test_multiple_decorated_middleware() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_wrap_model_call.py lines 1155–1189

    def test_multiple_decorated_middleware(self) -> None:
        """Test composition of multiple decorated middleware."""
        execution_order = []

        @wrap_model_call
        def outer_middleware(
            request: ModelRequest,
            handler: Callable[[ModelRequest], ModelResponse],
        ) -> ModelCallResult:
            execution_order.append("outer-before")
            result = handler(request)
            execution_order.append("outer-after")
            return result

        @wrap_model_call
        def inner_middleware(
            request: ModelRequest,
            handler: Callable[[ModelRequest], ModelResponse],
        ) -> ModelCallResult:
            execution_order.append("inner-before")
            result = handler(request)
            execution_order.append("inner-after")
            return result

        model = GenericFakeChatModel(messages=iter([AIMessage(content="Response")]))
        agent = create_agent(model=model, middleware=[outer_middleware, inner_middleware])

        agent.invoke({"messages": [HumanMessage("Test")]})

        assert execution_order == [
            "outer-before",
            "inner-before",
            "inner-after",
            "outer-after",
        ]