def test_promotion():
"""
When pawns reach the back rank they should become queens (currently we don't support under-promotion).
When other pieces move to the back rank, they should remain as themselves.
"""
position = empty_position()
position[(6, 0)] = ChessPiece['WP'] # a7
position[(1, 4)] = ChessPiece['BP'] # e2
position[(0, 0)] = ChessPiece['WK'] # a1
position[(0, 7)] = ChessPiece['BK'] # h1
position[(5, 5)] = ChessPiece['WB'] # f6
position[(1, 6)] = ChessPiece['BR'] # g2
can_castle = {'WKS': False, 'WQS': False, 'BKS': False, 'BQS': False}
board = ChessBoard(position=position,
can_castle=can_castle,
last_move=None,
player_to_move=Player['W'])
nb = board.make_move(((6, 0), (7, 0))) # a8=Q
assert nb.position[(7, 0)] == ChessPiece['WQ'], "white promotion"
nb = board.make_move(((5, 5), (7, 3))) # Bd8
assert nb.position[(
7, 3)] == ChessPiece['WB'], "white piece moves to back rank"
nb2 = nb.make_move(((1, 4), (0, 4))) # e1=Q
assert nb2.position[(0, 4)] == ChessPiece['BQ'], "black promotion"
nb2 = nb.make_move(((1, 6), (0, 6))) # Rg1
assert nb2.position[(
0, 6)] == ChessPiece['BR'], "black piece moves to back rank"
def test_castling_KS():
"""Test king side castling."""
b = ChessBoard()
b = b.make_move(((1, 4), (3, 4))) # e4
b = b.make_move(((6, 4), (4, 4))) # e5
b = b.make_move(((0, 6), (2, 5))) # Nf3
b = b.make_move(((7, 6), (5, 5))) # Nf6
b = b.make_move(((0, 5), (3, 2))) # Bc4
b = b.make_move(((7, 5), (4, 2))) # Bc5
# check white can castle now
white_castle = ((0, 4), (0, 6))
legal_moves = b.legal_moves()
assert white_castle in legal_moves
b = b.make_move(((0, 4), (1, 4))) # Ke2
# check black can castle now
black_castle = ((7, 4), (7, 6))
assert (black_castle in b.legal_moves())
b = b.make_move(((7, 4), (6, 4))) # Ke7
b = b.make_move(((1, 4), (0, 4))) # Ke1
b = b.make_move(((6, 4), (7, 4))) # Ke8
# check white cannot castle
assert white_castle not in b.legal_moves()
b = b.make_move(((0, 1), (2, 2))) # Nc3
# check black cannot castle
assert black_castle not in b.legal_moves()
