test_structured_output_retry_succeeds_first_attempt() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_structured_output_retry.py lines 187–224

def test_structured_output_retry_succeeds_first_attempt() -> None:
    """Test structured output retry when first attempt succeeds (no retry needed)."""
    # First attempt returns valid structured output
    tool_calls = [
        [
            {
                "name": "WeatherReport",
                "id": "1",
                "args": {"temperature": 68.0, "conditions": "cloudy"},
            }
        ],
    ]

    model = FakeToolCallingModel(tool_calls=tool_calls)
    retry_middleware = StructuredOutputRetryMiddleware(max_retries=2)

    agent = create_agent(
        model=model,
        tools=[get_weather],
        middleware=[retry_middleware],
        response_format=ToolStrategy(schema=WeatherReport, handle_errors=False),
        checkpointer=InMemorySaver(),
    )

    result = agent.invoke(
        {"messages": [HumanMessage("What's the weather in Paris?")]},
        {"configurable": {"thread_id": "test"}},
    )

    # Verify we got a structured response
    assert "structured_response" in result
    structured = result["structured_response"]
    assert isinstance(structured, WeatherReport)
    assert structured.temperature == 68.0
    assert structured.conditions == "cloudy"

    # Verify the model was called only once
    assert model.index == 1