test_summarization_middleware_zero_and_negative_target_tokens() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_summarization.py lines 882–898

def test_summarization_middleware_zero_and_negative_target_tokens() -> None:
    """Test handling of edge cases with target token calculations."""
    # Test with very small fraction that rounds to zero
    middleware = SummarizationMiddleware(
        model=ProfileChatModel(), trigger=("fraction", 0.0001), keep=("fraction", 0.0001)
    )

    # Should set threshold to 1 when calculated value is <= 0
    messages: list[AnyMessage] = [HumanMessage(content="test")]

    # The trigger fraction calculation: int(1000 * 0.0001) = 0, but should be set to 1
    # Token count of 1 message should exceed threshold of 1
    def token_counter(_: Iterable[MessageLikeRepresentation]) -> int:
        return 2

    middleware.token_counter = token_counter
    assert middleware._should_summarize(messages, 2)