make sure rubiks cube is scrambled deterministically based on seed+idx

tests/test_rubiks_cube.py

@@ -0,0 +1,42 @@
+import pytest
+
+from magiccube.cube import Cube
+from reasoning_gym.cognition.rubiks_cube import RubiksCubeConfig, RubiksCubeDataset
+
+
+def test_rubikscube_config_validation():
+    """Test that invalid configs raise appropriate errors"""
+    with pytest.raises(AssertionError):
+        config = RubiksCubeConfig(cube_size=1)  # Too small
+        config.validate()
+
+    with pytest.raises(AssertionError):
+        config = RubiksCubeConfig(scramble_steps=0)  # Don't give an unscrambled cube
+        config.validate()
+
+
+def test_rubikscube_items():
+    """Test basic properties and solution of generated items"""
+    config = RubiksCubeConfig(
+        cube_size=3,
+        scramble_steps=4
+    )
+    dataset = RubiksCubeDataset(config)
+
+    for item in dataset:
+        assert isinstance(item, dict)
+        assert "question" in item
+        assert "answer" in item
+        assert "metadata" in item
+
+        # Check metadata contains required fields
+        assert "cube_size" in item["metadata"]
+        assert "cube_size" in item["metadata"]
+        assert "scramble_steps" in item["metadata"]
+        assert "scramble_moves" in item["metadata"]
+        assert "example_correct_answer" in item["metadata"]
+
+        assert dataset.score_answer(answer=item['metadata']['example_correct_answer'], entry=item) == 1.0
+        assert dataset.score_answer(answer='R', entry=item) == 0.01
+        assert dataset.score_answer(answer=None, entry=item) == 0.0
+