Decorator pattern implementation in ts

decorator.ts

abstract class Beverage {
  description: string = "unknown beverage";
  public getDescription(): string {
    return this.description;
  }
  public abstract cost(): number;
}

abstract class CondimentDecorator extends Beverage {
  abstract getDescription(): string;
}

class Espresso extends Beverage {
  constructor() {
    super();
    this.description = "Espresso";
  }

  cost() {
    return 1.99;
  }
}

class HouseBlend extends Beverage {
  constructor() {
    super();
    this.description = "House Blend"
  }

  public cost(): number {
    return 2.99
  }
}

class TitusMaximus extends Beverage {
  constructor(){
    super();
    this.description = "Titus Black Power"
  }

  public cost(): number {
    return 29.0
  }
}

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

  getDescription(): string {
    return this.beverage.getDescription() + " Mocha";
  }

  public cost(): number {
    return 4.99 + this.beverage.cost();
  }
}

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

  getDescription(): string {
    return this.beverage.getDescription() + " Whip";
  } 

  public cost(): number {
    return 9.99 + this.beverage.cost();
  }
}

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

  getDescription(): string {
    return this.beverage.getDescription() + " Ink ";
  }

  public cost(): number {
    return 8.99 + this.beverage.cost();
  }
}

// let beverage = new Espresso();
// console.log(beverage.getDescription() + " $ " + beverage.cost());

let beverage2 = new HouseBlend();
beverage2 = new Mocha(beverage2);
beverage2 = new Mocha(beverage2);
console.log(beverage2.getDescription() + " $" + beverage2.cost());

let beverage3 = new TitusMaximus();
beverage3 = new Mocha(beverage3);
beverage3 = new Whip(beverage3);
beverage3 = new Ink(beverage3);
console.log(beverage3.getDescription() + beverage3.cost());