JS如何拒绝内部的包装承诺? [英] JS how to reject wrapper promise from inside one?

问题描述

如何拒绝一个或多个内部的包装承诺?换句话说，如何使数字"3"从不打印?当前输出:

how to reject wrapper promise from inside one or? in other words, how to make number '3' never printed? Current output:

1
2
3

预期输出:

1
2

new Promise(function(resolve, reject) {
  console.log(1)
  resolve()
})
.then(() => console.log(2))
.then(() => { // how to reject this one if internal fails?
  new Promise(function(resolve, reject) {
    reject(new Error('Polling failure'));
  })
  .then(() => console.log(21))
})
.then(() => console.log(3))

推荐答案

似乎您只是想念 return

new Promise(function(resolve, reject) {
    console.log(1)
    resolve()
  })
  .then(() => console.log(2))
  .then(() => { // how to reject this one if internal fails?
    return new Promise(function(resolve, reject) {
        reject(new Error('Polling failure'));
      })
      .then(() => console.log(21))
  })
  .then(() => console.log(3))

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