Nodejs Utililty Methods Object to String Convert

Object.toSource = function(object){
  if( object === null ) return 'null';
  if( object === undefined ) return 'undefined';
  if( typeof object.toSource === 'function' ){
    var source = object.toSource();
    if( typeof source != 'string' ) throw new TypeError('custom toSource() method must return string');
    return source;
  return String(object);
...

Object.prototype.toSource = function(seen){
  var source, props = Object.getOwnPropertyNames(this), i = 0, j = props.length, prop;
  seen = seen || [this];
  source = '({';
  for(;i<j;i++){
    prop = props[i];
    source+= prop.toSource() + ': ' + Object.sourceOf(this[prop], seen, '{}');
    if( i < j - 1 ) source += ', ';
  source+= '})';
  return source;
};

Object.prototype.json = function() { 
    return JSON.stringify(this) 

Object.prototype.to_s = function () {
  try {
    return JSON.stringify(this.valueOf());
  } catch (ex) {
    return this.valueOf().toString();
};