langchain/tests/integration_tests/vectorstores/test_faiss.py
Mike Salvatore d0c7f7c317
Remove None default value for FAISS relevance_score_fn (#7085)
## Description

The type hint for `FAISS.__init__()`'s `relevance_score_fn` parameter
allowed the parameter to be set to `None`. However, a default function
is provided by the constructor. This led to an unnecessary check in the
code, as well as a test to verify this check.

**ASSUMPTION**: There's no reason to ever set `relevance_score_fn` to
`None`.

This PR changes the type hint and removes the unnecessary code.
2023-07-03 10:11:49 -06:00

198 lines
7.5 KiB
Python

"""Test FAISS functionality."""
import datetime
import math
import tempfile
import pytest
from langchain.docstore.document import Document
from langchain.docstore.in_memory import InMemoryDocstore
from langchain.docstore.wikipedia import Wikipedia
from langchain.vectorstores.faiss import FAISS
from tests.integration_tests.vectorstores.fake_embeddings import FakeEmbeddings
def test_faiss() -> None:
"""Test end to end construction and search."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
index_to_id = docsearch.index_to_docstore_id
expected_docstore = InMemoryDocstore(
{
index_to_id[0]: Document(page_content="foo"),
index_to_id[1]: Document(page_content="bar"),
index_to_id[2]: Document(page_content="baz"),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
output = docsearch.similarity_search("foo", k=1)
assert output == [Document(page_content="foo")]
def test_faiss_vector_sim() -> None:
"""Test vector similarity."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
index_to_id = docsearch.index_to_docstore_id
expected_docstore = InMemoryDocstore(
{
index_to_id[0]: Document(page_content="foo"),
index_to_id[1]: Document(page_content="bar"),
index_to_id[2]: Document(page_content="baz"),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
query_vec = FakeEmbeddings().embed_query(text="foo")
output = docsearch.similarity_search_by_vector(query_vec, k=1)
assert output == [Document(page_content="foo")]
def test_faiss_mmr() -> None:
texts = ["foo", "foo", "fou", "foy"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
query_vec = FakeEmbeddings().embed_query(text="foo")
# make sure we can have k > docstore size
output = docsearch.max_marginal_relevance_search_with_score_by_vector(
query_vec, k=10, lambda_mult=0.1
)
assert len(output) == len(texts)
assert output[0][0] == Document(page_content="foo")
assert output[0][1] == 0.0
assert output[1][0] != Document(page_content="foo")
def test_faiss_with_metadatas() -> None:
"""Test end to end construction and search."""
texts = ["foo", "bar", "baz"]
metadatas = [{"page": i} for i in range(len(texts))]
docsearch = FAISS.from_texts(texts, FakeEmbeddings(), metadatas=metadatas)
expected_docstore = InMemoryDocstore(
{
docsearch.index_to_docstore_id[0]: Document(
page_content="foo", metadata={"page": 0}
),
docsearch.index_to_docstore_id[1]: Document(
page_content="bar", metadata={"page": 1}
),
docsearch.index_to_docstore_id[2]: Document(
page_content="baz", metadata={"page": 2}
),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
output = docsearch.similarity_search("foo", k=1)
assert output == [Document(page_content="foo", metadata={"page": 0})]
def test_faiss_with_metadatas_and_filter() -> None:
texts = ["foo", "bar", "baz"]
metadatas = [{"page": i} for i in range(len(texts))]
docsearch = FAISS.from_texts(texts, FakeEmbeddings(), metadatas=metadatas)
expected_docstore = InMemoryDocstore(
{
docsearch.index_to_docstore_id[0]: Document(
page_content="foo", metadata={"page": 0}
),
docsearch.index_to_docstore_id[1]: Document(
page_content="bar", metadata={"page": 1}
),
docsearch.index_to_docstore_id[2]: Document(
page_content="baz", metadata={"page": 2}
),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
output = docsearch.similarity_search("foo", k=1, filter={"page": 1})
assert output == [Document(page_content="bar", metadata={"page": 1})]
def test_faiss_with_metadatas_and_list_filter() -> None:
texts = ["foo", "bar", "baz", "foo", "qux"]
metadatas = [{"page": i} if i <= 3 else {"page": 3} for i in range(len(texts))]
docsearch = FAISS.from_texts(texts, FakeEmbeddings(), metadatas=metadatas)
expected_docstore = InMemoryDocstore(
{
docsearch.index_to_docstore_id[0]: Document(
page_content="foo", metadata={"page": 0}
),
docsearch.index_to_docstore_id[1]: Document(
page_content="bar", metadata={"page": 1}
),
docsearch.index_to_docstore_id[2]: Document(
page_content="baz", metadata={"page": 2}
),
docsearch.index_to_docstore_id[3]: Document(
page_content="foo", metadata={"page": 3}
),
docsearch.index_to_docstore_id[4]: Document(
page_content="qux", metadata={"page": 3}
),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
output = docsearch.similarity_search("foor", k=1, filter={"page": [0, 1, 2]})
assert output == [Document(page_content="foo", metadata={"page": 0})]
def test_faiss_search_not_found() -> None:
"""Test what happens when document is not found."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
# Get rid of the docstore to purposefully induce errors.
docsearch.docstore = InMemoryDocstore({})
with pytest.raises(ValueError):
docsearch.similarity_search("foo")
def test_faiss_add_texts() -> None:
"""Test end to end adding of texts."""
# Create initial doc store.
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
# Test adding a similar document as before.
docsearch.add_texts(["foo"])
output = docsearch.similarity_search("foo", k=2)
assert output == [Document(page_content="foo"), Document(page_content="foo")]
def test_faiss_add_texts_not_supported() -> None:
"""Test adding of texts to a docstore that doesn't support it."""
docsearch = FAISS(FakeEmbeddings().embed_query, None, Wikipedia(), {})
with pytest.raises(ValueError):
docsearch.add_texts(["foo"])
def test_faiss_local_save_load() -> None:
"""Test end to end serialization."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
temp_timestamp = datetime.datetime.utcnow().strftime("%Y%m%d-%H%M%S")
with tempfile.TemporaryDirectory(suffix="_" + temp_timestamp + "/") as temp_folder:
docsearch.save_local(temp_folder)
new_docsearch = FAISS.load_local(temp_folder, FakeEmbeddings())
assert new_docsearch.index is not None
def test_faiss_similarity_search_with_relevance_scores() -> None:
"""Test the similarity search with normalized similarities."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(
texts,
FakeEmbeddings(),
relevance_score_fn=lambda score: 1.0 - score / math.sqrt(2),
)
outputs = docsearch.similarity_search_with_relevance_scores("foo", k=1)
output, score = outputs[0]
assert output == Document(page_content="foo")
assert score == 1.0
def test_faiss_invalid_normalize_fn() -> None:
"""Test the similarity search with normalized similarities."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(
texts, FakeEmbeddings(), relevance_score_fn=lambda _: 2.0
)
with pytest.warns(Warning, match="scores must be between"):
docsearch.similarity_search_with_relevance_scores("foo", k=1)