chore: minor housekeeping changes

Changes:
- `child_exceptions` should be a tuple
- remove unecessary `else` statements
- add `pragma: no cover` for overload functions
- add test for an invalid DynamoDBPersistenceLayer

Author: Michael Brewer

aws_lambda_powertools/utilities/batch/base.py

@@ -384,7 +384,7 @@ def _clean(self):
             raise BatchProcessingError(
                 msg=f"All records failed processing. {len(self.exceptions)} individual errors logged"
                 f"separately below.",
-                child_exceptions=self.exceptions,
+                child_exceptions=tuple(self.exceptions),
             )
 
         messages = self._get_messages_to_report()
@@ -411,32 +411,28 @@ def _get_messages_to_report(self) -> Dict[str, str]:
     def _collect_sqs_failures(self):
         if self.model:
             return {"itemIdentifier": msg.messageId for msg in self.fail_messages}
-        else:
-            return {"itemIdentifier": msg.message_id for msg in self.fail_messages}
+        return {"itemIdentifier": msg.message_id for msg in self.fail_messages}
 
     def _collect_kinesis_failures(self):
         if self.model:
             # Pydantic model uses int but Lambda poller expects str
             return {"itemIdentifier": msg.kinesis.sequenceNumber for msg in self.fail_messages}
-        else:
-            return {"itemIdentifier": msg.kinesis.sequence_number for msg in self.fail_messages}
+        return {"itemIdentifier": msg.kinesis.sequence_number for msg in self.fail_messages}
 
     def _collect_dynamodb_failures(self):
         if self.model:
             return {"itemIdentifier": msg.dynamodb.SequenceNumber for msg in self.fail_messages}
-        else:
-            return {"itemIdentifier": msg.dynamodb.sequence_number for msg in self.fail_messages}
+        return {"itemIdentifier": msg.dynamodb.sequence_number for msg in self.fail_messages}
 
     @overload
     def _to_batch_type(self, record: dict, event_type: EventType, model: "BatchTypeModels") -> "BatchTypeModels":
-        ...
+        ...  # pragma: no cover
 
     @overload
     def _to_batch_type(self, record: dict, event_type: EventType) -> EventSourceDataClassTypes:
-        ...
+        ...  # pragma: no cover
 
     def _to_batch_type(self, record: dict, event_type: EventType, model: Optional["BatchTypeModels"] = None):
         if model is not None:
             return model.parse_obj(record)
-        else:
-            return self._DATA_CLASS_MAPPING[event_type](record)
+        return self._DATA_CLASS_MAPPING[event_type](record)

aws_lambda_powertools/utilities/parser/parser.py

@@ -86,12 +86,12 @@ def handler(event: Order, context: LambdaContext):
 
 @overload
 def parse(event: Dict[str, Any], model: Type[Model]) -> Model:
-    ...
+    ...  # pragma: no cover
 
 
 @overload
 def parse(event: Dict[str, Any], model: Type[Model], envelope: Type[Envelope]) -> EnvelopeModel:
-    ...
+    ...  # pragma: no cover
 
 
 def parse(event: Dict[str, Any], model: Type[Model], envelope: Optional[Type[Envelope]] = None):

tests/functional/idempotency/test_idempotency.py

@@ -1057,3 +1057,15 @@ def two(data):
     assert one(data=mock_event) == "one"
     assert two(data=mock_event) == "two"
     assert len(persistence_store.table.method_calls) == 4
+
+
+def test_invalid_dynamodb_persistence_layer():
+    # Scenario constructing a DynamoDBPersistenceLayer with a key_attr matching sort_key_attr should fail
+    with pytest.raises(ValueError) as ve:
+        DynamoDBPersistenceLayer(
+            table_name="Foo",
+            key_attr="id",
+            sort_key_attr="id",
+        )
+    # and raise a ValueError
+    assert str(ve.value) == "key_attr [id] and sort_key_attr [id] cannot be the same!"