refactor(client): replace all AsyncMilvusClient usage of has_collection() with list_collections()

Signed-off-by: Mustafa Elbehery <melbeher@redhat.com>

llama_stack/providers/remote/vector_io/milvus/milvus.py

@@ -67,7 +67,8 @@ class MilvusIndex(EmbeddingIndex):
 
     async def delete(self):
         try:
-            if await self.client.has_collection(self.collection_name):
+            collections = await self.client.list_collections()
+            if self.collection_name in collections:
                 await self.client.drop_collection(collection_name=self.collection_name)
         except Exception as e:
             logger.warning(f"Failed to check or delete collection {self.collection_name}: {e}")
@@ -78,7 +79,8 @@ class MilvusIndex(EmbeddingIndex):
         )
 
         try:
-            collection_exists = await self.client.has_collection(self.collection_name)
+            collections = await self.client.list_collections()
+            collection_exists = self.collection_name in collections
         except Exception as e:
             logger.error(f"Failed to check collection existence: {self.collection_name} ({e})")
             # If it's an event loop issue, try to recreate the client
@@ -87,7 +89,8 @@ class MilvusIndex(EmbeddingIndex):
 
                 if hasattr(self, "_parent_adapter"):
                     await self._parent_adapter._recreate_client()
-                    collection_exists = await self.client.has_collection(self.collection_name)
+                    collections = await self.client.list_collections()
+                    collection_exists = self.collection_name in collections
                 else:
                     # Assume collection doesn't exist if we can't check
                     collection_exists = False

tests/unit/providers/vector_io/remote/test_milvus.py

@@ -40,7 +40,7 @@ async def mock_milvus_client() -> MagicMock:
     """Create a mock Milvus client with common method behaviors."""
     client = MagicMock()
 
-    client.has_collection = AsyncMock(return_value=False)  # Initially no collection
+    client.list_collections = AsyncMock(return_value=[])  # Initially no collections
     client.create_collection = AsyncMock(return_value=None)
     client.drop_collection = AsyncMock(return_value=None)
 
@@ -103,7 +103,7 @@ async def milvus_index(mock_milvus_client):
 
 async def test_add_chunks(milvus_index, sample_chunks, sample_embeddings, mock_milvus_client):
     # Setup: collection doesn't exist initially, then exists after creation
-    mock_milvus_client.has_collection.side_effect = [False, True]
+    mock_milvus_client.list_collections.side_effect = [[], ["test_collection"]]
 
     await milvus_index.add_chunks(sample_chunks, sample_embeddings)
 
@@ -120,7 +120,7 @@ async def test_query_chunks_vector(
     milvus_index, sample_chunks, sample_embeddings, embedding_dimension, mock_milvus_client
 ):
     # Setup: Add chunks first
-    mock_milvus_client.has_collection.return_value = True
+    mock_milvus_client.list_collections.return_value = ["test_collection"]
     await milvus_index.add_chunks(sample_chunks, sample_embeddings)
 
     # Test vector search
@@ -133,7 +133,7 @@ async def test_query_chunks_vector(
 
 
 async def test_query_chunks_keyword_search(milvus_index, sample_chunks, sample_embeddings, mock_milvus_client):
-    mock_milvus_client.has_collection.return_value = True
+    mock_milvus_client.list_collections.return_value = ["test_collection"]
     await milvus_index.add_chunks(sample_chunks, sample_embeddings)
 
     # Test keyword search
@@ -146,7 +146,7 @@ async def test_query_chunks_keyword_search(milvus_index, sample_chunks, sample_e
 
 async def test_bm25_fallback_to_simple_search(milvus_index, sample_chunks, sample_embeddings, mock_milvus_client):
     """Test that when BM25 search fails, the system falls back to simple text search."""
-    mock_milvus_client.has_collection.return_value = True
+    mock_milvus_client.list_collections.return_value = ["test_collection"]
     await milvus_index.add_chunks(sample_chunks, sample_embeddings)
 
     # Force BM25 search to fail
@@ -188,7 +188,7 @@ async def test_bm25_fallback_to_simple_search(milvus_index, sample_chunks, sampl
 
 async def test_delete_collection(milvus_index, mock_milvus_client):
     # Test collection deletion
-    mock_milvus_client.has_collection.return_value = True
+    mock_milvus_client.list_collections.return_value = ["test_collection"]
 
     await milvus_index.delete()
 
@@ -199,7 +199,7 @@ async def test_query_hybrid_search_rrf(
     milvus_index, sample_chunks, sample_embeddings, embedding_dimension, mock_milvus_client
 ):
     """Test hybrid search with RRF reranker."""
-    mock_milvus_client.has_collection.return_value = True
+    mock_milvus_client.list_collections.return_value = ["test_collection"]
     await milvus_index.add_chunks(sample_chunks, sample_embeddings)
 
     # Mock hybrid search results
@@ -251,7 +251,7 @@ async def test_query_hybrid_search_weighted(
     milvus_index, sample_chunks, sample_embeddings, embedding_dimension, mock_milvus_client
 ):
     """Test hybrid search with weighted reranker."""
-    mock_milvus_client.has_collection.return_value = True
+    mock_milvus_client.list_collections.return_value = ["test_collection"]
     await milvus_index.add_chunks(sample_chunks, sample_embeddings)
 
     # Mock hybrid search results
@@ -297,7 +297,7 @@ async def test_query_hybrid_search_default_rrf(
     milvus_index, sample_chunks, sample_embeddings, embedding_dimension, mock_milvus_client
 ):
     """Test hybrid search with default RRF reranker (no reranker_type specified)."""
-    mock_milvus_client.has_collection.return_value = True
+    mock_milvus_client.list_collections.return_value = ["test_collection"]
     await milvus_index.add_chunks(sample_chunks, sample_embeddings)
 
     # Mock hybrid search results