import { Observable, of, concat, throwError } from 'rxjs';
import { map, catchError } from 'rxjs/operators';

concat(
  new Observable<string>(o => {
    o.next('first item');
    throw 'lol error';
  }).pipe(
    catchError(err => {
      console.log('caught', err);
      return of('blah');
    })
  ),
  of('this should be played'),
)
.subscribe({
  next(x) { console.log(x); },
  error(err) { console.log(err); },
})