Nodejs - Passport authenticate always return failure redirect

Question

I'm making a form login by passportJs and it always return failureRedirect. I have search in stack overflow for this issue, but still not have the correct answer. Here is my code:

• Form making form jade:

  form(method='post', action='/users/login', enctype='multipart/form-data')
   .form-group
     label Username
     input.form-control(name='username', type='text'     placeholder='Enter Username')
  .form-group
    label Password
    input.form-control(name='password', type='password' placeholder='Enter password')
  input.btn.btn-default(name='submit', type='submit', value='Login')
  

Router Hanlde is using express framework form Nodejs and passport middleware:

passport.serializeUser(function(user, done) {
 done(null, user.id);
});

passport.deserializeUser(function(id, done) {
User.getUserById(id, function(err, user) {
    done(err, user);
});
});

passport.use(new LocalStrategy({
    usernameField: 'username',
    passwordField: 'password'
},
function(username, password, done) {
    User.getUserByUsername(username, function(err, user) {
        if (err) throw err;
        if (!user) {
            console.log('Unknown User');
            return done(null, false, {
                message: 'Unknown User'
            });
        }

        User.comparePassword(password, user.password, function(err, isMatch) {
            if (err) throw err;
            if (isMatch) {
                return done(null, user);
            } else {
                console.log('Invalid Password');
                return done(null, false, {
                    message: 'Invalid Password'
                });
            }
         });
      });
   }
));

  router.post('/login', passport.authenticate('local', {
    failureRedirect: '/users/login',
    failureFlash: 'Invalid username or password'
}), function(req, res) {
console.log('Authentication Successful');
req.flash('success', 'You are logged in ');
res.redirect('/');
 });

Answer 1

Looking at getUserByUsername function you shared in comments, it looks like you are not making call to callback function of getUserByUsername in correct way and therefore it is not getting user object resulting into failure redirect. The function you shared was:

module.exports.getUserByUsername = function(username, callback){
  var query = {username: username}; 
  User.findOne(query, callback); 
} 

Changing it to following should fix your issue:

module.exports.getUserByUsername = function(username, callback){
  var query = {username: username}; 
  User.findOne(query, function(err, user) {
    callback(err, user);
  }); 
}