A minimal frontend service for updating user data in Angular

user.service.ts

@Injectable({ providedIn: 'root' })
constructor(private socketService: SocketService) {
    this.subs.add(
        this.socketService.userChange.subscribe((change: UserChange) => {
            const {user, action} = change;

            switch (change.action) {
                case UserAction.join:
                case TeamAction.position:
                    this._users.set(user.email, user);
                    break;
                case UserAction.leave:
                    this._users.delete(user.email);
                    break;
        })
    );
}