Makes GraphStore a Protocol (#35)

* Makes GraphStore a Protocol

* Updated CHANGELOG

CHANGELOG.md

@@ -10,6 +10,7 @@
 
 - Made the `source` parameter of `GraphDocument` optional and updated related methods to support this.
 - Suppressed AggregationSkippedNull warnings raised by the Neo4j driver in the Neo4jGraph class when fetching the enhanced_schema.
+- Updated `GraphStore` to be a Protocol, enabling compatibility with `GraphCypherQAChain` without requiring inheritance.
 
 ### Fixed
 

libs/neo4j/langchain_neo4j/graphs/graph_store.py

@@ -1,37 +1,32 @@
-from abc import abstractmethod
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Protocol, runtime_checkable
 
 from langchain_neo4j.graphs.graph_document import GraphDocument
 
 
-class GraphStore:
+@runtime_checkable
+class GraphStore(Protocol):
     """Abstract class for graph operations."""
 
     @property
-    @abstractmethod
     def get_schema(self) -> str:
         """Return the schema of the Graph database"""
-        pass
+        ...
 
     @property
-    @abstractmethod
     def get_structured_schema(self) -> Dict[str, Any]:
         """Return the schema of the Graph database"""
-        pass
+        ...
 
-    @abstractmethod
     def query(self, query: str, params: dict = {}) -> List[Dict[str, Any]]:
         """Query the graph."""
-        pass
+        ...
 
-    @abstractmethod
     def refresh_schema(self) -> None:
         """Refresh the graph schema information."""
         pass
 
-    @abstractmethod
     def add_graph_documents(
         self, graph_documents: List[GraphDocument], include_source: bool = False
     ) -> None:
         """Take GraphDocument as input as uses it to construct a graph."""
-        pass
+        ...

libs/neo4j/tests/unit_tests/chains/test_graph_qa.py

@@ -37,7 +37,7 @@
 from tests.llms.fake_llm import FakeLLM
 
 
-class FakeGraphStore(GraphStore):
+class FakeGraphStore:
     @property
     def get_schema(self) -> str:
         """Returns the schema of the Graph database"""
@@ -63,6 +63,12 @@ def add_graph_documents(
         pass
 
 
+def test_graph_store() -> None:
+    """Tests that FakeGraphStore satisfies the GraphStore protocol requirements."""
+    graph = FakeGraphStore()
+    assert isinstance(graph, GraphStore)
+
+
 def test_graph_cypher_qa_chain_prompt_selection_1() -> None:
     # Pass prompts directly. No kwargs is specified.
     qa_prompt_template = "QA Prompt"