is_move_valid should be complete(-ish) and tested

board.py

@@ -23,6 +23,14 @@ class Board:
     # bar. A fix of this is of course to check if the from_idx = bar and if so,
     # allow some extra stuff!
 
+    @staticmethod
+    def idxs_with_checkers_of_player(board, player):
+        idxs = []
+        for idx, checker_count in enumerate(board):
+            if checker_count * player >= 1:
+                idxs.append(idx)
+        return idxs
+
     # TODO: write tests
     # FIXME: make sure to disallow backwards movement
     # TODO: implement double roll feature (4 dice if dice are equal)
@@ -43,7 +51,8 @@ class Board:
         delta      = to_idx - from_idx
         direction  = sign(delta)
         bearing_off = None
-        
+
+        # FIXME: Use get instead of array-like indexing
         if to_idx >= 1 and to_idx <= 24:
             to_state   = board[to_idx]
             bearing_off = False
@@ -85,8 +94,24 @@ class Board:
                 return True
 
         def can_bear_off():
+            checker_idxs = Board.idxs_with_checkers_of_player(board, player)
+            def is_moving_backmost_checker():
+                if player == 1:
+                    return all([(idx >= from_idx) for idx in checker_idxs])
+                else:
+                    return all([(idx <= from_idx) for idx in checker_idxs])
+
+            def all_checkers_in_last_quadrant():
+                if player == 1:
+                    return all([(idx >= 19) for idx in checker_idxs])
+                else:
+                    return all([(idx >= 6) for idx in checker_idxs])
+
+            return all([ is_moving_backmost_checker(),
+                         all_checkers_in_last_quadrant() ])
+                
             # TODO
-            return True
+            # TODO: add switch here instead of wonky ternary in all        
 
             
         return all([ is_forward_move(),
@@ -94,15 +119,12 @@ class Board:
                      bear_in_if_checker_on_bar(),
                      checkers_at_from_idx(),
                      no_block_at_to_idx(),
-                     can_bear_off() if bearing_off else True])
+                     can_bear_off() if bearing_off else True ])
     
     @staticmethod
     def is_winner(board, player):
-        for i in range(1,25):
+        return Board.idxs_with_checkers_of_player(board, player) == []
-            if player * board[i] > 0:
+    
-                return False
-        return True
-        
     @staticmethod
     def calculate_legal_states(board, player, roll):
         # Find all pips with things on them belonging to the player
@@ -114,25 +136,18 @@ class Board:
         # TODO: make sure that it is not possible to do nothing on first part of
         #       turn and then do something with the second die
         print("Find legal moves: ",roll,"-"*20)
-
-        def idxs_with_checkers_of_current_player(board):
-            idxs = []
-            for idx, checker_count in enumerate(board):
-                if checker_count * player >= 1:
-                    idxs.append(idx)
-                return idxs
         
         def calc_moves(board, face_value):
-            idxs_with_checkers = idxs_with_checkers_of_current_player(board)
+            idxs_with_checkers = Board.idxs_with_checkers_of_player(board, player)
             boards = [(do_move(board,
                                player,
-                               (idx, idx + (face_value * player))) if
+                               (idx, idx + (face_value * player)))
-                       is_move_valid(board,
+                       if is_move_valid(board,
-                            player,
+                                        player,
-                            face_value,
+                                        face_value,
-                            (idx, idx + (face_value * player))) else None)
+                                        (idx, idx + (face_value * player)))
-             for idx
+                       else None)
-             in idxs_with_checkers]
+                      for idx in idxs_with_checkers]
 
             # If no move can be made, make sure to include current board
             if is_move_valid(board, player, face_value, None):
@@ -152,7 +167,7 @@ class Board:
             # Calculate boards resulting from first move
             boards = calc_moves(board, pair[0])
 
