ES6 Singleton

singleton.es6.js

class ImmutableClass {
  constructor() {
    // return value from class constructor
    return createInstance()
  } 
}

let instance = null;

function createInstance() {
  if(instance === null){
   instance = Object.create(ImmutableClass.prototype);
    instance.someData = {}
  }
}



(new ImmutableClass()) === (new ImmutableClass())