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/examples/prompts")
        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_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