RBS::Trace

RBS::Trace automatically collects argument and return types and saves RBS type declarations as RBS files or comments.

Install the gem and add to the application's Gemfile by executing:

$ bundle add rbs-trace

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install rbs-trace

For example, suppose you have the following class:

class User
  def initialize(first_name, last_name)
    @first_name = first_name
    @last_name = last_name
  end

  def full_name
    "#{@first_name} #{@last_name}"
  end

  def say_hello
    puts "hi, #{full_name}."
  end
end

Call target methods within the enable method block, and call the save_comments method.

trace = RBS::Trace.new

# Collects the types of methods called in the block.
trace.enable do
  user = User.new("Nanoha", "Takamachi")
  user.say_hello
end

# Save RBS type declarations as embedded comments
trace.save_comments

Automatically insert comments into the file.

class User
  # @rbs (String, String) -> void
  def initialize(first_name, last_name)
    @first_name = first_name
    @last_name = last_name
  end

  # @rbs () -> String
  def full_name
    "#{@first_name} #{@last_name}"
  end

  # @rbs () -> void
  def say_hello
    puts "hi, #{full_name}."
  end
end

Add the following code to spec/support/rbs_trace.rb.

RSpec.configure do |config|
  trace = RBS::Trace.new

  config.before(:suite) { trace.enable }
  config.after(:suite) do
    trace.disable
    trace.save_comments
  end
end

Add the following code to test_helper.rb.

trace = RBS::Trace.new
trace.enable

Minitest.after_run do
  trace.disable
  trace.save_comments
end

RBS::Trace.new(paths: Dir.glob("#{Dir.pwd}/app/models/**/*.rb"))

You can change the comment format.

trace.save_comments(:rbs_colon)

or

$ rbs-trace inline --rb-dir=app --rb-dir=lib --comment-format=rbs_colon

trace.save_files(out_dir: "sig/trace/")

By default, generics are applied to the generated results only in the following classes.

• Array
• Hash
• Range

If any other classes require generics, configure them as follows.

trace.add_generics_size!("CSV::Table" => 1, "ActiveSupport::HashWithIndifferentAccess" => 2)

If you are using a parallel testing gem such as parallel_tests or flatware, first save the type definitions in RBS files.

trace.save_files(out_dir: "tmp/sig-#{ENV["TEST_ENV_NUMBER"]}")

Then use rbs-trace merge to merge multiple RBS files into one.

$ rbs-trace merge --sig-dir='tmp/sig-*' > sig/merged.rbs

Finally, insert comments using the merged RBS files.

$ rbs-trace inline --rb-dir=app --rb-dir=lib

If you want to enable debug logging, specify the environment variable RBS_TRACE_DEBUG.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. 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 run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/sinsoku/rbs-trace. 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::Trace project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.