#适配器模式(Adapter)

// old api
class Mart {
  constructor() {
    this.cola = 3;
    this.bread = 5;
  }
  getPrice(type, num) {
    return this[type] * Math.floor(num);
  }
}

// new api
class NewMart {
  constructor() {
    this.cola = 3;
    this.bread = 5;
  }
  getTotalPrice(...rest) {
    let _result = 0;
    rest.forEach((e) => {
      _result += this[e.type] * e.length;
    });
    return _result;
  }
}

//adapter
class MartAdapter {
  constructor() {}

  getPrice(type, num) {
    return new Mart().getPrice(type, num);
  }

  getTotalPrice(...rest) {
    return new NewMart().getTotalPrice(...rest);
  }
}

export { Mart, NewMart, MartAdapter };

let martAdapter = new MartAdapter();
//old
martAdapter.getPrice("cola", 5);
//new
martAdapter.getTotalPrice({ type: "cola", length: 3 }, { type: "bread", length: 2 });