null -> undefined

apps/app/src/server/service/page/index.ts

@@ -4110,7 +4110,7 @@ class PageService implements IPageService {
 
     // Do not consider it for automatic deletion if updated at least once
     if (newPageData.wipExpiredAt != null) {
-      newPageData.wipExpiredAt = null;
+      newPageData.wipExpiredAt = undefined;
     }
 
     // use the previous data if absent

packages/core/src/interfaces/page.ts

@@ -40,7 +40,7 @@ export type IPage = {
   latestRevisionBodyLength?: number,
   expandContentWidth?: boolean,
   wip?: boolean,
-  wipExpiredAt?: Date | null,
+  wipExpiredAt?: Date
 }
 
 export type IPagePopulatedToList = Omit<IPageHasId, 'lastUpdateUser'> & {