test_sync_invoke_with_only_async_middleware_raises_error() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_wrap_model_call.py lines 1469–1488

    def test_sync_invoke_with_only_async_middleware_raises_error(self) -> None:
        """Test that sync invoke with only async middleware raises error."""

        class AsyncOnlyMiddleware(AgentMiddleware):
            async def awrap_model_call(
                self,
                request: ModelRequest,
                handler: Callable[[ModelRequest], Awaitable[ModelResponse]],
            ) -> ModelCallResult:
                return await handler(request)

        agent = create_agent(
            model=FakeToolCallingModel(),
            tools=[],
            system_prompt="You are a helpful assistant.",
            middleware=[AsyncOnlyMiddleware()],
        )

        with pytest.raises(NotImplementedError):
            agent.invoke({"messages": [HumanMessage("hello")]})