test_command_goto_raises_not_implemented() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_wrap_model_call_state_update.py lines 785–804

    def test_command_goto_raises_not_implemented(self) -> None:
        """Command with goto in wrap_model_call raises NotImplementedError."""

        class GotoMiddleware(AgentMiddleware):
            def wrap_model_call(
                self,
                request: ModelRequest,
                handler: Callable[[ModelRequest], ModelResponse],
            ) -> ExtendedModelResponse:
                response = handler(request)
                return ExtendedModelResponse(
                    model_response=response,
                    command=Command(goto="__end__"),
                )

        model = GenericFakeChatModel(messages=iter([AIMessage(content="Hello!")]))
        agent = create_agent(model=model, middleware=[GotoMiddleware()])

        with pytest.raises(NotImplementedError, match="Command goto is not yet supported"):
            agent.invoke({"messages": [HumanMessage(content="Hi")]})