retry-on-error.operator.ts

import { iif, Observable, throwError, timer } from 'rxjs';
import { mergeMap, retryWhen, take } from 'rxjs/operators';

export function retryOnError<T>(
  maximumRetries = 3,
  delayInMilliseconds = 1000,
): (source$: Observable<T>) => Observable<T> {
  return (source$) => {
    return source$.pipe(
      retryWhen((errors) => {
        return errors.pipe(
          mergeMap((error, retries) => {
            return iif(
              () => retries < maximumRetries,
              timer(delayInMilliseconds),
              throwError(error),
            );
          }),
        );
      }),
      take(1),
    );
  };
}

// Usage
@Injectable({  providedIn: 'root' })
export class AwesomeService {
  constructor(private readonly http: HttpClient) {}

  public retrieveAwesomeThing(): Observable<Array<Awesome>> {
    return this.http.get<Array<Awesome>>(`/awesome-endpoint`).pipe(retryOnError());
  }
}