Merge pull request #18 from thearst3rd/better-uci

Improve UCI position command support

communication.py

@@ -14,7 +14,6 @@ def talk():
 
     while True:
         msg = input()
-        print(f">>> {msg}", file=sys.stderr)
         command(depth, board, msg)
 
 
@@ -23,6 +22,11 @@ def command(depth: int, board: chess.Board, msg: str):
     Accept UCI commands and respond.
     The board state is also updated.
     """
+    msg = msg.strip()
+    tokens = msg.split(" ")
+    while "" in tokens:
+        tokens.remove("")
+
     if msg == "quit":
         sys.exit()
 
@@ -39,18 +43,32 @@ def command(depth: int, board: chess.Board, msg: str):
     if msg == "ucinewgame":
         return
 
-    if "position startpos moves" in msg:
-        moves = msg.split(" ")[3:]
-        board.clear()
-        board.set_fen(chess.STARTING_FEN)
-        for move in moves:
-            board.push(chess.Move.from_uci(move))
-        return
+    if msg.startswith("position"):
+        if len(tokens) < 2:
+            return
 
-    if "position fen" in msg:
-        fen = " ".join(msg.split(" ")[2:])
-        board.set_fen(fen)
-        return
+        # Set starting position
+        if tokens[1] == "startpos":
+            board.reset()
+            moves_start = 2
+        elif tokens[1] == "fen":
+            fen = " ".join(tokens[2:8])
+            board.set_fen(fen)
+            moves_start = 8
+        else:
+            return
+
+        # Apply moves
+        if len(tokens) <= moves_start or tokens[moves_start] != "moves":
+            return
+
+        for move in tokens[(moves_start+1):]:
+            board.push_uci(move)
+
+    if msg == "d":
+        # Non-standard command, but supported by Stockfish and helps debugging
+        print(board)
+        print(board.fen())
 
     if msg[0:2] == "go":
         _move = next_move(depth, board)

movegeneration.py

@@ -19,7 +19,7 @@ def next_move(depth: int, board: chess.Board, debug=True) -> chess.Move:
 
     debug_info["time"] = time.time() - t0
     if debug == True:
-        print(f">>> {debug_info}", file=sys.stderr)
+        print(f"info {debug_info}")
     return move
 
 

test/test_engine.py

@@ -17,16 +17,54 @@ def test_uci_command(self):
             self.assertEqual(len(lines), 3)
             self.assertEqual(lines[2], "uciok")
 
-    def test_startpos_command(self):
+    def test_position_startpos_command(self):
         """
-        Test position command setup a board one that has received one half-move
+        Test position command setup a board using identifier 'startpos'
         """
         board = chess.Board()
+
+        # Startpos and moves
         command(3, board, "position startpos moves e2e4")
         self.assertEqual(
             board.fen(), "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1"
         )
 
+        # Just startpos
+        command(3, board, "position startpos")
+        self.assertEqual(
+            board.fen(), "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
+        )
+
+        # Arbitrary whitespace
+        command(3, board, "   position  startpos   moves  e2e4 d7d5  e4d5   ")
+        self.assertEqual(
+            board.fen(), "rnbqkbnr/ppp1pppp/8/3P4/8/8/PPPP1PPP/RNBQKBNR b KQkq - 0 2"
+        )
+
+        # Token 'moves' but no moves
+        command(3, board, "position startpos moves")
+        self.assertEqual(
+            board.fen(), "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
+        )
+
+    def test_position_fen_command(self):
+        """
+        Test position command setup a board using fen string
+        """
+        board = chess.Board()
+
+        # Just fen
+        command(3, board, "position fen rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 2")
+        self.assertEqual(
+            board.fen(), "rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 2"
+        )
+
+        # Fen and moves
+        command(3, board, "position fen rnbqkbnr/pp2pppp/3p4/2p5/3PP3/5N2/PPP2PPP/RNBQKB1R b KQkq - 0 3 moves c5d4 f3d4 g7g6")
+        self.assertEqual(
+            board.fen(), "rnbqkbnr/pp2pp1p/3p2p1/8/3NP3/8/PPP2PPP/RNBQKB1R w KQkq - 0 5"
+        )
+
     def test_go_command_black(self):
         """
         Test go command with Andoma playing with black pieces
@@ -41,7 +79,7 @@ def test_go_command_black(self):
             command(3, board, "go")
 
             # black bishop should take a undefended rook
-            self.assertEqual(patched_output.getvalue().strip(), "bestmove d4b6")
+            self.assertEqual(patched_output.getvalue().splitlines()[1], "bestmove d4b6")
 
         board = chess.Board()
         with patch("sys.stdout", new=StringIO()) as patched_output:
@@ -53,7 +91,7 @@ def test_go_command_black(self):
             command(3, board, "go")
 
             # black will trade a bishop for a queen
-            self.assertEqual(patched_output.getvalue().strip(), "bestmove g7c3")
+            self.assertEqual(patched_output.getvalue().splitlines()[1], "bestmove g7c3")
 
         board = chess.Board()
         with patch("sys.stdout", new=StringIO()) as patched_output:
@@ -65,7 +103,7 @@ def test_go_command_black(self):
             command(3, board, "go")
 
             # black will threaten a bishop with a pawn (a very strong but not instantly obvious move)
-            self.assertEqual(patched_output.getvalue().strip(), "bestmove c5c4")
+            self.assertEqual(patched_output.getvalue().splitlines()[1], "bestmove c5c4")
 
     def test_go_command_white(self):
         """
@@ -79,7 +117,7 @@ def test_go_command_white(self):
             command(3, board, "go")
 
             # white bishop should take a undefended rook
-            self.assertEqual(patched_output.getvalue().strip(), "bestmove b3g8")
+            self.assertEqual(patched_output.getvalue().splitlines()[1], "bestmove b3g8")
 
         board = chess.Board()
         with patch("sys.stdout", new=StringIO()) as patched_output:
@@ -91,7 +129,7 @@ def test_go_command_white(self):
             command(3, board, "go")
 
             # white will trade a bishop for a queen
-            self.assertEqual(patched_output.getvalue().strip(), "bestmove b2g7")
+            self.assertEqual(patched_output.getvalue().splitlines()[1], "bestmove b2g7")
 
         board = chess.Board()
         with patch("sys.stdout", new=StringIO()) as patched_output:
@@ -103,7 +141,7 @@ def test_go_command_white(self):
             command(3, board, "go")
 
             # white will threaten a bishop with a pawn (a very strong but not instantly obvious move)
-            self.assertEqual(patched_output.getvalue().strip(), "bestmove f4f5")
+            self.assertEqual(patched_output.getvalue().splitlines()[1], "bestmove f4f5")
 
     def test_draw(self):
         """
@@ -119,4 +157,4 @@ def test_draw(self):
             command(3, board, "go")
 
             # bot is in a favorable position, should avoid threefold repetition
-            self.assertNotEqual(patched_output.getvalue().strip(), "bestmove c6a8")
+            self.assertNotEqual(patched_output.getvalue().splitlines()[1], "bestmove c6a8")