fix handling of description=None

src/nwbinspector/checks/_general.py

@@ -23,11 +23,15 @@ def check_description(neurodata_object: object) -> Optional[InspectorMessage]:
 
     Best Practice: :ref:`best_practice_placeholders`
     """
-    if not hasattr(neurodata_object, "description") or type(neurodata_object.description) is not str:
+    if not hasattr(neurodata_object, "description"):
         return None
-    if neurodata_object.description is None or neurodata_object.description.strip(" ") == "":
+
+    description = neurodata_object.description
+    if type(description) not in (str, None):
+        return None
+    if description is None or description.strip(" ") == "":
         return InspectorMessage(message="Description is missing.")
-    if neurodata_object.description.lower().strip(".") in COMMON_DESCRIPTION_PLACEHOLDERS:
-        return InspectorMessage(message=f"Description ('{neurodata_object.description}') is a placeholder.")
+    if description.lower().strip(".") in COMMON_DESCRIPTION_PLACEHOLDERS:
+        return InspectorMessage(message=f"Description ('{description}') is a placeholder.")
 
     return None