Implemented exception chaining for all re-raised exceptions (#66)

* Implemented exception chaining for all re-raised exceptions

* Made index.py error messages more consistent

* Updated CHANGELOG

Author: alexthomas93

CHANGELOG.md

@@ -13,6 +13,8 @@
 
 ### Changed
 -   Refactored import paths for retrievers to neo4j_genai.retrievers.
+-   Implemented exception chaining for all re-raised exceptions to improve stack trace readability.
+-   Made error messages in `index.py` more consistent.
 
 ## 0.2.0
 

src/neo4j_genai/embeddings/sentence_transformers.py

@@ -10,11 +10,11 @@ def __init__(
     ) -> None:
         try:
             from sentence_transformers import SentenceTransformer
-        except ImportError:
+        except ImportError as e:
             raise ImportError(
                 "Could not import sentence_transformers python package. "
                 "Please install it with `pip install sentence-transformers`."
-            )
+            ) from e
 
         self.model = SentenceTransformer(model, *args, **kwargs)
 

src/neo4j_genai/indexes.py

@@ -65,7 +65,9 @@ def create_vector_index(
             similarity_fn=similarity_fn,
         )
     except ValidationError as e:
-        raise Neo4jIndexError(f"Error for inputs to create_vector_index {str(e)}")
+        raise Neo4jIndexError(
+            f"Error for inputs to create_vector_index {e.errors()}"
+        ) from e
 
     try:
         query = (
@@ -78,7 +80,7 @@ def create_vector_index(
             {"name": name, "dimensions": dimensions, "similarity_fn": similarity_fn},
         )
     except neo4j.exceptions.ClientError as e:
-        raise Neo4jIndexError(f"Neo4j vector index creation failed: {e}")
+        raise Neo4jIndexError(f"Neo4j vector index creation failed: {e.message}") from e
 
 
 def create_fulltext_index(
@@ -108,7 +110,9 @@ def create_fulltext_index(
             driver=driver, name=name, label=label, node_properties=node_properties
         )
     except ValidationError as e:
-        raise Neo4jIndexError(f"Error for inputs to create_fulltext_index: {str(e)}")
+        raise Neo4jIndexError(
+            f"Error for inputs to create_fulltext_index: {e.errors()}"
+        ) from e
 
     try:
         query = (
@@ -119,7 +123,9 @@ def create_fulltext_index(
         logger.info(f"Creating fulltext index named '{name}'")
         driver.execute_query(query, {"name": name})
     except neo4j.exceptions.ClientError as e:
-        raise Neo4jIndexError(f"Neo4j fulltext index creation failed {e}")
+        raise Neo4jIndexError(
+            f"Neo4j fulltext index creation failed {e.message}"
+        ) from e
 
 
 def drop_index_if_exists(driver: neo4j.Driver, name: str) -> None:
@@ -143,7 +149,7 @@ def drop_index_if_exists(driver: neo4j.Driver, name: str) -> None:
         logger.info(f"Dropping index named '{name}'")
         driver.execute_query(query, parameters)
     except neo4j.exceptions.ClientError as e:
-        raise Neo4jIndexError(f"Dropping Neo4j index failed: {e}")
+        raise Neo4jIndexError(f"Dropping Neo4j index failed: {e.message}") from e
 
 
 def upsert_vector(
@@ -179,4 +185,6 @@ def upsert_vector(
         }
         driver.execute_query(query, parameters)
     except neo4j.exceptions.ClientError as e:
-        raise Neo4jInsertionError(f"Upserting vector to Neo4j failed: {e}")
+        raise Neo4jInsertionError(
+            f"Upserting vector to Neo4j failed: {e.message}"
+        ) from e

src/neo4j_genai/retrievers/base.py

@@ -73,8 +73,8 @@ def _fetch_index_infos(self) -> None:
             self._node_label = result["labels"][0]
             self._embedding_node_property = result["properties"][0]
             self._embedding_dimension = result["dimensions"]
-        except IndexError:
-            raise Exception(f"No index with name {self.index_name} found")
+        except IndexError as e:
+            raise Exception(f"No index with name {self.index_name} found") from e
 
     def search(self, *args: Any, **kwargs: Any) -> RetrieverResult:
         """

src/neo4j_genai/retrievers/external/pinecone/pinecone.py

@@ -109,7 +109,7 @@ def __init__(
                 result_formatter=result_formatter,
             )
         except ValidationError as e:
-            raise RetrieverInitializationError(e.errors())
+            raise RetrieverInitializationError(e.errors()) from e
 
         super().__init__(
             driver=driver,
@@ -190,7 +190,7 @@ def _get_search_results(
                 pinecone_filter=pinecone_filters,
             )
         except ValidationError as e:
-            raise SearchValidationError(e.errors())
+            raise SearchValidationError(e.errors()) from e
 
         if validated_data.query_text:
             if self.embedder:

src/neo4j_genai/retrievers/external/weaviate/weaviate.py

@@ -102,7 +102,7 @@ def __init__(
                 result_formatter=result_formatter,
             )
         except ValidationError as e:
-            raise RetrieverInitializationError(e.errors())
+            raise RetrieverInitializationError(e.errors()) from e
 
         super().__init__(driver, id_property_external, id_property_neo4j)
         self.client = validated_data.client_model.client
@@ -176,7 +176,7 @@ def _get_search_results(
             top_k = validated_data.top_k
             weaviate_filters = validated_data.weaviate_filters
         except ValidationError as e:
-            raise SearchValidationError(e.errors())
+            raise SearchValidationError(e.errors()) from e
 
