nodeValue of Attr

[ringel7]

Hi, I wrote the followings:

var DOMParser = require("xmldom").DOMParser;
var XMLSerializer = require("xmldom").XMLSerializer;

var xml = new DOMParser().parseFromString("<x></x>", 'text/xml');
var attr = xml.createAttribute("a");
attr.nodeValue = "b";
xml.documentElement.setAttributeNode(attr);

var str = new XMLSerializer().serializeToString(xml);
console.log(str);

The result:

> node domsample.js

C:\Users\xxx\AppData\Roaming\npm\node_modules\xmldom\dom.js:952
                return buf.push(' ',node.name,'="',node.value.replace(/[<&"]/g,_xmlEncoder),
                                                              ^
TypeError: Cannot call method 'replace' of undefined
    at serializeToString (C:\Users\xxx\AppData\Roaming\npm\node_modules\xmldom\dom.js:952:49)
    at serializeToString (C:\Users\xxx\AppData\Roaming\npm\node_modules\xmldom\dom.js:923:4)
    at serializeToString (C:\Users\xxx\AppData\Roaming\npm\node_modules\xmldom\dom.js:947:4)
    at XMLSerializer.serializeToString (C:\Users\xxx\AppData\Roaming\npm\node_modules\xmldom\dom.js:907:2)
    at Object.<anonymous> (C:\home\xmldom\domsample.js:9:31)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)

I think that nodeValue of Attr should be the alias of value property.

        Object.defineProperty(Attr.prototype,'nodeValue',{
            get:function(){
                return this.value;
            },
            set:function(data){
                this.value = data;
            }
        })

dom standard of whatwg (https://dom.spec.whatwg.org/#interface-attr) defines:

interface Attr {
  attribute DOMString value;
  attribute DOMString nodeValue; // legacy alias of .value