chore: return dict or empty list as default instead

Signed-off-by: Heitor Lessa <[email protected]>

Author: heitorlessa

aws_lambda_powertools/utilities/data_classes/common.py

@@ -105,8 +105,8 @@ def query_string_parameters(self) -> Optional[Dict[str, str]]:
         return self.get("queryStringParameters")
 
     @property
-    def multi_value_query_string_parameters(self) -> Optional[Dict[str, List[str]]]:
-        return self.get("multiValueQueryStringParameters")
+    def multi_value_query_string_parameters(self) -> Dict[str, List[str]]:
+        return self.get("multiValueQueryStringParameters") or {}
 
     @property
     def resolved_query_string_parameters(self) -> Dict[str, List[str]]:

aws_lambda_powertools/utilities/data_classes/shared_functions.py

@@ -90,7 +90,7 @@ def get_multi_value_query_string_values(
     multi_value_query_string_parameters: Dict[str, list[str]] | None,
     name: str,
     default_values: list[str] | None = None,
-) -> list[str] | None:
+) -> list[str]:
     """
     Retrieves the values of a multi-value string parameters specified by the given name.
 
@@ -107,5 +107,7 @@ def get_multi_value_query_string_values(
         The values of the query string parameter if found, or the default values if not found.
     """
 
-    params = multi_value_query_string_parameters
-    return default_values if not params else params.get(name, default_values)
+    default = default_values or []
+    params = multi_value_query_string_parameters or {}
+
+    return params.get(name) or default

tests/unit/test_data_classes.py

@@ -275,7 +275,7 @@ def test_base_proxy_event_get_multi_value_query_string_values():
     assert values == default_values
 
     values = event.get_multi_value_query_string_values("unknown")
-    assert values is None
+    assert values == []
 
 
 def test_base_proxy_event_get_header_value():