rbs_activesupport

rbs_activesupport is a RBS generator for Active Support.

Add a new entry to your Gemfile and run bundle install:

group :development do
  gem 'rbs_activesupport', require: false
end

After the installation, please run rake task generator:

bundle exec rails g rbs_activesupport:install

And then, please modify lib/tasks/rbs_activesupport.rake to fit your application. For example, set it up like this if you're using Rails configuration:

RbsActivesupport::RakeTask.new do |task|
  task.target_directories = [Rails.root / "app", Rails.root / "lib"]
end

Run rbs:activesupport:setup task:

bundle exec rake rbs:activesupport:setup

Then rbs_activesupport will scan your source code and generate RBS file into sig/activesupport directory.

rbs_activesupport will generate types for the following code:

• auto-extend on including ActiveSupport::Concern module
• delegate
• class_attribute, cattr_* and mattr_*

The concern modules using ActiveSupport::Concern can provide the sub module named ClassMethods. It is useful to define class methods to the including class.

Extending the ClassMethods on including the concern module goes automatically and silently. So developers who uses the concern modules don't know the concern modules automatically call "extend" in the background.

On the other hand, in the Type World, Steep and RBS does not support auto-extending. Therefore we need to define the "extend" call manually.

For example, we need to write the "extend" call like the following:

# user.rbs
class User
  include ActiveModel::Attribute
  extend ActiveModel::Attribute::ClassMethods
end

rbs_activesupport detects the including concern modules and generates the "extend" call automatically if the concern modules have ClassMethods module.

ActiveSupport provides delegate method to delegate the method calls to the other objects. It's very useful and powerful.

But RBS generators like rbs prototype rb and rbs-inline does not support it. As a result, the delegation methods are missing in the RBS files.

rbs_activesupport detects the delegate method call and generates the types for them automatically.

ActiveSupport provides some methods to define class attributes and accessors:

• class_attribute
• cattr_accessor, cattr_reader, cattr_writer
• mattr_accessor, mattr_reader, mattr_writer

rbs_activesupport detects the calls of these methods and generates the types for them.

Additionally, rbs_activesupport also supports the type annotation comment like RBS::Inline.

class User
  class_attribute :name  #: String
end

rbs_activesupport also supports class attributes definition inside the "included" block:

module MyConcern
  extend ActiveSupport::Concern

  included do
    class_attribute :name #: String
  end
end

class User
  include MyConcern
end

It is translated to the following RBS:

module MyConcern
  extend ActiveSupport::Concern
end

class User
  include MyConcern

  def self.name: () -> String
  def self.name=: (String) -> String
  def self.name?: () -> bool
  def name: () -> String
  def name=: (String) -> String
  def name?: () -> bool
end

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install.

To release a new version, update the version number in version.rb, and then put a git tag (ex. git tag v1.0.0) and push it to the GitHub. Then GitHub Actions will release a new package to rubygems.org automatically.

Bug reports and pull requests are welcome on GitHub at https://github.com/tk0miya/rbs_activesupport. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the rbs_activesupport project's codebases, issue trackers is expected to follow the code of conduct.