Async series doesn't work in an order as expected - node.js

Question

I have a function that downloads the user input(currently named app.json) from browser(client) to the server
function downloadUpload(callback){
//Using formidable node package for downloading user input to server
var form = new formidable.IncomingForm();
form.on('fileBegin', function(name, file) {
file.path = file.name;
});
form.parse(req, function(err, fields, files) {
res.writeHead(200, { 'content-type': 'text/plain' });
res.write('received upload:\n\n');
res.end(util.inspect({ fields: fields, files: files }));
});
callback(null);
}
I have another function that takes the file downloaded above and converts it into required format(final.json) something like this.
function UpdateCode(callback){
var obj = fs.readFileSync('app.json', 'utf8');
var object = JSON.parse(obj);
var data2 = [];
for (var j = 0; j < object.length; j++) {
if (object[j].value == "TEST") {
data2.push(object[j]);
}
}
console.log(data2);
fs.appendFile('final.json', JSON.stringify(data2), function(err) {
if (err) throw err;
console.log('Saved!');
});
callback(null);
}
I want them to run in an order, so I used async series method like this
async.series([
downloadUpload,
UpdateCode
],function(err,result){
if(err) throw err;
else{
console.log(result);
}
});
The problem is the file(app.json) is getting downloaded and an error is displayed saying that app.json doesn't exist in the current folder or directory. Where am I going wrong?

Answer 1

This is likely what you need.
function downloadUpload(callback) {
//Using formidable node package for downloading user input to server
var form = new formidable.IncomingForm();
form.on('fileBegin', function(name, file) {
file.path = "app.json";
});
form.parse(req, function(err, fields, files) {
res.writeHead(200, {
'content-type': 'text/plain'
});
res.write('received upload:\n\n');
res.end(util.inspect({
fields: fields,
files: files
}));
});
form.on('end', function() {
callback(null);
});
}
function UpdateCode(callback) {
var obj = fs.readFileSync('app.json', 'utf8');
var object = JSON.parse(obj);
var data2 = [];
for (var j = 0; j < object.length; j++) {
if (object[j].value == "TEST") {
data2.push(object[j]);
}
}
console.log(data2);
fs.appendFile('final.json', JSON.stringify(data2), function(err) {
if (err) throw err;
console.log('Saved!');
callback(null);
});
}
async.series([
downloadUpload,
UpdateCode
], function(err, result) {
if (err) throw err;
else {
console.log(result);
}
});
Also use nodemon -e js app.js. Otherwise nodemon will restart the program as soon as the json uploads.