langchain/tests/unit_tests/prompts/test_loading.py

"""Test loading functionality."""

import os
from contextlib import contextmanager
from pathlib import Path
from typing import Iterator

from langchain.prompts.few_shot import FewShotPromptTemplate
from langchain.prompts.loading import load_prompt
from langchain.prompts.prompt import PromptTemplate


@contextmanager
def change_directory() -> Iterator:
    """Change the working directory to the right folder."""
    origin = Path().absolute()
    try:
        os.chdir("docs/modules/prompts/examples")
        yield
    finally:
        os.chdir(origin)


def test_loading_from_YAML() -> None:
    """Test loading from yaml file."""
    with change_directory():
        prompt = load_prompt("simple_prompt.yaml")
        expected_prompt = PromptTemplate(
            input_variables=["adjective", "content"],
            template="Tell me a {adjective} joke about {content}.",
        )
        assert prompt == expected_prompt


def test_loading_from_JSON() -> None:
    """Test loading from json file."""
    with change_directory():
        prompt = load_prompt("simple_prompt.json")
        expected_prompt = PromptTemplate(
            input_variables=["adjective", "content"],
            template="Tell me a {adjective} joke about {content}.",
        )
        assert prompt == expected_prompt


def test_saving_loading_round_trip(tmp_path: Path) -> None:
    """Test equality when saving and loading a prompt."""
    simple_prompt = PromptTemplate(
        input_variables=["adjective", "content"],
        template="Tell me a {adjective} joke about {content}.",
    )
    simple_prompt.save(file_path=tmp_path / "prompt.yaml")
    loaded_prompt = load_prompt(tmp_path / "prompt.yaml")
    assert loaded_prompt == simple_prompt

    few_shot_prompt = FewShotPromptTemplate(
        input_variables=["adjective"],
        prefix="Write antonyms for the following words.",
        example_prompt=PromptTemplate(
            input_variables=["input", "output"],
            template="Input: {input}\nOutput: {output}",
        ),
        examples=[
            {"input": "happy", "output": "sad"},
            {"input": "tall", "output": "short"},
        ],
        suffix="Input: {adjective}\nOutput:",
    )
    few_shot_prompt.save(file_path=tmp_path / "few_shot.yaml")
    loaded_prompt = load_prompt(tmp_path / "few_shot.yaml")
    assert loaded_prompt == few_shot_prompt


def test_loading_with_template_as_file() -> None:
    """Test loading when the template is a file."""
    with change_directory():
        prompt = load_prompt("simple_prompt_with_template_file.json")
        expected_prompt = PromptTemplate(
            input_variables=["adjective", "content"],
            template="Tell me a {adjective} joke about {content}.",
        )
        assert prompt == expected_prompt


def test_loading_few_shot_prompt_from_yaml() -> None:
    """Test loading few shot prompt from yaml."""
    with change_directory():
        prompt = load_prompt("few_shot_prompt.yaml")
        expected_prompt = FewShotPromptTemplate(
            input_variables=["adjective"],
            prefix="Write antonyms for the following words.",
            example_prompt=PromptTemplate(
                input_variables=["input", "output"],
                template="Input: {input}\nOutput: {output}",
            ),
            examples=[
                {"input": "happy", "output": "sad"},
                {"input": "tall", "output": "short"},
            ],
            suffix="Input: {adjective}\nOutput:",
        )
        assert prompt == expected_prompt


def test_loading_few_shot_prompt_from_json() -> None:
    """Test loading few shot prompt from json."""
    with change_directory():
        prompt = load_prompt("few_shot_prompt.json")
        expected_prompt = FewShotPromptTemplate(
            input_variables=["adjective"],
            prefix="Write antonyms for the following words.",
            example_prompt=PromptTemplate(
                input_variables=["input", "output"],
                template="Input: {input}\nOutput: {output}",
            ),
            examples=[
                {"input": "happy", "output": "sad"},
                {"input": "tall", "output": "short"},
            ],
            suffix="Input: {adjective}\nOutput:",
        )
        assert prompt == expected_prompt


def test_loading_few_shot_prompt_when_examples_in_config() -> None:
    """Test loading few shot prompt when the examples are in the config."""
    with change_directory():
        prompt = load_prompt("few_shot_prompt_examples_in.json")
        expected_prompt = FewShotPromptTemplate(
            input_variables=["adjective"],
            prefix="Write antonyms for the following words.",
            example_prompt=PromptTemplate(
                input_variables=["input", "output"],
                template="Input: {input}\nOutput: {output}",
            ),
            examples=[
                {"input": "happy", "output": "sad"},
                {"input": "tall", "output": "short"},
            ],
            suffix="Input: {adjective}\nOutput:",
        )
        assert prompt == expected_prompt


def test_loading_few_shot_prompt_example_prompt() -> None:
    """Test loading few shot when the example prompt is in its own file."""
    with change_directory():
        prompt = load_prompt("few_shot_prompt_example_prompt.json")
        expected_prompt = FewShotPromptTemplate(
            input_variables=["adjective"],
            prefix="Write antonyms for the following words.",
            example_prompt=PromptTemplate(
                input_variables=["input", "output"],
                template="Input: {input}\nOutput: {output}",
            ),
            examples=[
                {"input": "happy", "output": "sad"},
                {"input": "tall", "output": "short"},
            ],
            suffix="Input: {adjective}\nOutput:",
        )
        assert prompt == expected_prompt