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();

@Wangenye thank you so much

import {
  ArgumentsHost,
  Catch,
  ExceptionFilter,
  HttpStatus,
} from '@nestjs/common';
import { Request, Response } from 'express';
import {
  CannotCreateEntityIdMapError,
  EntityNotFoundError,
  QueryFailedError,
} from 'typeorm';

@Catch()
export class GlobalExceptionFilter implements ExceptionFilter {
  catch(exception: unknown, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const request = ctx.getRequest<Request>();
    const response = ctx.getResponse<Response>();
    let status: HttpStatus, message: string, code: number;

    switch (exception.constructor) {
      case QueryFailedError:
        status = HttpStatus.BAD_REQUEST;
        message = (exception as QueryFailedError).message;
        code = (exception as any).code;
        break;
      case EntityNotFoundError:
        status = HttpStatus.NOT_FOUND;
        message = (exception as EntityNotFoundError).message;
        code = (exception as any).code;
        break;
      case CannotCreateEntityIdMapError:
        status = HttpStatus.UNPROCESSABLE_ENTITY;
        message = (exception as CannotCreateEntityIdMapError).message;
        code = (exception as any).code;
        break;
      default:
        status = (exception as any).status;
        message = (exception as any).message.message;
        code = (exception as any).code;
        break;
    }

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

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