gistfile1.txt

module Mhmr::DescendantsTracker
  def descendants_and_self
    [self].concat self.descendants
  end
end

ActiveSupport::DescendantsTracker.send(:include,Mhmr::DescendantsTracker)


jruby:

ActiveRecord::Base.descendants # works
ActiveRecord::Base.descendants_and_self # throws

NoMethodError: undefined method `descendants_and_self' for ActiveRecord::Base:Class
	from org/jruby/RubyBasicObject.java:1652:in `method_missing'
	from /home/aaron/.rvm/gems/jruby-head@mhmr/gems/activerecord-3.2.9/lib/active_record/dynamic_matchers.rb:50:in `method_missing'
	from (irb):8:in `evaluate'
	from org/jruby/RubyKernel.java:1066:in `eval'
	from org/jruby/RubyKernel.java:1392:in `loop'
	from org/jruby/RubyKernel.java:1174:in `catch'
	from org/jruby/RubyKernel.java:1174:in `catch'
	from /home/aaron/.rvm/gems/jruby-head@mhmr/gems/railties-3.2.9/lib/rails/commands/console.rb:47:in `start'
	from /home/aaron/.rvm/gems/jruby-head@mhmr/gems/railties-3.2.9/lib/rails/commands/console.rb:8:in `start'
	from /home/aaron/.rvm/gems/jruby-head@mhmr/gems/railties-3.2.9/lib/rails/commands.rb:41:in `(root)'
	from org/jruby/RubyKernel.java:1027:in `require'
	from script/rails:6:in `(root)'

ActiveRecord::Base.__metaclass__.ancestors.map(&:name).compact.select{|n| n["Des"]}
 => ["ActiveSupport::DescendantsTracker"]


mri193:

ActiveRecord::Base.descendants # works
ActiveRecord::Base.descendants_and_self # works

ActiveRecord::Base.__metaclass__.ancestors.map(&:name).compact.select{|n| n["Des"]}
 => ["ActiveSupport::DescendantsTracker", "Mhmr::DescendantsTracker"]