RBS and Rails, Present and Future

At Ginza Rails #43
https://ginza-rails.connpass.com/event/242685/

Transcript

1. スライドトップと

   してご利用ください

   マネーフォワード事業本部 

   山田 太郎

   © Money Forward, Inc.
   RBS and Rails,

   Present and Future

   Masataka Pocke Kuwabara

   © Money Forward, Inc.
   2022-03-25 銀座Rails#43 

   

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2. ● Money Forward Osaka Office
   

   ● Live in Okayama

   ● A maintainer of RBS

   I’m Masataka Pocke
   Kuwabara

   GitHub: @pocke

   © Money Forward, Inc.
   

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4. © Money Forward, Inc.
   ● I work since Feb. 15 2022

   ● 50% for developing a Rails app, 50% for
   developing OSS (RBS)

   ● Currently I'm working on updating Ruby 3.1
   and introducing Steep to the Rails app.

   I joined Money Forward, inc!

   

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5. © Money Forward, Inc.
   ● ruby/gem_rbs_collection#124: [activesupport] Remove Class#subclasses

   ● ruby/rbs#905: Remove CharScanner due to no longer used

   ● ruby/rbs#907: Reduce memory usage of RBS::Buffer

   ● kpumuk/meta-tags#237: Separate RBS files to _internal directory to avoid exposing RBS

   ● ruby/rbs#914: Accept Numeric by Integer#{upto,downto}

   ● ruby/rbs#919: Fix bin/sort for constants

   ● rbs/pull#921: Add manifest.yaml for rbs gem

   ● ruby/rbs#926: Fix bin/sort (WIP)

   ● pocke/rbs_rails#212: CI against Ruby 3.1

   ● pocke/rbs_rails#213: Bundle update to update rbs and steep

   ● pocke/rbs_rails#214: Documentation update

   ● pocke/rbs_rails#215: Fix spec

   ● pocke/rbs_rails#216: Generate dependency types of relations

   ● pocke/rbs_rails#217: Add rails generator to generate rbs.rake
   ● pocke/rbs_rails#218: Do not expose polyfil RBSs

   My works

   

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6. Okayama

   

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7. © Money Forward, Inc.
   

   

   #okayama in our slack (1/2)

   

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8. © Money Forward, Inc.
   

   

   #okayama in our slack (1/2)

   

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9. © Money Forward, Inc.
   

   

   I really recommend Kakioko (Oyster
   Okonomiyaki)🦪🦪🦪

   Go to Hinase (日生)!!!!!

   

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10. © Money Forward, Inc.
    Agenda
    

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11. © Money Forward, Inc.
    ● What is RBS

    ● RBS and Rails (Present)

    ● RBS and Rails (Future)

    Agenda
    

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12. © Money Forward, Inc.
    What is RBS
    

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13. © Money Forward, Inc.
    ● "RBS is a language to describe the
    structure of Ruby programs."

    ○ https://github.com/ruby/rbs#rbs

    ● Type Language for Ruby

    ● RBS is available since Ruby 2.6

    ○ But I highly recommend Ruby 2.7+

    RBS is …

    

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14. © Money Forward, Inc.
    class String
    def gsub: (String | Regexp pat, String rep) -> String
    end
    RBS Syntax

    See
    https://github.com/ruby/rbs/blob/master/docs/rbs_by_exa
    mple.md as a tutorial,
    https://github.com/ruby/rbs/blob/master/docs/syntax.md
    as a reference.

    

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15. © Money Forward, Inc.
    ● ruby/rbs

    ● ruby/gem_rbs_collection

    ● ruby/typeprof

    ● soutaro/steep

    ● pocke/rbs_rails

    

    Today I do not talk about Sorbet tools󰢛

    Related Projects

    

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16. Type Checkers
 Language

    © Money Forward, Inc.
    Related Projects

    ruby/

    rbs

    ruby/

    gem_rbs_

    collection

    soutaro/

    steep

    ruby/

    typeprof

    Tool

    pocke/

    rbs_rails

    Use
 Generate

    

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17. © Money Forward, Inc.
    ● You can use it with `gem install rbs`

    ● Defines RBS language

    ● Provides RBS loader for other tools

    ● Provides tools to support using RBS

    ● Contains core and stdlib's RBS files

    ruby/rbs

    

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18. © Money Forward, Inc.
    ● Provides gems' RBSs, such as activesupport
    gem

    ● Similar with DefinitelyTyped for TypeScript

    ● Contributions are welcome!

    ○ https://github.com/ruby/gem_rbs_collection/blob/main
    /docs/CONTRIBUTING.md

    ruby/gem_rbs_collection

    

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19. © Money Forward, Inc.
    ● A type checker for Ruby

    ruby/typeprof

    

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20. © Money Forward, Inc.
    ● A type checker for Ruby

    soutaro/steep

    

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21. © Money Forward, Inc.
    Difference between Steep and
    TypeProf

    https://www.slideshare.net/mametter/typeprof-for-ide-enrich-developm
    ent-experience-without-annotations 

    

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22. © Money Forward, Inc.
    ● RBS files generator for Ruby on Rails

    ● It focuses on generating methods generated
    by Rails.

    pocke/rbs_rails

    

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23. © Money Forward, Inc.
    RBS and Rails
    (Present)
    

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24. © Money Forward, Inc.
    How to introduce RBS
    to Rails app

    1. Add gems to Gemfile

    2. Setup rbs collection

    3. Setup RBS Rails

    4. Setup Steep

    5. Run🚀

    

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25. © Money Forward, Inc.
    ● Add rbs, steep, and rbs_rails gems to Gemfile

    ● Then run `bundle install`

    Add gems to Gemfile

    

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26. © Money Forward, Inc.
    ● rbs collection setups dependencies' RBSs.

