This is a gist made for Stackoverflow question: Returning values between different scopes in javascript

gistfile1.js

/**
 * Generates restful API
 * @desc Library handles all directory/file streams and IO
 * for the APIEngine structure. Asynchronous folder iteration
 * with proper cleanup. 
 * @Deps: fs, async, underscore
 * @Formalia: Free to use for whatever you like, do anything you want to it.
 * @param null
 * @return func
 */    
var fs   	= require('fs')
, async		= require('async')
, _			= require('underscore');

ApiFS = function(stgs){
	errLog						= [];
	errLog.fsEmpty 				= "No existing directories or empty, cannot continue.";	
	this.resultset				= [''];
}

/**
 * Simple error handling for IO
 * @desc response for post read of directories and files  
 * @param String
 * @return Object
 */    
 function ioResponse(err){
 	if(err){ throw new err; }
 }

/**
* @desc Validate that directories and files exist for the model path
* and perform necessary steps to load them into the Mongodb model
* @param function
* @return object
**/ 

ApiFS.prototype.scan = function(){			
	var self = this;
	var b;
	fs.readdir(stgs.fsPath, function(err,folders){		
		if(folders.length<1) { console.log(errLog.fsEmpty); return; }		
		rslt = self.walk(folders);			
		rslt.forEach(function(itm){
			if(!self.exclusion(rslt)){ b=self.loader(stgs.fsPath,itm); }		
		});						
	}, ioResponse);		
}

/**
 * Walk the folders and load, check for exclusions
 * @desc non-blocking IO, read and do exclusions, finally loader().
 * @param String
 * @return Object
 */    
ApiFS.prototype.walk = function(folders, callback){
	var fldrmap = [];
	async.each(folders, function(folder, callback){	fldrmap.push(folder); callback();				
	}, function(err){
		if(err) { throw new err; return;}										
	});	
	return fldrmap;
}

/**
 * Exclusion control for walk()
 * @desc control stgs.exclude for exclusions 
 * @param Object
 * @return Object
 */    
ApiFS.prototype.exclusion = function(folder){		
	var filt;
	if(stgs.exclude.length>0){ return filt= (!_.contains(stgs.exclude, folder)); }
}

/**
* Read directories and cache output
* @desc Just cache as necessary to minimize IO  
* @param function
* @return Object
*/    
ApiFS.prototype.loader = function(dir,obj){	
	var self = this;
	var itr = [];
	fs.readdir(dir+'/'+obj, function(err,cf){
		cf.forEach(function(fi){ tgt = dir+'/'+obj+'/'+cf; itr.push(self.modelMapper(obj,tgt)); });	
		console.log(itr);	 
	}, ioResponse);
};

/**
 * Add targets to the map
 * @desc Nothing fancy
 * @param String
 * @return Object
 */    
ApiFS.prototype.modelMapper = function(obj,tgt){	
	var modelMap=[];	
	modelMap.push(obj,tgt); //console.log(modelMap); 
	return modelMap;
}

exports = module.exports = ApiFS;