RangeError: Maximum call stack size exceeded when importing module

Regression

Unexpected RangeError: Maximum call stack size exceeded when importing the same module in conjunction with TypeOrmModule.forRootAsync

Potential Commit/PR that introduced the regression**

Can not say an exact commit

Describe the regression

When importing the same module inside the imports option of a module and also inside the imports options of TypeOrmModule.forRootAsync a RangeError: Maximum call stack size exceeded is thrown

Input Code

Install dependencies

npm i @nestjs/common@6.6.1 @nestjs/core@6.6.1 @nestjs/platform-express@6.6.1 express @nestjs/typeorm typeorm pg rxjs ts-node typescript

index.ts

import { TypeOrmModule } from '@nestjs/typeorm';
import { NestFactory } from '@nestjs/core';
import { Module, Injectable } from '@nestjs/common';

@Injectable()
class ConfigService {
  config() {
    return {
      postgres: { uri: 'postgres://user:pass@localhost:5432/testdb' }
    };
  }
}

@Module({
  exports: [ConfigService],
  providers: [ConfigService]
})
class ConfigModule {}

@Module({
  imports: [
    ConfigModule, // <--- importing the config module for my app
    TypeOrmModule.forRootAsync({
      imports: [ConfigModule], // <--- importing the config module for typeorm
      useFactory(config: ConfigService) {
        return {
          url: config.config().postgres.uri,
          type: 'postgres',
          entities: [],
          synchronize: true
        };
      },
      inject: [ConfigService]
    })
  ]
})
class AppModule {}

async function main() {
  const app = await NestFactory.create(AppModule, {
    // remove logger options when testing on 6.5.3 since it does not behave the same as 6.6.1
    logger: ['verbose', 'log', 'debug', 'warn', 'error'] 
  });

  app.listen(3000);
}

main().catch(err => console.log(err));

Launch the app

node -r ts-node/register/transpile-only index.ts

Expected behavior/code

The app should have started with no error

Environment

Nest version: 6.5.3 -> 6.6.1

For Tooling issues:
- Node version: v11.13.0  
- Platform: Linux (Ubuntu 18.04) 

[kamilmysliwiec]

Thanks for reporting. Fixed in 6.6.2. Please, upgrade your modules and let me know if you face any other issues!

[kgajowy]

Confirmed, 6.6.2 solved the issue. Thanks! ❤️