Typing fix: Narrow optional types with asserts

lms/events/subscribers.py

@@ -7,4 +7,5 @@
 @subscriber(BaseEvent)
 def handle_event(event: BaseEvent):
     """Record the event in the Event model's table."""
+    assert event.request
     event.request.find_service(EventService).insert_event(event)

lms/services/vitalsource/service.py

@@ -62,11 +62,13 @@ def page_ranges_enabled(self) -> bool:
 
     def get_book_info(self, book_id: str) -> dict:
         """Get details of a book."""
+        assert self._metadata_client
 
         return self._metadata_client.get_book_info(book_id)
 
     def get_table_of_contents(self, book_id: str) -> list[dict]:
         """Get the table of contents for a book."""
+        assert self._metadata_client
 
         return self._metadata_client.get_table_of_contents(book_id)
 
@@ -157,6 +159,7 @@ def get_sso_redirect(self, document_url, user_reference: str) -> str:
         :param user_reference: The user reference (you can use
             `get_user_reference()` to help you with this)
         """
+        assert self._sso_client
         return self._sso_client.get_sso_redirect(
             user_reference, self.get_book_reader_url(document_url)
         )