NestJS

Emmanuel DEMEY

@EmmanuelDemey

Consultant WEB

Aurélien LOYER

@AurelienLoyer

Software Engineer @QIMA

NestJS

You all already know NestJS or have heard of them!

Or maybe you just know Angular ?!

NestJS

overview in

~10 minutes !!

Nest (NestJS) is a framework for building efficient, scalable Node.js server-side applications

Node.js
TypeScript
Express or Fastify
"Plugins": GraphQL, WebSockets, ...
Inspired by the Angular framework
An awesome CLI 👌

npm install -g @nestjs/cli
nest new my-nest-project

// OR

npx @nestjs/cli new my-nest-project

@nestjs/cli

@nestjs/cli new app

@nestjs/cli --help

@nestjs Project Structure

.
|-- node_modules
|-- src
|   |-- app.controller.ts
|   |-- app.module.ts
|   |-- app.service.ts
|   `-- main.ts
|-- nest-cli.json
|-- package.json
|-- tsconfig.json
`-- .eslintrc.js

@nestjs main.ts

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  await app.listen(3000);
}
bootstrap();

Bootstrap our application
Main module definition
Port
And more...

@nestjs Controllers

import { Controller, Get } from '@nestjs/common';

@Controller('plants')
export class PlantsController {
  @Get()
  findAll(): string {
    return 'This action returns all plants';
  }
}

Use classes and decorators
Incoming requests
Returning responses
CRUD

@nestjs Providers

import { Injectable } from '@nestjs/common';
import { Plant } from './interfaces/plant.interface';


@Injectable()
export class PlantsService {
  private readonly plants: Plant[] = [];

  create(plant: Plant) {
    this.plants.push(plant);
  }
  //..
}

Use classes and decorators
Point of contact with the data
Injected as dependency

constructor(private catsService: CatsService) {}

@nestjs Modules

import { Module } from '@nestjs/common';
import { PlantsController } from './plants.controller';
import { PlantsService } from './plants.service';

@Module({
  controllers: [PlantsController],
  providers: [PlantsService],
  exports: [PlantsService],
})
export class PlantsModule {}

Use classes and decorators
Organize the application structure
Controllers / Providers / Exports

@nestjs ...

@Injectable()
export class LoggerMiddleware implements NestMiddleware {
  use(req: Request, res: Response, next: NextFunction) {
    console.log('Request...');
    next();
  }
}

Middleware

@Get(':id')
async findOne(@Param('id', ParseIntPipe) id: number) {
  return this.catsService.findOne(id);
}

Pipes

Pipes

Guards
Interceptors
...

👨🏻‍💻 Live Coding Session!

Gardener!