test_create_summary_passes_lc_source_metadata() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_summarization.py lines 1290–1312

async def test_create_summary_passes_lc_source_metadata(use_async: bool) -> None:  # noqa: FBT001
    """Test that summary creation passes `lc_source` metadata to the model.

    When called outside a LangGraph runnable context, `get_config()` raises
    `RuntimeError`. The middleware catches this and still passes the `lc_source`
    metadata to the model.
    """
    model = ConfigCapturingModel()
    model.captured_configs = []  # Reset for this test
    middleware = SummarizationMiddleware(model=model, trigger=("tokens", 1000))
    messages: list[AnyMessage] = [HumanMessage(content="Hello"), AIMessage(content="Hi")]

    if use_async:
        summary = await middleware._acreate_summary(messages)
    else:
        summary = middleware._create_summary(messages)

    assert summary == "Summary"
    assert len(model.captured_configs) == 1
    config = model.captured_configs[0]
    assert config is not None
    assert "metadata" in config
    assert config["metadata"]["lc_source"] == "summarization"