passport.use('local-signup', new LocalStrategy({

    // by default, local strategy uses username and password, we will override with email

    usernameField : 'email',

    passwordField : 'password',

    passReqToCallback : true // allows us to pass back the entire request to the callback

},

(req, email, password, done) => {

    // asynchronous

    // User.findOne wont fire unless data is sent back

    process.nextTick(() => {



    // find a user whose email is the same as the forms email

    // we are checking to see if the user trying to login already exists

    User.findOne({ 'email' :  email },function(err, user){

        // if there are any errors, return the error



        if (err)

            return done(err);



        // check to see if theres already a user with that email

        if (user) {

            return done(null, false, {'errorMessages': 'That email is already taken.'});

        } else {



            // if there is no user with that email

            // create the user

            let newUser            = new User();



            // set the user's local credentials

            newUser.name       = req.body.fullname;

            //newUser.email          = email;

            newUser.password       = newUser.generateHash(password);





            // save the user

            newUser.save((err)=>{

                if (err)

                    return done(err);

                return done(null, newUser);

            });

        }

    });    

    });

}));

The above code is in node js using passport js authentication and the code of local-signup is not working.

In the above code i am getting the error:

User.findOne() is not a function.

My schema is all right... please help