Return value from one function to another with Node.JS - node.js

Question

I am working on a login interface using the MEAN stack. I have managed to get it to work using PassportJS. My problem now is I need a way to let my client-side know whether the person logging in is an admin or user(user role). These info are available from my MongoDB.
The flow of my API call is as follow :
app.post('/login', passport.authenticate('local'), authRoutes.loginCheck);
First, it runs the passport.authenticate where it calls the function below
function verifyCredentials(username, password, done) // username & password from what user provide when logging in
{
console.log('VC');
User.findOne({username: username}, function(err, user) //query Mongo
{
console.log(user); // User role is available here, in JSON format
if(user === null) // if no username in database, do this
{
console.log('Username does not exist in database');
}
else
{
user.comparePassword(password, function(err, match) // function written to compare hashed password in Mongo & password provided by user
{
if(match)
{
done(null, {id: username, name: username});
return user; // this is not the correct syntax, but the idea is, I want to send over the user details here, so I can access the role later
}
else
{
done(null, null);
}
});
}
});
}
The verifyFunction is called with this syntax.
passport.use(new LocalStrategy(verifyCredentials));
Once that function is successfully called, the server executes the 2nd part of it which is the loginCheck.
module.exports.loginCheck = function(req, res)
{
console.log('Calling loginCheck route');
// I generate some sort of jwt token here
// payload, body, blah blah blah ...
console.log(req.body);
res.json({
authenticated: req.isAuthenticated(), //built-in authentication function, returns true or false
token: token // sends over token
role: user.role // want to send over something like this
}); // sends all these to client side as JSON
}
Since both functions are in different files, I am unclear if I have to require something or simply just pass an extra parameter to the loginCheck function. I have tried the latter though and it did not work.
One way that I could think of is do another Mongo query in the loginCheck function, but that would be kinda redundant.
Even a specific keyword for me to google up would definitely be of big help as don't I know what I should be looking for. The reason is because I am new to NodeJS, thus I am not familiarize with most of the terms yet.
I think these codes should suffice but if I am needed to provide more, let me know and I will do so. Thanks in advance !!

Answer 1

To pass control to next matching route you need to use next that passes as third argument in the routes:
function verifyCredentials(req, res, next) {
User.findOne({username: req.body.username}, function(err, user) //query Mongo
{
if(user === null) {
return next(new Error('Username does not exist in database'));
} else {
user.comparePassword(req.body.password, function(err, match) {
if(match) {
next(null, {id: username, name: username});
} else {
next(new Error('not match'));
}
});
}
});
}
app.post('/login', verifyCredentials, authRoutes.loginCheck);