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  1. Mongoid
  2. MONGOID-5816

attr_readonly leaks into sibling classes

    • Type: Icon: Bug Bug
    • Resolution: Unresolved
    • Priority: Icon: Unknown Unknown
    • None
    • Affects Version/s: None
    • Component/s: Attributes
    • None
    • Ruby Drivers

      (Seen in mongoid 8.1.5 and 9.0.1)

       

      Having two classes A and B that are subclasses from Base, declaring attr_readonly in the context of A or B leaks that declaration into the entire class hierarchy:

       

      irb(main):001> require 'mongoid'
      => true
      irb(main):002* class Base
      irb(main):003*   include Mongoid::Document
      irb(main):004*   field :a, type: String
      irb(main):005*   field :b, type: String
      irb(main):006> end
      =>
      #<Mongoid::Fields::Standard:0x00007b0dd3154300
       @default_val=nil,
       @label=nil,
       @name="b",
       @options={:type=>String, :klass=>Base}>
      irb(main):007* class A < Base
      irb(main):008*   attr_readonly :b
      irb(main):009> end
      => [:b]
      irb(main):010* class B < Base
      irb(main):011*   attr_readonly :a
      irb(main):012> end
      => [:a]
      irb(main):013> A.readonly_attributes
      => #<Set: {"b", "a"}> 

      The expectation would be, that a declaration in a class would inherit to its child-classes (e.g. from Base to A and B), but not the other way around (i.e. not from A to Base, and especially not from A to B via Base).

       

      A workaround is to set readonly_attributes in each subclass explicitly:

      class A < Base
        self.readonly_attributes = Set.new
      
        attr_readonly :b
      end

      however this is fragile and prone to errors of oversight when extending the class hierarchy.

            Assignee:
            Unassigned Unassigned
            Reporter:
            sven.riedel@givve.com Sven Riedel
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              Created:
              Updated: