android - Dagger2 Qualifier not working with Kotlin?

Question

I have a simple class as below

class MainString(val msg: String)

I want to inject with different argument to it, so I use the @Named Qualifier as per the guide shown in https://google.github.io/dagger/users-guide

With that my AppModule has

@Provides @Named("Two")
fun provideTwoMainString(): MainString {
    return MainString("Two")
}

@Provides @Named("One")
fun provideOneMainString(): MainString {
    return MainString("One")
}

And in my MainActivity, I just call

@Inject @Named("One")
lateinit var stringOne: MainString

@Inject @Named("Two")
lateinit var stringTwo: MainString

However, when I compile, it complains

Error:(11, 1) error: com.elyeproj.demo_dagger_scope.MainString cannot be provided without an @Inject constructor or from an @Provides- or @Produces-annotated method.

It seems to want me to provide another Provider without the qualifier. So if I add the below, all will compiles. But it is not of used to me, as I want to have different argument injection.

@Provides
fun provideMainString(): MainString {
    return MainString("Solo")
}

What have I done wrong?

Answer 1

Annotation work slightly different on kotlin. look this doc

You have to annotate the field as:

@Inject @field:Named("Two")
lateinit var stringOne: MainString