Function firstValueFrom

packages/router/src/utils/first_value_from.ts:13–20

(source: Observable<T>)

/** replacement for firstValueFrom in rxjs 7. We must support rxjs v6 so we cannot use it */
export function firstValueFrom<T>(source: Observable<T>): Promise<T> {
  return new Promise<T>((resolve, reject) => {
    source.pipe(first()).subscribe({
      next: (value) => resolve(value),
      error: (err) => reject(err),
    });
  });
}