RxJsObservable.js

Observable.create(
  (observer) => {
    try {
      observer.next('item');
    } catch(e) {
      observer.error(e);
    } finally {
      observer.complete();
    }
}).subscribe(
  (x) => console.log(x),
  (err) => console.error(err),
  () => console.log('complete')
)