test_async_only_middleware_raises_on_sync_path() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_sync_async_wrappers.py lines 144–173

    def test_async_only_middleware_raises_on_sync_path(self) -> None:
        """Middleware with only async awrap_tool_call raises NotImplementedError on sync path."""

        class AsyncOnlyMiddleware(AgentMiddleware):
            async def awrap_tool_call(
                self,
                request: ToolCallRequest,
                handler: Callable[[ToolCallRequest], Awaitable[ToolMessage | Command[Any]]],
            ) -> ToolMessage | Command[Any]:
                return await handler(request)

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

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

        with pytest.raises(NotImplementedError):
            agent.invoke(
                {"messages": [HumanMessage("Search")]},
                {"configurable": {"thread_id": "test"}},
            )