Migration notes missing for 7.0

[wujek-srujek]

Describe the bug
Now Cubit extends Bloc, contrary to the previous Bloc extends Cubit introduced in 6.0.0. It doesn't cause any issues for me and I actually noticed this by accident after migrating my app to null safety, and flutter_bloc to 7.0.0-nullsafety - I am experimenting with a change and was looking for the cubit parameter in a BlocBuilder that is now gone. I looked into migration.md and there isn't written anything about it yet. I understand that the 7.0.0 version isn't final yet so I'm just making sure this doesn't get forgotten in all the work that is necessary for null safety support.

As a side question: why this change, how is it beneficial for the hierarchy to be reversed? Does it make something possible that wasn't before? It has disadvantages, it does introduce a weird API for Cubit in which the user can actually call add (with null only, I guess) but it will always fail due to an error throw by Cubit.mapEventToState.

[dawidd6]

cubit parameter for BlocBuilder is now changed to bloc, which accepts both a Bloc and a Cubit since the latter extends the former. As of why this change was introduced, I don't know, but 7.0.0 is still a prerelease I think.

[wujek-srujek]

@dawidd6 Yes I am aware of that, I checked the code. I just wanted to make sure the migration docs get updated, and also wanted to ask about the rationale - I am a big fan of BLoC and this library, it is a vital part of my apps, and I like to understand things. I haven't found any issue relating to it, hence the question.

[felangel]

Hi @wujek-srujek 👋
Thanks for opening an issue!

I haven't forgotten about the migration guide but there are still several changes that may or may not land before a stable release can be published and we'll be sure to have the migration guide ready before v7.0.0 is released 👍

Regarding your second question, I was just working on a proposal to hopefully address this and several other issues at #2235. I would love your feedback/thoughts and thanks as always for being an extremely valuable member of the community! 🙏