test_empty_tools_to_emulate_does_nothing() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_tool_emulator.py lines 218–251

    def test_empty_tools_to_emulate_does_nothing(self) -> None:
        """Test that empty tools_to_emulate list means no emulation occurs."""
        agent_model = FakeModel(
            messages=cycle(
                [
                    AIMessage(
                        content="",
                        tool_calls=[
                            {"name": "calculator", "id": "1", "args": {"expression": "5*5"}}
                        ],
                    ),
                    AIMessage(content="Done."),
                ]
            )
        )

        emulator_model = FakeEmulatorModel(responses=["Should not be used"])

        emulator = LLMToolEmulator(tools=[], model=emulator_model)

        agent = create_agent(
            model=agent_model,
            tools=[calculator],
            middleware=[emulator],
        )

        result = agent.invoke({"messages": [HumanMessage("Calculate 5*5")]})

        # Calculator should execute normally
        tool_messages = [
            msg for msg in result["messages"] if hasattr(msg, "name") and msg.name == "calculator"
        ]
        assert len(tool_messages) > 0
        assert "Result: 25" in tool_messages[0].content