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langchain/tests/unit_tests/chains/test_llm.py

72 lines
2.3 KiB
Python

"""Test LLM chain."""
from tempfile import TemporaryDirectory
from typing import Dict, List, Union
from unittest.mock import patch
import pytest
from langchain.chains.llm import LLMChain
from langchain.chains.loading import load_chain
from langchain.prompts.prompt import PromptTemplate
from langchain.schema import BaseOutputParser
from tests.unit_tests.llms.fake_llm import FakeLLM
class FakeOutputParser(BaseOutputParser):
"""Fake output parser class for testing."""
def parse(self, text: str) -> Union[str, List[str], Dict[str, str]]:
"""Parse by splitting."""
return text.split()
@pytest.fixture
def fake_llm_chain() -> LLMChain:
"""Fake LLM chain for testing purposes."""
prompt = PromptTemplate(input_variables=["bar"], template="This is a {bar}:")
return LLMChain(prompt=prompt, llm=FakeLLM(), output_key="text1")
@patch("langchain.llms.loading.type_to_cls_dict", {"fake": FakeLLM})
def test_serialization(fake_llm_chain: LLMChain) -> None:
"""Test serialization."""
with TemporaryDirectory() as temp_dir:
file = temp_dir + "/llm.json"
fake_llm_chain.save(file)
loaded_chain = load_chain(file)
assert loaded_chain == fake_llm_chain
def test_missing_inputs(fake_llm_chain: LLMChain) -> None:
"""Test error is raised if inputs are missing."""
with pytest.raises(ValueError):
fake_llm_chain({"foo": "bar"})
def test_valid_call(fake_llm_chain: LLMChain) -> None:
"""Test valid call of LLM chain."""
output = fake_llm_chain({"bar": "baz"})
assert output == {"bar": "baz", "text1": "foo"}
# Test with stop words.
output = fake_llm_chain({"bar": "baz", "stop": ["foo"]})
# Response should be `bar` now.
assert output == {"bar": "baz", "stop": ["foo"], "text1": "bar"}
def test_predict_method(fake_llm_chain: LLMChain) -> None:
"""Test predict method works."""
output = fake_llm_chain.predict(bar="baz")
assert output == "foo"
def test_predict_and_parse() -> None:
"""Test parsing ability."""
prompt = PromptTemplate(
input_variables=["foo"], template="{foo}", output_parser=FakeOutputParser()
)
llm = FakeLLM(queries={"foo": "foo bar"})
chain = LLMChain(prompt=prompt, llm=llm)
output = chain.predict_and_parse(foo="foo")
assert output == ["foo", "bar"]