required_arg

Ruby keyword arguments are awesome:

class AwesomeValidator
  def is_awesome?(suspect:)
    suspect == "keyword arguments"
  end
end

AwesomeValidator.new.is_awesome?(suspect: "keyword arguments") #=> true!

That's great code. It even uses the sweet feature introduced in Ruby 2.1 where keyword arguments can be required, so if you called that method without providing the keyword, this exception would be raised:

missing keyword: suspect (ArgumentError)

Designing method interfaces is easier when you can require keywords.

Ruby 2.0.0 is in kind of an awkward position, where it has keywords, but it can't require them. If you try that code above, you get this gnarly syntax error:

awesome.rb:6: syntax error, unexpected ')'
  def is_awesome?(suspect:)                             ...
                           ^
awesome.rb:9: syntax error, unexpected keyword_end, expecting end-of-input
end                             ...
   ^

So let's say you're using Ruby 2.0.0, using keyword arguments, and wish you could require them... this gem is for you.

Add this line to your application's Gemfile:

gem 'required_arg'

And then execute:

$ bundle

Or install it yourself as:

$ gem install required_arg

require "required_arg"

class AwesomeValidator
  def is_awesome?(suspect: RequiredArg.new(:suspect))
    suspect == "keyword arguments"
  end
end

After checking out the repo, run bin/setup to install dependencies. Then, run rake rspec 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 tags, and push the .gem file to rubygems.org.

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

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