test_get_buffer_string_xml_server_tool_result_output_truncation() — langchain Function Reference

Source Code

libs/core/tests/unit_tests/messages/test_utils.py lines 2616–2634

def test_get_buffer_string_xml_server_tool_result_output_truncation() -> None:
    """Test that server_tool_result output is truncated to 500 chars."""
    long_output = "z" * 600
    messages: list[BaseMessage] = [
        HumanMessage(
            content=[
                {
                    "type": "server_tool_result",
                    "tool_call_id": "call_1",
                    "status": "success",
                    "output": {"result": long_output},
                },
            ]
        ),
    ]
    result = get_buffer_string(messages, format="xml")
    assert "..." in result
    # The full 600-char value should not appear
    assert long_output not in result