Deletion handlers: Make protocol implementation explicit; tweak handl…

…er check.

src/codehelp/deletion_handler.py

@@ -4,11 +4,11 @@
 
 """Implementation of personal data deletion for CodeHelp."""
 
-from gened.data_deletion import register_handler
+from gened.data_deletion import DeletionHandler, register_handler
 from gened.db import get_db
 
 
-class CodeHelpDeletionHandler:
+class CodeHelpDeletionHandler(DeletionHandler):
     """CodeHelp implementation of personal data deletion."""
 
     def delete_user_data(self, user_id: int) -> None:

src/gened/base.py

@@ -181,7 +181,7 @@ def create_app_base(import_name: str, app_config: dict[str, Any], instance_path:
     app.config.from_mapping(total_config)
 
     # verify deletion handler is registered
-    if data_deletion.get_handler() is None:
+    if not data_deletion.has_handler():
         app.logger.error("No deletion handler registered. All Gen-Ed applications must provide one.")
         sys.exit(1)
 

src/gened/data_deletion.py

@@ -32,9 +32,9 @@ def register_handler(handler: DeletionHandler) -> None:
     _handler = handler
 
 
-def get_handler() -> DeletionHandler | None:
-    """Get the registered deletion handler."""
-    return _handler
+def has_handler() -> bool:
+    """Return whether a deletion handler has been registered (True) or not (False)."""
+    return _handler is not None
 
 
 def delete_user_data(user_id: int) -> None:

src/starburst/deletion_handler.py

@@ -2,11 +2,11 @@
 #
 # SPDX-License-Identifier: AGPL-3.0-only
 
-from gened.data_deletion import register_handler
+from gened.data_deletion import DeletionHandler, register_handler
 from gened.db import get_db
 
 
-class StarburstDeletionHandler:
+class StarburstDeletionHandler(DeletionHandler):
     """Handler for deleting Starburst user data."""
 
     def delete_user_data(self, user_id: int) -> None: