Quacks

Quacks makes ducktyping easy!

Installation

Add this line to your application's Gemfile:

gem 'quack'

And then execute:

$ bundle

Or install it yourself as:

$ gem install quack

Usage

To use Quacks you annotate your methods with the .quacks_like method.

def add(int_a, int_b)
  int_a + int_b
end
quacks_like :add, :to_i, :to_i

This will automatically convert the arguments if possible:

add('1', 2)
#=> 3

If the arguments can not be converted an error will be raised:

add(1, {})
#=> Quacks::SignatureError: `{}` must respond to `to_i`.

You can force symbol arguments to be converted like so:

def divide(int_a, divisor: 2)
  int_a / divisor
end
quacks_like :divide, :to_i, divisor: :to_f

If you want to add a signature to a class method you use the singleton class:

class Calculator
  def self.add(int_a, int_b)
    int_a + int_b
  end
  singleton_class.quacks_like :add, :int_a, :int_b
end

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 tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/quack.

License

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