Nested objects in mongoose schemas

// address model
    var addressModelSchema = new Schema({
        city: String,
        street: String,
        houseNumber: String
    })
    mongoose.model('address',addressModelSchema ,'address' )

// contactInfo model
    var contactInfoModelSchema = new Schema({
        tel: [Number],
        email: [String],
        address: {
            type: mongoose.Schema.Type.ObjectId,
            ref: 'address'
        }
    })
    mongoose.model('contactInfo ',contactInfoModelSchema ,'contactInfo ')

// customer model
    var customerModelSchema = new Schema({
        firstName: String,
        lastName: String,
        company: String,
        contactInfo: {
            type: mongoose.Schema.Type.ObjectId,
            ref: 'contactInfo'
        }  
    });
    mongoose.model('customer', customerModelSchema, 'customer')

// add new address then contact info then the customer info
// it is better to create model for each part.

const mongoose = require("mongoose");

// Make connection
// https://mongoosejs.com/docs/connections.html#error-handling
mongoose.connect("mongodb://localhost:27017/test", {
  useNewUrlParser: true,
  useUnifiedTopology: true,
});

// Define schema
// https://mongoosejs.com/docs/models.html#compiling
const AddressSchema = mongoose.Schema({
  city: String,
  street: String,
  houseNumber: String,
});

const ContactInfoSchema = mongoose.Schema({
  tel: [Number],
  email: [String],
  address: {
    type: AddressSchema,
    required: true,
  },
});

const CustomerSchema = mongoose.Schema({
  firstName: String,
  lastName: String,
  company: String,
  connectInfo: ContactInfoSchema,
});

const CustomerModel = mongoose.model("Customer", CustomerSchema);

// Create a record
// https://mongoosejs.com/docs/models.html#constructing-documents
const customer = new CustomerModel({
  firstName: "Ashish",
  lastName: "Suthar",
  company: "BitOrbits",
  connectInfo: {
    tel: [8154080079, 6354492692],
    email: ["[email protected]", "[email protected]"],
  },
});

// Insert customer object
// https://mongoosejs.com/docs/api.html#model_Model-save
customer.save((err, cust) => {
  if (err) return console.error(err);

  // This will print inserted record from database
  // console.log(cust);
});

// Display any data from CustomerModel
// https://mongoosejs.com/docs/api.html#model_Model.findOne
CustomerModel.findOne({ firstName: "Ashish" }, (err, cust) => {
  if (err) return console.error(err);

  // To print stored data
  console.log(cust.connectInfo.tel[0]); // output 8154080079
});

// Update inner record
// https://mongoosejs.com/docs/api.html#model_Model.update
CustomerModel.updateOne(
  { firstName: "Ashish" },
  {
    $set: {
      "connectInfo.tel.0": 8154099999,
    },
  }
);