This Gist is a part of the Article: https://prokash-sarkar.medium.com/unit-testing-with-dagger-2-brewing-a-potion-with-fakes-mocks-and-custom-rules-in-android-7f0ab7b22cb

ActivityBuildersModule.kt

@Module()
interface ActivityBuildersModule {
    @ActivityScope
    @ContributesAndroidInjector(modules = [LoginModule::class,  LoginFragmentsBuilderModule::class])
    fun contributeMainActivity(): MainActivity
}