Demonstrate issue with class_attribute not cloning hash value in subclasses

test_class_attribute.rb

require 'rubygems'
require 'active_support/all'

class Base
  class_attribute :settings
  class_inheritable_accessor :old_settings

  self.settings = { :foo => 'bar' }
  self.old_settings = { :foo => 'bar' }
end

class Child < Base
  self.settings.update(:foo => 'child_bar')
  self.old_settings.update(:foo => 'child_bar')
end


p "Base: class_attribute - " + Base.settings.inspect
p "Base: class_inheritable_accessor - " + Base.old_settings.inspect
p "Child: class_attribute - " + Child.settings.inspect
p "Child: class_inheritable_accessor - " + Child.old_settings.inspect


# On investigation into class_attribute, I read in the AS comments that this is by design. You need to assign a new
# object to avoid overwriting the parent value. Like this:

Child.settings = Base.settings.merge(:foo => 'child_bar')