Trying to make an NPM package

Question

Basically, im trying to make a package that would look like this in my main project file

const package = require("package");
const newPackage = new package({
  param: 'value',
  otherParam: 'otherValue'
});

and then in every other project file I could use

const { someFunction } = require('package')

someFunction()

and then the SomeFunction() function should return value and otherValue without needing to do

const package = require("package");
const newPackage = new package({
  param: 'value',
  otherParam: 'otherValue'
});

newPackage.someFunction()

in every project file.

Im not sure how to do this or if this is even possible, but would love something that would work like (or similar to) this.

Answer 1

While it would be possible to do this, it would involve some pretty smelly code - the package would have to have calling the constructor produce side-effects and return an unused instance. For a very slight tweak, consider instead if you could change the init code from

const package = require("package");
const newPackage = new package({
  param: 'value',
  otherParam: 'otherValue'
});

to something like

const { init } = require("package");
init({
  param: 'value',
  otherParam: 'otherValue'
});

That would be quite doable and not smelly. Put a variable in the package's scope that gets assigned to when init is called, and return that variable when someFunction is called.

let initObj;
module.exports = {
  init(obj) {
    initObj = obj;
  },
  someFunction() {
    return initObj;
  }
};

Live snippet:

 const theModule = (() => { let initObj; return { init(obj) { initObj = obj; }, someFunction() { return initObj; } } })(); theModule.init({ param: 'value', otherParam: 'otherValue' }); console.log(theModule.someFunction());