Antidote

Antidote is a small, highly experimental library that performs runtime type assertions in Ruby in the same vein as Rubype, contracts.ruby, sig, and so on. This repository should mainly be considered a proof of concept.

It relies heavily on metaprogramming, and it is unsafe for method calls with side-effects. Nonetheless, it works.

Antidote exposes two methods: annotate, and annotate_class_method which can be used a such:

require_relative 'lib/antidote'

class Adder
  include Antidote

  annotate Fixnum, Fixnum, Fixnum do
  def add(x, y)
    x + y
  end
  end
end

adder = Adder.new.add(1, 2)

Here, annotate Fixnum, Fixnum, Fixnum means that we expect two Fixnum as input, and we should return a Fixnum as result.

This program returns 3 as expected since we comply with the type signature, but if we change x to be a String, we receive the following error message:

Variable `x` in method `add` expected a String, but received a Fixnum
(Antidote::VariableTypeError)

If we change the return type, we'll see a similar message:

Expected `add` to return a String, but it returned a Fixnum instead
(Antidote::ReturnTypeError)

You can obviously handle both Antidote::VariableTypeError and Antidote::ReturnTypeError in your code if needed.

Please, visit example.rb for a full example.

• Ruby 2.2.0 or newer.

Add this line to your Gemfile:

gem 'antidote-types'

And then run:

bundle

Or simply install it yourself:

gem install antidote-types

1. Fork it.
2. Create your feature branch (git checkout -b my-new-feature).
3. Commit your changes (git commit -am 'Add some new feature.').
4. Push to the branch (git push origin my-new-feature).
5. Create a new pull request.

See LICENSE. Copyright (c) 2014 Mathias Jean Johansen <mathias@mjj.io>