TypeError: Cannot read properties of undefined (reading '_id')

Question

I'm working on a personal project and i really need some help

I'm having this error and i don't understand why:(

Here is my code:

 //authRoutes.js


const { Router } = require('express');
const authController = require('../controllers/authController');
const { requireAuth } = require('../middleware/authMiddleware');
var Post = require('../models/post')
const router = Router();


router.use(function(req,res, next){
 res.locals.user = req.user;
next();
});

router.get('/signup', authController.signup_get);
router.post('/signup', authController.signup_post);
router.get('/login', authController.login_get);
router.post('/login', authController.login_post);
router.get('/logout', authController.logout_get);


router.get("/home", function (req, res) {
 res.render("home");
});


router.get("/about", function (req, res) {
 res.render("about");
});


router.get("/", requireAuth, function(req,res){
 Post.find({userID:req.user._id}).exec(function(err, posts){
  if(err){
   console.log(err);
  }
 res.render("posts",{posts:posts})
})
})

 router.get("/add", requireAuth, function(req,res){
  res.render("addpost")
 })

Everything was working fine until I tried to add a new post to the database

This is the part of the code that's causing the error:

 router.post("/add",requireAuth, function(req,res){


  var newPost = new Post({
   title:req.body.title,
   content:req.body.content,
   userID:req.user._id
  })
  newPost.save(function(err,post){
   if(err){
    console.log(err)
    res.redirect("/posts")
   }
  })
 })




 module.exports = router;

can someone help me?

Answer 1

The error is because in here:

var newPost = new Post({
   title:req.body.title,
   content:req.body.content,
   userID:req.user._id
})

you're trying to access "user._id", but there is not "_id" inside user, so check what is inside user.

Answer 2

Quite literally, it is what it say it is

Cannot read properties of undefined (reading '_id')

This means that there's no _id property inside req.user (the object user inside the req object). It seems you're not sending _id (maybe your payload is using id instead of _id ? Could you share your payload with us?

Answer 3

it seems like req.user is undefined and that is the reason of why it gives you that error. Try to find out where you get your id from: )

Answer 4

Here is user.js

    const mongoose = require('mongoose');
const { isEmail } = require('validator');
const bcrypt = require('bcrypt');

const userSchema = new mongoose.Schema({
  email: {
    type: String,
    required: [true, 'Please enter an email'],
    unique: true,
    lowercase: true,
    validate: [isEmail, 'Please enter a valid email']
  },
  password: {   
    type: String,
    required: [true, 'Please enter a password'],
    minlength: [6, 'Minimum password length is 6 characters'],
  }
});


// fire a function before doc saved to db
userSchema.pre('save', async function(next) {
  const salt = await bcrypt.genSalt();
  this.password = await bcrypt.hash(this.password, salt);
  next();
});

// static method to login user
userSchema.statics.login = async function(email, password) {
  const user = await this.findOne({ email });
  if (user) {
    const auth = await bcrypt.compare(password, user.password);
    if (auth) {
      return user;
    }
    throw Error('incorrect password');
  }
  throw Error('incorrect email');
};

const User = mongoose.model('user', userSchema);

module.exports = User;