Ataul FeedCache module

@Singleton
@Component(modules = [FeedCacheModule::class, DatabaseModule::class])
interface AppComponent { ... }

@Module
object FeedCacheModule {

    @Provides
    fun feedCache(feedDatabase: FeedDatabase): FeedCache {
        return RoomFeedCache(database.feedDao())
    }
}

@Module
object DatabaseModule {

    @Provides
    @Singleton
    fun providesDatabase(context: Context): FeedDatabase {
        return Room.databaseBuilder(
                    context,
                    FeedDatabase::class.java,
                    DATABASE_NAME
            ).build()
    }
}


// Other options: If DB is always needed but the FeedCache doesn't need to be always available
@Singleton
@Component(modules = [DatabaseModule::class])
interface AppComponent { ... }

@Subcomponent(modules = [FeedCacheModule::class])
interface FeedComponent { ... }