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IdentityCache in combination with module causes "undefined method `all'" #298
Description
Hi,
Thanks for developing this, it's neat (when it works ;)).
Recently I encountered a rather peculiar bug that I eventually traced down to IdentityCache.
At one point my code looked like this:
class Card < Identifiable
cache_index :card, unique: :true
belongs_to :employee, inverse_of: :cards
cache_belongs_to :employee
validates_associated :employee
validates :employee, presence: true
end
class PlateOwner < ApplicationRecord
self.abstract_class = true
include IdentityCache
acts_as_paranoid
end
class Numberplate < Identifiable
cache_index :plate, unique: :true
belongs_to :plate_owner, -> { with_deleted }, polymorphic: true, inverse_of: :numberplates
cache_belongs_to :plate_owner
validates_associated :plate_owner
validates :plate_owner, presence: true
end
I then refactored it to use concerns rather than using inheritance for identifiable. After the refactor, my code looked like this:
class Card < ApplicationRecord
include Identifiable
cache_index :card, unique: :true
belongs_to :employee, inverse_of: :cards
cache_belongs_to :employee
validates_associated :employee
validates :employee, presence: true
end
module Identifiable
extend ActiveSupport::Concern
included do
include IdentityCache
acts_as_paranoid
has_many :events, as: :identifiable, inverse_of: :identifiable
cache_has_many :events, embed: true
end
module ClassMethods
end
end
class Numberplate < ApplicationRecord
include Identifiable
cache_index :plate, unique: :true
belongs_to :plate_owner, -> { with_deleted }, polymorphic: true, inverse_of: :numberplates
cache_belongs_to :plate_owner
validates_associated :plate_owner
validates :plate_owner, presence: true
end
Then things went south. I started to get very weird errors like undefined methodall' for Identifiable:Module` when saving a new Card for instance.
Here's a stack trace:
app/controllers/cards_controller.rb:34:in `block in create'
app/controllers/cards_controller.rb:33:in `create'
app/controllers/application_controller.rb:22:in `block in identity_cache_memoization'
app/controllers/application_controller.rb:22:in `identity_cache_memoization'
It took quite some time to pinpoint the issue being caused by IdentityCache in combination with the new module. I'm not sure what's actually causing it, but no longer including identity cache in my code solves the problem for me.
Activity
samratjp commentedon Mar 25, 2017
@edwardmp did you ever end up giving this another shot by chance? What version were you using?
I just experienced a similar issue with v0.3.2 (Ruby 2.2.0 + Rails 4.2.7.1) with memoization + a lookup method from a concern.
The input for the method that triggered this trace was 'd60f9b'. Fwiw, I've had this code running in prod for months now and was surprised to see it break today and tracing through my logs found the exception trace attached below.
I'm not even sure if this an issue anymore - so if any of the contributors seeing this know anything about this, please chime in / happy to help test. Unfortunately, I don't have any repro steps on this.
I'm gonna go ahead and upgrade to the latest version and add an exception handler for now with exception notifications to monitor.
I just wanted to report this issue here for posterity if anyone else would find it useful to debug or share any insights.
The concern/module where it broke:
The exception trace
edwardmp commentedon Mar 27, 2017
@samratjp
No eventually I stopped using IdentityCache. Not necessarily because of this issue, but because I found this way of caching to unelegant/introducing technical debt.
According to my Gemfile.lock I would have been using IdentityCache 0.3.2 at the time, but I used it with Rails 5.0.0.1 and Ruby 2.3.0