ClassHierarchy

//jsa2/19 PROTOTYPES AND INHERITANCE/05ClassHierarchy.js
const figures = () => {
  class Figure {
    constructor(units) {
      if (!units) units = 'cm';
      this.units = units;
      if (new.target === Figure) {
        throw new TypeError('Figure class is abstract');
      }
    }
    changeUnits(value) {
      this.units = value;
    }
    scaleParam(param) {
      const values = { mm: 1, cm: 10, m: 1000 };
      return (values.cm * param) / values[this.units];
    }
    toString() {
      return `Figures units: ${this.units}`;
    }
  }
  class Circle extends Figure {
    constructor(radius, units) {
      super(units);
      this._radius = radius;
    }
    get area() {
      return Math.PI * this.radius * this.radius;
    }
    get radius() {
      return this.scaleParam(this._radius);
    }
    toString() {
      return `${super.toString()} Area: ${this.area} - radius: ${this.radius}`;
    }
  }
  class Rectangle extends Figure {
    constructor(width, height, units) {
      super(units);
      this._width = width;
      this._height = height;
    }
    get area() {
      return this.width * this.height;
    }
    get width() {
      return this.scaleParam(this._width);
    }
    get height() {
      return this.scaleParam(this._height);
    }
    toString() {
      return `${super.toString()} Area: ${this.area} - width: ${this.width
        }, height: ${this.height}`;
    }
  }
  return { Figure, Circle, Rectangle };
};