-            for x in dice_permutations[1:None]:
+            for x in dice_permutations[1:]:
                 # Calculate boards resulting from second move
                 nested_boards = [calc_moves(board, x) for board in boards]
                 boards = [board for boards in nested_boards for board in boards]

test.py

@@ -2,21 +2,21 @@ import unittest
 from board import Board
 
 class TestIsMoveValid(unittest.TestCase):
+    def setUp(self):
+        self.initial = Board.initial_state
+
     
     def test_simple_movement(self):
-        board = Board.initial_state
+        self.assertEqual(Board.is_move_valid(self.initial,  1, 2, (1, 3)), True)    # White
-        self.assertEqual(Board.is_move_valid(board,  1, 2, (1, 3)), True)    # White
+        self.assertEqual(Board.is_move_valid(self.initial, -1, 3, (24, 21)), True) # Black
-        self.assertEqual(Board.is_move_valid(board, -1, 3, (24, 21)), True) # Black
 
     def test_backwards_movement_invalid(self):
-        board = Board.initial_state
+        self.assertEqual(Board.is_move_valid(self.initial,  1, 2, (12, 10)), False)
-        self.assertEqual(Board.is_move_valid(board,  1, 2, (12, 10)), False)
+        self.assertEqual(Board.is_move_valid(self.initial, -1, 3, (8, 11)), False)
-        self.assertEqual(Board.is_move_valid(board, -1, 3, (8, 11)), False)
 
     def test_face_value_match_move_length(self):
-        board = Board.initial_state
+        self.assertEqual(Board.is_move_valid(self.initial, 1, 2, (1, 3)), True)
-        self.assertEqual(Board.is_move_valid(board, 1, 2, (1, 3)), True)
+        self.assertEqual(Board.is_move_valid(self.initial, 1, 2, (1, 4)), False)
-        self.assertEqual(Board.is_move_valid(board, 1, 2, (1, 4)), False)
 
     def test_bear_in(self):
         board = [ 1,
@@ -57,16 +57,14 @@ class TestIsMoveValid(unittest.TestCase):
 
         
     def test_owned_checker_at_from(self):
-        board = Board.initial_state
+        self.assertEqual(Board.is_move_valid(self.initial,  1, 2, (3, 5)), False)     # No checkers
-        self.assertEqual(Board.is_move_valid(board,  1, 2, (3, 5)), False)     # No checkers
+        self.assertEqual(Board.is_move_valid(self.initial, -1, 2, (23, 21)), False)  # No checkers
-        self.assertEqual(Board.is_move_valid(board, -1, 2, (23, 21)), False)  # No checkers
+        self.assertEqual(Board.is_move_valid(self.initial,  1, 2, (8, 10)), False)    # Opponent checkers
-        self.assertEqual(Board.is_move_valid(board,  1, 2, (8, 10)), False)    # Opponent checkers
+        self.assertEqual(Board.is_move_valid(self.initial, -1, 2, (1, 3)), False)    # Opponent checkers
-        self.assertEqual(Board.is_move_valid(board, -1, 2, (1, 3)), False)    # Opponent checkers
         
     def test_no_block_at_to(self):
-        board = Board.initial_state
+        self.assertEqual(Board.is_move_valid(self.initial,  1, 5, (1, 6)), False)
-        self.assertEqual(Board.is_move_valid(board,  1, 5, (1, 6)), False)
+        self.assertEqual(Board.is_move_valid(self.initial, -1, 5, (24, 19)), False)
-        self.assertEqual(Board.is_move_valid(board, -1, 5, (24, 19)), False)
 
     def test_able_to_hit_opponent_checkers(self):
         board = [ 0,
@@ -88,7 +86,138 @@ class TestIsMoveValid(unittest.TestCase):
         self.assertEqual(Board.is_move_valid(board, 1, 2, (24, 26)), True)
         self.assertEqual(Board.is_move_valid(board, 1, 1, (24, 25)), True)
 
