add ActiveRecord::Calculations module to ActiveRecord::Base

[tasuku-lab280]

I wanted to use ActiveRecord::Calculations methods like User.count as class methods of the model, so added code to extend ActiveRecord::Calculations module in ActiveRecord::Base.

[tasuku-lab280]

[ref]

• https://github.com/rails/rails/blob/main/activerecord/lib/active_record/relation/calculations.rb#L94-L104
• https://github.com/ruby/gem_rbs_collection/blob/main/gems/activerecord/6.0/activerecord-generated.rbs#L17575-L17576

[github-actions]

@tasuku-lab280 Thanks for your contribution!

Please follow the instructions below for each change.
See also: https://github.com/ruby/gem_rbs_collection/blob/main/docs/CONTRIBUTING.md

Available commands

You can use the following commands by commenting on this PR.

• /merge: Merge this PR if CI passes

---

activerecord

You changed RBS files for an existing gem.
You need to get approval from the reviewers of this gem.

@hibariya, @ksss, @Little-Rubyist, @tk0miya, please review this pull request.
If this change is acceptable, please make a review comment including APPROVE from here.

After that, the PR author or the reviewers can merge this PR.
Just comment /merge to merge this PR.

[tk0miya]

Thank you for your contribution.

Unfortunately, this is not correct. ActiveRecord::Base does not extend ActiveRecord::Calculations directly.
The reason why ActiveRecord::Base provides the .count method is ActiveRecord::Querying.
It delegates tons of methods to the .all method.

You can see the .count method in the list:
https://github.com/rails/rails/blob/v8.0.0/activerecord/lib/active_record/querying.rb#L19

Therefore, extending the Calculation module in this class is not good.

Instead, in activerecord.rbs, we list such methods up to ActiveRecord::Base::ClassMethods and _ActiveRecord_Relation_ClassMethods.

gem_rbs_collection/gems/activerecord/6.0/activerecord.rbs

Line 422 in 443b293

module ClassMethods[Model, Relation, PrimaryKey]

gem_rbs_collection/gems/activerecord/6.0/activerecord.rbs

Line 590 in 443b293

interface _ActiveRecord_Relation_ClassMethods[Model, Relation, PrimaryKey]

[tasuku-lab280]

@tk0miya
Thanks for the review! I understand!
I will close this PR once I have implemented the type definitions based on the information you gave me, and I will remake the PR again once I have implemented the type definitions.