fix: small changes

Author: leandrodamascena

aws_lambda_powertools/utilities/idempotency/persistence/redis.py

@@ -332,8 +332,8 @@ def _item_to_data_record(self, idempotency_key: str, item: dict[str, Any]) -> Da
             idempotency_key=idempotency_key,
             status=item[self.status_attr],
             in_progress_expiry_timestamp=in_progress_expiry_timestamp,
-            response_data=item.get(self.data_attr),
-            payload_hash=item.get(self.validation_key_attr),
+            response_data=item.get(self.data_attr, ""),
+            payload_hash=item.get(self.validation_key_attr, ""),
             expiry_timestamp=item.get("expiration"),
         )
 

tests/functional/idempotency/_redis/test_redis_layer.py

@@ -333,7 +333,7 @@ def test_item_to_datarecord_conversion(valid_record):
 def test_item_to_datarecord_conversion_missing_optional_attributes(persistence_store_standalone_redis):
     """
     When data_attr or validation_key_attr is missing from Redis,
-    response_data and payload_hash should be None — not the string "None".
+    response_data and payload_hash should be empty string, not the string "None".
     Regression test for: https://github.com/aws-powertools/powertools-lambda-python/issues/8090
     """
     idempotency_key = "test-func#abc123"
@@ -345,8 +345,8 @@ def test_item_to_datarecord_conversion_missing_optional_attributes(persistence_s
 
     record = persistence_store_standalone_redis._item_to_data_record(idempotency_key, item)
 
-    assert record.response_data is None
-    assert record.payload_hash is None
+    assert record.response_data == ""
+    assert record.payload_hash == ""
 
 
 def test_idempotent_function_and_lambda_handler_redis_basic(