Styjun

I am kinda new at Angular, I build small PoC but I am missing some points before I move, is there any way to make this code synchronous?
What I mean by this is that until you have no response from the User method which calls REST API, what I want in my ErrorInterceptor is that...

Once someone login to the web correctly, he is moved to the home page, and token (User object) is stored in localStorage, so after user came back in a next day the REST token is already expired, so I implemented refresh token methodology and once someone will navigate to any page he basically fetch data via REST API in the background, to do this he need a new token, so method this.userService.refreshToken(currentUser) to refresh the token and update the one that is stored for User, everything looks good in this code but I need to somehow prevent Error to not be shown to user (as the token is refreshed in the meantime and next calls will work just fine).

If I wanted to return the "throwError" in the subscribe block, it did not work at all, it does return error in the end, so is there any chance to restrict to not show the error if token is refreshed and it is valid one now?

import Injectable from '@angular/core';
import HttpRequest, HttpHandler, HttpEvent, HttpInterceptor from '@angular/common/http';
import Observable, throwError from 'rxjs';
import catchError, first, tap from 'rxjs/operators';

import AuthenticationService, UserService from '@/_services';
import rejects from "assert";
@Injectable()
export class ErrorInterceptor implements HttpInterceptor 
 constructor(private authenticationService: AuthenticationService, private userService: UserService) 
 

 intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> 
 let currentUser = this.authenticationService.currentUserValue;
 return next.handle(request).pipe(
 catchError(err => 
 console.log(JSON.stringify(err));
 if (err.status === 401 && !location.pathname.includes('/login')) 
 if (err.error.message && err.error.message.toString().includes("Not authorized!") && currentUser.refreshToken) 
 this.userService.refreshToken(currentUser)
 .pipe(first())
 .subscribe(
 data => 
 currentUser.token = data['token'];
 return next.handle(request);
 , error => 
 this.authenticationService.logout();
 location.reload(true);//
 
 )
 
 
 return throwError(JSON.stringify(err.error));
 
 ))