Make NestJs returns 404 when EntityNotFoundError exception is thrown

custom-entity-not-found-exception-filter.md

Make NestJs returns 404 when EntityNotFoundError exception is thrown

When using findOrFail() or findOneOrFail() from typeORM, a 500 error is returned if there is no entity (EntityNotFoundError).

To make it returns a 404, use an exception filter as described in https://docs.nestjs.com/exception-filters .

file /src/filters/entity-not-found-exception.filter.ts

import { Catch, ExceptionFilter, ArgumentsHost} from "@nestjs/common";
import { EntityNotFoundError } from 'typeorm/error/EntityNotFoundError'
import { Response } from 'express';


/**
 * Custom exception filter to convert EntityNotFoundError from TypeOrm to NestJs responses
 * @see also @https://docs.nestjs.com/exception-filters
 */
@Catch(EntityNotFoundError, Error)
export class EntityNotFoundExceptionFilter implements ExceptionFilter {
  public catch(exception: EntityNotFoundError, host: ArgumentsHost) {

    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response>();
    return response.status(404).json({ message: { statusCode: 404, error: 'Not Found', message: exception.message } });
  }
}

Use it in your main module

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { EntityNotFoundExceptionFilter } from './filters/entity-not-found-exception.filter';

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

Add cases of specific TypeORMError or any other error that needs special treatment.