chess/board_castling_test.go

@@ -7,6 +7,76 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func Test_Board_WhiteCastlesLeft(t *testing.T) {
+	board := newBoard()
+
+	board.position[types.Coordinate{Col: 5, Row: 1}] = King{Color: types.White}
+	board.position[types.Coordinate{Col: 1, Row: 1}] = Rook{Color: types.White}
+
+	castling := types.Move{
+		StartSquare: types.Coordinate{Col: 5, Row: 1},
+		EndSquare:   types.Coordinate{Col: 3, Row: 1},
+		ColorMoved:  types.White,
+	}
+
+	valid, _ := board.CheckAndPlay(&castling)
+
+	assert.True(t, valid)
+}
+
+func Test_Board_WhiteCastlesRight(t *testing.T) {
+	board := newBoard()
+
+	board.position[types.Coordinate{Col: 5, Row: 1}] = King{Color: types.White}
+	board.position[types.Coordinate{Col: 8, Row: 1}] = Rook{Color: types.White}
+
+	castling := types.Move{
+		StartSquare: types.Coordinate{Col: 5, Row: 1},
+		EndSquare:   types.Coordinate{Col: 7, Row: 1},
+		ColorMoved:  types.White,
+	}
+
+	valid, _ := board.CheckAndPlay(&castling)
+
+	assert.True(t, valid)
+}
+
+func Test_Board_BlackCastlesLeft(t *testing.T) {
+	board := newBoard()
+	board.colorToMove = types.Black
+
+	board.position[types.Coordinate{Col: 5, Row: 8}] = King{Color: types.Black}
+	board.position[types.Coordinate{Col: 1, Row: 8}] = Rook{Color: types.Black}
+
+	castling := types.Move{
+		StartSquare: types.Coordinate{Col: 5, Row: 8},
+		EndSquare:   types.Coordinate{Col: 3, Row: 8},
+		ColorMoved:  types.Black,
+	}
+
+	valid, _ := board.CheckAndPlay(&castling)
+
+	assert.True(t, valid)
+}
+
+func Test_Board_BlackCastlesRight(t *testing.T) {
+	board := newBoard()
+	board.colorToMove = types.Black
+
+	board.position[types.Coordinate{Col: 5, Row: 8}] = King{Color: types.Black}
+	board.position[types.Coordinate{Col: 8, Row: 8}] = Rook{Color: types.Black}
+
+	castling := types.Move{
+		StartSquare: types.Coordinate{Col: 5, Row: 8},
+		EndSquare:   types.Coordinate{Col: 7, Row: 8},
+		ColorMoved:  types.Black,
+	}
+
+	valid, _ := board.CheckAndPlay(&castling)
+
+	assert.True(t, valid)
+}
+
 func Test_Board_WhiteCastlesLeft_QueenCoversSquareInBetween(t *testing.T) {
 	board := newBoard()
 
@@ -156,3 +226,73 @@ func Test_Board_BlackCastlesLeft_QueenCoversKingsSquare(t *testing.T) {
 
