ecmascript snippet to copy properties to another object

extend.coffee

Object.defineProperty(Object.prototype, "extend",
    enumerable: false
    value: (from)-> 
        props = Object.getOwnPropertyNames(from)
        dest = this
        props.forEach((name)->
          if (name in dest)
            destination = Object.getOwnPropertyDescriptor(from, name)
            Object.defineProperty(dest, name, destination)
          return this;
        )
)