ES6 singleton pattern: using objects

NoClassSingleton.js

// http://www.2ality.com/2011/04/singleton-pattern-in-javascript-not.html

const NoClassSingleton = {
  _instance: null,
  get instance() {
    if (!this._instance) {
      this._instance = {
        singletonMethod() {
          return 'singletonMethod';
        },

        _type: 'NoClassSingleton',

        get type() {
          return this._type;
        },

        set type(value) {
          this._type = value;
        }
      };
    }
    return this._instance;
  }
};

export default NoClassSingleton;

// Flux store way
export const NoClassSingletonObjectAssign = Object.assign({}, {
  singletonMethod() {
    return 'singletonMethod';
  },

  _type: 'NoClassSingletonObjectAssign',

  get type() {
    return this._type;
  },

  set type(value) {
    this._type = value;
  }
});

// ...

// index.js
import NoClassSingleton, { NoClassSingletonObjectAssign } from './NoClassSingleton';

// Instance
const instance = NoClassSingleton.instance;

// Prototype Method
console.log(instance.type, instance.singletonMethod());

// Getter/Setter
instance.type = 'type updated';
console.log(instance.type);

/*
Flux
*/
// Prototype Method
console.log(NoClassSingletonObjectAssign.type, NoClassSingletonObjectAssign.singletonMethod());

// Getter/Setter
NoClassSingletonObjectAssign.type = 'type updated';
console.log(NoClassSingletonObjectAssign.type);