node.js loop through array to write files - arrays

Question

I've been working through a few others, also this of looping through array to http.get data from a variety of sources. I understand that nodeJS is working asynchronously which is allowing the files to be written empty or with incomplete data, but I can't seem to get past this point.
Problem: calls are made, files are built but the files are always empty
Goal: loop through an array to create files locally from the sites data. Here is what I've got so far:
var file_url = 'http://js.arcgis.com/3.8amd/js/esri/',
DOWNLOAD_DIR = './esri/',
esriAMD = [ '_coremap.js', 'arcgis/csv.js'];
function readFile(callback) {
if (esriAMD.length > 0) {
var setFile = esriAMD.shift(),
file_name = url.parse(file_url).pathname.split('/').pop(),
trial = setFile.split('/').pop(),
file = fs.createWriteStream(DOWNLOAD_DIR + trial);
http.get(file_url + esriAMD, function(res) {
res.on('data', function(data) {
file.write(data);
console.log(setFile + ' has been written successfully');
});
res.on('end', function(){
console.log(setFile + ' written, moving on');
console.log(esriAMD.length);
readFile(callback);
});
//readFile(callback);
});
} else {
callback();
}
}
readFile(function() {
console.log("reading finishes");
});
Any insight would really help.
thanks,

Answer 1

var esriAMD = [....];
...
function readFile(callback) {
...
http.get(file_url + esriAMD, function(res) {
...
concatenating strings with arrays may yield unexpected results.
you want to make sure that
you know what URLs your program is accessing
your program deals with error situations (where the fsck is res.on('error', ...)?)

Answer 2

Solution: I was passing the wrong variable into the http.get
Working code:
var file_url = 'http://.....',
DOWNLOAD_DIR = './location/';
esriAMD = ['one', 'two', 'three'..0;
function readFile(callback) {
if(esriAMD.length > 0) {
var setFile = esriAMD.shift(),
file_name = url.parse(setFile).pathname.split('/').pop(),
trial = setFile.split('/').pop(),
file = fs.createWriteStream(DOWNLOAD_DIR + trial);
http.get(file_url + setFile, function(res){
res.on('error', function(err){
console.log(err);
});
res.on('data', function(data){
file.write(data);
console.log(setFile + ' started');
});
res.on('end', function(){
console.log(setFile + ' completed, moving on');
});
});
} else {
callback();
}
}