Observable.prototype.debug = function(message: any) { return this.do( (next) => { if(!environment.production) { console.log(message, next); } }, (err) => { if(!environment.production) { console.error(message, err) } }, () => { if(!environment.production) { console.info("Observable completed", message) } } ); }; declare module 'rxjs/observable' { interface Observable<T> { debug: (...any) => Observable<T> } }