,7 @@ describe('Testing GameEngine.getLegalMoves() while playing Pawn', () => {
         // Test
         expect(legalMoves).toEqual(expected);
     });
+
     test(`White En Passat removes Black Pawn`, () => {
         // Setup
         const gameEngine = new GameEngine();
@@ -49,3 +56,32 @@ describe('Testing GameEngine.getLegalMoves() while playing Pawn', () => {
         expect(removedPiece).toBe(null);
     });
 });
+
+test(`should target king`, () => {
+    const piece = gameEngine.board.getPiece(new Square(1, 4));
+    const king = gameEngine.getKingForCheck(piece);
+    const expected = new Square(0, 4);
+
+    expect(king instanceof King).toBe(true);
+    expect(king.position).toStrictEqual(expected);
+});
+
+test(`should return true when check`, () => {
+    const color = Colors.BLACK;
+    const piece = new King({ column: 7, row: 3 }, Colors.WHITE);
+
+    const isKingChecked = gameEngine.isKingUnderCheck(color, piece.position);
+
+    expect(isKingChecked).toBe(true);
+});
+
+test(`should verify if oponent move result with check`, () => {
+    const board = new Board();
+    const square = { row: 6, column: 3 };
+    const move = new Square(4, 3);
+    const piece = board.getPiece(square);
+
+    const notCheck = gameEngine.moveNotResultWithCheck(move, piece, square);
+
+    expect(notCheck).toBe(true);
+});

test/services/game-logic/pieces/Knight.test.ts

@@ -3,35 +3,12 @@ import { Square } from '../../../../src/models/Square';
 import { Knight } from '../../../../src/services/game-logic/pieces/Knight';
 
 test.each([
-    [
-        Colors.WHITE,
-        7,
-        5,
-        [
-            new Square(9, 6),
-            new Square(8, 7),
-            new Square(6, 7),
-            new Square(5, 6),
-            new Square(5, 4),
-            new Square(6, 3),
-            new Square(8, 3),
-            new Square(9, 4)
-        ]
-    ],
+    [Colors.WHITE, 7, 5, [new Square(6, 7), new Square(5, 6), new Square(5, 4), new Square(6, 3)]],
     [
         Colors.BLACK,
         3,
         6,
-        [
-            new Square(5, 7),
-            new Square(4, 8),
-            new Square(2, 8),
-            new Square(1, 7),
-            new Square(1, 5),
-            new Square(2, 4),
-            new Square(4, 4),
-            new Square(5, 5)
-        ]
+        [new Square(5, 7), new Square(1, 7), new Square(1, 5), new Square(2, 4), new Square(4, 4), new Square(5, 5)]
     ]
 ])(
     'should return knights possible moves',