test_validation_error_with_invalid_response() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/test_response_format.py lines 706–730

    def test_validation_error_with_invalid_response(self) -> None:
        """Test validation error with invalid response.

        Test that StructuredOutputValidationError is raised when provider strategy
        receives invalid response.
        """
        tool_calls = [
            [{"args": {}, "id": "1", "name": "get_weather"}],
        ]

        # But we're using WeatherBaseModel which has different field requirements
        model = FakeToolCallingModel(
            tool_calls=tool_calls,
            structured_response={"invalid": "data"},  # Wrong structure
        )

        agent = create_agent(
            model, [get_weather], response_format=ProviderStrategy(WeatherBaseModel)
        )

        with pytest.raises(
            StructuredOutputValidationError,
            match=r".*WeatherBaseModel.*",
        ):
            agent.invoke({"messages": [HumanMessage("What's the weather?")]})