What is the nestjs error handling approach (business logic error vs. http error)?

Question

While using NestJS to create API\'s I was wondering which is the best way to handle errors/exception. I have found two different approaches :

1. Have individual servic

Answer 1

You may want to bind services not only to HTTP interface, but also for GraphQL or any other interface. So it is better to cast business-logic level exceptions from services to Http-level exceptions (BadRequestException, ForbiddenException) in controllers.

In the simpliest way it could look like

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

@Injectable()
export class HttpHelperService {
  async transformExceptions(action: Promise): Promise {
    try {
      return await action;
    } catch (error) {
      if (error.name === 'QueryFailedError') {
        if (/^duplicate key value violates unique constraint/.test(error.message)) {
          throw new BadRequestException(error.detail);
        } else if (/violates foreign key constraint/.test(error.message)) {
          throw new BadRequestException(error.detail);
        } else {
          throw error;
        }
      } else {
        throw error;
      }
    }
  }
}

and then