How to organize multiple related modules?

Question

JavaScript

Hey! Suppose there are 3 related files.
index.js second.js
let modules = require('./second.js');

let modules = require('./third.js');

function doSmth() {
  //do something
}

third.js Requirement: You need to make the index module just go through the second code and execute it, making export only for those functions that need to be exported to index. But doSmth(), for example, does not need to be exported to index. But in the third - it is vital. In short, doSmth should only be available to third. How to properly organize it? There was an idea to operate with the module object and its properties, but I can’t imagine how. Can you give me a push in the right direction?
let modules = require('./second.js');

Answer 1

No way. You cannot make an exclusive import for a particular file. Here, either take away doSmth in third, or create fourth if you need to use it in both second and third, but then it will also be available for import into index