ES6 singleton pattern: prevent the creation of an instance

SingletonNoInstance.js

// Implementation 4: prevent the creation of an instance
class SingletonNoInstance {
  constructor(enforcer) {
    throw new Error('Cannot construct singleton');
  }

  static singletonMethod() {
    return 'singletonMethod';
  }

  static staticMethod() {
    return 'staticMethod';
  }
}

SingletonNoInstance.type = 'SingletonNoInstance';

export default SingletonNoInstance;

// ...

// index.js
import SingletonNoInstance from './SingletonNoInstance';

// Instantiate
// console.log(new SingletonNoInstance); // Cannot construct singleton

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

// Object property
SingletonNoInstance.type = 'type updated'; // Not using getter/setters
console.log(SingletonNoInstance.type); // Not using getter/setters

// Static method
console.log(SingletonNoInstance.staticMethod());