Google oAuth with passportjs + Vue - node.js

Question

I am currently stuck to handle a google oAuth login in a vue app which is connecting to my own node express api server.
On the express api server i am using passport as a middleware to handle google oauth and after succesfully logged in through google i am generating a jwt in the callback on my backend.
passport.use(new GoogleStrategy({
clientID: config.get('google.clientID'),
clientSecret: config.get('google.clientSecret'),
callbackURL: config.get('google.callbackUrl'),
},
function(accessToken, refreshToken, profile, done) {
User.findOne(
{ socialID: profile.id },
function (err, user) {
if (err) {
return done(err);
}
//No user was found... so create a new user with values from Facebook (all the profile. stuff)
if (!user) {
user = new User({
name: profile.displayName,
email: profile.emails[0].value,
provider: profile.provider,
socialID: profile.id,
});
user.save(function(err) {
if (err) console.log(err);
});
}
// the information which shall be inside the jsonwebtoken
const payload = {
user: {
id: user.id
}
};
// create jsonwebtoken and return it
jwt.sign(
payload,
config.get('jwt.secret'), // get the secret from default.json to hash jsonwebtoken
{ expiresIn: config.get('jwt.lifetime') },
(err, token) => {
if(err) throw err; // if there is error, throw it and exit
return done(JSON.stringify(token)); // return jwt token
}
);
}
);
}
));
I have theses routes on my api server
// #route GET api/auth/google
// #desc Google auth route - get User From Google, store it if not exists yet
// #access Public
router.get('/google',
passport.authenticate('google', { scope: ['profile', 'email'], session: false })
);
// #route GET api/auth/google/callback
// #desc Google callback route
// #access Public
router.get('/google/callback',
passport.authenticate('google', { failureRedirect: '/', session: false }),
function (req, res) {
res.redirect('http://localhost:8080/?token=' + res);
}
);
When i call my backend api route at /auth/google i successfully get redirected to the google login page. But with my approach i am trying to redirect from the callback url back to my vue app with a get parameter "token" to recieve the token in the frontend. The redirect in my backend callback route is not working. How do i pass the token which is generated in the backend to my frontend?

Answer 1

I came across that the redirect wasn't working because the return done() function expects two parameters to work correctly.
I changed inside the google passport middleware the done function like this
jwt.sign(
payload,
config.get('jwt.secret'), // get the secret from default.json to hash jsonwebtoken
{ expiresIn: config.get('jwt.lifetime') },
(err, token) => {
if(err) throw err; // if there is error, throw it and exit
return done(null, token); // return jwt token
}
);
Now inside my route i can successfully redirect + add the token as a get parameter - so with this workaround i am recieving my jwt which is generated in my backend in my frontend.
// #route GET api/auth/google/callback
// #desc Google callback route
// #access Public
router.get('/google/callback',
passport.authenticate('google', { failureRedirect: '/', session: false }),
function (req, res) {
let token = res.req.user;
res.redirect('//localhost:8080/?token=' + token);
}
);