    ○ See my talk at RubyKaigi Takeout 2021
    https://rubykaigi.org/2021-takeout/presentations/p_c
    k_.html

    ● Run the following commands

    ○ `rbs collection init`

    ○ `rbs collection install`

    Setup rbs collection

    

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27. © Money Forward, Inc.
    ● Run `rails g rbs_rails:install`

    ● Then, run `rake rbs_rails:all` to generate
    RBSs for AR models

    Setup RBS Rails

    

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28. © Money Forward, Inc.
    ● Run `steep init`

    ● Edit Steepfile

    ● Run `steep check`

    Setup & run Steep

    

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29. © Money Forward, Inc.
    ● Use `steep langserver`

    ○ https://github.com/soutaro/steep-vscode

    ○ https://github.com/emacs-lsp/lsp-mode

    ○ https://github.com/prabirshrestha/vim-lsp

    Using steep from editor

    

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30. Now we can use type checking
    with Steep! Is it ready to
    production?

    © Money Forward, Inc.
    

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31. No

    © Money Forward, Inc.
    

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32. © Money Forward, Inc.
    Currently I got 410 type errors on our Rails app,
    and it does not analyze whole of code.

    

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33. © Money Forward, Inc.
    ● More accurate type checking

    ○ Generating RBS

    ○ Enhance RBS Rails

    ○ Write more RBSs in gem_rbs_collection 

    ○ Support meta-programming in RBS 

    ● Introducing RBS to a team smoothly

    ○ Run Steep on CI

    ○ Improve performance 

    ○ Generating RBS "continuously" 

    ○ Share knowledge to team 

    Issues

    

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34. © Money Forward, Inc.
    RBS and Rails
    (Future)
    

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35. © Money Forward, Inc.
    ● More accurate type checking

    ○ Generating RBS

    ○ Enhance RBS Rails

    ○ Write more RBSs in gem_rbs_collection 

    ○ Support meta-programming in RBS 

    ● Introducing RBS to a team smoothly

    ○ Run Steep on CI

    ○ Improve performance 

    ○ Generating RBS "continuously" 

    ○ Share knowledge to team 

    Issues (again)

    

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36. © Money Forward, Inc.
    Generating RBS
    (continuously)

    1. Current Behavior

    2. Problem

    3. Goal

    

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37. © Money Forward, Inc.
    ● There are three command to generate RBS

    ○ `rbs prototype rb`

    ○ `rbs prototype runtime`

    ○ `typeprof` (I don't talk today󰢛)

    Generating RBS: Current Behavior

    

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38. © Money Forward, Inc.
    ● It parses `.rb` file, and generate RBS

    ○ `rbs prototype rb path/to/file.rb`

    ● 👍 Easy to run, easy to guess what will be generated

    ● 👎 Not good at meta-programming

    ○ e.g. eval, define_method, etc...

    rbs prototype rb

    

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39. © Money Forward, Inc.
    ● It executes Ruby program, then extract method
    information with meta-programming

    ○ `rbs prototype runtime KlassName`

    ● 👍 Good at meta-programming

    ● 👎 It may raise an error, generate dirty RBSs.

    ● 👎 User needs to specify class name.

    rbs prototype runtime

    

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40. © Money Forward, Inc.
    ● I recommend using `rbs prototype rb`

    ● But it is not the "Silver Bullet"

    

    Why?

    Current state of generating RBS

    

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41. © Money Forward, Inc.
    ● `rbs prototype rb` is not good at meta programming

    ● It may generate RBS does not work standalone

    ○ e.g. on `class C < D`, it generates C but doesn't generate
    D.

    ● We still get type errors even if it runs with generated
    RBSs

    ● It is not aware of existing RBSs

    Problems

    

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42. © Money Forward, Inc.
    ● For meta-programming

    ○ → It should be based on `prototype runtime`

    ● To work standalone

    ○ → Fix bugs, generate dependency types

    ● To avoid type errors

    ○ → Generate more lenient types

    ● To be aware of existing RBSs

    ○ `rbs subtract` may solve this issue

    Goals

    

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43. © Money Forward, Inc.
    Support
    meta-programming

    

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44. © Money Forward, Inc.
    ● takahasim-san wrote an article about this problem
    few days ago (Japanese).

    ○ Rails + RBS & Steepを試してみて困ったところとか感想
    とか - Qiita

    ● e.g. different self in lambda

    ○ validate :foobar, if: -> { new_record? }

    Support meta-programming

    

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45. © Money Forward, Inc.
    Conclusion
    

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46. © Money Forward, Inc.
    ● We can start introducing RBS easily, but it
    still has many problems.

    ● I'm working on generating RBS. It should
    generate RBSs that work out of the box.

    ● Go to Hinase, Eat Kakioko🦪🦪🦪

    Conclusion

    

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47. ©Money Forward, Inc.
    We are hiring!

    

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