YARD の `@example` tag の内容を収集して Ruby コードとして出力してくれる君 (TypeProf とセットで使うと便利かも)

generate-runner-from-yard.rb

require "yard"
require "stringio"
require "fileutils"

Example = Struct.new(:path, :name, :code, :file, :lineno, keyword_init: true)

def generate(*args)
  ::YARD.parse(*args)

  code_objects = ::YARD::Registry.all.select do |code_object|
    code_object.tag("example")
  end

  examples = code_objects.flat_map do |code_object|
    code_object.tags("example").map do |example|
      file, lineno = code_object.files.first || [nil, nil]
      Example.new(path: code_object.path, name: example.name, code: example.text, file: file, lineno: lineno)
    end
  end

  code = examples.reduce(StringIO.new) do |stringio, example|
    stringio << <<~RUBY
      # #{example.path} #{example.name} (#{example.file}:#{example.lineno})
      #{example.code}
    RUBY
  end

  FileUtils.mkdir_p("runner")
  File.write("runner/runner_from_yard.rb", code.string)
end

generate