Token Refresh HttpInterceptor with Reactive Error Handling

import { HttpInterceptorFn, HttpErrorResponse } from '@angular/common/http';
import { inject } from '@angular/core';
import { catchError, switchMap, throwError } from 'rxjs';
import { AuthService } from './auth.service';
 
export const authRefreshInterceptor: HttpInterceptorFn = (req, next) => {
  const authService = inject(AuthService);
 
  return next(req).pipe(
    catchError((error: unknown) => {
      if (error instanceof HttpErrorResponse && error.status === 401 && !req.url.includes('/auth/refresh')) {
        return authService.refreshToken().pipe(
          switchMap(newToken => {
            const secureReq = req.clone({
              setHeaders: { Authorization: `Bearer ${newToken}` }
            });
            return next(secureReq);
          }),
          catchError(refreshErr => {
            authService.forceLogout();
            return throwError(() => refreshErr);
          })
        );
      }
      return throwError(() => error);
    })
  );
};