解决承诺的先后顺序/执行时间？

Question

我在本主题中看到的几乎每个问题都讨论了如何解决顺序为的一系列承诺。

然而，我想解决它们的顺序完成时间。

例如：

​

const files = [{
    name: 'test1.txt',
    fileContents: 'abasdadsjadas',
  },
  {
    name: 'test2.txt',
    fileContents: 'asldjknaisdha',
  },
  {
    name: 'test3.txt',
    fileContents: 'hifhdsfyads',
  },
  {
    name: 'test4.txt',
    fileContents: 'kjhakjhfjhagdsjhagdkaj',
  },
  {
    name: 'test5.txt',
    fileContents: 'kjasdhbasd',
  }
];

const uploadPromise = (name) => {
  return new Promise((resolve) => {
    setTimeout(() => resolve(name), Math.random() * 1000)
  })
}


//Prints file names in order:
const filesInOrder = files.map(x => uploadPromise(x.name))
Promise.all(filesInOrder).then(x => console.log("In order: ", x))

//Print file names in order of resolve time
const logs = [];
files.forEach(x => logs.push(uploadPromise(x.name)))
logs.forEach(x => x.then(y => console.log(y))) // eg: test2.text, test3.text, test1.text, test5.text, test4.text

​

正如你所看到的，我按照分解时间的顺序打印它们的方式令人难以置信的丑陋和难以理解。关于怎么简单地在这里做这件事，我缺少什么吗？我的大脑被冻僵了。

Answer 1

这就是你可能做到的；分别处理每一个承诺。

​

finishedOrder = []
files1 = [{
    name: 'test1.txt',
    fileContents: 'abasdadsjadas',
  },
  {
    name: 'test2.txt',
    fileContents: 'asldjknaisdha',
  },
  {
    name: 'test3.txt',
    fileContents: 'hifhdsfyads',
  },
  {
    name: 'test4.txt',
    fileContents: 'kjhakjhfjhagdsjhagdkaj',
  },
  {
    name: 'test5.txt',
    fileContents: 'kjasdhbasd',
  }
];

uploadPromise1 = (name) => {
  return new Promise((resolve) => {
    setTimeout(() => resolve(name), Math.random() * 1000)
  }).then(name => {
    console.log(`Finished ${name}`);
    finishedOrder.push(name);
  })
}


//Prints file names in order:
filesInOrder1 = files1.map(x => uploadPromise1(x.name))
Promise.all(filesInOrder1).then(x => console.log("Done", files1, finishedOrder))

​