关于Javascript的ES6 extends 多重继承办法

在对openmodelica的部件基类js重写时候遇到了多重继承问题，js本身是不支持多重继承的。用了以下办法做了多重继承

function mix (...mixins) { 
  class Mix { }
  for (let mixin of mixins) { 
    copyProperties(Mix, mixin)
    copyProperties(Mix.prototype,mixin.prototype)
  }
  return Mix;
}
function copyProperties (target, source) { 
  for (let key of Reflect.ownKeys(source)) { 
    if (key !== "constructor" && key !== "prototype" && key !== "name") {
      let desc = Object.getOwnPropertyDescriptor(source, key)
      Object.defineProperty(target,key,desc)
    }
  }
}
// class DistributedEdit extends mix(Loggable, Serializable) { }

直接调用mix()方法就行，例如下面代码：

// 多边形
class Polygon extends mix(GraphicItem,FilledShape) {
  constructor(lineColor, fillColor, fillPattern, points) {
    this.lineColor = lineColor;
    this.fillColor = fillColor;
    this.fillPattern = fillPattern;
    this.points = points; //数组字符串
  }
}