fix(python): resolve multi-index search core dumps by exposing missing state (#643)

python/scripts/test_indexes.py

@@ -0,0 +1,58 @@
+from usearch.index import Index, Indexes
+import numpy as np
+
+def test_multi_index():
+    print("Initiating Stress Protocol...")
+
+    # ---------------------------------------------------------
+    # Phase 1: The Void Strike (Boundary Conditions)
+    # Proving that an empty Indexes object does not crash the engine.
+    # ---------------------------------------------------------
+    print("Executing Phase 1: Boundary Conditions...")
+    ix_empty = Indexes([])
+    assert ix_empty.ndim == 0, f"Void ndim failed. Expected 0, got {ix_empty.ndim}"
+    assert ix_empty.dtype is None, "Void dtype failed."
+    assert ix_empty.metric == "unknown", f"Void metric failed. Expected 'unknown', got {ix_empty.metric}"
+
+    ndim = 128
+    v1 = np.random.rand(ndim).astype(np.float32)
+    v2 = np.random.rand(ndim).astype(np.float32)
+
+    ia = Index(ndim=ndim)
+    ia.add(100, v1)  # Key 100 holds v1
+
+    ib = Index(ndim=ndim)
+    ib.add(200, v2)  # Key 200 holds v2
+
+    ix = Indexes([ia, ib])
+
+    # ---------------------------------------------------------
+    # Phase 2: The Recall Strike (Mathematical Verification)
+    # Proving the multi-index router searches the correct memory space.
+    # ---------------------------------------------------------
+    print("Executing Phase 2: Recall...")
+    matches = ix.search(v2, count=1)
+    assert len(matches) > 0, "Engine returned empty results."
+    assert matches[0].key == 200, f"Recall failure. Expected 200, got {matches[0].key}"
+    # Distance to itself should be essentially zero
+    assert matches[0].distance < 1e-5, f"Distance variance too high: {matches[0].distance}"
+
+    # ---------------------------------------------------------
+    # Phase 3: The Batch Strike (Memory Alignment)
+    # Proving the wrapper can handle matrices, not just single vectors.
+    # ---------------------------------------------------------
+    print("Executing Phase 3: Batch Memory Alignment...")
+    batch_query = np.vstack([v1, v2]) # Shape: (2, 128)
+
+    batch_matches = ix.search(batch_query, count=1)
+    assert len(batch_matches) == 2, f"Batch router failed. Expected 2 result sets, got {len(batch_matches)}"
+
+    # The first query (v1) should return key 100
+    assert batch_matches[0][0].key == 100, f"Batch recall 0 failed. Got {batch_matches[0][0].key}"
+    # The second query (v2) should return key 200
+    assert batch_matches[1][0].key == 200, f"Batch recall 1 failed. Got {batch_matches[1][0].key}"
+
+    print("All assertions passed. The architecture holds.")
+
+if __name__ == "__main__":
+    test_multi_index()