Nestjs, Why you should use it!

What is the Nodejs framework?

Node.js is an open-source, cross-platform, runtime JavaScript environment that enables you to write server-side applications. It runs on Google Chrome’s V8 JavaScript engine and thus runs JavaScript outside the web browser.

NestJS is an open-source framework that helps you build scalable Node.js server-side applications. Heavily inspired by Angular, it is built on Typescript and uses progressive JavaScript. It has a simple design with 3 main components: controllers, modules, and providers.

NestJS Architecture

Modules :

A module allows you to group together related controllers and service providers.

@Modules() **decorator is used for modules.

Controllers :

It is responsible for handling incoming HTTP requests, processing them

@Controller(), it groups a set of route handlers together that are responsible for processing the request under a base endpoint. Nest supports @Get, @Post(), @Put(), @Delete(), @Header(), @UseFilters(), @UsePipes(), @All(), and other Route handler decorators.

Service Providers :

It encapsulates related business logic and function into a single class.

Nest collects the list of providers defined by all modules in the application, creates a single instance of each provider, and injects the provider instance to any controller requesting it.

@Injectable() decorator that helps in injecting the service into any controller.

Features :

• It combines the elements of OOPs (Object-Oriented Programming), FP (Functional Programming), and FRP (Functional Reactive Programming).
• It supports various databases like PostgreSQL, MongoDB, MySQL, Redis, Apache Cassandra, etc.
• NestJS is platform agnostic - it uses Express by default but you can configure it to work with any HTTP framework like Fastify.
• It provides a wide range of functionalities, APIs, and libraries so that developers can build applications with fewer lines of code.
• It was created for building Monoliths and Micro-services.
• It contains a built-in Dependency Injection container thus keeping your code clean, and easy to read and use.
• You can easily integrate with technologies such as Mongoose, Prisma, TypeORM, GraphQL, and concepts like Logging, Validation, Caching, and Web Sockets.

Pros :

• Extensible: Thanks to its modular architecture, NestJS is flexible and allows you to use the other existing libraries within your project (more on this below).
• Architecture: NestJS has a project architecture that provides testing, scaling, and maintenance
• Versatile: Provides an adaptable ecosystem
• Progressive: NestJS makes use of JavaScript functions and implements mature solutions and design patterns in software development
• TypeScript: Leverages TypeScript, a superset of JavaScript
• Documentation: NestJS encourages documentation thanks to the use of decorators.
• Testing: due to dependency injection and modularity, performing testing becomes much simpler.
• CLI: NestJS includes its own CLI tool for project management and handling scaffolding is definitely nice to have.

Cons :

• Scaffolding: In NestJS, everything has a highly defined structure, so sometimes we can get lost or derailed in generating or navigating so many files.
• Learning Curve: New developer needs to learn the framework, it is not as easygoing as Express.
• A whole lot of magic: magic means that something is working just because it is working. Until it stops working, that is. There are instances where doing certain things would be a thousand times simpler if done with Express rather than NestJS, and when a developer encounters these blockers, they will need someone more experienced to assist them. Someone with knowledge of dependency injection, and experience working with more seasoned frameworks like Spring.
• Feels Old: Given its resemblance to .NET Core, Spring and others.

NestJS vs ExpressJS