chore: make delete user method keep working without relying on msg db watcher

apps/meteor/app/lib/server/functions/deleteUser.ts

@@ -41,9 +41,11 @@ export async function deleteUser(userId: string, confirmRelinquish = false, dele
 
 	// Users without username can't do anything, so there is nothing to remove
 	if (user.username != null) {
+		let userToReplaceWhenUnlinking: IUser | null = null;
+		const nameAlias = i18n.t('Removed_User');
 		await relinquishRoomOwnerships(userId, subscribedRooms);
 
-		const messageErasureType = settings.get('Message_ErasureType');
+		const messageErasureType = settings.get<'Delete' | 'Unlink' | 'Keep'>('Message_ErasureType');
 		switch (messageErasureType) {
 			case 'Delete':
 				const store = FileUpload.getStore('Uploads');
@@ -68,12 +70,11 @@ export async function deleteUser(userId: string, confirmRelinquish = false, dele
 
 				break;
 			case 'Unlink':
-				const rocketCat = await Users.findOneById('rocket.cat');
-				const nameAlias = i18n.t('Removed_User');
-				if (!rocketCat?._id || !rocketCat?.username) {
+				userToReplaceWhenUnlinking = await Users.findOneById('rocket.cat');
+				if (!userToReplaceWhenUnlinking?._id || !userToReplaceWhenUnlinking?.username) {
 					break;
 				}
-				await Messages.unlinkUserId(userId, rocketCat?._id, rocketCat?.username, nameAlias);
+				await Messages.unlinkUserId(userId, userToReplaceWhenUnlinking?._id, userToReplaceWhenUnlinking?.username, nameAlias);
 				break;
 		}
 
@@ -104,8 +105,16 @@ export async function deleteUser(userId: string, confirmRelinquish = false, dele
 		await Integrations.disableByUserId(userId); // Disables all the integrations which rely on the user being deleted.
 
 		// Don't broadcast user.deleted for Erasure Type of 'Keep' so that messages don't disappear from logged in sessions
-		if (messageErasureType !== 'Keep') {
-			void api.broadcast('user.deleted', user);
+		if (messageErasureType === 'Delete') {
+			void api.broadcast('user.deleted', user, {
+				messageErasureType,
+			});
+		}
+		if (messageErasureType === 'Unlink' && userToReplaceWhenUnlinking) {
+			void api.broadcast('user.deleted', user, {
+				messageErasureType,
+				replaceByUser: { _id: userToReplaceWhenUnlinking._id, username: userToReplaceWhenUnlinking?.username, alias: nameAlias },
+			});
 		}
 	}
 

apps/meteor/client/startup/UserDeleted.ts

@@ -4,7 +4,23 @@ import { ChatMessage } from '../../app/models/client';
 import { Notifications } from '../../app/notifications/client';
 
 Meteor.startup(() => {
-	Notifications.onLogged('Users:Deleted', ({ userId }) => {
+	Notifications.onLogged('Users:Deleted', ({ userId, messageErasureType, replaceByUser }) => {
+		if (messageErasureType === 'Unlink' && replaceByUser) {
+			return ChatMessage.update(
+				{
+					'u._id': userId,
+				},
+				{
+					$set: {
+						'alias': replaceByUser.alias,
+						'u._id': replaceByUser._id,
+						'u.username': replaceByUser.username,
+						'u.name': undefined,
+					},
+				},
+				{ multi: true },
+			);
+		}
 		ChatMessage.remove({
 			'u._id': userId,
 		});

apps/meteor/server/modules/listeners/listeners.module.ts

@@ -99,9 +99,10 @@ export class ListenersModule {
 			});
 		});
 
-		service.onEvent('user.deleted', ({ _id: userId }) => {
+		service.onEvent('user.deleted', ({ _id: userId }, data) => {
 			notifications.notifyLoggedInThisInstance('Users:Deleted', {
 				userId,
+				...data,
 			});
 		});
 

ee/packages/ddp-client/src/types/streams.ts

@@ -226,9 +226,16 @@ export interface StreamerEvents {
 		{
 			key: 'Users:Deleted';
 			args: [
-				{
-					userId: IUser['_id'];
-				},
+				| {
+						userId: IUser['_id'];
+						messageErasureType: 'Delete';
+						replaceByUser?: never;
+				  }
+				| {
+						userId: IUser['_id'];
+						messageErasureType: 'Unlink';
+						replaceByUser?: { _id: IUser['_id']; username: IUser['username']; alias: string };
+				  },
 			];
 		},
 		{

packages/core-services/src/events/Events.ts

@@ -100,7 +100,17 @@ export type EventSignatures = {
 	'stream'([streamer, eventName, payload]: [string, string, any[]]): void;
 	'subscription'(data: { action: string; subscription: Partial<ISubscription> }): void;
 	'user.avatarUpdate'(user: Partial<IUser>): void;
-	'user.deleted'(user: Pick<IUser, '_id'>): void;
+	'user.deleted'(
+		user: Pick<IUser, '_id'>,
+		data:
+			| {
+					messageErasureType: 'Delete';
+			  }
+			| {
+					messageErasureType: 'Unlink';
+					replaceByUser: { _id: IUser['_id']; username: IUser['username']; alias: string };
+			  },
+	): void;
 	'user.deleteCustomStatus'(userStatus: IUserStatus): void;
 	'user.nameChanged'(user: Pick<IUser, '_id' | 'name' | 'username'>): void;
 	'user.realNameChanged'(user: Partial<IUser>): void;