+
+    def test_bear_off_with_higher_face_value(self):
+        board = [ 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 1, 1, 0,
+                  0 ]
+        self.assertEqual(Board.is_move_valid(board, 1, 5, (23, 28)), False)
+        self.assertEqual(Board.is_move_valid(board, 1, 5, (22, 27)), True)
+
+    def test_bear_off_all_in_last_quadrant(self):
+        board = [ 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 1, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 1,
+                  0 ]
+        self.assertEqual(Board.is_move_valid(board, 1, 1, (24, 25)), False)
+        board = [ 1,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 1,
+                  0 ]
+        self.assertEqual(Board.is_move_valid(board, 1, 1, (24, 25)), False)
+
+        board = [ 0,
+                  -1, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  -1 ]
+        self.assertEqual(Board.is_move_valid(board, -1, 1, (1, 0)), False)
+        board = [ 0,
+                  -1, 0, 0, 0, 0, 0,
+                  0, 0, 0, -1, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0 ]
+        self.assertEqual(Board.is_move_valid(board, -1, 1, (1, 0)), False)
+        
     # TODO: More tests for bearing off are needed
+
+
+class TestIsWinner(unittest.TestCase):
+    def test_is_winner(self):
+        board = [ 0,
+                  2, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 5,
+                  0, 0, 0, 0, 3, 0,
+                  4, 0, 1, 0, 0, 0,
+                  0 ]
+        self.assertEqual(Board.is_winner(board, 1), False)
+        self.assertEqual(Board.is_winner(board, -1), True)
+
+        board = [ 0,
+                  0, 0, 0, -1, 0, -4,
+                  0, -3, 0, 0, 0, 0,
+                  -5, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, -2,
+                  0 ]
+        self.assertEqual(Board.is_winner(board, 1), True)
+        self.assertEqual(Board.is_winner(board, -1), False)
+        
+class TestDoMove(unittest.TestCase):
+    def test_simple_move(self):
+        board = [ 0,
+                  2, 0, -1, 0, 0, 0,
+                  0, 0, 0, 0, 0, 5,
+                  0, 0, 0, 0, 3, 0,
+                  4, 0, 1, 0, 0, 0,
+                  0 ]
+        expected_board = [ 0,
+                           2, -1, 0, 0, 0, 0,
+                           0, 0, 0, 0, 0, 5,
+                           0, 0, 0, 0, 3, 0,
+                           4, 0, 1, 0, 0, 0,
+                           0 ]
+        self.assertEqual(Board.do_move(board, -1, (3, 2)), expected_board)
+
+    def test_bear_in(self):
+        board = [ 1,
+                  1, 0, 0, 0, 0, -5,
+                  0, -3, 0, 0, 0, 5,
+                  -5, 0, 0, 0, 3, 0,
+                  5, 0, 0, 0, 0, -2,
+                  0 ]
+        expected_board = [ 0,
+                           2, 0, 0, 0, 0, -5,
+                           0, -3, 0, 0, 0, 5,
+                           -5, 0, 0, 0, 3, 0,
+                           5, 0, 0, 0, 0, -2,
+                           0 ]
+        self.assertEqual(Board.do_move(board, 1, (0, 1)), expected_board)
+
+        board = [ 0,
+                  2, 0, 0, 0, 0, -5,
+                  0, -3, 0, 0, 0, 5,
+                  -5, 0, 0, 0, 3, 0,
+                  5, 0, 0, 0, 0, -1,
+                  -1 ]
+        expected_board = [ 0,
+                           2, 0, 0, 0, 0, -5,
+                           0, -3, 0, 0, 0, 5,
+                           -5, 0, 0, 0, 3, 0,
+                           5, 0, 0, 0, 0, -2,
+                           0 ]
+        self.assertEqual(Board.do_move(board, -1, (25, 24)), expected_board)
+        
+    def test_bear_off(self):
+        board = [ 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 1,
+                  0 ]
+        expected_board = [0] * 26
+        self.assertEqual(Board.do_move(board, 1, (24, 30)), expected_board)
+        self.assertEqual(Board.do_move(board, 1, (24, 26)), expected_board)
+        self.assertEqual(Board.do_move(board, 1, (24, 25)), expected_board)
+
+        board = [ 0,
+                  -1, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0, 0, 0, 0, 0, 0,
+                  0 ]
+        expected_board = [0] * 26
+        self.assertEqual(Board.do_move(board, -1, (1, 0)), expected_board)
+        self.assertEqual(Board.do_move(board, -1, (1, -1)), expected_board)
+        self.assertEqual(Board.do_move(board, -1, (1, -4)), expected_board)
         
 if __name__ == '__main__':
     unittest.main()