Detect premature initialization of androidx ViewModel

[jacob-peterson]

When lazy loading a ViewModel any references to the ViewModel property before Fragment.onAttach will cause an IllegalStateException.

We should detect premature access of a ViewModel during Fragment initialization in Kotlin and Java.

[jacob-peterson]

class ExampleFragment: Fragment() {
    @Inject
    lateinit var exampleViewModelFactory: ExampleViewModel.Factory
    
    private val viewModel by viewModels<ExampleViewModel> {
        ExampleViewModel.provideFactory(exampleViewModelFactory)
    }
    
    // Violation
    private val exampleComponent = ExampleComponent(viewModel.state)
    
    init {
        // Violation
        viewModel.state.collectLatest {

        }
    }
}

[jzbrooks]

It might be prudent to double check that androidx.lifecycle hasn't shipped this in more recent version of the lifecycle library. They might be interested in an external contribution if we get something working, also.