         # If we want to use a local embedder, we still want to call the near_vector method
         # so we want to create the vector as early as possible here

src/neo4j_genai/retrievers/hybrid.py

@@ -88,7 +88,7 @@ def __init__(
                 return_properties=return_properties,
             )
         except ValidationError as e:
-            raise RetrieverInitializationError(e.errors())
+            raise RetrieverInitializationError(e.errors()) from e
 
         super().__init__(validated_data.driver_model.driver)
         self.vector_index_name = validated_data.vector_index_name
@@ -152,7 +152,7 @@ def _get_search_results(
                 query_text=query_text,
             )
         except ValidationError as e:
-            raise SearchValidationError(e.errors())
+            raise SearchValidationError(e.errors()) from e
 
         parameters = validated_data.model_dump(exclude_none=True)
 
@@ -229,7 +229,7 @@ def __init__(
                 embedder_model=embedder_model,
             )
         except ValidationError as e:
-            raise RetrieverInitializationError(e.errors())
+            raise RetrieverInitializationError(e.errors()) from e
 
         super().__init__(validated_data.driver_model.driver)
         self.vector_index_name = validated_data.vector_index_name
@@ -283,7 +283,7 @@ def _get_search_results(
                 query_params=query_params,
             )
         except ValidationError as e:
-            raise SearchValidationError(e.errors())
+            raise SearchValidationError(e.errors()) from e
 
         parameters = validated_data.model_dump(exclude_none=True)
 

src/neo4j_genai/retrievers/text2cypher.py

@@ -77,7 +77,7 @@ def __init__(
                 examples=examples,
             )
         except ValidationError as e:
-            raise RetrieverInitializationError(e.errors())
+            raise RetrieverInitializationError(e.errors()) from e
 
         super().__init__(validated_data.driver_model.driver)
         self.llm = validated_data.llm_model.llm
@@ -92,7 +92,7 @@ def __init__(
             error_message = getattr(e, "message", str(e))
             raise SchemaFetchError(
                 f"Failed to fetch schema for Text2CypherRetriever: {error_message}"
-            )
+            ) from e
 
     def _get_search_results(
         self,
@@ -114,7 +114,7 @@ def _get_search_results(
         try:
             validated_data = Text2CypherSearchModel(query_text=query_text)
         except ValidationError as e:
-            raise SearchValidationError(e.errors())
+            raise SearchValidationError(e.errors()) from e
 
         prompt_template = Text2CypherTemplate()
         prompt = prompt_template.format(
@@ -130,7 +130,9 @@ def _get_search_results(
             logger.debug("Text2CypherRetriever Cypher query: %s", t2c_query)
             records, _, _ = self.driver.execute_query(query_=t2c_query)
         except CypherSyntaxError as e:
-            raise Text2CypherRetrievalError(f"Failed to get search result: {e.message}")
+            raise Text2CypherRetrievalError(
+                f"Failed to get search result: {e.message}"
+            ) from e
 
         return RawSearchResult(
             records=records,

src/neo4j_genai/retrievers/vector.py

@@ -86,7 +86,7 @@ def __init__(
                 return_properties=return_properties,
             )
         except ValidationError as e:
-            raise RetrieverInitializationError(e.errors())
+            raise RetrieverInitializationError(e.errors()) from e
 
         super().__init__(driver)
         self.index_name = validated_data.index_name
@@ -151,7 +151,7 @@ def _get_search_results(
                 query_text=query_text,
             )
         except ValidationError as e:
-            raise SearchValidationError(e.errors())
+            raise SearchValidationError(e.errors()) from e
 
         parameters = validated_data.model_dump(exclude_none=True)
 
@@ -228,7 +228,7 @@ def __init__(
                 embedder_model=embedder_model,
             )
         except ValidationError as e:
-            raise RetrieverInitializationError(e.errors())
+            raise RetrieverInitializationError(e.errors()) from e
 
         super().__init__(driver)
         self.index_name = validated_data.index_name
@@ -281,7 +281,7 @@ def _get_search_results(
                 query_params=query_params,
             )
         except ValidationError as e:
-            raise SearchValidationError(e.errors())
+            raise SearchValidationError(e.errors()) from e
 
         parameters = validated_data.model_dump(exclude_none=True)