RxJS Operator to pipe into zone

zone-enter.operator.ts

export function enterZone(zone: NgZone) {
return <T>(source: Observable<T>) =>
    new Observable<T>(observer =>
    source.subscribe({
        next: (x) => zone.run(() => observer.next(x)),
        error: (err) => observer.error(err),
        complete: () => observer.complete()
    })
    );
}