nest cannot resolve Middleware dependency injection when targeting es2017

[sloan-dog]

Bug Report

Current behavior

Nest cannot resolve a middleware's dependencies when targeting es2017
When applying a middleware to a module class (module A) which implements NestModule, where the middleware depends on a service within its own module (module B), nest cannot resolve the dependencies of the middleware, even if module B exports the dependency, and module A imports module B

targeting es6 resolved the issue

Input Code

-- Module A
Module({
  imports: [
    EnvironmentModule,

    // api modules
    AuthModule,
    StoreModule,
    UserModule,
    OrderModule,

    // core api module
    CoreApiModule,

    // storage
    StorageModule,
  ],
  controllers: [
    AppController,
  ],
  providers: [
    AppService,
  ],
})
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer
      .apply(ClientAccessMiddleware)
      .forRoutes('auth/*');
  }
}

-- Middleware
@Injectable()
export class ClientAccessMiddleware implements NestMiddleware {
  constructor(private readonly authService: AuthService) { }
  async use(req: Request, res: Response, next: Function) {
    const id = req.headers.get('client-id');
    const secret = req.headers.get('client-secret');
    const clientWithScopes = await this.authService.validateClient(id, secret);
    let clientAuth = {};
    if (clientWithScopes) {
      clientAuth = {
        apiClientScopes: clientWithScopes.scopes,
        clientId: clientWithScopes.clientId,
      };
    }
    (req as RequestWithClientAuth).clientAuth = clientAuth as any;
    next();
  }
}

-- Module B
@Module({
  imports: [
    EnvironmentModule,
    CoreApiModule,
    StorageModule,
  ],
  controllers: [
    AuthController,
  ],
  providers: [
    AuthService,
  ],
  exports: [
    AuthService,
  ],
})
export class AuthModule {
}

-- File structure
src/
   app/
      app.module/
         app.module.ts <- middleware applied here, auth.module imported here
      auth.module/
         auth.module.ts <- middleware dependency exported here
         middleware/
            api-client-middleware.ts

-- tsconfig
{
"compilerOptions": {
"module": "commonjs",
"declaration": true,
"removeComments": true,
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
"target": "es6",
"sourceMap": true,
"outDir": "./dist",
"baseUrl": "./",
"paths": {
"src/": [
"src/"
]
},
"incremental": true
},
"exclude": [
"node_modules",
"dist",
".scaffs"
]
}

Expected behavior

Expect that nest DI is able to resolve middleware's dependencies

Possible Solution

Environment

Nest version: 
    "@nestjs/common": "^6.10.14",
    "@nestjs/core": "^6.10.14",
    "@nestjs/platform-express": "^6.10.14",
    "@nestjs/platform-fastify": "^6.11.8",


For Tooling issues:
- Node version: 12.14.1
- Platform: macOS catalina

Others:

[jmcdo29]

Where is ClientAccessMiddleware added to the providers array? Do you have a minimum reproduction of this?

[kamilmysliwiec]

Where is ClientAccessMiddleware added to the providers array?

Middleware doesn't have to be added to the providers array :)

Please, provide a minimal repository which reproduces your issue.

[sloan-dog]

@kamilmysliwiec

https://github.com/sloan-dog/nest-injection-issue

[jmcdo29]

In your reproduction, you don't have AuthModule, which exports AuthService, imported into the AppModule, so the dependencies of the middleware class could not be resolved.

[sloan-dog]

-Oops i did not commit that, will fix. But I am confident issue will persist. -

[sloan-dog]

Welllll shoot. I played myself. Whats scary is that in my actual code...it is imported/exported :(

...must be another dragon. Thanks for taking a look. @jmcdo29
Going to revise my repro to bring it closer to my actual module structure

nest is gr8

[sloan-dog]

@jmcdo29 Is there a cli command to output a nest dependency graph ?

[jmcdo29]

Sadly, no. I'm working on a custom module that does it, but the application needs to compile before hand for it to work 🙁. You can take a look if you want

[sloan-dog]

@jmcdo29 just took a look, thats pretty helpful, despite the caveat. Tried to find you on discord but your tag tweren't there. Know this isn't the appropriate channel (or repo), but i love what you're doing. I've been running nest in production for about 2 years, and have been looking for exactly what your tool does. Some day...when you stabilize it would be interesting to output an svg representation of those dependency graphs. Although, i suppose...i could do that myself, given that I could use the module tokens as graph node identifiers.

[jmcdo29]

@sloan-dog interesting. Well there is the Nest Discord where I'm incredibly active. You could always find me from there. Just put a message in the #introductions channel, that way we can take the discussion away from here.

[kamilmysliwiec]

Great module @jmcdo29, can't wait to see the final version!

@sloan-dog Let's move this discussion to our Discord instead. We are using GitHub to track bugs, feature requests, and potential improvements.

[hellokvn]

Ran into the same issue, how did you make injections working in your middleware?