shape.js

var Point = function (xloc,yloc) {
  var x = xloc;
  var y = yloc;
  var constructor = function(){ }
  constructor.prototype.getX = function() { return x; }
  constructor.prototype.getY = function() { return y; }
  constructor.prototype.translate = function(xdelta,ydelta) {
    x = x + xdelta;
    y = y + ydelta;
  }
  constructor.prototype.toString = function() {
    return "(" + x + "," + y + ")";
  }
  return new constructor();
}

var Shape = function (point) {
  var anchor = point;
  var constructor = function() { }
  constructor.prototype.move = function(xdelta,ydelta) {
    anchor.translate(xdelta,ydelta);
  }
  constructor.prototype.getAnchor = function() {
    return anchor;
  }
  return new constructor();
}

var Rectangle = function (point,width,height) {
  var width = width;
  var height = height;
  var constructor = function() {}
  constructor.prototype = new Shape(point);
  constructor.prototype.area = function() {
    return width*height;
  }
  return new constructor();
}

module.exports.Point = Point;
module.exports.Shape = Shape;
module.exports.Rectangle = Rectangle;