test_decorator_async_only_works_async_path() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_sync_async_wrappers.py lines 429–460

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

        @wrap_tool_call
        async def my_async_wrapper(
            request: ToolCallRequest,
            handler: Callable[[ToolCallRequest], Awaitable[ToolMessage | Command[Any]]],
        ) -> ToolMessage | Command[Any]:
            call_log.append("decorator_async")
            return await handler(request)

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

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

        result = await agent.ainvoke(
            {"messages": [HumanMessage("Search")]},
            {"configurable": {"thread_id": "test"}},
        )
        assert "decorator_async" in call_log
        assert len([m for m in result["messages"] if isinstance(m, ToolMessage)]) == 1