Question

I am trying to import a class from one file to another, but when I do import it, it returns undefined for a couple hundred milliseconds, then I get the value that I am looking for:

// commands.js
export class Command {
  // ...
}

// cmds/Help.js
import {Command} from './../commands.js'

console.log(Command)                         // => undefined
setTimeout(() => console.log(Command), 1000) // => [Function: Command]

So, of course, when I try to extend the imported class, I get errors saying that undefined in not a constructor. The only solution that I can see is to wrap everything inside the cmds/ directory with a setTimeout(), but that would not be efficient. I have messed around with using async/await functions and promises, but neither of those solved the issue.

Edit 1

I'm trying to post as much of the requested information as I can, but I am away from my computer so I'm posting all that I can for right now.

The code is running on Node 9.5, and is transpiled by Babel env set to "node": "current".

As for the code, here is all I can give you right now:

// Directory structure
[src]
|- cmds/
|  |- Help.js
|  |- Gh.js
|  \...
|- commands.js
|- data.js
|- send-msg.js
\... several more js and json files
// commands.js
import {readData, updateUserData} from './data.js'
import {sendMsg} from './send-msg.js'
//import * as cmdList from './cmds/*' // using babel-plugin-wildcard

export class Command {
  constructor (msg) {
    this.id = msg.author.id
    this.msg = msg
  }
  action () {}
  get data () {
   return readData().user[this.id]
  }
  updateUserData (key, val) {
    updateUserData(this.id, key, val)
  }
  sendMsg (data) {
    sendMsg(this.msg, data)
  } 
}
// there is an exported function, but I do not have the contents atm

// cmds/Gh.js
// There are several similar files in cmds/, including this one and the one
// mentioned in the question, Help.js; there are more. They all have
// the same issue, though.
import {Command} from '../commands'

export class Gh extends Command {
  constructor (msg) {
    super(msg)
    this.desc = 'Returns GitHub repository link and exits'
  }
  action () {
    this.sendMsg('GitHub link: https://github.com/owm111/knife-wife')
  }
}

BTW: the GitHub repository above does not have this code in it yet, but everything that is in it is functioning (i.e. not experiencing this issue).

Imports undefined, but defined after timeout

0 个答案: