在外部类对象中访问时，Cancelable Promise会丢失cancel属性

class ExternalClass {
  constructor() {
    this.cancelablePromise = this.createCancelablePromise();
  }

  createCancelablePromise() {
    let cancel;
    const promise = new Promise((resolve, reject) => {
      // 模拟长时间任务
      setTimeout(() => resolve('Task completed'), 5000);
      cancel = () => reject(new Error('Task canceled'));
    });
    return { promise, cancel };
  }

  runTask() {
    this.cancelablePromise.promise.then(console.log).catch(console.error);
  }

  cancelTask() {
    if (this.cancelablePromise.cancel) {
      this.cancelablePromise.cancel();
    }
  }
}

const external = new ExternalClass();
external.runTask();
// 如果需要取消任务
// external.cancelTask();

const deepCopy = (obj) => JSON.parse(JSON.stringify(obj));

class ExternalClass {
  constructor() {
    this.cancelablePromise = this.createCancelablePromise();
  }

  createCancelablePromise() {
    let cancel;
    const promise = new Promise((resolve, reject) => {
      // 模拟长时间任务
      setTimeout(() => resolve('Task completed'), 5000);
      cancel = () => reject(new Error('Task canceled'));
    });
    return { promise, cancel };
  }

  runTask() {
    const copiedPromise = deepCopy(this.cancelablePromise);
    copiedPromise.promise.then(console.log).catch(console.error);
  }

  cancelTask() {
    if (this.cancelablePromise.cancel) {
      this.cancelablePromise.cancel();
    }
  }
}

const external = new ExternalClass();
external.runTask();
// 如果需要取消任务
// external.cancelTask();