fix: unnecessary return; better error handling

Author: heitorlessa

aws_lambda_powertools/utilities/parser/envelopes/base.py

@@ -23,9 +23,6 @@ def _parse_user_dict_schema(user_event: Dict[str, Any], schema: BaseModel) -> An
 
     @staticmethod
     def _parse_user_json_string_schema(user_event: str, schema: BaseModel) -> Any:
-        if user_event is None:
-            return None
-
         # this is used in cases where the underlying schema is not a Dict that can be parsed as baseModel
         # but a plain string as payload i.e. SQS: "body": "Test message."
         if schema is str:
@@ -40,7 +37,7 @@ def _parse_user_json_string_schema(user_event: str, schema: BaseModel) -> Any:
 
     @abstractmethod
     def parse(self, event: Dict[str, Any], schema: BaseModel):
-        return NotImplemented
+        return NotImplemented  # pragma: no cover
 
 
 def parse_envelope(event: Dict[str, Any], envelope: BaseEnvelope, schema: BaseModel):

aws_lambda_powertools/utilities/parser/envelopes/event_bridge.py

@@ -36,6 +36,6 @@ def parse(self, event: Dict[str, Any], schema: BaseModel) -> BaseModel:
         """
         try:
             parsed_envelope = EventBridgeSchema(**event)
-        except (ValidationError, TypeError):
-            raise SchemaValidationError("EventBridge input doesn't conform with schema") from ValidationError
+        except ValidationError as e:
+            raise SchemaValidationError("EventBridge input doesn't conform with schema") from e
         return self._parse_user_dict_schema(parsed_envelope.detail, schema)

aws_lambda_powertools/utilities/parser/parser.py

@@ -53,15 +53,16 @@ def handler(event: MyBusiness , context: LambdaContext):
         SchemaValidationError
             When input event doesn't conform with schema provided
     """
-    lambda_handler_name = handler.__name__
     if envelope is None:
         try:
             logger.debug("Parsing and validating event schema; no envelope used")
             parsed_event = schema(**event)
-        except (ValidationError, TypeError) as e:
+        except ValidationError as e:
             raise SchemaValidationError("Input event doesn't conform with schema") from e
+
     else:
         parsed_event = parse_envelope(event, envelope, schema)
 
+    lambda_handler_name = handler.__name__
     logger.debug(f"Calling handler {lambda_handler_name}")
     return handler(parsed_event, context)