Suggestion to add isInit() api to dagger.Lazy

[xncHung]

In my sample application, I collect closeable lazy objects (such as database connections) through a set, and then close these objects at the right time. However, I cannot determine whether the lazy object has been initialized. If a closeable object has not been accessed anywhere, it should be uninitialized. This object should be skipped when traversing the collection and closing it. However, I cannot determine whether the lazy object has been initialized. If I access the closeable object at this time, the object may be initialized when it is created, and then closed immediately. This behavior is meaningless and may be a time-consuming operation. Therefore, if lazy has an API to determine whether it has been initialized, this problem can be solved.

@HiltAndroidApp
class App : MultiDexApplication() {
    companion object {
        private const val TAG = "App"
    }

    @Inject
    @JvmSuppressWildcards
    internal lateinit var closeables: Set<Lazy<Closeable>>
    override fun onTerminate() {
        closeables.forEach {
            if (it.isInit()) {
                it.get().close()
            }
        }
        super.onTerminate()
    }
}

interface DbConnect : Closeable {

}

class DbConnectImpl @Inject constructor() : DbConnect {
    override fun close() {
//        close the db connect
    }

}

@Module
@InstallIn(SingletonComponent::class)
abstract class DbModule {
    @Binds
    @Singleton
    abstract fun bindDbConnect(impl: DbConnectImpl): DbConnect

}

@Module
@InstallIn(SingletonComponent::class)
object CloseModule {
    @Suppress("UNCHECKED_CAST")
    @Provides
    @IntoSet
    fun provideClosableWithDb(dbConnect: Lazy<DbConnect>): Lazy<Closeable> {
        return dbConnect as Lazy<Closeable>
    }
}

[bcorso]

@Chang-Eric and I discussed this briefly. It seems reasonable.

I think #2353 would likely also solve your issue since you are using Kotlin. Fwiw, you can probably use the same workarounds suggested in #2353 to convert to kotlin.Lazy.