Method finally

packages/core/src/utils/syncpromise.ts:102–131

@inheritdoc

(onfinally?: (() => void) | null)

  /** @inheritdoc */
  public finally<TResult>(onfinally?: (() => void) | null): PromiseLike<TResult> {
    return new SyncPromise<TResult>((resolve, reject) => {
      let val: TResult | any;
      let isRejected: boolean;

      return this.then(
        value => {
          isRejected = false;
          val = value;
          if (onfinally) {
            onfinally();
          }
        },
        reason => {
          isRejected = true;
          val = reason;
          if (onfinally) {
            onfinally();
          }
        },
      ).then(() => {
        if (isRejected) {
          reject(val);
          return;
        }

        resolve(val as unknown as any);
      });
    });
  }

  /** Excute the resolve/reject handlers. */
  private _executeHandlers(): void {