Rocket.Chat/app/channel-settings/server/functions/saveRoomReadOnly.js

import { Meteor } from 'meteor/meteor';
import { Match } from 'meteor/check';

import { Rooms, Messages } from '../../../models';
import { hasPermission } from '../../../authorization';

export const saveRoomReadOnly = function (rid, readOnly, user, sendMessage = true) {
	if (!Match.test(rid, String)) {
		throw new Meteor.Error('invalid-room', 'Invalid room', {
			function: 'RocketChat.saveRoomReadOnly',
		});
	}
	const result = Rooms.setReadOnlyById(rid, readOnly, hasPermission);

	if (result && sendMessage) {
		readOnly ? Messages.createRoomSetReadOnlyByRoomIdAndUser(rid, user) : Messages.createRoomRemovedReadOnlyByRoomIdAndUser(rid, user);
	}
	return result;
};