如何在javascript中导出await多个对象？

Question

这里有一个例子MDN，

const colors = fetch("../data/colors.json").then((response) => response.json());

export default await colors;

但是，我有多个常量在单个函数中异步填充：

const _receiversById = {}; 
const _receiversByServer = {}; 
const _sequenceReceivers = {}; // name - k-v receivers
const _sequences = {}; 

// init
async function _fetchAllReceivers(){
    // go to the database and copy data into those consts. multiple awaits.
}

我很困惑如何使常量成为函数运行时得到解决的承诺。

我试图将常量分配给不带参数的 Promise 对象

const _receiversById = new Promise(); 
const _receiversByServer = new Promise(); 
const _sequenceReceivers = new Promise();
const _sequences = new Promise();

考虑在

.resolve(_receivers...)

函数中调用

_fetch..

，但我非常怀疑它是否有效并且易于调试。

实现这一目标的正确/优雅的方法是什么？

Answer 1

设计

_fetchAllReceivers

，以便它返回您异步填充的四个对象。换句话说，使

_fetchAllReceivers()

返回的 Promise 解析为解析为四个对象（嵌套在包装对象内）的 Promise。

async function _fetchAllReceivers(){
    // Make these constants local to the async function
    const receiversById = {}; 
    const receiversByServer = {}; 
    const sequenceReceivers = {}; // name - k-v receivers
    const sequences = {}; 
    // go to the database and copy data into those consts. multiple awaits.
    // ...
    // Return (i.e. resolve with) an object that has all the gathered data
    return {
        receiversById, 
        receiversByServer,
        sequenceReceivers,
        sequences 
    }
}

export default return await _fetchAllReceivers();

在导入方面，您可以执行以下操作：

import obj from './mymodule.mjs' 
console.log(obj.receiversById);