test: cover whitened layer and subspace branches

tests/test_analysis.py

@@ -142,6 +142,20 @@ class TestWhitenedSVD:
             assert idx in results
             assert results[idx].directions.shape[0] == 2
 
+    def test_extract_all_layers_skips_unpaired_harmful_layer(self):
+        extractor = WhitenedSVDExtractor()
+        harmful = {
+            0: [torch.tensor([1.0, 0.0]), torch.tensor([0.0, 1.0])],
+            1: [torch.tensor([1.0, 1.0]), torch.tensor([2.0, 2.0])],
+        }
+        harmless = {
+            0: [torch.tensor([0.0, 0.0]), torch.tensor([0.0, 0.0])],
+        }
+
+        results = extractor.extract_all_layers(harmful, harmless, n_directions=1)
+
+        assert results.keys() == {0}
+
     def test_compare_with_standard(self):
         """Comparison should return valid cosine similarities."""
         torch.manual_seed(42)
@@ -159,6 +173,13 @@ class TestWhitenedSVD:
         assert "subspace_principal_cosine" in comparison
         assert 0 <= comparison["primary_direction_cosine"] <= 1.0
 
+        standard_subspace = torch.linalg.qr(torch.randn(16, 2)).Q.T
+        subspace_comparison = WhitenedSVDExtractor.compare_with_standard(
+            result,
+            standard_subspace,
+        )
+        assert 0 <= subspace_comparison["subspace_principal_cosine"] <= 1.0
+
     def test_handles_3d_activations(self):
         """Should handle activations with an extra batch dimension."""
         torch.manual_seed(42)