Fix error when collection is null in collection notification (#38831)

app/javascript/mastodon/features/collections/detail/revoke_collection_inclusion_modal.tsx

@@ -27,7 +27,7 @@ const messages = defineMessages({
   },
 });
 
-export function useConfirmRevoke(collection?: ApiCollectionJSON) {
+export function useConfirmRevoke(collection?: ApiCollectionJSON | null) {
   const dispatch = useAppDispatch();
   const { id, items = [] } = collection ?? {};
   const ownCollectionItemId = items.find((item) => item.account_id === me)?.id;

app/javascript/mastodon/features/notifications_v2/components/notification_collection.tsx

@@ -24,9 +24,14 @@ export const NotificationCollection: React.FC<{
   unread: boolean;
 }> = ({ notification, unread }) => {
   const { collection, type } = notification;
-  const collectionCreatorAccount = useAccount(collection.account_id);
+
+  const collectionCreatorAccount = useAccount(collection?.account_id);
   const confirmRevoke = useConfirmRevoke(collection);
 
+  if (!collection) {
+    return null;
+  }
+
   return (
     <div
       className={classNames(

app/javascript/mastodon/models/notification_group.ts

@@ -91,11 +91,11 @@ export interface NotificationGroupAdminReport extends BaseNotification<'admin.re
 
 type Collection = ApiCollectionJSON;
 export interface NotificationGroupAddedToCollection extends BaseNotification<'added_to_collection'> {
-  collection: Collection;
+  collection: Collection | null;
 }
 
 export interface NotificationGroupCollectionUpdate extends BaseNotification<'collection_update'> {
-  collection: Collection;
+  collection: Collection | null;
 }
 
 export type NotificationGroup =