Payload error in jsonwebtoken

Question

I am making a web application using nodejs and angular cli I'm using JWT to authenticate my login function . But when I process it threw this error

Error: Expected "payload" to be a plain object. at validate (D:\Mean_Projects\meanauthapp\node_modules\jsonwebtoken\sign.js:34:11) at validatePayload (D:\Mean_Projects\meanauthapp\node_modules\jsonwebtoken\sign.js:56:10) at Object.module.exports [as sign] (D:\Mean_Projects\meanauthapp\node_modules\jsonwebtoken\sign.js:108:7) at User.comparePassword (D:\Mean_Projects\meanauthapp\routes\users.js:86:27) at bcrypt.compare (D:\Mean_Projects\meanauthapp\models\user.js:53:9) at D:\Mean_Projects\meanauthapp\node_modules\bcryptjs\dist\bcrypt.js:297:21 at D:\Mean_Projects\meanauthapp\node_modules\bcryptjs\dist\bcrypt.js:1353:21 at Immediate.next [as _onImmediate] (D:\Mean_Projects\meanauthapp\node_modules\bcryptjs\dist\bcrypt.js:1233:21) at runCallback (timers.js:785:20) at tryOnImmediate (timers.js:747:5) at processImmediate [as _immediateCallback] (timers.js:718:5)

Here my passport code

    const JwtStrategy= require('passport-jwt').Strategy;     const ExtractJwt=require('passport-jwt').ExtractJwt;     const User= require('../models/user');     const config=require('../config/database');             module.exports=function(passport){     let opts={};     opts.jwtFromRequest=ExtractJwt.fromAuthHeader();     opts.secretOrKey=config.secret;     opts.issuer = 'accounts.examplesoft.com';     opts.audience = 'yoursite.net';     passport.use(new JwtStrategy(opts,(jwt_payload,done)=>{         console.log(jwt_payload);         User.getUserById(jwt_payload._doc._id,(err,user)=>{             if(err){                 return done(err,false);             }             if(user){                 return done(null,user);             }             else{                 return done(null,false);             }         });     })); } 

My code for authenticate and get profile

// Authenticate router.post('/authenticate', (req, res, next) => {   const username = req.body.username;   const password = req.body.password;    User.getUserByUsername(username, (err, user) => {     if(err) throw err;     if(!user){       return res.json({success: false, msg: 'User not found'});     }      User.comparePassword(password, user.password, (err, isMatch) => {       if(err) throw err;       if(isMatch){         const token = jwt.sign(user, config.secret, {           expiresIn: 604800 // 1 week         });          res.json({           success: true,           token: 'JWT '+token,           user: {             id: user._id,             name: user.name,             username: user.username,             email: user.email           }         });       } else {         return res.json({success: false, msg: 'Wrong password'});       }     });   }); });  // Profile router.get('/profile', passport.authenticate('jwt', {session:false}), (req, res, next) => {   res.json({user: req.user}); }); 

Answer 1

It fails at the line

const token = jwt.sign(user, config.secret, { 

With error "Expected "payload" to be a plain object"

Your user object is initialized here:

User.getUserByUsername(username, (err, user) 

Which I assume is mongoosejs object, which contains many methods and is not "serializable". You could handle this by passing a plain object, by either using .lean() from mongoose or plain toJSON method:

const token = jwt.sign(user.toJSON(), config.secret, {   expiresIn: 604800 // 1 week });