【面试题】前端中 JS 发起的请求可以暂停吗？

function _request () {
  return new Promise<number>((res) => setTimeout(() => {
    res(123)
  }, 3000))
}
// 原本想使用 class extends Promise 来实现
// 结果一直出现这个问题 https://github.com/nodejs/node/issues/13678
function createPauseControllerPromise () {
  const result = {
    isPause: false,
    resolveWhenResume: false,
    resolve (value?: any) {},
    pause () {
      this.isPause = true
    },
    resume () {
      if (!this.isPause) return
      this.isPause = false
      if (this.resolveWhenResume) {
          this.resolve()
      }
    },
    promise: Promise.resolve()
  }
  const promise = new Promise<void>((res) => {
    result.resolve = res
  })
  result.promise = promise
  return result
}
function requestWithPauseControl <T extends () => Promise<any>>(request: T) {
  const controller = createPauseControllerPromise()
  const controlRequest = request().then((data) => {
      if (!controller.isPause) controller.resolve()
      return data
  }).finally(() => {
      controller.resolveWhenResume = true
  })
  const result = Promise.all([controlRequest, controller.promise]).then(data => {
      controller.resolve()
      return data[0]
  });
  (result as any).pause = controller.pause.bind(controller);
  (result as any).resume = controller.resume.bind(controller);
  return result as ReturnType<T> & { pause: () => void, resume: () => void }
}

const result = requestWithPauseControl(_request).then((data) => {
    console.log(data)
})
if (Math.random() > 0.5) { result.pause() }
setTimeout(() => {
    result.resume()
}, 4000)