Cannot depend on dynamic created exports from another module.

Bug Report

• FooModule.forRoot creates configurable FooService.
• BarModule imports FooModule and tries to provide BarService which depends on FooService
• Resulting BarModule cannot finds FooService and cannot create BarService

Current behavior

Error: Nest can't resolve dependencies of the BarService (?). Please make sure that the argument at index [0] is available in the BarModule context.
    at Injector.lookupComponentInExports (node_modules/@nestjs/core/injector/injector.js:183:19)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)
    at Function.Module.runMain (module.js:695:11)
    at startup (bootstrap_node.js:191:16)
    at bootstrap_node.js:612:3

Input Code

import { Injectable, Module, DynamicModule } from "@nestjs/common";

@Injectable()
export class FooService {}

@Module({})
export class FooModule {
  static forRoot(): DynamicModule {
    return {
      module: FooModule,
      providers: [FooService],
      exports: [FooService]
    }
  }
}

@Injectable()
export class BarService {
  constructor(fooService: FooService) {}
}

@Module({
  imports: [FooModule],
  providers: [BarService],
  exports: [BarService]
})
export class BarModule {}

@Module({
  imports: [
    FooModule.forRoot(),
    BarModule,
  ]
})
export class AppModule {}

Expected behavior

BarModule should see all of FooModule-s exports, even dynamic ones

Possible Solution

When ModuleBar importing ModuleFoo, nest should wait for creating all of ModuleFoo exports (even dynamic ones) and then should try to initialize modules depending on ModuleFoo, for example ModuleBar.

Environment

Nest version: 6.5.2

 
For Tooling issues:
- Node version: 8 LTS
- Platform:  Linux

Others:

[kamilmysliwiec]

Angular modules are different (providers are available globally). In Nest, everything is isolated, encapsulated in the module scope.

[peterreisz]

@kamilmysliwiec

My use case is to create dynamic service which I would like to configure only at root level. I though FooModule.forRoot is the same as FooModule. The only different is the forRoot provides services at root level (or where you import it).

In angular it works as I described, you can try it here: https://codesandbox.io/s/angular-qld59

@Injectable()
export class FooService {}

@NgModule({})
export class FooModule {
  static forRoot(): ModuleWithProviders {
    return {
      ngModule: FooModule,
      providers: [FooService]
    };
  }
}

@Injectable()
export class BarService {
  constructor(readonly fooService: FooService) {}
}

@NgModule({
  imports: [FooModule],
  providers: [BarService]
})
export class BarModule {}

@NgModule({
  imports: [FooModule.forRoot(), BarModule],
})
export class AppModule {}

Can you provide me a solution for my use case?