javascript - 具有嵌套 Promise 数组的对象

Question

我有一个带有嵌套 promise 数组的对象。

 let promise = new Promise(resolve => setTimeout(resolve, 1000, 'url'));
 let object = {
  registration: [promise, promise, promise],
   contract: [promise, promise, promise],
   businessLicense: [promise, promise, promise],
   businessPlan: [promise, promise, promise]
 };

我需要一个使用 Promise.all 给出以下结果的函数

   resolvePromisesFunction(object).then(result => console.log(result))

   // the output should be
   {
     registration: [ 'url', 'url', 'url' ],
     contract: [ 'url', 'url', 'url' ],
     businessLicense: [ 'url', 'url', 'url' ],
     businessPlan: [ 'url', 'url', 'url' ]
   }

谢谢!

Answer 1

您可以使用chaining promises与 Promise.all 一起:

let promise = new Promise(resolve => setTimeout(resolve, 1000, 'url'));
var obj = {
   registration: [promise, promise, promise],
   contract: [promise, promise, promise],
   businessLicense: [promise, promise, promise],
   businessPlan: [promise, promise, promise]
 };
 
function resolvePromisesFunction(obj) {
 let resolvedObj = {};
 return Promise.all(Object.keys(obj).map(service => {
   return Promise.all(obj[service])
      .then(result => resolvedObj[service] = result);
 })).then(result => resolvedObj);
  
}

resolvePromisesFunction(obj).then(result => console.log(result));