how to terminate pipe operation in @ngrx/effects?

In below code, I'm getting the length of the collection as observable from Firestore.

getUserCartLength(uid:string){
    return this.db.collection('users/'+uid+'/cart').valueChanges()
        .pipe(
            map(docs=>{return docs.length})
        )
}

And this method is accessed by the @ngrx/effects as follows

@Effect()
userExist$ = this.actions$.ofType(UserAuthTypes.YES_USER_EXIST).pipe(
    map((action:YesUserExist)=>action.user),
    switchMap((user)=>{
        return this.userService.getUserCartLength(user.uid)
                .pipe(
                    map(length=>{
                        console.log(length);
                        return new InitializeUserCart(length);
                    })
                )
    }),
)

And in the component, I'm using store method to dispatch actions after checking user exists or not

ngOnInit() {
  this.logService.isUserExist().subscribe(user=>{
      if(user) this.store.dispatch(new fromUser.YesUserExist(user));
      else this.store.dispatch(new fromUser.NoUser());
  })
}

everything works fine as long as user logged-In. When user logged-out it throws an error as below

core.js:1673 ERROR Error: Missing or insufficient permissions.

My understanding about this error is that pipe operation is still trying to access database

Is there any way to close pipe operation in ngrx/effects or any other approach please help me !