Representation is using Fixnum which is deprecated in Ruby >= 2.4

[mbigras]

Reproduction steps

git clone https://github.com/mbigras/kashmir
cd kashmir/
git co ce9164251f7f27911f64a528e2cdb19c81533bc7
bundle install
ruby --version
# ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-darwin16]
bundle exec ruby <<'EOF'
require 'kashmir'
class Person
  include Kashmir
  
  def initialize(name, age)
    @name = name
    @age = age
  end
  
  representations do
    rep :name
    rep :age
  end
end
p Person.new('Netto Farah', 26).represent([:name, :age])
EOF
# /private/tmp/kashmir/lib/kashmir/representation.rb:114: warning: constant ::Fixnum is deprecated
# {:name=>"Netto Farah", :age=>26}

More details at:

• https://www.ruby-lang.org/en/news/2016/12/25/ruby-2-4-0-released/#unify-fixnum-and-bignum-into-integer
• https://bugs.ruby-lang.org/issues/12005
• http://www.a-k-r.org/pub/2016-09-08-rubykaigi-unified-integer.pdf

Unify Fixnum and Bignum into Integer
Though ISO/IEC 30170:2012 doesn’t specify details of the Integer class, Ruby had two visible Integer classes: Fixnum and Bignum. Ruby 2.4 unifies them into Integer. All C extensions which touch the Fixnum or Bignum class need to be fixed.

See also the ticket and akr’s slides.