How to make io scope?

Question

JavaScript

/index.js

var express = require('express')
      , app = express()
      , path = require('path')
      , server = require('http').createServer(app)
      , io = require('socket.io')(server)
      , mod = require("./mod")

        mod.run();

server.listen(8080);
app.use(express.static(path.join(__dirname, 'public'));

/mod.js

mod =  {
      run:()=> {
   
      //Как тут использовать io?

      }
}

module.exports = mod;

How to make it possible to use io in mod.run?

Answer 1

mod.js

module.exports = class Mod {
  constructor({ io }) {
    this.io = io;
  }

  run() {
    this.io.something();
  }
}

index.js

var express = require('express')
      , app = express()
      , path = require('path')
      , server = require('http').createServer(app)
      , io = require('socket.io')(server)
      , Mod = require("./mod")

      
const mod = new Mod({ io });

mod.run();

server.listen(8080);
app.use(express.static(path.join(__dirname, 'public'));

Answer 2

And cho, to transfer as parameter is not present, in any way?
run: (io) => {

Answer 3

In principle, you can move the loading of io to the mod.js file, but on the condition that these variables are not used elsewhere.
If this is not possible, then you need to transfer already created variables to other components during initialization.
For example, create mod as a class and pass io to the constructor. Or call mod.run(io) and get it in the run function.