firebase-token-generator.js

exports.firebase = function (req, res) {
  if(req.user) {    
    var generator = new FirebaseTokenGenerator(process.env.FIREBASE_SECRET);
    var token = generator.createToken({uid: req.user.id});
    res.send(token);
  } else {
    res.send(401, {error: "You must be logged in to perform this operation"});
  }
};