test_summarization_middleware_trim_limit_none_keeps_all_messages() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_summarization.py lines 223–237

def test_summarization_middleware_trim_limit_none_keeps_all_messages() -> None:
    """Verify disabling trim limit preserves full message sequence."""
    messages: list[AnyMessage] = [HumanMessage(content=str(i)) for i in range(10)]
    middleware = SummarizationMiddleware(
        model=MockChatModel(),
        trim_tokens_to_summarize=None,
    )

    def token_counter(messages: Iterable[MessageLikeRepresentation]) -> int:
        return len(list(messages))

    middleware.token_counter = token_counter

    trimmed = middleware._trim_messages_for_summary(messages)
    assert trimmed is messages