Inheritance class << self problem

[pavel-manylov]

Bare-minimum code to reproduce the problem:

require 'contracts'

class A
  include Contracts::Core
  include Contracts::Builtin
end

class B < A
  Contract Num => Num
  def self.plus_two(num)
    num + 2
  end
end

class C < A

  class << self
    Contract Num => Num
    def plus_two(num)
      num + 2
    end
  end

end

classes B and C should be identical, however, Contracts raises an error for class C:

/Users/rk/.rvm/gems/ruby-2.2.3@soft24/gems/contracts-0.12.0/lib/contracts/engine/eigenclass.rb:38:in `validate!': In order to use contracts in singleton class, please include Contracts module in original class (Contracts::ContractsNotIncluded)
    Example:

    ```ruby
    class Example
      include Contracts  # this line is required
      class << self
        # you can use `Contract` definition here now
      end
    end

from /Users/rk/.rvm/gems/ruby-2.2.3@soft24/gems/contracts-0.12.0/lib/contracts/engine/base.rb:42:in `decorate'
from /Users/rk/.rvm/gems/ruby-2.2.3@soft24/gems/contracts-0.12.0/lib/contracts/decorators.rb:33:in `Contract'
from contracts_test.rb:18:in `singleton class'
from contracts_test.rb:17:in `<class:C>'
from contracts_test.rb:15:in `<main>'

[egonSchiele]

Interesting. I can reproduce this. It happens even if I add an include Contracts in class C.

[waterlink]

Fixed on master since #211 landed