NestJS does not await asynchronous shutdown hooks in some circumstances

[andrew-sol]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

I use JaniAnttonen/winston-loki package.

After creating a transport, NestJS stops awaiting shutdown hooks. app.enableShutdownHooks() is enabled.
See the reproduction code repo.

app.module.ts:

import { Logger, Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';

@Module({
  imports: [],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {
  private readonly logger = new Logger(AppModule.name);

  async beforeApplicationShutdown(): Promise<void> {
    this.logger.log(1);

    await new Promise((resolve) => setTimeout(resolve, 1000));

    this.logger.log(2);
  }
}

main.ts:

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import LokiTransport from 'winston-loki';

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

  app.enableShutdownHooks();

  // comment out the following statement and shutdown hooks will be awaited
  const lokiTransport = new LokiTransport({
    host: 'http://qweasd',
  });

  await app.listen(3000);
}

bootstrap();

Only the first log appears.

Minimum reproduction code

https://github.com/andrew-sol/nestjs-reproduction-1

Steps to reproduce

1. yarn install --frozen-lockfile or npm install
2. yarn start:dev or npm run start:dev
3. Ctrl+C

Expected behavior

Both logs from the shutdown hook should be printed.

Package

• I don't know. Or some 3rd-party package
• @nestjs/common
• @nestjs/core
• @nestjs/microservices
• @nestjs/platform-express
• @nestjs/platform-fastify
• @nestjs/platform-socket.io
• @nestjs/platform-ws
• @nestjs/testing
• @nestjs/websockets
• Other (see below)

Other package

JaniAnttonen/winston-loki

NestJS version

8.4.5

Packages versions

@nestjs/cli@8.2.6
@nestjs/common@8.4.5
@nestjs/core@8.4.5
@nestjs/platform-express@8.4.5
@nestjs/schematics@8.0.11
@nestjs/testing@8.4.5

Node.js version

16.14.2

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response

[micalevisk]

I believe this is duplicate of nestjs/nest-cli#1487

[kamilmysliwiec]

winston-loki uses async-exit-hook which overrides the default framework's behavior. This issue should be reported there (in the winston-loki repo) instead. There's nothing we can do on the NestJS side.