extend @ContributesTo to capture @Provides on top-level functions

[JvmName]

I think it'd be pretty cool if you didn't need to wrap @Provides inside a @Component.

This doesn't work:

//in file network.kt
@Provides
fun provideOkhttpClient(): OkHttpClient {
    return OkHttpClient.Builder().build()
}

Today, you have to write something like this instead:

@ContributesTo(AppScope::class)
interface NetworkComponent {
  @Provides fun okhttp(): OkHttpClient { ... }
}

What if, instead, you could write this:

@Provides @ContributesTo(AppScope::class) 
fun provideOkhttpClient(): OkHttpClient {
    return OkHttpClient.Builder().build()
}

Or if tracking another annotation via ContributesTo would be annoying, I would even be fine with @ContributesTo(AppScope::class, provides = true) or something similar.

(also linking evant/kotlin-inject#389 (comment), since that was the basis for this)

[vRallev]

This approach has downsides, e.g. you can replace or exclude contributed types, but you wouldn't be able to reference a contributed function. If you have multiple contributed functions, then you'd repeat the @ContributesTo annotation several times.

You can easily implement such a feature by yourself, though. kotlin-inject-anvil is extensible. Maybe consider adding your own annotation @ProvidesInto(AppScope::class) for top level functions and then you can can generate the needed interface.