How to learn Nest JS? (2024)

Table of Contents
Step 1: Understand the Basics of Node.js and TypeScript Step 2: Set Up Your Development Environment Step 3: Create a New NestJS Project Step 4: Understand the Project Structure Step 5: Learn the Basics of NestJS Step 6: Create a Simple Application Step 7: Learn More Advanced NestJS Features Step 8: Testing and Debugging Step 9: Learning Resources Step 10: Build Real-World Projects Step 11: Stay Updated Step 1: Set Up the Development Environment Step 2: Create a New NestJS Project Step 3: Understand the Project Structure Step 4: Learn the Basics of NestJS Step 5: Create a Simple Application Step 6: Learn More Advanced NestJS Features Step 7: Testing and Debugging Step 8: Learning Resources Step 9: Build Real-World Projects Step 10: Stay Updated

Learning NestJS can be a rewarding experience as it is a powerful framework for building efficient and scalable server-side applications. Here's a structured guide to help you get started with NestJS:

Step 1: Understand the Basics of Node.js and TypeScript

Before diving into NestJS, make sure you have a solid understanding of Node.js and TypeScript.

  1. Node.js Basics:

    • Understand the event-driven architecture.
    • Learn how to create a basic server using Node.js and Express.js.
    • Familiarize yourself with asynchronous programming using callbacks, promises, and async/await.

  2. TypeScript Basics:

    • Learn the basic syntax and features of TypeScript.
    • Understand interfaces, classes, and modules.
    • Learn about decorators and their usage.

Step 2: Set Up Your Development Environment

  1. Install Node.js:
    Download and install Node.js from nodejs.org.

  2. Install Nest CLI:
    The Nest CLI is a powerful tool to initialize, develop, and maintain NestJS applications.

 npm install -g @nestjs/cli

Step 3: Create a New NestJS Project

  1. Create a New Project:
 nest new my-nestjs-app cd my-nestjs-app

  1. Run the Application:
 npm run start

This will start the development server and your application will be running on http://localhost:3000.

Step 4: Understand the Project Structure

When you create a new NestJS project, you'll see the following structure:

my-nestjs-app/├── src/│ ├── app.controller.spec.ts│ ├── app.controller.ts│ ├── app.module.ts│ ├── app.service.ts│ ├── main.ts├── test/├── node_modules/├── .eslintrc.js├── .prettierrc├── nest-cli.json├── package.json├── README.md├── tsconfig.build.json└── tsconfig.json

Step 5: Learn the Basics of NestJS

  1. Modules:

    • Modules are the building blocks of a NestJS application. They help in organizing the application structure.
    • Example: app.module.ts
     import { Module } from '@nestjs/common'; import { AppController } from './app.controller'; import { AppService } from './app.service'; @Module({ imports: [], controllers: [AppController], providers: [AppService], }) export class AppModule {}

  2. Controllers:

    • Controllers handle incoming requests and return responses to the client.
    • Example: app.controller.ts
     import { Controller, Get } from '@nestjs/common'; import { AppService } from './app.service'; @Controller() export class AppController { constructor(private readonly appService: AppService) {} @Get() getHello(): string { return this.appService.getHello(); } }

  3. Services:

    • Services are used to handle business logic.
    • Example: app.service.ts
     import { Injectable } from '@nestjs/common'; @Injectable() export class AppService { getHello(): string { return 'Hello World!'; } }

Step 6: Create a Simple Application

Let's create a simple CRUD application to manage users.

  1. Generate a New Module:
 nest generate module users

  1. Generate a Controller:
 nest generate controller users

  1. Generate a Service:
  1. Update Users Service:Open src/users/users.service.ts and implement basic CRUD operations.
 import { Injectable } from '@nestjs/common'; interface User { id: number; name: string; age: number; } @Injectable() export class UsersService { private users: User[] = []; findAll(): User[] { return this.users; } findOne(id: number): User { return this.users.find(user => user.id === id); } create(user: User): void { this.users.push(user); } update(id: number, updatedUser: User): void { const userIndex = this.users.findIndex(user => user.id === id); if (userIndex > -1) { this.users[userIndex] = updatedUser; } } delete(id: number): void { this.users = this.users.filter(user => user.id !== id); } }

