test_trim_messages_token_counter_shortcut_approximate() — langchain Function Reference

Source Code

libs/core/tests/unit_tests/messages/test_utils.py lines 680–707

def test_trim_messages_token_counter_shortcut_approximate() -> None:
    """Test that `'approximate'` shortcut works for `token_counter`."""
    messages = [
        SystemMessage("This is a test message"),
        HumanMessage("Another test message", id="first"),
        AIMessage("AI response here", id="second"),
    ]
    messages_copy = [m.model_copy(deep=True) for m in messages]

    # Test using the "approximate" shortcut
    result_shortcut = trim_messages(
        messages,
        max_tokens=50,
        token_counter="approximate",
        strategy="last",
    )

    # Test using count_tokens_approximately directly
    result_direct = trim_messages(
        messages,
        max_tokens=50,
        token_counter=count_tokens_approximately,
        strategy="last",
    )

    # Both should produce the same result
    assert result_shortcut == result_direct
    assert messages == messages_copy