Factory Method Missing Return

class Circle {
  draw() { return 'drawing circle'; }
}

class Square {
  draw() { return 'drawing square'; }
}

class ShapeFactory {
  createShape(type) {
    switch (type) {
      case 'circle':
        new Circle();
        break;
      case 'square':
        return new Square();
      default:
        throw new Error('Unknown shape: ' + type);
    }
  }
}

const factory = new ShapeFactory();
const shape = factory.createShape('circle');
console.log(shape.draw());