  1. Update Users Controller:Open src/users/users.controller.ts and implement the endpoints.
 import { Controller, Get, Post, Body, Param, Put, Delete } from '@nestjs/common'; import { UsersService } from './users.service'; @Controller('users') export class UsersController { constructor(private readonly usersService: UsersService) {} @Get() findAll() { return this.usersService.findAll(); } @Get(':id') findOne(@Param('id') id: number) { return this.usersService.findOne(id); } @Post() create(@Body() user: { id: number; name: string; age: number }) { this.usersService.create(user); } @Put(':id') update(@Param('id') id: number, @Body() user: { id: number; name: string; age: number }) { this.usersService.update(id, user); } @Delete(':id') remove(@Param('id') id: number) { this.usersService.delete(id); } }

  1. Update Users Module:Open src/users/users.module.ts and import the service and controller.
 import { Module } from '@nestjs/common'; import { UsersService } from './users.service'; import { UsersController } from './users.controller'; @Module({ controllers: [UsersController], providers: [UsersService], }) export class UsersModule {}

  1. Integrate Users Module in App Module:Open src/app.module.ts and import the UsersModule.
 import { Module } from '@nestjs/common'; import { AppController } from './app.controller'; import { AppService } from './app.service'; import { UsersModule } from './users/users.module'; @Module({ imports: [UsersModule], controllers: [AppController], providers: [AppService], }) export class AppModule {}

  1. Run the Application:
 npm run start

  1. Test the Application:Use a tool like Postman or curl to test the CRUD endpoints.

Step 7: Learn More Advanced NestJS Features

  1. Middleware:

    • Middleware functions are executed before the route handler.
    • Example:
     import { Injectable, NestMiddleware } from '@nestjs/common'; import { Request, Response, NextFunction } from 'express'; @Injectable() export class LoggerMiddleware implements NestMiddleware { use(req: Request, res: Response, next: NextFunction) { console.log(`Request...`); next(); } }

  2. Interceptors:

    • Interceptors are used to transform the response or handle exceptions.
    • Example:
     import { Injectable, NestInterceptor, ExecutionContext, CallHandler } from '@nestjs/common'; import { Observable } from 'rxjs'; import { map } from 'rxjs/operators'; @Injectable() export class TransformInterceptor implements NestInterceptor { intercept(context: ExecutionContext, next: CallHandler): Observable<any> { return next.handle().pipe(map(data => ({ data }))); } }

  3. Guards:

    • Guards are used for authentication and authorization.
    • Example:
     import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common'; import { Observable } from 'rxjs'; @Injectable() export class AuthGuard implements CanActivate { canActivate( context: ExecutionContext, ): boolean | Promise<boolean> | Observable<boolean> { const request = context.switchToHttp().getRequest(); return validateRequest(request); } }

  4. Pipes:

    • Pipes are used to transform and validate data.
    • Example:
     import { PipeTransform, Injectable, ArgumentMetadata, BadRequestException } from '@nestjs/common'; @Injectable() export class ParseIntPipe implements PipeTransform<string, number> { transform(value: string, metadata: ArgumentMetadata): number { const val = parseInt(value, 10); if (isNaN(val)) { throw new BadRequestException('Validation failed'); } return val; } }

Step 8: Testing and Debugging

  1. Unit Testing:

    • NestJS uses Jest for unit testing.
    • Example:
     import { Test, TestingModule } from '@nestjs/testing'; import

{ UsersService } from './users.service';

 describe('UsersService', () => { let service: UsersService; beforeEach(async () => { const module: TestingModule = await Test.createTestingModule({ providers: [UsersService], }).compile(); service = module.get<UsersService>(UsersService); }); it('should be defined', () => { expect(service).toBeDefined(); }); }); ```

  1. End-to-End Testing:

    • Use Supertest for end-to-end testing.
    • Example:
     import { Test, TestingModule } from '@nestjs/testing'; import { INestApplication } from '@nestjs/common'; import * as request from 'supertest'; import { AppModule } from './../src/app.module'; describe('AppController (e2e)', () => { let app: INestApplication; beforeEach(async () => { const moduleFixture: TestingModule = await Test.createTestingModule({ imports: [AppModule], }).compile(); app = moduleFixture.createNestApplication(); await app.init(); }); it('/ (GET)', () => { return request(app.getHttpServer()) .get('/') .expect(200) .expect('Hello World!'); }); });

Step 9: Learning Resources

  1. Official Documentation:

  2. Online Courses:

  3. Books:

    • "Mastering NestJS" by Kamil Myśliwiec

  4. Tutorials and Articles:

  5. Community and Forums:

Step 10: Build Real-World Projects

  1. Choose Real-World Projects:

    • Build applications like an e-commerce platform, blog, or social media app.

