How to configure route for oauth callback in Node.js

Question

This works perfectly fine in the server.js :

app.get('/auth/google/callback',
    passport.authenticate('google', {
        failureRedirect: '/login'
    }),
    (req, res) => {}
);

But the following doesn't when used in route.js :

exports.googleCallback = function(req, res, next) {
  passport.authenticate('google', { failureRedirect: '/login' });
  const handler = function(req, res) {
    // Successful authentication, redirect home.
    res.redirect('/');
  };
  handler(req, res, next);
};

I have the following in route.js :

app.route(path + 'auth/google').get(auth.googleLogin);

What happens: The second code directly goes to / path without waiting for Passport Google strategy to completely execute.

If I remove res.redirect('/'); It does not go anywhere and keep loading.

Answer 1

This worked just fine:

exports.googleCallback = function(req, res, next) {
  passport.authenticate('google', { failureRedirect: '/login' })(req, res, next);
};

Added callback method on the passport.