The two mostly used Node.js frameworks nowadays are Nest and Express. For building web applications, it is important to understand their basic features and differences.
In recent times, the Express web application has become the first choice for building a web application framework since it is fast, flexible, and minimal.
For building large-scale applications, developers often go for lightweight frameworks, and thus creating the NestJS app is gaining popularity.
NestJS
What is NestJS?
NestJS is an open-source, cross-platform framework that enables to write of server-side and networking applications.
This framework is mainly inspired by Angular and is built on Typescript using progressive JavaScript.
Nest makes use of the Express HTTP framework by default and can work with any Node HTTP framework. For example, it can optionally be configured to use Fastify.
One of the best things about NestJS is that anything supported in the ExpressJS framework is also supported in the NestJS application.
How to install NestJS?
Nest has an excellent CLI that makes it easy to build the application.In the Command Prompt terminal, type the following: npmi-g @nestjs/cli Now use the cd command to change into the directory where we want to build our app.
Execute the commands as:
nest new nest-blog-api
cd nest-blog-api
npm run start:dev
In any browser, go to http://localhost:3000 . You should see a “Hello World” message.
NestJS core components
NestJS core components have three main components: modules, providers, and controllers.
Nest module system is simple in design. A module is a class that has been annotated with the @Module() decorator. NestJS integration uses the metadata provided by the @Module() decorator to arrange the application structure.
There is a root module in each NestJS which is used as a starting point to resolve the structure and relationships of the application. Another powerful feature of the Nest module is the Dynamic module. This allows you to create customizable modules that can dynamically register and configure providers easily.
Nest relies heavily on Providers to build relationships between different objects. A provider can be injected as a dependency. Classes like repositories, services, and helpers can be treated as providers.
When an HTTP request is received, the routing mechanism routes it to the correct controller within NestJS. Controllers handle the incoming requests and respond to the application’s client side.
Features of NestJS
Some notable features that make NestJS a good choice among developers are here:
For heavy applications:
Working with Express and Node is great for building a lightweight application where the code is easy to read and write. However, when you add more features to your application and it becomes complex, your code will start to get a little messier and harder to manage. This problem is eliminated with the use of NestJS.
Components:
It combines the elements of OOPs (Object-Oriented Programming), FP (Functional Programming), and FRP (Functional Reactive Programming).
Support for Databases:
It supports various databases like PostgreSQL, MongoDB, MySQL, Redis, Apache Cassandra, etc.
Support for dependency injection:
Nest also supports dependency injection.
Fewer lines of code:
It provides a wide range of functionalities, libraries, and APIs, and so that you can build applications with fewer lines of code.
Using Express middleware:
NestJS uses the Express web application framework by default as the request processing pipeline.
Express.js
What is Express.js?
Express is a Node.js web application framework that provides a wide range of functionality for mobile applications and web app development. You can use Express with Node to create single-page, multi-page, or hybrid web application development. Hence, Express is the most popular web development frameworks.
Since it is written in Javascript frameworks, absolute beginners can also get into a framework for web development easily.
How to install Express.js?
To use Express for our project, we first need to install it:
npm install express
Then import Express inside the project:
import express from ‘express’;
Next, initialize the application, give it a port to listen to, and respond to a request on that path:
const app = express();
app.get(‘/’,(req, res)=>{
res.send(‘Hello World!’);
});
app.listen(3000,()=>
console.log(‘Example app listening on port 3000!’),
);
Express.js Components
Express has no specific structure. Hence, there remains a possibility for an application to end up inefficient and less optimized. However, this can become a problem as the complexity of the application grows.
Features of Express.js
Some of the features of ExpressJS are described below.
Middleware:
Middleware is a program component that has access to a database, client requests, and other middleware. It is majorly responsible for the systematic organization of various Express.js functions.
Routing mechanism:
When it comes to routing, Express includes a sophisticated routing mechanism that uses URLs to preserve the state of the webpage.
Template:
Express includes template engines that help developers to create dynamic content for web pages by creating HTML templates on the server side.
Shedding Light on both for better understanding
The below table shows the comparison of NestJS vs ExpressJS:
| Feature | NestJS | ExpressJS |
| Usage | It is used to build server-side, input-output, and event-driven apps. | It is used to build web apps using the approaches and principles of Node.js. |
| Level of features | Fewer features. | More features than Node.js. |
| Building Block | It is built on Google’s V8 engine. | It is built on Node.js. |
| Written in | C, C++, JavaScript | JavaScript |
| Coding time | It requires more coding time. | It requires less coding time. |
| Controllers | Controllers are not provided. | Controllers are provided. |
| Routing | Routing is not provided. | Routing is provided. |
| Middleware | Does not use such a provision. | Uses middleware for the arrangement of functions systematically server-side. |
| Framework/Platform | Run-time platform or environment designed for server-side execution of JavaScript. | Framework based on Node.js. |
Concluding
Express.js is one of the best and most popular backend development frameworks using JavaScript and will likely remain so for some time. But, according to some developers, NestJS has a significant advantage early on. Both have their unique pros and cons. Now you can get a understanding between those two frameworks which helps you decide to take a right decision to opt. Get expert advice and assistance for using both NestJS and Express JS technologies at CG-VAK and clear out all queries in one place.