IceDecorator.ts

class Ice extends BeverageDecorator {
  private beverage: Beverage;
  constructor(beverage: Beverage) {
    super();
    this.beverage = beverage;
  }

  getDescription() {
    return this.beverage.getDescription() + ", 아이스";
  }

  cost() {
    return this.beverage.cost() + 500;
  }
}