Added authentication error interceptor

Author: Bernardo-MG

src/app/authentication/authentication.module.ts

@@ -2,14 +2,16 @@ import { CommonModule } from '@angular/common';
 import { HTTP_INTERCEPTORS } from '@angular/common/http';
 import { NgModule } from '@angular/core';
 import { BasicAuthenticationInterceptor } from './interceptor/basic-authentication.interceptor';
+import { UnauthorizedInterceptor } from './interceptor/unauthorized.interceptor';
 
 @NgModule({
   declarations: [],
   imports: [
     CommonModule
   ],
   providers: [
-    { provide: HTTP_INTERCEPTORS, useClass: BasicAuthenticationInterceptor, multi: true }
+    { provide: HTTP_INTERCEPTORS, useClass: BasicAuthenticationInterceptor, multi: true },
+    { provide: HTTP_INTERCEPTORS, useClass: UnauthorizedInterceptor, multi: true }
   ]
 })
 export class AuthenticationModule { }

src/app/authentication/interceptor/basic-authentication.interceptor.ts

@@ -11,7 +11,9 @@ export class BasicAuthenticationInterceptor implements HttpInterceptor {
 
   private tokenHeaderIdentifier = 'Basic'
 
-  constructor(private authenticationService: AuthenticationService) { }
+  constructor(
+    private authenticationService: AuthenticationService
+  ) { }
 
   intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
     let authReq;

src/app/authentication/interceptor/unauthorized.interceptor.spec.ts

@@ -0,0 +1,16 @@
+import { TestBed } from '@angular/core/testing';
+
+import { UnauthorizedInterceptor } from './unauthorized.interceptor';
+
+describe('UnauthorizedInterceptor', () => {
+  beforeEach(() => TestBed.configureTestingModule({
+    providers: [
+      UnauthorizedInterceptor
+      ]
+  }));
+
+  it('should be created', () => {
+    const interceptor: UnauthorizedInterceptor = TestBed.inject(UnauthorizedInterceptor);
+    expect(interceptor).toBeTruthy();
+  });
+});

src/app/authentication/interceptor/unauthorized.interceptor.ts

@@ -0,0 +1,27 @@
+import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from '@angular/common/http';
+import { Injectable } from '@angular/core';
+import { catchError, Observable, throwError } from 'rxjs';
+import { AuthenticationService } from '../service/authentication.service';
+
+@Injectable()
+export class UnauthorizedInterceptor implements HttpInterceptor {
+
+  constructor(
+    private authenticationService: AuthenticationService
+  ) { }
+
+  intercept(request: HttpRequest<unknown>, next: HttpHandler): Observable<HttpEvent<unknown>> {
+    return next.handle(request).pipe(catchError(err => {
+      if (err.status === 401) {
+        // Unauthenticated
+        // Logs out
+        this.authenticationService.logout();
+        location.reload();
+      }
+
+      const error = err.error.message || err.statusText;
+      return throwError(() => new Error(error));
+    }))
+  }
+
+}