factory-design-pattern-ts.ts

abstract class Bike {
  abstract brandname: string;
  ride() {
    return `I ride ${this.brandname}`;
  }
}

class Giant extends Bike {
  brandname = 'Giant';
}

class Merida extends Bike {
  brandname = 'Merida';
}

class BikeMaker {
  static factory(brandname: string) {
    switch (brandname) {
      case 'giant':
        return new Giant();

      case 'merida':
        return new Merida();

      default:
        throw {
          name: 'Error',
          message: `${brandname} doesn't exist`,
        };
    }
  }
}

const mybike = BikeMaker.factory('giant');
const yourbike = BikeMaker.factory('merida');
console.log(mybike.ride()); // This bike is Giant
console.log(yourbike.ride()); // This bike is Merida