Function traceUntilFirst

src/compat/performance/performance.ts:126–134

(name: string)

});

export const traceUntilFirst = <T = any>(name: string) => (source$: Observable<T>) => new Observable<T>(subscriber => {
  const traceSubscription = trace$(name).subscribe();
  return source$.pipe(
    tap(
      () => traceSubscription.unsubscribe(),
      () => undefined,
      () => undefined    )
  ).subscribe(subscriber);
});

export const trace = <T = any>(name: string) => (source$: Observable<T>) => new Observable<T>(subscriber => {
  const traceSubscription = trace$(name).subscribe();