feat: init and fork some code from angular-auth-oidc-client

test/create-retriable-stream.helper.ts

@@ -0,0 +1,12 @@
+import { Observable, of } from 'rxjs';
+import { switchMap } from 'rxjs/operators';
+
+// Create retriable observable stream to test retry / retryWhen. Credits to:
+// https://stackoverflow.com/questions/51399819/how-to-create-a-mock-observable-to-test-http-rxjs-retry-retrywhen-in-angular
+export const createRetriableStream = (...resp$: any): Observable<any> => {
+  const fetchData: jasmine.Spy = jasmine.createSpy('fetchData');
+
+  fetchData.and.returnValues(...resp$);
+
+  return of(null).pipe(switchMap((_) => fetchData()));
+};