test_decorator_sync_only_raises_on_async_path() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_sync_async_wrappers.py lines 396–427

    async def test_decorator_sync_only_raises_on_async_path(self) -> None:
        """Decorator-created sync-only middleware raises on async path."""
        call_log = []

        @wrap_tool_call
        def my_wrapper(
            request: ToolCallRequest,
            handler: Callable[[ToolCallRequest], ToolMessage | Command[Any]],
        ) -> ToolMessage | Command[Any]:
            call_log.append("decorator_sync")
            return handler(request)

        model = FakeToolCallingModel(
            tool_calls=[
                [ToolCall(name="search", args={"query": "test"}, id="1")],
                [],
            ]
        )

        agent = create_agent(
            model=model,
            tools=[search],
            middleware=[my_wrapper],
            checkpointer=InMemorySaver(),
        )

        # Should raise NotImplementedError because sync-only decorator doesn't support async path
        with pytest.raises(NotImplementedError):
            await agent.ainvoke(
                {"messages": [HumanMessage("Search")]},
                {"configurable": {"thread_id": "test2"}},
            )