Shared Android ViewModel between Activity and Fragment

LoginFragment.kt

@AndroidEntryPoint
class LoginFragment : Fragment() {
  
  private val viewModel: LoginViewModel by viewModels()
  private val mainViewModel: MainViewModel by activityViewModels()
  
  override fun onResume() {
    super.onResume()
    Log.d(LoginFragment::class.java.simpleName, "${activityVM.testState}")
  }
}

MainActivity.kt

@AndroidEntryPoint
class MainActivity : AppCompatActivity() {
  override fun onResume() {
        super.onResume()
        viewModel.testState++
    }
}

MainViewModel.kt

//@ActivityRetainedScoped if want to survive on configuration changes
@ActivityScoped
class MainViewModel @ViewModelInject constructor() : ViewModel() {
    var testState: Int = 0
}