MissingSchemaError: Schema hasn't been registered for model “User”

Question

In my models/user.js file:

var mongoose = require(\'mongoose\');
var Schema = mongoose.Schema;

var userSchema = new Schema({
    (define schema         


        

Answer 1

I literally research lot and I found a solution so, I share this solution to you so, no one can face that cheap mistake that I did.

Please remember, you just need to add the same name in ref as you gave in your model because its case sensitive ( Product !== product ).

const Product = new mongoose.model('Product', productSchema);

product: {
    type: mongoose.Schema.ObjectId,
    ref: 'Product', <-- Should be same as modelName
    required: [true, 'Cart must belong to a product']
}