Vatsalya-singhi

import { Controller, Get, UseInterceptors } from '@nestjs/common';
import { LoggingInterceptor } from './logging.interceptor';

@Controller('users')
export class UsersController {
  @Get()
  @UseInterceptors(LoggingInterceptor) // Apply logging interceptor to this route
  findAll() {
    return { message: 'List of users' };
  }

Vatsalya-singhi

import { Injectable, NestInterceptor, ExecutionContext, CallHandler } from '@nestjs/common';
import { Observable } from 'rxjs';
import { tap } from 'rxjs/operators';

@Injectable()
export class LoggingInterceptor implements NestInterceptor {
  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
    console.log('Before handler execution');
    const startTime = new Date();
    // Proceed with the request and log the response

Vatsalya-singhi

import { Controller, Get, UseGuards } from '@nestjs/common';
import { AuthGuard } from './auth.guard';
import { RoleGuard } from './role.guard';

@Controller('admin')
export class AdminController {
  @Get()
  @UseGuards(AuthGuard, new RoleGuard('admin')) // applying mulitple guards
  findAll() {
    return { message: 'Admin dashboard' };

Vatsalya-singhi

// guard implementation in Controller
import { Controller, Get, UseGuards } from '@nestjs/common';
import { RoleGuard } from './role.guard';

@Controller('admin')
export class AdminController {
  @Get()
  @UseGuards(new RoleGuard('admin')) // Apply the guard for 'admin' role
  findAll() {
    return { message: 'Admin dashboard' };

Vatsalya-singhi

import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common';

@Injectable()
export class RoleGuard implements CanActivate {
  constructor(private requiredRole: string) {}

  canActivate(context: ExecutionContext): boolean {
    const request = context.switchToHttp().getRequest();
    const user = request.user;  // User is assumed to be attached to the request
    return user?.role === this.requiredRole;  // Check if user's role matches

Vatsalya-singhi

// main.ts
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { AuthGuard } from './auth.guard';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useGlobalGuards(new AuthGuard()); // Apply globally
  await app.listen(3000);
}

Vatsalya-singhi

import { Controller, Get, UseGuards } from '@nestjs/common';
import { AuthGuard } from './auth.guard';

@Controller('users')
@UseGuards(AuthGuard) // Apply guard to all routes in this controller
export class UsersController {
  @Get()
  findAll() {
    return { message: 'List of users' };
  }

Vatsalya-singhi

import { Controller, Get, UseGuards } from '@nestjs/common';
import { AuthGuard } from './auth.guard';

@Controller('users')
export class UsersController {
  @Get()
  @UseGuards(AuthGuard) // Apply guard to this method
  findAll() {
    return { message: 'List of users' };
  }

Vatsalya-singhi

import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common';

@Injectable()
export class AuthGuard implements CanActivate {
  canActivate(context: ExecutionContext): boolean {
    const request = context.switchToHttp().getRequest();
    // Check if request has a valid user (authentication logic)
    return Boolean(request.user);  // Assume `request.user` is set after successful login
  }
}

Vatsalya-singhi

// main.ts
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { ValidationPipe } from '@nestjs/common';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useGlobalPipes(new ValidationPipe()); // Apply to all routes
  await app.listen(3000);
}