@reactivex/rxjs/src/add/observable/fromPromise.ts

Reactive Extensions for modern JavaScript

import {Observable} from '../../Observable';
import {fromPromise as staticFromPromise} from '../../observable/fromPromise';

Observable.fromPromise = staticFromPromise;

declare module '../../Observable' {
  namespace Observable {
    export let fromPromise: typeof staticFromPromise;
  }
}