RBS::Trace

RBS::Trace collects argument types and return value types using TracePoint, and inserts inline RBS type declarations into files.

Installation

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

Usage

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 insert_rbs method.

tracing = RBS::Trace::MethodTracing.new

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

tracing.insert_rbs

Automatically inserts inline RBS definitions 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

Integration

RSpec

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

return unless ENV["RBS_TRACE"]

RSpec.configure do |config|
  tracing = RBS::Trace::MethodTracing.new

  config.before(:suite) { tracing.enable }
  config.after(:suite) do
    tracing.disable
    tracing.insert_rbs
  end
end

Then run RSpec with the environment variables.

$ RBS_TRACE=1 bundle exec rspec

Minitest

Add the following code to test_helper.rb.

tracing = RBS::Trace::MethodTracing.new
tracing.enable

Minitest.after_run do
  tracing.disable
  tracing.insert_rbs
end

Tips

Insert RBS declarations for specific files only

tracing.files.each do |path, file|
  file.rewrite if path.include?("app/models/")
end

Enable debug logging

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

Development

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.

Contributing

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.