Mongoose update query keeps on inserting data with upsert true without updating and adding only 1 field

I am working on Facebook login in Node js with Mongoose. i am getting issues while updating data.

This is my Scheme file

var mongoose = require('mongoose');


var Schema = mongoose.Schema;

 // Schema
var RegSchema = mongoose.Schema({
    UserName: String,
    UserEmail: String,
    userprofileImage : String,
    userId: String,
    reg_time : {
        type : Date, default: Date.now
    }
}, { collection: 'user' });

// Model
module.exports = mongoose.model('UserReg', RegSchema);

and this is my main file where update and insert(if not found) is placed

var express = require('express');
var mongoose = require('mongoose');
var bodyParser = require('body-parser');
var app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true })); 



var UserReg = require('./myschema.js');

module.exports = function(userdetail, callback){
var bb;

                  var UserAdd = new UserReg({
                                "UserName": userdetail.username,
                                "UserEmail": userdetail.useremail,
                                "userId": userdetail.userId,
                                "userprofileImage": userdetail.userprofileImage
                            });

                    var userdetailchange = {
                                "UserName": userdetail.username,
                                "UserEmail": userdetail.useremail,
                                "userId": userdetail.userId,
                                "userprofileImage": userdetail.userprofileImage
                    };

                    // Update if found otherwise Insert
                    UserAdd.update({"userId":userdetail.userId },{ $set:userdetailchange, $setOnInsert:userdetailchange ,upsert:true, new: true, setDefaultsOnInsert: true}, function (err, data) {
                            if (err) {
                                callback(err);
                            } 
                                callback(data);                             
                    });

};

Now it keeps on inserting user data in collection with only 1 field which is userId and also a default _id field. Please help me in updating whole data if match found or Insert whole data in Collection. Any help will be highly appreciated.

via noobcode