Add extraProviders to registerQueueAsync

[1valdis]

I'm submitting a...

[ ] Regression 
[ ] Bug report
[x] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

Currently I can't inject extra providers while using BullModule.registerQueueAsync, and thus I can't effectively use useFactory because I cannot pass any options there.

Expected behavior

I use HttpModule where there is a key extraProviders and I can pass providers my factory needs, and I'd like to be able to do a similar thing with BullModule:

HttpModule.registerAsync({
  useFactory: (options: MyOptions) => {
    return {
      baseURL: options.baseURL,
      timeout: 3000,
    }
  },
  inject: [MyOptionsSymbol],
  extraProviders: [
    MyOptionsProvider,
  ],
  imports: options.imports
})

Minimal reproduction of the problem with instructions

export interface ModuleOptions {
  redisConnectionOptions: {}
}

export interface AsyncModuleOptions {
  inject?: any[],
  imports?: any[],
  useFactory: (...args: any[]) => Promise<ModuleOptions> | ModuleOptions,
}

export const ModuleOptionsSymbol = Symbol('ModuleOptions interface symbol for Nest DI')

export class SomeModule {
  static registerAsync(options: AsyncModuleOptions): DynamicModule {
    return {
      module: SomeModule,
      imports: [
        BullModule.registerQueueAsync({
          useFactory: (options: ModuleOptions) => {
            return options.redisConnectionOptions;
          },
          // right there, how do I provide "module options" factory (options.useFactory)?
          // in HttpModule it would be:
          // extraProviders: {
          //   provide: ModuleOptionsSymbol,
          //   useFactory: options.useFactory,
          //   inject: options.inject,
          // }
          // but as I can't pass the extra provider, I effectively can't inject it to my factory
          // so Nest says it "can't resolve dependencies"
          inject: [ModuleOptionsSymbol],
        }),
        ...options.imports ?? []
      ],
      providers: [
        {
          provide: ModuleOptionsSymbol,
          useFactory: options.useFactory,
          inject: options.inject,
        }
      ],
      exports: []
    }
  }
}

I will also appreciate suggestions of alternative approach, since I can't really move forward with my project now.

What is the motivation / use case for changing the behavior?

It already works in HttpModule this way so I'd like to see this working this way in BullModule also.

Environment

Nest version: 7.3.2
`@nestjs/bull` version: 0.1.2

[kamilmysliwiec]

Would you like to create a PR for this issue?

[1valdis]

@kamilmysliwiec I'm afraid it'll take too much time to look up contributing guides, learn the code and write the tests (I haven't written tests before so I will also have to learn how to do it). If HttpModule and BullModule have similar codebases, I could have a look, but I think there are people who would be able to implement this many times faster.

[micalevisk]

an workaround for this (I guess):

export class SomeModule {
  static registerAsync(options: AsyncModuleOptions): DynamicModule {
    return {
      module: SomeModule,
      imports: [
        BullModule.registerQueueAsync({
          // ====================================== //
          imports: [
            {
              module: class {},
              providers: [
                provide: ModuleOptionsSymbol,
                useFactory: options.useFactory,
                inject: options.inject,
              ],
              exports: [ModuleOptionsSymbol]
            }
          ],
          // ====================================== //
          useFactory: (options: ModuleOptions) => {
            return options.redisConnectionOptions;
          },
          inject: [ModuleOptionsSymbol],
        }),
        ...options.imports ?? []
      ],
      providers: [
        {
          provide: ModuleOptionsSymbol,
          useFactory: options.useFactory,
          inject: options.inject,
        }
      ],
      exports: []
    }
  }
}

[micalevisk]

btw I just prototyped the implementation for this feature here and it worked. If you want to give it a try, just install it doing
npm i github:micalevisk/bull#build-of-feat-issue-459

@1valdis, Feel free to improve that code and add tests to open a PR adding this here :)