Kotlin tools for WorkManager Dagger injection

AndroidWorkerInjection.kt

interface HasWorkerInjector {
    fun workerInjector(): AndroidInjector<Worker>
}

class AndroidInjection {
    companion object {}
}

fun AndroidInjection.Companion.inject(worker: Worker) {

    val application = worker.applicationContext

    if (application !is HasWorkerInjector) {

        throw RuntimeException(
            String.format(
                "%s does not implement %s",
                application.javaClass.canonicalName,
                lu.neopixl.menj.dagger.worker.HasWorkerInjector::class.java.canonicalName
            )
        )
    }

    val workerInjector = application.workerInjector()
    workerInjector.inject(worker)

}

abstract class DaggerWorker (
    appContext: Context,
    workerParams: WorkerParameters
) : Worker(appContext, workerParams) {

    init {
        AndroidInjection.inject(this)
    }
}

@Module
abstract class AndroidWorkerInjectionModule {

    @Multibinds
    internal abstract fun workerInjectorFactories(): Map<Class<out Worker>, AndroidInjector.Factory<out Worker>>
}

MyWorker.kt

@Module
internal abstract class MyWorkerDaggerModule {

    @ContributesAndroidInjector(modules = [])
    abstract fun worker(): MyWorker
}

class MyWorker(
        appContext: Context,
        workerParams: WorkerParameters
    ) : DaggerWorker(appContext, workerParams) {

    @Inject
    lateinit var objectToInject: String

    override fun doWork(): Result {
        // Code ...
        return Result.success()
    }

}