 	assert.False(t, valid)
 }
+
+func Test_Board_WhiteCastlesLeft_NoRook(t *testing.T) {
+	board := newBoard()
+
+	board.position[types.Coordinate{Col: 5, Row: 1}] = King{Color: types.White}
+
+	castling := types.Move{
+		StartSquare: types.Coordinate{Col: 5, Row: 1},
+		EndSquare:   types.Coordinate{Col: 3, Row: 1},
+		ColorMoved:  types.White,
+	}
+
+	valid, _ := board.CheckAndPlay(&castling)
+
+	assert.False(t, valid)
+}
+
+func Test_Board_WhiteCastlesRight_NoRook(t *testing.T) {
+	board := newBoard()
+
+	board.position[types.Coordinate{Col: 5, Row: 1}] = King{Color: types.White}
+
+	castling := types.Move{
+		StartSquare: types.Coordinate{Col: 5, Row: 1},
+		EndSquare:   types.Coordinate{Col: 7, Row: 1},
+		ColorMoved:  types.White,
+	}
+
+	valid, _ := board.CheckAndPlay(&castling)
+
+	assert.False(t, valid)
+}
+
+func Test_Board_BlackCastlesLeft_NoRook(t *testing.T) {
+	board := newBoard()
+	board.colorToMove = types.Black
+
+	kingSquare := types.Coordinate{Col: 5, Row: 8}
+	kingDestinationSquare := types.Coordinate{Col: 3, Row: 8}
+
+	board.position[kingSquare] = King{Color: types.Black}
+
+	castling := types.Move{
+		StartSquare: kingSquare,
+		EndSquare:   kingDestinationSquare,
+		ColorMoved:  types.Black,
+	}
+
+	valid, _ := board.CheckAndPlay(&castling)
+
+	assert.False(t, valid)
+	assert.Equal(t, nil, board.getPieceAt(kingDestinationSquare))
+}
+
+func Test_Board_BlackCastlesRight_NoRook(t *testing.T) {
+	board := newBoard()
+	board.colorToMove = types.Black
+
+	board.position[types.Coordinate{Col: 5, Row: 8}] = King{Color: types.Black}
+
+	castling := types.Move{
+		StartSquare: types.Coordinate{Col: 5, Row: 8},
+		EndSquare:   types.Coordinate{Col: 7, Row: 8},
+		ColorMoved:  types.Black,
+	}
+
+	valid, _ := board.CheckAndPlay(&castling)
+
+	assert.False(t, valid)
+}

chess/king.go

@@ -80,8 +80,11 @@ func (k King) isCastlingAllowed(b *Board, move types.Move) (bool, CastlingDirect
 			!b.isSquareAttacked(destinationSquareForKingRight, types.Black) &&
 			!b.isSquareAttacked(*destinationSquareForKingRight.Left(1), types.Black) &&
 			!b.state.WhiteHRookMoved {
+			_, ok := b.getPieceAt(types.Coordinate{Col: 8, Row: 1}).(Rook)
+			if ok {
 				return true, CastlingRight
 			}
+		}
 
 		if move.EndSquare == destinationSquareForKingLeft &&
 			b.getPieceAt(destinationSquareForKingLeft) == nil &&
@@ -90,8 +93,11 @@ func (k King) isCastlingAllowed(b *Board, move types.Move) (bool, CastlingDirect
 			!b.isSquareAttacked(destinationSquareForKingLeft, types.Black) &&
 			!b.isSquareAttacked(*destinationSquareForKingLeft.Right(1), types.Black) &&
 			!b.state.WhiteARookMoved {
+			_, ok := b.getPieceAt(types.Coordinate{Col: 1, Row: 1}).(Rook)
+			if ok {
 				return true, CastlingLeft
 			}
+		}
 	case types.Black:
 		destinationSquareForKingRight := types.Coordinate{Col: 7, Row: 8}
 		destinationSquareForKingLeft := types.Coordinate{Col: 3, Row: 8}
@@ -102,8 +108,11 @@ func (k King) isCastlingAllowed(b *Board, move types.Move) (bool, CastlingDirect
 			!b.isSquareAttacked(destinationSquareForKingRight, types.White) &&
 			!b.isSquareAttacked(*destinationSquareForKingRight.Left(1), types.White) &&
 			!b.state.BlackHRookMoved {
+			_, ok := b.getPieceAt(types.Coordinate{Col: 8, Row: 8}).(Rook)
+			if ok {
 				return true, CastlingRight
 			}
+		}
 
 		if move.EndSquare == destinationSquareForKingLeft &&
 			b.getPieceAt(destinationSquareForKingLeft) == nil &&
@@ -112,9 +121,12 @@ func (k King) isCastlingAllowed(b *Board, move types.Move) (bool, CastlingDirect
 			!b.isSquareAttacked(destinationSquareForKingLeft, types.White) &&
 			!b.isSquareAttacked(*destinationSquareForKingLeft.Right(1), types.White) &&
 			!b.state.BlackARookMoved {
+			_, ok := b.getPieceAt(types.Coordinate{Col: 1, Row: 8}).(Rook)
+			if ok {
 				return true, CastlingLeft
 			}
 		}
+	}
 	return valid, NoDirection
 }