Constructing document yields semi-empty result - express

Question

After executing Customer.create({customerName: 'John'}), the following document is created without error and without the 'customerName' node.
Can anyone tell me why this seemingly simple document creation call yields a semi-blank document? The document in the response from Mongoose is the same as it is in the database itself.
I can't tell if I'm using Mongoose incorrectly or Express incorrectly. Thanks in advance for your help.
{ __v: 0, _id: 5452dc48d687bad849d70816 }
routes/customer.js
var mongoose = require( 'mongoose' );
var Customer = mongoose.model( 'Customer');
exports.create = function(req, res) {
Customer.create({
customerName: 'John'
}, function(err, customer) {
if (err) return err;
console.log('Customer created', customer);
res.send(customer);
});
}
schema/customer.js
var mongoose = require('mongoose');
var customerSchema = new mongoose.Schema({
customerName: {
type: String,
required: false
}
});
db.js
var mongoose = require( 'mongoose' );
var dbURI = 'mongodb://localhost/CustomerDatabase';
mongoose.connect(dbURI);
var customerSchema = require( '../schema/customer.js' );
var Customer = mongoose.model( 'Customer', customerSchema);
routes.js
function SetupRoutes(app, PATH) {
var db = require('../model/db.js')
var customer = require( '../routes/customer.js' );
app.post('/Customer', customer.create);
}
module.exports.SetupRoutes = SetupRoutes;

Answer 1

You need to export customerSchema from customer.js so that when db.js requires that file, its value is the exported schema:
var mongoose = require('mongoose');
var customerSchema = new mongoose.Schema({
customerName: {
type: String,
required: false
}
});
module.exports = customerSchema;
However, the more typical pattern is to create the model in customer.js and then export that:
var mongoose = require('mongoose');
var customerSchema = new mongoose.Schema({
customerName: {
type: String,
required: false
}
});
module.exports = mongoose.model('Customer', customerSchema);