I create a user inside a mongo database. The model looks like the following:

import mongoose from 'mongoose';

const userSchema = new mongoose.Schema({
  username: {
    type: String,
    required: true,
    unqiue: true,
  },
  password: {
    type: String,
    required: true,
    minlength: 6,
  },
  email: {
    type: String,
    required: true,
  },
  avatar: {
    type: String,
    default: 'https://via.placeholder.com/150',
  },
  authority: {
    type: String,
    enum: ['user', 'admin'],
    default: 'user',
  },
  vCoins: {
    type: Number,
    default: 0,
  },
  vCard: {
    type: Number,
    default: 0,
  },
  married: {
    type: Number,
    default: 0,
  },
});

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

export default User;

Now I’m using the users objects _id inside the user-state to create a socket.io connection the following way:

const socket = io('http://localhost:5000', {
    query: {
        userId: id,
    },
})

The user-state data is being taken this way: const id = useAppSelector((state) => state.auth.user._id)

On the backend I receive the ID in this way: const userId = socket.handshake.query.userId as string

And try to create the user object again using: const user = await User.findById(id); using the mongo model.

Which gives me the following error: Cast to ObjectId failed for value "0" (type string) at path "_id" for model "User"

What could I do in this scenario? Since it’s saved as a mongoose.Types.ObjectId in the backend database. But should be used within client and socket backend as number / string?