steep-playground.rb

require 'tmpdir'
require 'pathname'

Dir.mktmpdir('steep-playground-') do |dir|
  dir = Pathname(dir)
  dir.join('Steepfile').write(<<~END)
    target :test do
      signature "."
      check "test.rb"
    end
  END

  dir.join('test.rb').write(<<~END)
    user = User.new(name: "John", age: 20)

    user.test(user.name)
    user.test(user.age)
  END

  dir.join('test.rbs').write(<<~END)
    class User
      def initialize: (name: String, age: Integer) -> void

      attr_reader name: String
      attr_reader age: Integer

      def test: (String s) -> void
    end
  END

  system('vim', '-O', 'test.rb', 'test.rbs', '-c', 'terminal',  chdir: dir.to_s)
end

Screen.Recording.2022-06-02.at.16.42.48.mov