community[minor]: Added integrations for ThirdAI's NeuralDB as a Retriever (#17334)

**Description:** Adds ThirdAI NeuralDB retriever integration. NeuralDB
is a CPU-friendly and fine-tunable text retrieval engine. We previously
added a vector store integration but we think that it will be easier for
our customers if they can also find us under under
langchain-community/retrievers.

---------

Co-authored-by: kartikTAI <129414343+kartikTAI@users.noreply.github.com>
Co-authored-by: Kartik Sarangmath <kartik@thirdai.com>

libs/community/tests/integration_tests/retrievers/test_thirdai_neuraldb.py

@@ -0,0 +1,58 @@
+import os
+import shutil
+from typing import Generator
+
+import pytest
+
+from langchain_community.retrievers import NeuralDBRetriever
+
+
+@pytest.fixture(scope="session")
+def test_csv() -> Generator[str, None, None]:
+    csv = "thirdai-test.csv"
+    with open(csv, "w") as o:
+        o.write("column_1,column_2\n")
+        o.write("column one,column two\n")
+    yield csv
+    os.remove(csv)
+
+
+def assert_result_correctness(documents: list) -> None:
+    assert len(documents) == 1
+    assert documents[0].page_content == "column_1: column one\n\ncolumn_2: column two"
+
+
+@pytest.mark.requires("thirdai[neural_db]")
+def test_neuraldb_retriever_from_scratch(test_csv: str) -> None:
+    retriever = NeuralDBRetriever.from_scratch()
+    retriever.insert([test_csv])
+    documents = retriever.get_relevant_documents("column")
+    assert_result_correctness(documents)
+
+
+@pytest.mark.requires("thirdai[neural_db]")
+def test_neuraldb_retriever_from_checkpoint(test_csv: str) -> None:
+    checkpoint = "thirdai-test-save.ndb"
+    if os.path.exists(checkpoint):
+        shutil.rmtree(checkpoint)
+    try:
+        retriever = NeuralDBRetriever.from_scratch()
+        retriever.insert([test_csv])
+        retriever.save(checkpoint)
+        loaded_retriever = NeuralDBRetriever.from_checkpoint(checkpoint)
+        documents = loaded_retriever.get_relevant_documents("column")
+        assert_result_correctness(documents)
+    finally:
+        if os.path.exists(checkpoint):
+            shutil.rmtree(checkpoint)
+
+
+@pytest.mark.requires("thirdai[neural_db]")
+def test_neuraldb_retriever_other_methods(test_csv: str) -> None:
+    retriever = NeuralDBRetriever.from_scratch()
+    retriever.insert([test_csv])
+    # Make sure they don't throw an error.
+    retriever.associate("A", "B")
+    retriever.associate_batch([("A", "B"), ("C", "D")])
+    retriever.upvote("A", 0)
+    retriever.upvote_batch([("A", 0), ("B", 0)])

libs/community/tests/integration_tests/vectorstores/test_thirdai_neuraldb.py

@@ -46,14 +46,6 @@ def test_neuraldb_retriever_from_checkpoint(test_csv):  # type: ignore[no-untype
             shutil.rmtree(checkpoint)
 
 
-@pytest.mark.requires("thirdai[neural_db]")
-def test_neuraldb_retriever_from_bazaar(test_csv):  # type: ignore[no-untyped-def]
-    retriever = NeuralDBVectorStore.from_bazaar("General QnA")
-    retriever.insert([test_csv])
-    documents = retriever.similarity_search("column")
-    assert_result_correctness(documents)
-
-
 @pytest.mark.requires("thirdai[neural_db]")
 def test_neuraldb_retriever_other_methods(test_csv):  # type: ignore[no-untyped-def]
     retriever = NeuralDBVectorStore.from_scratch()

libs/community/tests/unit_tests/retrievers/test_imports.py

@@ -40,6 +40,7 @@ EXPECTED_ALL = [
     "ZepRetriever",
     "ZillizRetriever",
     "DocArrayRetriever",
+    "NeuralDBRetriever",
 ]