ActiveRecord::Base doesn't serialize instance variables

gistfile1.rb

~/Code/playground/rails-3-2-stable $ cat app/models/person.rb 
class Person
  attr_accessor :abc
end


~/Code/playground/rails-3-2-stable $ cat app/models/story.rb
class Story < ActiveRecord::Base
  attr_accessor :abc
end

~/Code/playground/rails-3-2-stable $ cat app/models/user.rb 
class User < ActiveRecord::Base
  attr_accessor :abc

  def encode_with(coder)
    super
    coder['abc'] = abc
  end

  def init_with(coder)
    super
    @abc = coder['abc']
    self
  end
end


~/Code/playground/rails-3-2-stable $ bundle exec rails c
Loading development environment (Rails 3.2.2)
# Person is a plain old ruby object which serializes instance variables correctly in 1.9.3:
1.9.3p125 :001 > Person.new.tap {|p| p.abc = 123}
 => #<Person:0x007fd325c07290 @abc=123> 
1.9.3p125 :002 > Person.new.tap {|p| p.abc = 123}.abc
 => 123 
1.9.3p125 :003 > Person.new.tap {|p| p.abc = 123}.to_yaml
 => "--- !ruby/object:Person\nabc: 123\n" 
1.9.3p125 :004 > YAML.load(Person.new.tap {|p| p.abc = 123}.to_yaml)
 => #<Person:0x007fd325cdfcd0 @abc=123> 
1.9.3p125 :005 > YAML.load(Person.new.tap {|p| p.abc = 123}.to_yaml).abc
 => 123 

# Story is a ActiveRecord::Base object which only serializes @attributes but not instance variables
# (see: https://github.com/rails/rails/blob/3-2-stable/activerecord/lib/active_record/base.rb#L582)
1.9.3p125 :001 > Story.new.tap {|s| s.abc = 123}
 => #<Story id: nil, type: nil, name: nil, created_at: nil, updated_at: nil> 
1.9.3p125 :002 > Story.new.tap {|s| s.abc = 123}.abc
 => 123 
1.9.3p125 :003 > Story.new.tap {|s| s.abc = 123}.to_yaml
 => "--- !ruby/object:Story\nattributes:\n  id: \n  type: \n  name: \n  created_at: \n  updated_at: \n" 
1.9.3p125 :004 > YAML.load(Story.new.tap {|s| s.abc = 123}.to_yaml)
 => #<Story id: nil, type: nil, name: nil, created_at: nil, updated_at: nil> 
1.9.3p125 :005 > YAML.load(Story.new.tap {|s| s.abc = 123}.to_yaml).abc
 => nil 

# User is a ActiveRecord::Base object which has a custom encode_with and init_with methods to 
# properly serialize the abc instance variable.
1.9.3p125 :001 > User.new.tap {|u| u.abc = 123}
 => #<User id: nil, type: nil, name: nil, created_at: nil, updated_at: nil> 
1.9.3p125 :002 > User.new.tap {|u| u.abc = 123}.abc
 => 123 
1.9.3p125 :003 > User.new.tap {|u| u.abc = 123}.to_yaml
 => "--- !ruby/object:User\nattributes:\n  id: \n  type: \n  name: \n  created_at: \n  updated_at: \nabc: 123\n" 
1.9.3p125 :004 > YAML.load(User.new.tap {|u| u.abc = 123}.to_yaml)
 => #<User id: nil, type: nil, name: nil, created_at: nil, updated_at: nil> 
1.9.3p125 :005 > YAML.load(User.new.tap {|u| u.abc = 123}.to_yaml).abc
 => 123 

Hi jrafanie,

You saved us a lot of time running around tweaking between delayed_jobs 2 (uses syck yaml parser) and delayed_jobs 3 (uses psych yaml parser). In the older version we persisted attr_accessors but the newer version doesn't care about them. So we applied your style of overriding encode_with and init_with methods to add attr_accessors to the coder hash and that took care of Psych parser's behavior of being ignorant towards instance variables.
Thanks you so much!