Rails RBSを試す

こちらを参考にRBSを入れる

https://speakerdeck.com/aki19035vc/roppongi-dot-rb-number-26
とりあえずRails8をAPIモードでインストール

https://zenn.dev/kuronekopunk/scraps/223745551d4d59
Ruby 3.4.1

Rails 8.0.1

あっきー

Gemfileにrbs関係を追加、bundle install

Gemfile

  gem "rbs-inline", require: false
  gem "rbs_rails", require: false
  gem "steep", require: false

あっきー

rbs初期化

🐑 ~/work/rails/rails8_rbs (main)
$ bundle exec rbs collection init
created: rbs_collection.yaml
🐑 ~/work/rails/rails8_rbs (main) x
$ bundle exec rbs collection install

あっきー

rbs_collectionの説明にもあるように、.gem_rbs_collection/ を .gitignore に追加
https://github.com/ruby/rbs/blob/master/docs/collection.md

$ echo /.gem_rbs_collection/ >> .gitignore

あっきー

steep init

🐑 ~/work/rails/rails8_rbs (main)
$ steep init
Writing Steepfile...

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Steepfile書き換え

Steepfile

target :app do
  check 'app'
  signature 'sig'
end

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rbs_rails install

🐑 ~/work/rails/rails8_rbs (main)
$ rails g rbs_rails:install
      create  lib/tasks/rbs.rake
🐑 ~/work/rails/rails8_rbs (main) x
$ rails rbs_rails:all
warning: parser/current is loading parser/ruby34, which recognizes 3.4.0-compliant syntax, but you are running 3.4.1.
Please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.

あっきー

lib/tasks/rbs.rake sig/ が作られた

$ g st
On branch main
Untracked files:
  (use "git add <file>..." to include in what will be committed)
        lib/tasks/rbs.rake
        sig/

あっきー

rbs_railsが出す型情報はバージョン管理しなくて良さそうなのでgitignore

$ echo /sig/rbs_rails/ >> .gitignore

このあたりを参考にした

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rbs-inline 実行

$ rbs-inline app --output=sig/rbs_inline/app --opt-out

あっきー

inlineの型を書いていないので空っぽの型情報が出力された

sig/rbs_inline/app/controllers/posts_controller.rbs

# Generated from app/controllers/posts_controller.rb with RBS::Inline

class PostsController < ApplicationController
  # GET /posts
  def index: () -> untyped

  # GET /posts/1
  def show: () -> untyped

  # POST /posts
  def create: () -> untyped

  # PATCH/PUT /posts/1
  def update: () -> untyped

  # DELETE /posts/1
  def destroy: () -> untyped

  private

  # Use callbacks to share common setup or constraints between actions.
  def set_post: () -> untyped

  # Only allow a list of trusted parameters through.
  def post_params: () -> untyped
end

あっきー

型チェック実行

$ steep check
# Type checking files:

.............

No type error detected. 🫖

特に問題なし

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rakeタスク用意

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typecheckでエラーになってしまった

$ rails typecheck
warning: parser/current is loading parser/ruby34, which recognizes 3.4.0-compliant syntax, but you are running 3.4.1.
Please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
🎉 Generated 1 RBS files under sig/rbs_inline/app
# Type checking files:

.....F.......

sig/rbs_inline/app/controllers/posts_controller.rbs:21:10: [error] Cannot find type `::Post::ActiveRecord_Relation`
│ Diagnostic ID: RBS::UnknownTypeName
│
└   @posts: Post::ActiveRecord_Relation
            ~~~~~~~~~~~~~~~~~~~~~~~~~~~

あっきー

steep 1.8.0以上で #: シンタックスが使えるということで書き換え

- # @rbs () -> void
+ #: () -> void