  2. Contribute to Open Source:

    See Also
    (NestJS -1) Introduction to NestJS

    • Contribute to open source NestJS projects on GitHub.

Step 11: Stay Updated

  1. Follow NestJS Updates:
    • Follow the NestJS blog
    • Join NestJS newsletters
    • Attend NestJS conferences and meetups

By following this structured guide and practicing regularly, you'll build up your knowledge and skills in NestJS, enabling you to create powerful and efficient server-side applications. If you have any specific questions or need further details on any step, feel free to ask!

Sure! Let's dive into NestJS, a powerful, efficient, and scalable server-side Node.js framework built with TypeScript. Here's a step-by-step guide to help you get started with NestJS:

Step 1: Set Up the Development Environment

  1. Install Node.js:
    Download and install Node.js from nodejs.org.

  2. Install Nest CLI:
    The Nest CLI is a powerful tool to initialize, develop, and maintain NestJS applications.

 npm install -g @nestjs/cli

Step 2: Create a New NestJS Project

  1. Create a New Project:
 nest new my-nestjs-app cd my-nestjs-app

  1. Run the Application:
 npm run start

This will start the development server and your application will be running on http://localhost:3000.

Step 3: Understand the Project Structure

When you create a new NestJS project, you'll see the following structure:

my-nestjs-app/├── src/│ ├── app.controller.spec.ts│ ├── app.controller.ts│ ├── app.module.ts│ ├── app.service.ts│ ├── main.ts├── test/├── node_modules/├── .eslintrc.js├── .prettierrc├── nest-cli.json├── package.json├── README.md├── tsconfig.build.json└── tsconfig.json

Step 4: Learn the Basics of NestJS

  1. Main Entry Point:
    • src/main.ts is the entry point of the application.
 import { NestFactory } from '@nestjs/core'; import { AppModule } from './app.module'; async function bootstrap() { const app = await NestFactory.create(AppModule); await app.listen(3000); } bootstrap();

  1. Modules:

    • Modules are the building blocks of a NestJS application.
    • src/app.module.ts:
     import { Module } from '@nestjs/common'; import { AppController } from './app.controller'; import { AppService } from './app.service'; @Module({ imports: [], controllers: [AppController], providers: [AppService], }) export class AppModule {}

  2. Controllers:

    • Controllers handle incoming requests and return responses to the client.
    • src/app.controller.ts:
     import { Controller, Get } from '@nestjs/common'; import { AppService } from './app.service'; @Controller() export class AppController { constructor(private readonly appService: AppService) {} @Get() getHello(): string { return this.appService.getHello(); } }

  3. Services:

    • Services are used to handle business logic.
    • src/app.service.ts:
     import { Injectable } from '@nestjs/common'; @Injectable() export class AppService { getHello(): string { return 'Hello World!'; } }

Step 5: Create a Simple Application

Let's create a simple CRUD application to manage users.

  1. Generate a New Module:
 nest generate module users

  1. Generate a Controller:
 nest generate controller users

  1. Generate a Service:
 nest generate service users

  1. Update Users Service:Open src/users/users.service.ts and implement basic CRUD operations.
 import { Injectable } from '@nestjs/common'; interface User { id: number; name: string; age: number; } @Injectable() export class UsersService { private users: User[] = []; findAll(): User[] { return this.users; } findOne(id: number): User { return this.users.find(user => user.id === id); } create(user: User): void { this.users.push(user); } update(id: number, updatedUser: User): void { const userIndex = this.users.findIndex(user => user.id === id); if (userIndex > -1) { this.users[userIndex] = updatedUser; } } delete(id: number): void { this.users = this.users.filter(user => user.id !== id); } }

