Do Ruby::Box dream of Modular Monolith?

Rubykaigi 2026 LT

Transcript

1. Do Ruby::Box dream of Modular Monolith? joker1007 (Repro株式会社) Rubykaigi 2026 LT 1
2. self.inspect 橋立友宏 (@joker1007) Repro inc. Chief Architect I love , , and Karaoke 2
3. Gold Sponsor 3
4. I come from Asakusa(.rb) 4
5. Ruby::Box comes!! It's very interesting feature!! 5
6. Have you touched Ruby::Box? 6
7. I tried to use Ruby::Box on Ruby on Rails. I want to separate the domain logic by Ruby::Box. To achieve a fully independent modular monolith. 7
8. And It works!! (minimal and not practical) However, it required a few workarounds. 8
9. Demo time!! 9
10. Yeah!! The class space is separated for each URL!! 10
11. Good parts (?) of Ruby::Box Ruby::Box instances can freely reference one another. In other words, a class in one box can be inherited by a class in another box. Of course, you can also prepend or include modules in another box. see. Ruby::Box ダイジェスト紹介（Ruby 4.0.0 新機能） - STORES Product Blog 11
12. How it works There are 2 boxes. module BoxA def foo puts "BoxA" + Ruby::Box.current.inspect super end end module BoxB def foo = puts "BoxB" + Ruby::Box.current.inspect end 12
13. A = Ruby::Box.new; A.require_relative "box_a" B = Ruby::Box.new; B.require_relative "box_b" class Foo prepend A::BoxA include B::BoxB def foo puts "Main" + Ruby::Box.current.inspect super end end Foo.new.foo # => returns: BoxA#<Ruby::Box:3,user,optional> Main#<Ruby::Box:2,user,main> BoxB#<Ruby::Box:4,user,optional> 13
14. Just by calling super you can seamlessly switch between the Box. dangerous (interesting)!! By the way, tagomoris-san said. 14
15. Applying to Rails A controller within a box inherits ApplicationController in the main box. You can evaluate controller and model logic within the child box, And once the controller logic is complete, transparently transfer process to the controller running in the main box. Render views in the main box. Views invoke model method, the logic works on the child box. 15
17. Thank you tagomoris-san!! Ruby::Box is fun!! 17
18. What you need to get started For now, we need to apply a patch to zeitwerk we need to override Ruby::Box#require to work automatic module generation. Otherwise, if you run it with RUBY_BOX=1 , it can't load rails components. This issue is related. https://bugs.ruby-lang.org/issues/21830 18
19. By the way, can't we use Ruby::Box with Rails::Engine? 19
20. It crashes for now require fails to execute in the first place. 20
21. Actually, this demo app crashes with a SEGV quite often when it starts up. I recommend ruby-4.0.2 to run this sample. 21
22. Things I want related to Ruby::Box require doesn't crash Ruby::Box#name : Box#inspect is confusing. I want to rename it to make it clearer. Ruby::Box#fork : I want to create a box while retaining the LOADED_FEATURE that has already been required in the base box. 22
23. Difficulties How to coordinate zeitwerk. When you cross between boxes, it becomes unclear which box the autoload require is being executed in. 23
24. Conclusion Currently, it is possible to run Ruby::Box on Rails. However, it’s very minimal and very experimental. Still, the way Box works is really interesting!! I can sense its potential!! Let's try to use Ruby::Box and play around with it!! 24
25. For more details at the 松江Ruby会議. Stay Tuned!! 25