What's New in Mongoose 5.7?

What's New in Mongoose 5.7?

In this article, I'll cover two other major improvements: conditionally immutable properties and much faster document arrays in Mongoose 5.7

Originally published by Valeri Karpov at http://thecodebarbarian.com

Mongoose 5.7.0 was released on September 9 and is packed with new features. One major highlight is that Mongoose 5.7 supports the newly released MongoDB 4.2, which means transactions on sharded clusters. In this article, I'll cover two other major improvements: conditionally immutable properties and much faster document arrays.

Conditionally Immutable Properties

Mongoose 5.6 introduced immutable properties, which are properties that cannot change after the document is stored in the database.

const Model = mongoose.model('Test', new Schema({
 createdById: {
   type: Number,
   immutable: true // Mark `createdById` as immutable
 }
}));

const doc = await Model.create({ createdById: 1 });

// Trying to modify createdById is a no-op doc.createdById = 2; doc.createdById; // 1 await doc.save(); // Doesn't change createdById

// Also does nothing since createdById is immutable await Model.updateOne({}, { createdById: 2 });

However, immutability in Mongoose 5.6 was all or nothing: either a property was immutable for all instances of a model, or it wasn't. With Mongoose 5.7, you can set the immutable option to a function that takes the document as a parameter. For example, this means you can make a field immutable based on a user's role:

// Only an admin can modify the number of credits they have
const User = mongoose.model('User', new Schema({
 numCredits: {
   type: Number,
   default: 0,
   immutable: doc => doc.role !== 'ADMIN'
 },
 role: {
   type: String,
   default: 'USER',
   enum: ['USER', 'MODERATOR', 'ADMIN'],
   immutable: true
 }
}));

const user1 = await Model.create({ role: 'USER' }); user1.set({ numCredits: 25 }); user1.numCredits; // 0

const user2 = await Model.create({ role: 'ADMIN' }); user2.set({ numCredits: 25 }); user2.numCredits; // 25

Faster Document Arrays

In Mongoose 5.6.0, we overhauled Mongoose's array class to use ES6 array inheritance as opposed to mixins. In some rudimentary benchmarks this resulted in a 20% performance improvement. This change was long overdue: ES6 introduced the ability to subclass the built-in Array class, which enables faster custom array classes. In Mongoose 5.7.0, we refactored the document array class to use ES6 array inheritance as well.

For example, consider the below script that creates a document array with 100 elements, each with 5 keys, 5000 times.

'use strict';

const mongoose = require('mongoose');

const subdocs = 100; const reps = 5000;

const SubdocSchema = mongoose.Schema({ a: String, b: String, c: String, d: String, e: String }); const Schema = mongoose.Schema({ name: String, subdocs: { type: [SubdocSchema] } }); const Model = mongoose.model('Test', Schema); const data = {  _id: new mongoose.Types.ObjectId(),  name: 'test',  subdocs: Array(subdocs).fill({a: 'a', b: 'b', c: 'c', d: 'd', e: 'e' }) }; const model = new Model();

for (let i = 0; i < reps; i++) {  model.init(data); }

Mongoose 5.7 is about 35% faster than Mongoose 5.6 on the above script.

$ npm install [email protected]

real   0m10.878s user   0m11.444s sys   0m0.293s $ $ npm install [email protected]

  • [email protected] added 1 package, removed 1 package and updated 1 package in 0.648s $ $ time node test.js

real   0m6.940s user   0m7.087s sys   0m0.053s $

Moving On

Conditionally immutable properties and faster document arrays are just 2 of the 9 new improvements and features in Mongoose 5.7.0. We also introduced MongoDB 4.2 support, middleware for query validation, and a Query#get() function. Make sure you upgrade to take advantage of all the new features!

Thanks for reading

If you liked this post, share it with all of your programming buddies!

Follow us on Facebook | Twitter

Further reading

Building A REST API With MongoDB, Mongoose, And Node.js

How to build a real time chat application in Node.js using Express, Mongoose and Socket.io

Use MongoDB Node.js Native Driver Without Mongoose





mongodb node-js web-development

Bootstrap 5 Complete Course with Examples

Bootstrap 5 Tutorial - Bootstrap 5 Crash Course for Beginners

Nest.JS Tutorial for Beginners

Hello Vue 3: A First Look at Vue 3 and the Composition API

Building a simple Applications with Vue 3

Deno Crash Course: Explore Deno and Create a full REST API with Deno

How to Build a Real-time Chat App with Deno and WebSockets

Convert HTML to Markdown Online

HTML entity encoder decoder Online

Hire Node.JS Developers | Skenix Infotech

We are providing robust Node.JS Development Services with expert Node.js Developers. Get affordable Node.JS Web Development services from Skenix Infotech.

How to Hire Node.js Developers And How Much Does It Cost?

A Guide to Hire Node.js Developers who can help you create fast and efficient web applications. Also, know how much does it cost to hire Node.js Developers.

Top Node.js Development Companies and Expert NodeJS Developers

A thoroughly researched list of top NodeJS development companies with ratings & reviews to help hire the best Node.JS developers who provide development services and solutions across the world. List of Leading Node.js development Service Providers...

Hire Web Developer

Looking for an attractive & user-friendly web developer? HourlyDeveloper.io, a leading web, and mobile app development company, offers web developers for hire through flexible engagement models. You can **[Hire Web...

Hire Node JS Developer from Expert Node JS Development Company

NodeJS Development Company-Hire Node JS developer from the most prominent NodeJS development company, Mobiweb and get remarkable Node.js app development services.