是否可以将在 main.ts 中创建的 NestJS 应用程序注入到模块服务中？

Question

Assuming you have the basic NestJS setup:

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

  app.enableCors(corsOptions);

  app.useGlobalPipes(
    new ValidationPipe({
      validateCustomDecorators: true,
      transform: true,
      whitelist: true,
      exceptionFactory: exceptionFactory,
    }),
  );
  app.useGlobalFilters(new CustomExceptionsFilter());

  const port = parseInt(process.env.PORT);
  await app.listen(port);
}

Can I access the app variable created with NestFactory from a service in a different module?

@Injectable()
export class TestService {
  constructor(
    ...
  ) {}

  async useApp(): Promise<any> {
    const app = ... // use Injected app instance created from AppModule
  }

I've tried importing AppModule and creating a NestFactory again, but it just resolves into redundancies.

Answer 1

NestFactory.create will create the app , which depends on modules & their providers. Using app before it has been created does not make sense.

---

Instead, you could tell us what you're trying to do with that app at TestService .

Answer 2

There is no way to get the app instance itself from the Nest containers, you could simply export the app once it is created by NestFactory.create() .

However, if you're looking for the instance of AppModule , this bellow snippet might help you.

const app = await NestFactory.createApplicationContext(AppModule);