fix(event-sources): return for none for null types

Author: Michael Brewer

aws_lambda_powertools/utilities/data_classes/dynamo_db_stream_event.py

@@ -106,14 +106,13 @@ def ns_value(self) -> Optional[List[str]]:
         return self.get("NS")
 
     @property
-    def null_value(self) -> Optional[bool]:
+    def null_value(self) -> None:
         """An attribute of type Null.
 
         Example:
             >>> {"NULL": True}
         """
-        item = self.get("NULL")
-        return None if item is None else bool(item)
+        return None
 
     @property
     def s_value(self) -> Optional[str]:

tests/functional/test_data_classes.py

@@ -544,9 +544,19 @@ def test_dynamo_attribute_value_null_value():
     attribute_value = AttributeValue(example_attribute_value)
 
     assert attribute_value.get_type == AttributeValueType.Null
+    assert attribute_value.null_value is None
     assert attribute_value.null_value == attribute_value.get_value
 
 
+def test_dynamo_attribute_value_null_value_invalid():
+    example_attribute_value = {"NULL": False}
+
+    attribute_value = AttributeValue(example_attribute_value)
+
+    assert attribute_value.get_type == AttributeValueType.Null
+    assert attribute_value.null_value is None
+
+
 def test_dynamo_attribute_value_s_value():
     example_attribute_value = {"S": "Hello"}