#singleton, #singleton reinfircer

singletonReinforcer.js

const _singletonEnforncer = Symbol('private');
let _instance;

export default class EventHandler extends EventTarget {
  static getInstance() {
    return _instance || new EventHandler(_singletonEnforncer);
  }

  static throwSingletonError() {
    throw new Error(`
    Singleton Error instantiation:
    EventHandler can only be instantiate by its static method EventHandler.getInstance()
    `);
  }

  constructor(enfonrcer) {
    enfonrcer !== _singletonEnforncer && EventHandler.throwSingletonError();
    super();
    _instance = this;
  }
}