JavaScript class-based dependency injection

di.js

// implementing http://misko.hevery.com/2010/05/29/dependency-injection-and-javascript-closures/ with classes
class Factory {
  constructor(alert) {
    return {
      greetFactory(greeting) {
        return new GreetFactory(alert, greeting)
      }
    }
  }
}

class GreetFactory {
  constructor(alert, greeting) {
    return function(greet) {
      alert(greeting + greet)
    }
  }
}

const factory = new Factory(console.log)
const greet = factory.greetFactory('Hello ')
greet('Misko')