test_count_tokens_approximately_with_tools() — langchain Function Reference

Architecture documentation for the test_count_tokens_approximately_with_tools() function in test_utils.py from the langchain codebase.

Function python LangChainCore MessageInterface

Entity Profile

LangChainCore→ MessageInterface→ test_count_tokens_approximately_with_tools() — langchain Function Reference

Dependency Diagram

graph TD
  5be7afcb_ba57_76f7_bfe6_4355506f55bf["test_count_tokens_approximately_with_tools()"]
  03f6a5ae_d57a_eb66_626a_b9e082b763ea["test_utils.py"]
  5be7afcb_ba57_76f7_bfe6_4355506f55bf -->|defined in| 03f6a5ae_d57a_eb66_626a_b9e082b763ea
  style 5be7afcb_ba57_76f7_bfe6_4355506f55bf fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/tests/unit_tests/messages/test_utils.py lines 2913–2960

def test_count_tokens_approximately_with_tools() -> None:
    """Test that tools parameter adds to token count."""
    messages = [HumanMessage(content="Hello")]
    base_count = count_tokens_approximately(messages)

    # Test with a BaseTool instance
    @tool
    def get_weather(location: str) -> str:
        """Get the weather for a location."""
        return f"Weather in {location}"

    count_with_tool = count_tokens_approximately(messages, tools=[get_weather])
    assert count_with_tool > base_count

    # Test with a dict tool schema
    tool_schema = {
        "type": "function",
        "function": {
            "name": "get_weather",
            "description": "Get the weather for a location.",
            "parameters": {
                "type": "object",
                "properties": {"location": {"type": "string"}},
                "required": ["location"],
            },
        },
    }
    count_with_dict_tool = count_tokens_approximately(messages, tools=[tool_schema])
    assert count_with_dict_tool > base_count

    # Test with multiple tools
    @tool
    def get_time(timezone: str) -> str:
        """Get the current time in a timezone."""
        return f"Time in {timezone}"

    count_with_multiple = count_tokens_approximately(
        messages, tools=[get_weather, get_time]
    )
    assert count_with_multiple > count_with_tool

    # Test with no tools (None) should equal base count
    count_no_tools = count_tokens_approximately(messages, tools=None)
    assert count_no_tools == base_count

    # Test with empty tools list should equal base count
    count_empty_tools = count_tokens_approximately(messages, tools=[])
    assert count_empty_tools == base_count