test_count_tokens_approximately_with_image_content() — langchain Function Reference

Source Code

libs/core/tests/unit_tests/messages/test_utils.py lines 2764–2780

def test_count_tokens_approximately_with_image_content() -> None:
    """Test approximate token counting with image content blocks."""
    message_with_image = HumanMessage(
        content=[
            {"type": "text", "text": "What's in this image?"},
            {
                "type": "image_url",
                "image_url": {"url": "data:image/jpeg;base64," + "A" * 100000},
            },
        ]
    )

    token_count = count_tokens_approximately([message_with_image])

    # Should be ~85 (image) + ~5 (text) + 3 (extra) = ~93 tokens, NOT 25,000+
    assert token_count < 200, f"Expected <200 tokens, got {token_count}"
    assert token_count > 80, f"Expected >80 tokens, got {token_count}"