  1. Update Users Controller:Open src/users/users.controller.ts and implement the endpoints.
 import { Controller, Get, Post, Body, Param, Put, Delete } from '@nestjs/common'; import { UsersService } from './users.service'; @Controller('users') export class UsersController { constructor(private readonly usersService: UsersService) {} @Get() findAll() { return this.usersService.findAll(); } @Get(':id') findOne(@Param('id') id: number) { return this.usersService.findOne(id); } @Post() create(@Body() user: { id: number; name: string; age: number }) { this.usersService.create(user); } @Put(':id') update(@Param('id') id: number, @Body() user: { id: number; name: string; age: number }) { this.usersService.update(id, user); } @Delete(':id') remove(@Param('id') id: number) { this.usersService.delete(id); } }

  1. Update Users Module:Open src/users/users.module.ts and import the service and controller.
 import { Module } from '@nestjs/common'; import { UsersService } from './users.service'; import { UsersController } from './users.controller'; @Module({ controllers: [UsersController], providers: [UsersService], }) export class UsersModule {}

  1. Integrate Users Module in App Module:Open src/app.module.ts and import the UsersModule.
 import { Module } from '@nestjs/common'; import { AppController } from './app.controller'; import { AppService } from './app.service'; import { UsersModule } from './users/users.module'; @Module({ imports: [UsersModule], controllers: [AppController], providers: [AppService], }) export class AppModule {}

  1. Run the Application:
 npm run start

  1. Test the Application:Use a tool like Postman or curl to test the CRUD endpoints.

Step 6: Learn More Advanced NestJS Features

  1. Middleware:
    Middleware functions are executed before the route handler.

    • Example:
     import { Injectable, NestMiddleware } from '@nestjs/common'; import { Request, Response, NextFunction } from 'express'; @Injectable() export class LoggerMiddleware implements NestMiddleware { use(req: Request, res: Response, next: NextFunction) { console.log(`Request...`); next(); } }

  2. Interceptors:
    Interceptors are used to transform the response or handle exceptions.

    • Example:
     import { Injectable, NestInterceptor, ExecutionContext, CallHandler } from '@nestjs/common'; import { Observable } from 'rxjs'; import { map } from 'rxjs/operators'; @Injectable() export class TransformInterceptor implements NestInterceptor { intercept(context: ExecutionContext, next: CallHandler): Observable<any> { return next.handle().pipe(map(data => ({ data }))); } }

  3. Guards:
    Guards are used for authentication and authorization.

    • Example:
     import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common'; import { Observable } from 'rxjs'; @Injectable() export class AuthGuard implements CanActivate { canActivate( context: ExecutionContext, ): boolean | Promise<boolean> | Observable<boolean> { const request = context.switchToHttp().getRequest(); return validateRequest(request); } }

  4. Pipes:
    Pipes are used to transform and validate data.

    • Example:
     import { PipeTransform, Injectable, ArgumentMetadata, BadRequestException } from '@nestjs/common'; @Injectable() export class ParseIntPipe implements PipeTransform<string, number> { transform(value: string, metadata: ArgumentMetadata): number { const val = parseInt(value, 10); if (isNaN(val)) { throw new BadRequestException('Validation failed'); } return val; } }

Step 7: Testing and Debugging

  1. Unit Testing:

    • NestJS uses Jest for unit testing.
    • Example:
     import { Test, TestingModule } from '@nestjs/testing'; import { UsersService } from './users.service'; describe('UsersService', () => { let service: UsersService; beforeEach(async () => { const module: TestingModule = await Test.createTestingModule({ providers: [Users

Service],
}).compile();

 service = module.get<UsersService>(UsersService); }); it('should be defined', () => { expect(service).toBeDefined(); }); }); ```

  1. End-to-End Testing:

    • Use Supertest for end-to-end testing.
    • Example:
     import { Test, TestingModule } from '@nestjs/testing'; import { INestApplication } from '@nestjs/common'; import * as request from 'supertest'; import { AppModule } from './../src/app.module'; describe('AppController (e2e)', () => { let app: INestApplication; beforeEach(async () => { const moduleFixture: TestingModule = await Test.createTestingModule({ imports: [AppModule], }).compile(); app = moduleFixture.createNestApplication(); await app.init(); }); it('/ (GET)', () => { return request(app.getHttpServer()) .get('/') .expect(200) .expect('Hello World!'); }); });

Step 8: Learning Resources

  1. Official Documentation:

  2. Online Courses:

  3. Books:

    • "Mastering NestJS" by Kamil Myśliwiec

  4. Tutorials and Articles:

  5. Community and Forums:

Step 9: Build Real-World Projects

  1. Choose Real-World Projects:

    • Build applications like an e-commerce platform, blog, or social media app.

