HttpExceptionFilterMiddleware Documentation

HttpExceptionFilterMiddleware is a custom http exception filter middleware that displays the error response with the following json format

{
  "message": "A short description of the error",
  "statusCode": 400,
  "timestamp": "2024-11-19T22:59:47.025Z",
  "errorCode": "000003",
  "description": "A descriptive or long description of the error"
}

Installation

To install the necessary dependencies, run:

npm install abs-nestjs-http-exception-filter-middleware

Usage with NestJS

1. Import the HttpExceptionFilterMiddleware into your main.ts:

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { HttpExceptionFilterMiddleware } from 'abs-nestjs-exception-filter-middleware';
import { config } from './config';

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

  // use global http exception filter middleware
  app.useGlobalFilters(new HttpExceptionFilterMiddleware());

  await app.listen(config.port);
}
bootstrap();

2. Extend the ErrorCodes class

import { HttpStatus } from '@nestjs/common';
import { ErrorCodes } from 'abs-nestjs-exception-filter-middleware';

export class CustomErrors extends ErrorCodes {
  public static CUSTOM_ERROR = {
    CODE: '000021',
    STATUS_CODE: HttpStatus.INTERNAL_SERVER_ERROR,
    MESSAGE: 'Something went wrong. Please try again later',
    DESCRIPTION:
      'An internal issue occurred. Either you or the system may have done something wrong. Please try again later or contact support.',
  };

  public static CUSTOM_ERROR_WITH_PARAMS ({ args1, args2 }) {
    CODE: '000021',
    STATUS_CODE: HttpStatus.INTERNAL_SERVER_ERROR,
    MESSAGE: `Passed params ${args1} and ${args2}`,
    DESCRIPTION:
      'An internal issue occurred. Either you or the system may have done something wrong. Please try again later or contact support.',
  }
}

3. Somewhere in your code, you can import the helper throwExceptionError then use it to throw your Custom Error

import { Controller, Get } from '@nestjs/common';
import { AppService } from './app.service';
import { throwExceptionError } from 'abs-nestjs-exception-filter-middleware';
import { CustomErrors } './custom-errors.constants';

@Controller()
export class AppController {
  constructor(private readonly appService: AppService) {}

  @Get('/error-1')
  someMethod(): string {
    throwExceptionError(CustomErrors.CUSTOM_ERROR);
  }

  @Get('/error-2')
  someMethod(): string {
    throwExceptionError(CustomErrors.CUSTOM_ERROR_WITH_PARAMS({ args1: 'test1', args2: 'test2'}));
  }
}