rbs subtract を試しに使ってみる

個人的な興味で RBS を一度調べたことがあって，今回もその辺りを後で確認していく流れ

$ rbs subtract

ignore するのが欲しかったので，subract がポイントなのかも．

試してみる

• https://github.com/r7kamura/mem

$ ruby -v
ruby 2.7.6p219 (2022-04-12 revision c9c2245c0a) [x86_64-linux]
$ gh repo clone https://github.com/r7kamura/mem
$ cd mem
$ git diff
diff --git a/mem.gemspec b/mem.gemspec
index 2d578ae..eb8c9b8 100644
--- a/mem.gemspec
+++ b/mem.gemspec
@@ -18,5 +18,7 @@ Gem::Specification.new do |spec|

   spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
-  spec.add_development_dependency "rspec", "2.14.1"
+  spec.add_development_dependency "rspec"
+  spec.add_development_dependency "typeprof"
+  spec.add_development_dependency "steep"
 end
$ bundle install
$ typeprof lib/mem.rb lib/mem/core_ext.rb lib/mem/version.rb spec/mem_spec.rb spec/spec_helper.rb > sig/mem.rbs
$ cat Steepfile
target :lib do
  signature "sig"
  check "lib"
end
$ steep check
# Type checking files:

........................................F......................[Steep 1.4.0] [typecheck:typecheck@1] [background] Unexpected error: #<RBS::RecursiveAncestorError: /usr/local/bundle/gems/rbs-3.1.0/core/object.rbs:108:
0...1075:3: Detected recursive ancestors: ::Object < ::Mem < ::Object>
(snip)

Recursive らしい

sig/mem.rbs

# TypeProf 0.21.7

# Classes
class Object
  extend Mem::ClassMethods
  include Mem

  private
  def a: (untyped value) -> [untyped, untyped]
       | -> nil
  def b: (untyped value) -> [untyped, untyped]
       | (untyped value) -> [untyped, untyped]
       | -> nil
  def c: -> String
       | -> nil
  def a!: (untyped value) -> [untyped, untyped]
end

module Mem
  VERSION: String
  @memoized_table: Hash[untyped, untyped]

  def self.included: (singleton(Object) base) -> singleton(Object)
  def has_memoized?: (untyped key) -> bool
  def memoize: (untyped key, untyped value) -> untyped
  def memoized: (untyped key) -> nil
  def memoized_table: -> Hash[untyped, untyped]
  def unmemoize: (untyped key) -> nil

  module ClassMethods
    def memoize: (untyped method_name) -> nil
  end
end

• Object include Mem が怪しい．

sig-ignore/hand-written.rbs

class Object
  include Mem
end

$ rbs subtract -w sig/mem.rbs sig-ignore/hand-writte.rbs

この時点で，include Mem が無くなっていることは確認した

$ steep check
# Type checking files:

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

lib/mem.rb:32:13: [error] Type `(::Object & ::Mem::ClassMethods)` does not have method `protected_instance_methods`
(snip)

結果が変わったので，使えているのはわかった．

NOTE

最初，hand-written.rbs を 同じディレクトリに入れていてハマっていた．
考えればあたりまえだった．

余談

• 全然関係ないけど，Rouge が RBS 対応して欲しい．
  • https://rouge-ruby.github.io/docs/file.Languages.html

Refs

• https://tech.stmn.co.jp/entry/rubykaigi-2023-report
• https://github.com/ruby/rbs