fix: Chroma DocumentStore creation for pre-existing collection name (#…

…157)

* fix: Error on Chroma DocumentStore creation for pre-existing collection name

* linting done

integrations/chroma/src/chroma_haystack/document_store.py

@@ -41,7 +41,7 @@ def __init__(
         self._embedding_function_params = embedding_function_params
         # Create the client instance
         self._chroma_client = chromadb.Client()
-        self._collection = self._chroma_client.create_collection(
+        self._collection = self._chroma_client.get_or_create_collection(
             name=collection_name,
             embedding_function=get_embedding_function(embedding_function, **embedding_function_params),
         )

integrations/chroma/tests/test_document_store.py

@@ -112,6 +112,11 @@ def test_from_json(self):
         assert ds._embedding_function == function_name
         assert ds._embedding_function_params == {"api_key": "1234567890"}
 
+    @pytest.mark.integration
+    def test_same_collection_name_reinitialization(self):
+        ChromaDocumentStore("test_name")
+        ChromaDocumentStore("test_name")
+
     @pytest.mark.skip(reason="Filter on array contents is not supported.")
     @pytest.mark.unit
     def test_filter_document_array(self, document_store: ChromaDocumentStore, filterable_docs: List[Document]):