fix: correct sonar quality checks (#1568)

Signed-off-by: Alejandro Jose Leiva Palomo <[email protected]>

trestle/core/catalog/catalog_interface.py

@@ -469,9 +469,9 @@ def _get_groups_from_group(group: cat.Group) -> Iterator[cat.Group]:
     def get_group_info_by_control(self, control_id: str) -> Tuple[str, str, str]:
         """Get the group_id, title, class for this control from the dict."""
         return (
-            self._control_dict[control_id].group_id,
-            self._control_dict[control_id].group_title,
-            self._control_dict[control_id].group_class
+            '' if self._control_dict is None else self._control_dict[control_id].group_id,
+            '' if self._control_dict is None else self._control_dict[control_id].group_title,
+            '' if self._control_dict is None else self._control_dict[control_id].group_class
         )
 
     def get_control_path(self, control_id: str) -> List[str]:

trestle/core/catalog/catalog_merger.py

@@ -94,7 +94,10 @@ def merge_catalog(self, catalog: cat.Catalog, replace_params: bool) -> None:
                 self._catalog_interface._control_dict[src.id] = new_control_handle  # type: ignore
 
         # now need to cull any controls that are not in the src catalog
-        handled_ids = set(cat_interface._control_dict.keys())
+        if cat_interface._control_dict is None:
+            handled_ids = None
+        else:
+            handled_ids = set(cat_interface._control_dict.keys())
         orig_ids = set(self._catalog_interface._control_dict.keys())
         extra_ids = orig_ids.difference(handled_ids)
         for extra_id in sorted(extra_ids):