NestJS – Exception Handling

NestJS

Exception Handling

Handling errors and custom exceptions in NestJS.

Custom Exception Filter: Create a filter to catch and format specific exceptions globally or locally.

📄http-exception.filter.ts
TypeScript

import { ExceptionFilter, Catch, ArgumentsHost, HttpException } from '@nestjs/common';
import { Request, Response } from 'express';

@Catch(HttpException)
export class HttpExceptionFilter implements ExceptionFilter {
  catch(exception: HttpException, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response>();
    const request = ctx.getRequest<Request>();
    const status = exception.getStatus();

    response
      .status(status)
      .json({
        statusCode: status,
        timestamp: new Date().toISOString(),
        path: request.url,
      });
  }
}

Using the Custom Filter: Apply the custom filter globally in your main application file.

📄main.ts
TypeScript

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { HttpExceptionFilter } from './http-exception.filter';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  
  // Apply the custom exception filter globally
  app.useGlobalFilters(new HttpExceptionFilter());
  
  await app.listen(3000);
}
bootstrap();