Could not resolve MikroORM

[klerick]

Describe the bug
If use context, and try using forFeature with this context, module cannot resolve MicroORM in MikroOrmMiddleware

Stack trace

/project/node_modules/@nestjs/core/injector/injector.js:262
            throw new unknown_dependencies_exception_1.UnknownDependenciesException(wrapper.name, dependencyContext, moduleRef, { id: wrapper.id });
                  ^

Error: Nest can't resolve dependencies of the MikroOrmMiddleware (?). Please make sure that the argument MikroORM at index [0] is available in the MikroOrmCoreModule context.

Potential solutions:
- Is MikroOrmCoreModule a valid NestJS module?
- If MikroORM is a provider, is it part of the current MikroOrmCoreModule?
- If MikroORM is exported from a separate @Module, is that module imported within MikroOrmCoreModule?
  @Module({
    imports: [ /* the Module containing MikroORM */ ]
  })

To Reproduce
Steps to reproduce the behavior:

import {microOrmConfig} from './config';
const contextName = 'default'
@Module({
  imports: [MikroOrmModule.forFeature([], contextName)],
})
class Test {}

@Module({
  imports: [
    MikroOrmModule.forRoot({
...microOrmConfig,
contextName
}),

Posible solution
Create function which return provider for current context

export function ContextMicroOrmProvider(
  contextName: string
): FactoryProvider<MikroORM> {
  return {
    provide: ORM_CONTEXT,
    useFactory: (mikroORM: MikroORM) => mikroORM,
    inject: [connectionName ? getMikroORMToken(contextName) : MikroORM],
  };
}

@Injectable()
export class MikroOrmMiddleware implements NestMiddleware {

  @inject(ORM_CONTEXT) private readonly orm!: MikroORM

  use(req: unknown, res: unknown, next: (...args: any[]) => void) {
    RequestContext.create(this.orm.em, next);
  }

}

[B4nan]

A complete reproduction would be preferred, this is likely a misusage.

When you use multiple contexts, you should disable the automatic middleware via registerRequestContext: false in the forRoot call (this is likely the reason why you see this error, it's coming from the default middleware which shouldn't resolve to any context) and use the forMiddleware to register all context-specific ones.

https://github.com/mikro-orm/nestjs#multiple-database-connections

[klerick]

Yes, im understand it. But I'm using a shared database module that returns a MicroOrm instance. Ideally, I wouldn't have to tie the logic to a fixed number of connections or contexts. It would be more convenient if the MicroOrm injector were more generic. For example, in TypeORM there's a concept of a default connection name, which simplifies handling multiple connections. I'd love to see similar flexibility in MicroOrm so that a module can work out of the box without needing prior knowledge of how many contexts will be used. I would be have more abstraction about connection. Because I dont now what use users.

[B4nan]

We also have a default connection. But in your example, you provide a context name in the forRoot call, in other words, you never register the default one. To register the default one, you cannot provide a context name.