Approaches to create and combine models in mongoose. Document referencing, model composition and many more.

money.model.js

'use strict';

const DEF_CURRENCY = 'USD';
const DEF_SCALE_FACTOR = 100;

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const ObjectId = Schema.ObjectId;

const MoneySchema = new Schema({
  amount:   { type: Number, default: 0 },
  currency: { type: String, default: DEF_CURRENCY },
  factor:   { type: Number, default: DEF_SCALE_FACTOR }
}, {
  _id:      false,
  toObject: { virtuals: true },
  toJSON:   { virtuals: true }
});

// implements exact precision model
MoneySchema
.virtual('value')
.set(function(value) {
  if (value) {
    this.set('amount', value * this.factor);
  }
})
.get(function() {
  return this.amount / this.factor;
});

module.exports = mongoose.model('Money', MoneySchema);

order.model.js

'use strict';

const mongoose = require('mongoose');
const Money = require('./money.model').schema;
const Schema = mongoose.Schema;
const ObjectId = Schema.ObjectId;
const Mixed = Schema.Types.Mixed;

const OrderSchema = new Schema({
  identifier:   { type: String },
  user:         { type: ObjectId, ref: 'User' },
  status:       { type: String, default: 'active' },
  total:        { type: Money },
  details:      { type: Mixed },
  shipping:     { type: Mixed },
  items:        { type: [
    {
      sku:      { type: String },
      qty:      { type: Number, default: 1},
      title:    { type: String },
      price:    { type: Money },
      product:  { type: ObjectId, ref: 'Product' }
    }
  ]},
  expiresAt:    { type: Date, default: null },
  updatedAt:    { type: Date, default: Date.now },
  createdAt:    { type: Date, default: Date.now }
},  {
  toObject:     { virtuals: true },
  toJSON:       { virtuals: true }
});

module.exports = mongoose.model('Order', OrderSchema);

product-detail.model.js

'use strict';

const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const ObjectId = Schema.ObjectId;

const ProductDetailSchema = new Schema({
  title:        { type: String, required: true },
  description:  { type: String },
  summary:      { type: String, required: true }
}, {
  _id: false,
  strict: false,
  toObject: { virtuals: true },
  toJSON: { virtuals: true }
});

module.exports = mongoose.model('ProductDetail', ProductDetailSchema);

product.model.js

'use strict';

const mongoose = require('mongoose');
// your common helpers file
const commonHelper = require('../helpers/common');
// custom schema
const Money = require('./money.model').schema;
const ProductDetail = require('./product-detail.model').schema;
const Schema = mongoose.Schema;
// mongoose schema
const ObjectId = Schema.ObjectId;
const Mixed = Schema.Types.Mixed;

const ProductSchema = new Schema({
  sku:          { type: String, required: true },
  category:     { type: String },
  slug:         { type: String },
  images:       { type: [
    {
      caption:  { type: String },
      filename: { type: String }
    }
  ] },
  details:      { type: ProductDetail },
  price:        { type: Money },
  active:       { type: Boolean, default: false }  
});

ProductSchema.pre('save', function(next) {
  // generic `slug` creation method
  this.slug = commonHelper.createSlug(this.title);
  next();
});

ProductSchema.statics.findBySKU = function findBySKU(sku, callback) {
  this.findOne({ sku: sku }, callback);
}

ProductSchema.statics.findBySlug = function findBySlug(sku, callback) {
  this.findOne({ slug: slug }, callback);
}

module.exports = mongoose.model('Product', ProductSchema);

user.model.js

'use strict';

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const UserSchema = new Schema({
  email:  {
    type: String,
    required: true,
    unique: true
  },
  name: {
    type: String
  },
  password: {
    type: String,
    required: true,
    select: false
  },
  passwordSalt: {
    type: String,
    required: true,
    select: false
  },
  active: {
    type: Boolean,
    default: true
  },
  createdAt: {
    type: Date,
    default: Date.now
  }
});

module.exports = mongoose.model('User', UserSchema);