haystack/test/preview/components/builders/test_prompt_builder.py

import pytest

from haystack.preview.components.builders.prompt_builder import PromptBuilder
from haystack.preview.dataclasses import ChatMessage


@pytest.mark.unit
def test_init():
    builder = PromptBuilder(template="This is a {{ variable }}")
    assert builder._template_string == "This is a {{ variable }}"


@pytest.mark.unit
def test_to_dict():
    builder = PromptBuilder(template="This is a {{ variable }}")
    res = builder.to_dict()
    assert res == {
        "type": "PromptBuilder",
        "init_parameters": {"template": "This is a {{ variable }}", "template_variables": None},
    }


@pytest.mark.unit
def test_run():
    builder = PromptBuilder(template="This is a {{ variable }}")
    res = builder.run(variable="test")
    assert res == {"prompt": "This is a test"}


@pytest.mark.unit
def test_run_without_input():
    builder = PromptBuilder(template="This is a template without input")
    res = builder.run()
    assert res == {"prompt": "This is a template without input"}


@pytest.mark.unit
def test_run_with_missing_input():
    builder = PromptBuilder(template="This is a {{ variable }}")
    res = builder.run()
    assert res == {"prompt": "This is a "}


@pytest.mark.unit
def test_init_with_template_and_template_variables():
    # Initialize the PromptBuilder object with both template and template_variables
    with pytest.raises(ValueError, match="template and template_variables cannot be provided at the same time."):
        PromptBuilder(template="This is a {{ variable }}", template_variables=["variable"])


@pytest.mark.unit
def test_init_with_no_template_and_no_template_variables():
    # Initialize the PromptBuilder object with no template and no template_variables
    with pytest.raises(ValueError, match="Either template or template_variables must be provided."):
        PromptBuilder()


@pytest.mark.unit
def test_dynamic_template_with_input_variables_no_messages():
    # Initialize the PromptBuilder object with dynamic template variables
    template_variables = ["location", "time"]
    builder = PromptBuilder(template_variables=template_variables)

    # Call the run method with input variables
    with pytest.raises(ValueError, match="PromptBuilder was initialized with template_variables"):
        builder.run(location="New York", time="tomorrow")


@pytest.mark.unit
def test_dynamic_template_with_input_variables_and_messages():
    # Initialize the PromptBuilder object with dynamic template variables
    template_variables = ["location", "time"]
    builder = PromptBuilder(template_variables=template_variables)

    system_message = (
        "Always start response to user with Herr Blagojevic. "
        "Respond in German even if some input data is in other languages"
    )

    # Create a list of ChatMessage objects
    messages = [
        ChatMessage.from_system(system_message),
        ChatMessage.from_user("What's the weather like in {{ location }}?"),
    ]

    # Call the run method with input variables and messages
    result = builder.run(messages=messages, location="New York", time="tomorrow")

    # Assert that the prompt is generated correctly
    assert result["prompt"] == [
        ChatMessage.from_system(system_message),
        ChatMessage.from_user("What's the weather like in New York?"),
    ]


@pytest.mark.unit
def test_static_template_without_input_variables():
    # Initialize the PromptBuilder object with a static template and no input variables
    template = "Translate the following context to Spanish."
    builder = PromptBuilder(template=template)

    # Call the run method without input variables
    result = builder.run()

    # Assert that the prompt is generated correctly
    assert result["prompt"] == "Translate the following context to Spanish."


@pytest.mark.unit
def test_dynamic_template_without_input_variables():
    # Initialize the PromptBuilder object with dynamic template variables
    template_variables = ["location", "time"]
    builder = PromptBuilder(template_variables=template_variables)

    messages = [ChatMessage.from_user("What's LLM?")]

    # Call the run method without input variables
    result = builder.run(messages=messages)

    # Assert that the prompt is generated correctly
    assert result["prompt"] == [ChatMessage.from_user("What's LLM?")]


@pytest.mark.unit
def test_dynamic_template_with_input_variables_and_multiple_user_messages():
    # Initialize the PromptBuilder object with dynamic template variables
    template_variables = ["location", "time"]
    builder = PromptBuilder(template_variables=template_variables)

    system_message = (
        "Always start response to user with Herr Blagojevic. "
        "Respond in German even if some input data is in other languages"
    )
    # Create a list of ChatMessage objects with multiple user messages
    messages = [
        ChatMessage.from_system(system_message),
        ChatMessage.from_user("Here is improper use of {{ location }} as it is not the last message"),
        ChatMessage.from_user("What's the weather like in {{ location }}?"),
    ]

    result = builder.run(messages=messages, location="New York", time="tomorrow")

    assert result["prompt"] == [
        ChatMessage.from_system(system_message),
        ChatMessage.from_user("Here is improper use of {{ location }} as it is not the last message"),
        ChatMessage.from_user("What's the weather like in New York?"),
    ]


def test_dynamic_template_with_invalid_input_variables_and_messages():
    # Initialize the PromptBuilder object with dynamic template variables
    template_variables = ["location", "time"]
    builder = PromptBuilder(template_variables=template_variables)

    system_message = (
        "Always start response to user with Herr Blagojevic. "
        "Respond in German even if some input data is in other languages"
    )

    # Create a list of ChatMessage objects
    messages = [ChatMessage.from_system(system_message), ChatMessage.from_user("What is {{ topic }}?")]

    # Call the run method with input variables and messages
    result = builder.run(messages=messages, location="New York", time="tomorrow")

    # same behaviour as for static template
    # as topic is not a template variable, it is ignored
    assert result["prompt"] == [ChatMessage.from_system(system_message), ChatMessage.from_user("What is ?")]