def test_can_en_passant(self):
"""
Test that a pawn can perform en passant move.
:return:
"""
board = ChessBoard()
# En passant from white's perspective.
board['b5'] = Pawn(Color.WHITE)
board['a7'] = Pawn(Color.BLACK)
board.move_piece('a7', 'a5')
self.assertTrue(board.can_en_passant('b5', MoveDirection.F_LEFT_DIAG),
'Pawn should be able to perform en passant')
# En passant from black's perspective.
board['g4'] = Pawn(Color.BLACK)
board['h2'] = Pawn(Color.WHITE)
board.move_piece('h2', 'h4')
self.assertTrue(board.can_en_passant('g4', MoveDirection.F_LEFT_DIAG),
'Pawn should be able to perform en passant')
def test_cannot_en_passant(self):
"""
Test that a pawn cannot perform en passant move.
:return:
"""
board = ChessBoard()
# Confirm pawn that just moved 2 spaces can't perform enpassant.
board['b5'] = Pawn(Color.WHITE)
board['a7'] = Pawn(Color.BLACK)
board.move_piece('a7', 'a5')
self.assertFalse(board.can_en_passant('a5', MoveDirection.F_LEFT_DIAG),
'Pawn should not be able to perform en passant')
# Confirm when all condition have been met but push pawn moved one square twice, en passant can't happen.
board['g4'] = Pawn(Color.BLACK)
board['h2'] = Pawn(Color.WHITE)
board.move_piece('h2', 'h3')
board.move_piece('h3', 'h4')
self.assertFalse(board.can_en_passant('g4', MoveDirection.F_LEFT_DIAG),
'Pawn should be able to perform en passant')
