snapshot of https://github.com/RocketChat/Rocket.Chat.git (develop, 2026-09-16; blobs > 131072B omitted)

apps/meteor/server/lib/messaging/mentions/Mentions.ts

@@ -0,0 +1,128 @@
+/*
+ * Mentions is a named function that will process Mentions
+ * @param {Object} message - The message object
+ */
+import { isE2EEMessage, type IMessage, type IRoom, type IUser } from '@rocket.chat/core-typings';
+
+import { type MentionsParserArgs, MentionsParser } from '../../../../app/mentions/lib/MentionsParser';
+import { extractMentionsFromMessageAST } from '../../messages/extractMentionsFromMessageAST';
+
+type MentionsServerArgs = MentionsParserArgs & {
+	messageMaxAll: () => number;
+	getChannels: (c: string[]) => Promise<Pick<IRoom, '_id' | 'name' | 'fname' | 'federated'>[]>;
+	getUsers: (u: string[]) => Promise<{ type: 'team' | 'user'; _id: string; username?: string; name?: string }[]>;
+	getUser: (u: string) => Promise<IUser | null>;
+	getTotalChannelMembers: (rid: string) => Promise<number>;
+	onMaxRoomMembersExceeded: ({ sender, rid }: { sender: IMessage['u']; rid: string }) => Promise<void>;
+};
+
+export class MentionsServer extends MentionsParser {
+	messageMaxAll: MentionsServerArgs['messageMaxAll'];
+
+	getChannels: MentionsServerArgs['getChannels'];
+
+	getUsers: MentionsServerArgs['getUsers'];
+
+	getUser: MentionsServerArgs['getUser'];
+
+	getTotalChannelMembers: MentionsServerArgs['getTotalChannelMembers'];
+
+	onMaxRoomMembersExceeded: MentionsServerArgs['onMaxRoomMembersExceeded'];
+
+	constructor(args: MentionsServerArgs) {
+		super(args);
+
+		this.messageMaxAll = args.messageMaxAll;
+		this.getChannels = args.getChannels;
+		this.getUsers = args.getUsers;
+		this.getUser = args.getUser;
+		this.getTotalChannelMembers = args.getTotalChannelMembers;
+		this.onMaxRoomMembersExceeded =
+			args.onMaxRoomMembersExceeded ||
+			(() => {
+				/* do nothing */
+			});
+	}
+
+	async getUsersByMentions(message: IMessage): Promise<IMessage['mentions']> {
+		const { msg, rid, u: sender, e2eMentions }: Pick<IMessage, 'msg' | 'rid' | 'u' | 't' | 'e2eMentions'> = message;
+
+		const mentions =
+			isE2EEMessage(message) && e2eMentions?.e2eUserMentions && e2eMentions?.e2eUserMentions.length > 0
+				? e2eMentions?.e2eUserMentions
+				: this.getUserMentions(msg);
+
+		return this.convertMentionsToUsers(mentions, rid, sender);
+	}
+
+	async convertMentionsToUsers(mentions: string[], rid: string, sender: IMessage['u']): Promise<IMessage['mentions']> {
+		const mentionsAll: { _id: string; username: string }[] = [];
+		const userMentions = new Set<string>();
+
+		// A message may mention both @all and @here; fetch the member count at
+		// most once per message instead of once per mention.
+		let totalChannelMembers: number | undefined;
+
+		for (const m of mentions) {
+			let mention: string;
+			if (m.includes(':')) {
+				mention = m.trim();
+			} else if (m.startsWith('@')) {
+				mention = m.substring(1);
+			} else {
+				mention = m;
+			}
+			if (mention !== 'all' && mention !== 'here') {
+				userMentions.add(mention);
+				continue;
+			}
+			if (this.messageMaxAll() > 0) {
+				totalChannelMembers ??= await this.getTotalChannelMembers(rid);
+				if (totalChannelMembers > this.messageMaxAll()) {
+					await this.onMaxRoomMembersExceeded({ sender, rid });
+					continue;
+				}
+			}
+			mentionsAll.push({
+				_id: mention,
+				username: mention,
+			});
+		}
+
+		return [...mentionsAll, ...(userMentions.size ? await this.getUsers(Array.from(userMentions)) : [])];
+	}
+
+	async getChannelbyMentions(message: IMessage) {
+		const { msg, e2eMentions }: Pick<IMessage, 'msg' | 't' | 'e2eMentions'> = message;
+
+		const channels =
+			isE2EEMessage(message) && e2eMentions?.e2eChannelMentions && e2eMentions?.e2eChannelMentions.length > 0
+				? e2eMentions?.e2eChannelMentions
+				: this.getChannelMentions(msg);
+		return this.convertMentionsToChannels(channels);
+	}
+
+	async convertMentionsToChannels(channels: string[]): Promise<Pick<IRoom, '_id' | 'name' | 'fname' | 'federated'>[]> {
+		// Most messages don't mention any channel; skip the (empty) database
+		// query entirely in that case. An empty $in matches nothing anyway.
+		if (channels.length === 0) {
+			return [];
+		}
+
+		return this.getChannels(channels.map((c) => (c.startsWith('#') ? c.substring(1) : c)));
+	}
+
+	async execute(message: IMessage) {
+		if (message.md) {
+			const { mentions, channels } = extractMentionsFromMessageAST(message.md);
+			message.mentions = await this.convertMentionsToUsers(mentions, message.rid, message.u);
+			message.channels = await this.convertMentionsToChannels(channels);
+			return message;
+		}
+
+		message.mentions = await this.getUsersByMentions(message);
+		message.channels = await this.getChannelbyMentions(message);
+
+		return message;
+	}
+}