test: Add unit test for score_answer method in N-Queens dataset

tests/test_n_queens.py

@@ -102,6 +102,27 @@ def test_nqueens_board_generation():
             assert is_valid_solution(board)
 
 
+def test_nqueens_score_answer():
+    """Test the score_answer method"""
+    config = NQueensConfig(n=8, size=10, seed=42)
+    dataset = NQueensDataset(config)
+
+    # Test a few items
+    for i in range(len(dataset)):
+        item = dataset[i]
+        
+        # Test correct answer gets score 1.0
+        valid_answer = item["metadata"]["valid_answers"][0]
+        assert dataset.score_answer(valid_answer, item) == 1.0
+        
+        # Test invalid answer gets score 0.01
+        invalid_answer = "_ _ _ _\n_ _ _ _\n_ _ _ _\n_ _ _ _"
+        assert dataset.score_answer(invalid_answer, item) == 0.01
+        
+        # Test None answer gets score 0.0
+        assert dataset.score_answer(None, item) == 0.0
+
+
 def is_valid_solution(board: list[list[str]]) -> bool:
     """Helper function to verify N Queens solution validity"""
     rows, cols, diags, off_diags = set(), set(), set(), set()