refactor: use arrow function

src/messaging/notifications.js

@@ -53,9 +53,7 @@ module.exports = function (Messaging) {
 
 	async function sendNotifications(fromuid, uids, roomId, messageObj) {
 		const isOnline = await user.isOnline(uids);
-		uids = uids.filter(function (uid, index) {
+		uids = uids.filter((uid, index) => !isOnline[index] && parseInt(fromuid, 10) !== parseInt(uid, 10));
-			return !isOnline[index] && parseInt(fromuid, 10) !== parseInt(uid, 10);
-		});
 		if (!uids.length) {
 			return;
 		}