Expected "payload" to be a plain object : MEAN

Question

This is my code from routes file(users.js)

User.findOne({linkedin_id: req.body.linkedin_id}, function(err, linkedinUser) {
    if(err) {
      console.log('err in finding linkedin user '+err);
    }
    // if user exits
    else if(linkedinUser) {
      console.log('user exist');
      const token = jwt.sign(linkedinUser, config.secret, {expiresIn: 604800});
      res.json({success: true, token: 'JWT '+token, user: {
          id: linkedinUser._id,
          linkedin_id: linkedinUser.linkedin_id,
          name: linkedinUser.name,
          username: linkedinUser.username,
          email: linkedinUser.email,
          lkprofilePic: linkedinUser.profilePic
        }, msg: 'user exits'
      });
    }
    // if user doesn't exist
    else {
      User.create({
        linkedin_id: req.body.linkedin_id,
        name: req.body.name,
        username: req.body.username,
        email: req.body.email,
        lkprofilePic: req.body.lkprofilePic
      }, function(err, result) {
        if(err) {
          res.json({success: false, msg: 'failed to add'})
          console.log('error in adding the data '+err);
        }
        else if(result) {
          const token = jwt.sign(linkedinUser,config.secret,{ expiresIn: 604800 });
          res.json({success: true, token: 'JWT '+token, user: {
            id: result._id,
            linkedin_id: result.linkedin_id,
            name: result.name,
            username: result.username,
            email: result.email,
            lkprofilePic: result.profilePic
          }, msg: 'User added '  });
        }
      });
    }
  });

This from the config -> secret

module.exports = {
    secret: 'bigfish'
  }

This is the error I'm getting in the nodejs console

Receiving linkedin data D:\product\project-1\node_modules\mongodb\lib\utils.js:132 throw err; ^

Error: Expected "payload" to be a plain object. at validate (D:\product\project-1\node_modules\jsonwebtoken\sign.js:34:11) at validatePayload (D:\product\project-1\node_modules\jsonwebtoken\sign.js:56:10) at Object.module.exports [as sign] (D:\product\project-1\node_modules\jsonwebtoken\sign.js:108:7) at D:\product\project-1\routes\users.js:415:29 at Function. (D:\product\project-1\node_modules\mongoose\lib\model.js:4177:16) at parallel (D:\product\project-1\node_modules\mongoose\lib\model.js:2230:12) at D:\product\project-1\node_modules\mongoose\node_modules\async\internal\parallel.js:35:9 at D:\product\project-1\node_modules\mongoose\node_modules\async\internal\once.js:12:16 at iteratorCallback (D:\product\project-1\node_modules\mongoose\node_modules\async\eachOf.js:52:13) at D:\product\project-1\node_modules\mongoose\node_modules\async\internal\onlyOnce.js:12:16 at D:\product\project-1\node_modules\mongoose\node_modules\async\internal\parallel.js:32:13 at apply (D:\product\project-1\node_modules\lodash_apply.js:15:25) at D:\product\project-1\node_modules\lodash_overRest.js:32:12 at callbackWrapper (D:\product\project-1\node_modules\mongoose\lib\model.js:2199:11) at D:\product\project-1\node_modules\mongoose\lib\model.js:4177:16 at model.$__save.error (D:\product\project-1\node_modules\mongoose\lib\model.js:359:7)

But the data is getting saved in the database & doesn't return the

res.json({success: true, token: 'JWT '+token, user: {
            id: result._id,
            linkedin_id: result.linkedin_id,
            name: result.name,
            username: result.username,
            email: result.email,
            lkprofilePic: result.profilePic
          }, msg: 'User added '  });

Answer 1

The issue is with the way you signed your token

The user you are using is a returned user from mongoose so you will need to use YOUR_USER.toJSON. if the user is not coming from mongoose use JSON.stringify(YOUR_USER) instead

change your code to either

const token = jwt.sign({linkedinUser}, config.secret, {expiresIn: 604800});
//if you want to set expiration on the token

OR

const token = jwt.sign(linkedinUser.toJSON(), config.secret);
//if you just want to sign the token without setting the expiration