Dependency injection - app.get(UploadService) on INestApplication doesn't resolve its dependencies - node.js

Question

I am trying to create external CLI, which uses my Nest context. I've made entry-point, which creates app with NestFactory.create. After accessing service with app.get, the service exists and works itself. The problem is, that it doesn't resolve any of its dependencies. There is no example on Docs and neither have I found anything related to this issue on Internet.
I am using the newest version of Nest.js on Node 10 as on 17.07.2019.
main.ts
import { NestFactory } from '#nestjs/core';
import { AppModule } from '../app.module';
import { UploadService } from 'src/api/upload/upload.service';
import { UploadModule } from 'src/api/upload/upload.module';
async function bootstrap(): Promise<void> {
const app = await NestFactory.create(AppModule);
await app.init();
const service: UploadService = app.select(UploadModule).get(UploadService);
console.log(service); // OK - returns UploadService instance
console.log(service.uploadModel); // X - returns `undefined`
console.log(service.configService); // X - returns `undefined`
}
bootstrap();
app.module.ts
import { Module } from '#nestjs/common';
import { MongooseModule } from '#nestjs/mongoose';
import { ConfigModule } from './config/config.module';
import { ConfigService } from './config/config.service';
import { AwsModule } from './services/aws/aws.module';
import { UploadModule } from './api/upload/upload.module';
#Module({
imports: [
ConfigModule,
MongooseModule.forRootAsync({
useFactory: async (configService: ConfigService): Promise<object> => ({
uri: configService.data.database.mongo.uri,
useCreateIndex: true,
useNewUrlParser: true,
}),
inject: [ConfigService],
}),
AwsModule,
UploadModule,
],
})
export class AppModule {}
upload.module.ts
import { Module } from '#nestjs/common';
import { MongooseModule } from '#nestjs/mongoose';
import { AwsModule } from '../../services/aws/aws.module';
import { UploadService } from './upload.service';
import { UploadSchema } from './upload.schema';
#Module({
imports: [MongooseModule.forFeature([{ name: 'Upload', schema: UploadSchema }]), AwsModule],
providers: [UploadService],
exports: [UploadService],
})
export class UploadModule {}
upload.service.ts
import { Injectable } from '#nestjs/common';
import { AwsService } from '../../services/aws/aws.service';
import { Upload } from './upload.schema';
import { InjectModel } from '#nestjs/mongoose';
import { Model } from 'mongoose';
#Injectable()
export class UploadService {
constructor(
#InjectModel('Upload')
readonly uploadModel: Model<Upload>,
readonly awsService: AwsService,
) {}
}
Expected outputs of
console.log(service.uploadModel); // X - returns `undefined`
console.log(service.configService); // X - returns `undefined`
are model/service instances. Unfortunately they return both undefined, as the dependency-injection doesn't take a place.

Answer 1

I tried what You did, and in nestjs version: 7.6 it works as expected.
So my assumption is they fixed it in meantime.

Answer 2

I had the same issue. The docs are actually pretty clear about this: https://docs.nestjs.com/standalone-applications
But I actually run into the same problem and I dont think this an intended behaviour. I tried removing a dependency after another to see if something changes.
I had request scoped services injected. As long there was an "unresolvable dependency" (request-scoped ones) all injected dependencies were undefined. I'd expect a "dependency cannot be resolved" error but it just silently failed.
See also https://github.com/nestjs/nest/issues/4630
Make sure all your dependencies can be created successfully within the correct scope for standalone apps.
To get a service with for example request-scoped dependencies use module.resolve(Service) instead of get.