How to mock a templated class in Flutter? - flutter

Question

I am currently developing an application that uses MVVM architecture, but I don't think this is relevant to my problem. When I was adding tests to my View Model I ran into a problem, when I was trying to mock my View Model, since it was being passed to the Screen State class only the type of the View Model via template, I couldn't find a way to mock it.
Something like this:
class MenuScreen extends Screen {
const MenuScreen({Key? key}) : super(key: key);
#override
_MenuScreenState createState() => _MenuScreenState();
}
_MenuScreenState class extends ScreenState<MenuScreen,
MenuViewModel, MenuData> {
...
}
abstract class ScreenState<T extends Screen, T2 extends ViewModel<T3>,
T3 extends StateData> extends State<T> {
ScreenState();
late final T2 viewModel;
Widget buildScreen(BuildContext context);
#override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
ValueListenableProvider<T3>.value(value: viewModel),
],
builder: (context, _) => buildScreen(context),
);
}
#override
#mustCallSuper
void initState() {
super.initState();
viewModel = context.read<ViewModelFactory>().create<T2>();
}
#override
#mustCallSuper
void dispose() {
viewModel.dispose();
super.dispose();
}
}
ViewModelFactory is responsible for create an instance of MenuViewModel, that for my unit tests scenario should be something like MockMenuViewModel.
Is there any way I can mock up MenuViewModel within this ScreenState class or somehow inject the mock view model instance i want in the screen state instance?