  2. Contribute to Open Source:

    • Contribute to open source NestJS projects on GitHub.

Step 10: Stay Updated

  1. Follow NestJS Updates:
    • Follow the NestJS blog
    • Join NestJS newsletters
    • Attend NestJS conferences and meetups

By following this structured guide and practicing regularly, you'll build up your knowledge and skills in NestJS, enabling you to create powerful and efficient server-side applications. If you have any specific questions or need further details on any step, feel free to ask!

Disclaimer: This content is generated by AI.

How to learn Nest JS? (2024)
Top Articles
Is A Gym Membership Worth It? - MoneyByRamey.com
Capital Gains: Definition, Rules, Taxes, and Asset Types
Evil Dead Movies In Order & Timeline
Dr Klabzuba Okc
Optimal Perks Rs3
Buckaroo Blog
Kagtwt
Vardis Olive Garden (Georgioupolis, Kreta) ✈️ inkl. Flug buchen
Sams Gas Price Fairview Heights Il
Items/Tm/Hm cheats for Pokemon FireRed on GBA
Cvs Learnet Modules
The Binding of Isaac
Dumb Money
Oro probablemente a duna Playa e nomber Oranjestad un 200 aña pasa, pero Playa su historia ta bay hopi mas aña atras
Radio Aleluya Dialogo Pastoral
Sony E 18-200mm F3.5-6.3 OSS LE Review
7543460065
Q33 Bus Schedule Pdf
Navy Female Prt Standards 30 34
Byui Calendar Fall 2023
Accident On May River Road Today
Morristown Daily Record Obituary
Gopher Hockey Forum
Geometry Review Quiz 5 Answer Key
Beverage Lyons Funeral Home Obituaries
Today Was A Good Day With Lyrics
Mj Nails Derby Ct
When Does Subway Open And Close
Expression&nbsp;Home&nbsp;XP-452 | Grand public | Imprimantes jet d'encre | Imprimantes | Produits | Epson France
Biografie - Geertjan Lassche
Rock Salt Font Free by Sideshow » Font Squirrel
The Ultimate Guide to Obtaining Bark in Conan Exiles: Tips and Tricks for the Best Results
Average weekly earnings in Great Britain
The 38 Best Restaurants in Montreal
The Syracuse Journal-Democrat from Syracuse, Nebraska
19 Best Seafood Restaurants in San Antonio - The Texas Tasty
Can You Buy Pedialyte On Food Stamps
Cherry Spa Madison
Latest Nigerian Music (Next 2020)
Cheetah Pitbull For Sale
Legit Ticket Sites - Seatgeek vs Stubhub [Fees, Customer Service, Security]
Janaki Kalaganaledu Serial Today Episode Written Update
Emily Tosta Butt
R: Getting Help with R
Spurs Basketball Reference
Gary Vandenheuvel Net Worth
Vci Classified Paducah
Sapphire Pine Grove
Motorcycle For Sale In Deep East Texas By Owner
10 Bedroom Airbnb Kissimmee Fl
91 East Freeway Accident Today 2022
The Missile Is Eepy Origin
Latest Posts
HS296 Capital Gains Tax and Debts (2022)
Scenes from A New England Winter in Bethel Maine
Article information

Author: Gregorio Kreiger

Last Updated:

Views: 5914

Rating: 4.7 / 5 (57 voted)

Reviews: 88% of readers found this page helpful

Author information

Name: Gregorio Kreiger

Birthday: 1994-12-18

Address: 89212 Tracey Ramp, Sunside, MT 08453-0951

Phone: +9014805370218

Job: Customer Designer

Hobby: Mountain biking, Orienteering, Hiking, Sewing, Backpacking, Mushroom hunting, Backpacking

Introduction: My name is Gregorio Kreiger, I am a tender, brainy, enthusiastic, combative, agreeable, gentle, gentle person who loves writing and wants to share my knowledge and understanding with you.