Question

Getting this error when I successfully log in with passport JS. Trying to redirect to the home page once I log in.

Code that does it:

app.post('/login', 
  passport.authenticate('local', {failureRedirect: '/login' }),
  function(req, res) {
    res.redirect('/');
  });

Full Error:

Error: Can't set headers after they are sent.
    at ServerResponse.OutgoingMessage.setHeader (http.js:644:11)

Am I missing something? Not sure why this error is happening. I’m still able to use the app, I just dont want the error.

Answer 1

You are redirecting the user so serializeUser function is being called twice. And in

 passport.use(new FacebookStrategy({
 ...

be sure to add this else or it gets called twice, thus sending the headers twice and causing error. Try this:

passport.use(new FacebookStrategy({
...
},
function(accessToken, refreshToken, profile, done) {
// asynchronous verification, for effect...
process.nextTick(function () {

  // To keep the example simple, the user's Facebook profile is returned to
  // represent the logged-in user.  In a typical application, you would want
  // to associate the Facebook account with a user record in your database,
  // and return that user instead.
    User.findByFacebookId({facebookId: profile.id}, function(err, user) {
        if (err) { return done(err); }
        if (!user) {
            //create user User.create...
            return done(null, createdUser);
        } else { //add this else
            return done(null, user);
        }
    });
  });
 }
));