Undefined dependencies and private fields in rabbitmq subscriber

Hello everyone. ✋ I have one strange issue with RabbitSubscribe. There is module with the exchange consumer that handle files in base64 format. Module:

import { Module } from '@nestjs/common';
import { RabbitMQModule } from '@golevelup/nestjs-rabbitmq';
import { FileConsumer } from './file.consumer';
import { FILE_SERVICE } from './di.constants';
import { FileService } from './file.service';
import { rabbitExchangesConfig } from '../config/rabbitmq';

@Module({
  imports: [
    RabbitMQModule.forRoot(RabbitMQModule, {
      uri: rabbitExchangesConfig.fileSaver.uri,
      exchanges: [
        {
          type: 'fanout',
          name: rabbitExchangesConfig.fileSaver.exchange,
        },
      ],
    }),
  ],
  providers: [
    FileConsumer,
    {
      provide: FILE_SERVICE,
      useClass: FileService,
    },
  ],
})
export class FileModule {}

Consumer:

import { Inject, Injectable } from '@nestjs/common';
import { Nack, RabbitSubscribe } from '@golevelup/nestjs-rabbitmq';
import { LoggerFactory } from '@company/logger-winston';
import { FILE_SERVICE } from './di.constants';
import { IFileService } from './file.service';
import { rabbitExchangesConfig } from '../config/rabbitmq';
import { FileSaveData } from './types';
import { FileWasNotFoundError } from './errors';

@Injectable()
export class FileConsumer {
  private readonly logger = LoggerFactory.getLogger(FileConsumer.name);

  constructor(@Inject(FILE_SERVICE) private readonly fileService: IFileService) {}

  @RabbitSubscribe({
    exchange: rabbitExchangesConfig.fileSaver.exchange,
    queue: rabbitExchangesConfig.fileSaver.queue,
    routingKey: rabbitExchangesConfig.fileSaver.routingKey,
  })
  public async uploadFile(msg: FileSaveData): Promise<null | Nack> {
    if (!msg.fileId || !msg.rawData) {
      this.logger.error('Incoming message is broken', { msg });
      return new Nack(false);
    }
    this.logger.info(`Income new message: ${msg}`, { fileId: msg.fileId });
    try {
      await this.fileService.uploadFile(msg);
      return null;
    } catch (err) {
      this.logger.error('Failed processing data', err, { fileId: msg.fileId });
      switch (true) {
        case err instanceof FileWasNotFoundError:
          return new Nack(false);
        default:
          return new Nack(true);
      }
    }
  }
}

main.ts:

import { NestFactory } from '@nestjs/core';
import { NestExpressApplication } from '@nestjs/platform-express';
import { ValidationPipe } from '@nestjs/common';
import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
import * as bodyParser from 'body-parser';
import { AppModule } from './app.module';
import { AppConfigService } from './config';
import { WinstonLogger } from './logger';

async function bootstrap() {
  const app = await NestFactory.create<NestExpressApplication>(AppModule, {
    // logger: false,
  });
  const appConfig = app.get<AppConfigService>('AppConfigService');
  const logger = new WinstonLogger('APP');
  app.useLogger(logger);
  app.useGlobalPipes(new ValidationPipe());

  app.setGlobalPrefix('api');
  app.use(bodyParser.json({ limit: '10mb' }));
  app.use(bodyParser.urlencoded({ limit: '10mb', extended: true }));
  const options = new DocumentBuilder()
    .setTitle('Core service')
    .setDescription('Core API description')
    .setVersion('1.0')
    .build();
  const document = SwaggerModule.createDocument(app, options);
  SwaggerModule.setup('api-doc', app, document);

  return app.listen(appConfig.port);
}
bootstrap();

I see in my logs that subscriber has connected to my exchange with set queue and routing key:

2021-03-15 21:11:30 [APP] info: Initializing RabbitMQ Handlers { env: 'local', server_env: 'local', pid: 308 }
2021-03-15 21:11:30 [APP] info: Registering rabbitmq handlers from FileConsumer { env: 'local', server_env: 'local', pid: 308 }
2021-03-15 21:11:30 [APP] info: FileConsumer.uploadFile {subscribe} -> rc-oc.file_saver.spool.exchange::rc-oc.file_saver::rc-oc.file_saver.spool { env: 'local', server_env: 'local', pid: 308 }
2021-03-15 21:11:30 [APP] info: Successfully connected a RabbitMQ channel { env: 'local', server_env: 'local', pid: 308 }
2021-03-15 21:11:30 [APP] info: Nest application successfully started { env: 'local', server_env: 'local', pid: 308 }

But I have a problem with accessing to my private fields and injected dependencies because after receiving message from exchange my logger and injected service are undefined. I’ve tested an invocation of constructor of FileConsumer, and saw that It wasn’t called before handling message from exchange. 🤯

I also have a http controllers in another modules and don’t have any problems with injection. Can anyone help me? It’s really strange bug. 🤔

Version of @golevelup/nestjs-rabbitmq is 1.16.0.

[WonderPanda]

@Scrib3r I can see how Unit of Work would be a desirable pattern to be able to implement when processing messages from RabbitMQ. I’m not sure how much work is involved with being able to leverage Scope.Request outside the context of HTTP or if it is even possible but I will take a look and see what is possible

[silentroach]

+1 for request scoped consumers like in nest