Passport JS Google oauth20 callback missing req object - node.js

Question

I have seen some similar questions here but the answer is irrelevant to mine, as I have declared passReqToCallback.
I am trying to create an authentication system with passport. I have successfully integrated passport-local, which register/logs in user and creates a session but am having an issue in the logic of the google strategy:
passport.use(new GoogleStrategy(
{
clientID: process.env.GOOGLE_CLIENT_ID,
clientSecret: process.env.GOOGLE_CLIENT_SECRET,
callbackURL: process.env.GOOGLE_CALLBACK_URL,
passReqToCallback: true
},
(req, accessToken, refreshToken, profile, done) => {
/**
*
* This if statement is failing, as far as I can tell there is no req object being passed despite declaring it above
*
*/
// If user is logged in, proceed to simply link account
if (req.user) {
req.user.googleid = profile.id;
req.user.googleEmail = profile.emails[0].value;
req.user.googleDisplayName = profile.displayname;
pool.query('UPDATE users SET googleid = ?, google_email = ?, google_display_name = ? WHERE id = ?', [
req.user.googleid,
req.user.googleEmail,
req.user.googleDisplayName,
req.id
],
function(err, rows) {
// If google account is duplicate (linked to different account) will return error
if (err) {
return done(err, false, {message: "The Google account you tried to link is associated with another account."});
}
return done(null, req.user);
})
}
// Check if google account is registered
pool.query('SELECT * FROM users WHERE googleid = ?', [profile.id], function(err, rows) {
if (err) {
return done(err);
}
// If not logged in but user already registered, log in
if (rows.length) {
return done(null, rows[0]);
}
// If no existing record, register the user.
else {
let newUser = {
email: profile.emails[0].value,
// Google account specific fields
googleid: profile.id,
googleDisplayName: profile.displayName,
method: "gl", // This field ties this new user to the google account
// General fields (taken from the stuff google gives us)
firstName: profile.name.givenName,
lastName: profile.name.familyName,
googleEmail: profile.emails[0].value
}
let insertQuery = "INSERT INTO users (email, googleid, google_display_name, method, first_name, last_name, google_email) VALUES (?,?,?,?,?,?,?)";
pool.query(insertQuery, [
newUser.email,
newUser.googleid,
newUser.googleDisplayName,
newUser.method,
newUser.firstName,
newUser.lastName,
newUser.googleEmail
],
function(err, rows) {
if (err) return done(err, null);
newUser.id = rows.insertId;
return done(null, newUser);
})
}
})}));
So essentially the first if is supposed to see if the user is already authenticated and then just link the account as so. However, in practice, it will skip this even when authenticated and proceed to the rest of the logic, which works absolutely fine. It will go on to create a new account at the else statement (or return error if email is taken, I still need to implement that part).
But, interestingly, if I am logged in while using it, it doesn't log me in as the new user as it otherwise would, instead it keeps me logged in as the current session.
Where have I gone wrong? Why is the req.user not detected? I have also tried using req.isAuthenticated() with the same result.
Below is my callback route, if helpful:
// Google
router.get('/oauth/google', passport.authenticate('google', {
scope: ['email', 'profile']
}));
// Callback
router.get('/oauth/google/redirect', passport.authenticate('google', {
successRedirect: '/account',
failureFlash: 'Something went wrong. Please enable third party cookies to allow Google to sign in.',
failureRedirect: '/login'
}
));
UPDATE 1: If I try (!req.user), same result, skips to below, not sure what that means is happening