test_create_agent_sync_invoke_with_only_async_middleware_raises_error() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_framework.py lines 481–500

def test_create_agent_sync_invoke_with_only_async_middleware_raises_error() -> None:
    """Test that sync invoke with only async middleware works via run_in_executor."""

    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")]})