deepset-ai--haystack/test/utils/test_hf.py

# SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
#
# SPDX-License-Identifier: Apache-2.0

import pytest

from haystack.dataclasses import ChatMessage, ChatRole, ImageContent, ReasoningContent, TextContent, ToolCall
from haystack.dataclasses.chat_message import ToolCallResult
from haystack.utils.hf import convert_message_to_hf_format


def test_convert_message_to_hf_format():
    message = ChatMessage.from_system("You are good assistant")
    assert convert_message_to_hf_format(message) == {"role": "system", "content": "You are good assistant"}

    message = ChatMessage.from_user("I have a question")
    assert convert_message_to_hf_format(message) == {"role": "user", "content": "I have a question"}

    message = ChatMessage.from_assistant(text="I have an answer", meta={"finish_reason": "stop"})
    assert convert_message_to_hf_format(message) == {"role": "assistant", "content": "I have an answer"}

    message = ChatMessage.from_assistant(
        tool_calls=[ToolCall(id="123", tool_name="weather", arguments={"city": "Paris"})]
    )
    assert convert_message_to_hf_format(message) == {
        "role": "assistant",
        "content": "",
        "tool_calls": [
            {"id": "123", "type": "function", "function": {"name": "weather", "arguments": {"city": "Paris"}}}
        ],
    }

    message = ChatMessage.from_assistant(tool_calls=[ToolCall(tool_name="weather", arguments={"city": "Paris"})])
    assert convert_message_to_hf_format(message) == {
        "role": "assistant",
        "content": "",
        "tool_calls": [{"type": "function", "function": {"name": "weather", "arguments": {"city": "Paris"}}}],
    }

    tool_result = '{"weather": "sunny", "temperature": "25"}'
    message = ChatMessage.from_tool(
        tool_result=tool_result, origin=ToolCall(id="123", tool_name="weather", arguments={"city": "Paris"})
    )
    assert convert_message_to_hf_format(message) == {"role": "tool", "content": tool_result, "tool_call_id": "123"}

    message = ChatMessage.from_tool(
        tool_result=tool_result, origin=ToolCall(tool_name="weather", arguments={"city": "Paris"})
    )
    assert convert_message_to_hf_format(message) == {"role": "tool", "content": tool_result}


def test_convert_message_to_hf_invalid():
    message = ChatMessage(_role=ChatRole.ASSISTANT, _content=[])
    with pytest.raises(ValueError):
        convert_message_to_hf_format(message)

    message = ChatMessage(
        _role=ChatRole.USER,
        _content=[
            TextContent(text="I have an answer"),
            ToolCallResult(
                result="result!",
                origin=ToolCall(id="123", tool_name="weather", arguments={"city": "Paris"}),
                error=None,  # type: ignore[arg-type]
            ),
        ],
    )
    with pytest.raises(ValueError):
        convert_message_to_hf_format(message)


def test_convert_message_to_hf_format_with_multiple_images(base64_image_string):
    image1 = ImageContent(base64_image=base64_image_string)
    image2 = ImageContent(base64_image=base64_image_string)
    message = ChatMessage.from_user(content_parts=["Compare these images", image1, image2])

    result = convert_message_to_hf_format(message)
    expected = {
        "role": "user",
        "content": [
            {"type": "text", "text": "Compare these images"},
            {"type": "image_url", "image_url": {"url": f"data:image/png;base64,{base64_image_string}"}},
            {"type": "image_url", "image_url": {"url": f"data:image/png;base64,{base64_image_string}"}},
        ],
    }
    assert result == expected


def test_convert_message_to_hf_format_skips_reasoning_content():
    """
    Test that ReasoningContent is properly skipped during conversion.

    ReasoningContent is for human transparency only and is not sent to the HuggingFace API
    because the API (which follows OpenAI-compatible format) does not support reasoning
    in input messages.
    """
    # Assistant message with text and reasoning
    message = ChatMessage(
        _role=ChatRole.ASSISTANT,
        _content=[
            TextContent(text="The answer is 42."),
            ReasoningContent(reasoning_text="Let me think step by step..."),
        ],
    )
    result = convert_message_to_hf_format(message)
    # ReasoningContent should be skipped, only text should be in the output
    assert result == {"role": "assistant", "content": "The answer is 42."}


def test_convert_message_to_hf_format_with_tool_call_and_reasoning():
    """
    Test that ReasoningContent is skipped when message contains tool calls.
    """
    message = ChatMessage(
        _role=ChatRole.ASSISTANT,
        _content=[
            ReasoningContent(reasoning_text="I need to check the weather."),
            ToolCall(id="123", tool_name="weather", arguments={"city": "Paris"}),
        ],
    )
    result = convert_message_to_hf_format(message)
    # ReasoningContent should be skipped
    assert result == {
        "role": "assistant",
        "content": "",
        "tool_calls": [
            {"id": "123", "type": "function", "function": {"name": "weather", "arguments": {"city": "Paris"}}}
        ],
    }