As #10079 is not merged yet this PR contains that PR's commit too. After it got merged this one needs to be re-targeted.

Great, I could not resist cleaning up the fixup commits, I'll leave the rest to you now, except you need me to resolve merge conflicts or so :)

Btw unrelated, but if you need help in increasing the phpstan level or cleanup some more code for phpstan by adding/fixing types and so on, feel free to create issues for that or ping me. I would gladly help out, but will not touch too much if you're also working on it

Also: I had to remove the static keyword in the anonymous function in array_map. PHP 5.3 was not quite happy with that..

Btw unrelated, but if you need help in increasing the phpstan level or cleanup some more code for phpstan by adding/fixing types and so on, feel free to create issues for that or ping me. I would gladly help out, but will not touch too much if you're also working on it

Yeah that would be great, I have been working on typing all properties already, because that gives a good foundation to then type method return values and parameters, which will then force more typing in various places to fix usage warnings surely.

I'm almost done with properties, then maybe I can create an issue with some instructions how to run this and what would be the most valuable, but I'm not entirely sure how much is worth doing right now and how much would be best to wait for us to drop old PHP then we can add proper scalar types instead of adding docblocks now and having to migrate them in a few months. So yeah happy to get help at some point but probably it's too soon :)

rebased to fix a conflict

types instead of adding docblocks now and having to migrate them in a few months

We can automate this step with rector

rebased to fix a conflict

As promised in #10083 (comment) - here is #10159 if you still want to help @herndlm (or anyone:)

rebased after the precondition was merged 🎉

Thanks!