Added test for the starting position

src/Chess/board.nim

@@ -72,41 +72,35 @@ for _ in countup(0, 63):
     empty.add(Piece(kind: Empty, color: None))
 
 
-proc algebraicToPosition(s: string): Location {.inline.} =
+func rankToColumn(rank: int): int =
+    ## Converts a chess rank (1-indexed) 
+    ## into a 0-indexed column value for our 
+    ## board. This converter is necessary because
+    ## chess positions are indexed differently with
+    ## respect to our internal representation
+    const indeces = [7, 6, 5, 4, 3, 2, 1, 0]
+    return indeces[rank - 1]
+
+
+proc algebraicToPosition*(s: string): Location {.inline.} =
     ## Converts a square location from algebraic
     ## notation to its corresponding row and column
     ## in the chess grid (0 indexed)
     if len(s) != 2:
         raise newException(ValueError, "algebraic position must be of length 2")
-    var s = s.toLowerAscii()
 
+    var s = s.toLowerAscii()
     if s[0] notin 'a'..'h':
         raise newException(ValueError, &"algebraic position has invalid first character ('{s[0]}')")
     if s[1] notin '1'..'8':
         raise newException(ValueError, &"algebraic position has invalid second character ('{s[1]}')")
+
     let file = int(uint8(s[0]) - uint8('a'))
-    var rank: int
-    case s[1]:
-        of '1':
-            rank = 7
-        of '2':
-            rank = 6
-        of '3':
-            rank = 5
-        of '4':
-            rank = 4
-        of '5':
-            rank = 3
-        of '6':
-            rank = 2
-        of '7':
-            rank = 1
-        of '8':
-            rank = 0
-        else:
-            discard
+    # Convert the rank character to a number
+    let rank = rankToColumn(int(uint8(s[1]) - uint8('0')))
     return (rank, file)
 
+
 proc getPiece*(self: ChessBoard, square: string): Piece =
     ## Gets the piece on the given square
     ## in algebraic notation
@@ -116,16 +110,20 @@ proc getPiece*(self: ChessBoard, square: string): Piece =
 
 proc `$`*(self: ChessBoard): string =
     result &= "- - - - - - - -"
-    for row in self.grid:
+    #const indeces = [7, 6, 5, 4, 3, 2, 1, 0]
+    for i, row in self.grid:
         result &= "\n"
         for piece in row:
             if piece.kind == Empty:
                 result &= "  "
+                continue
             if piece.color == White:
                 result &= &"{char(piece.kind).toUpperAscii()} "
             else:
                 result &= &"{char(piece.kind)} "
+        result &= &"{rankToColumn(i + 1) + 1}"
     result &= "\n- - - - - - - -"
+    result &= "\na b c d e f g h"
 
 
 proc newChessboard: ChessBoard =
@@ -325,4 +323,39 @@ proc newChessboardFromFEN*(state: string): ChessBoard =
 proc newDefaultChessboard*: ChessBoard =
     ## Initializes a chessboard with the
     ## starting position
-    return newChessboardFromFEN("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")
+    return newChessboardFromFEN("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")
+
+
+when isMainModule:
+    proc testPiece(piece: Piece, kind: PieceKind, color: PieceColor) =
+        doAssert piece.kind == kind and piece.color == color, &"expected piece of kind {kind} and color {color}, got {piece.kind} / {piece.color} instead"
+
+    echo "Running tests"
+    var b = newDefaultChessboard()
+    # Ensure pawns are in the correct location
+    for loc in ["a2", "b2", "c2", "d2", "e2", "f2", "g2", "h2"]:
+        testPiece(b.getPiece(loc), Pawn, White)
+    for loc in ["a7", "b7", "c7", "d7", "e7", "f7", "g7", "h7"]:
+        testPiece(b.getPiece(loc), Pawn, Black)
+    # Rooks
+    testPiece(b.getPiece("a1"), Rook, White)
+    testPiece(b.getPiece("h1"), Rook, White)
+    testPiece(b.getPiece("a8"), Rook, Black)
+    testPiece(b.getPiece("h8"), Rook, Black)
+    # Knights
+    testPiece(b.getPiece("b1"), Knight, White)
+    testPiece(b.getPiece("g1"), Knight, White)
+    testPiece(b.getPiece("b8"), Knight, Black)
+    testPiece(b.getPiece("g8"), Knight, Black)
+    # Bishops
+    testPiece(b.getPiece("c1"), Bishop, White)
+    testPiece(b.getPiece("f1"), Bishop, White)
+    testPiece(b.getPiece("c8"), Bishop, Black)
+    testPiece(b.getPiece("f8"), Bishop, Black)
+    # Kings
+    testPiece(b.getPiece("e1"), King, White)
+    testPiece(b.getPiece("e8"), King, Black)
+    # Queens
+    testPiece(b.getPiece("d1"), Queen, White)
+    testPiece(b.getPiece("d8"), Queen, Black)
+    echo "All tests were successful"

src/Chess/player.nim

@@ -1,10 +1,7 @@
-import board
+import board as chess
 
 
-var b = newDefaultChessboard()
-echo b
-echo b.getPiece("a2")
-echo b.getPiece("a7")
-echo b.getPiece("a1")
-echo b.getPiece("a8")
+var board = newDefaultChessboard()
+echo board
+