feat(flutter_bloc): disallow providing a bloc via RepositoryProvider

[felangel]

I spent a ridiculous amount debugging a scenario where a context.select never updated its widget, only to find out that the Bloc it was accessing was registered through a RepositoryProvider rather than a BlocProvider. The main issue why I didn't figure it out sooner was that the context.select in this case still works... only like a context.read 😅 do you think making this at least a runtime error, if not possible as compile-time, would be an option?

Originally posted by @Lootwig in https://github.com/felangel/bloc/issues/3054#issuecomment-991817877

[alestiago]

A temporary solution would be to do as follows:

  RepositoryProvider({
    Key? key,
    required Create<T> create,
    Widget? child,
    bool? lazy,
  })  : assert(
          T is! BlocBase,
          'Use BlocProvider to provide instances of type $T',
        ),
        super(
          key: key,
          create: create,
          dispose: (_, __) {},
          child: child,
          lazy: lazy,
        );

However, this results in a runtime issue. It would be technically a breaking change for those users who are incorrectly using the API.

A better solution would be relying on custom lint rules. If so this can be considered as BLOCKED until the dart language supports custom lint rules.

[erlangparasu]

May be custom class (but need implementation for static checking), eg. :

void main() {
  if (kDebugMode) {
    BlocUtils.ensureBlocProvidedViaBlocProvider();
  }
}

? 😅