mvidner
commented
1 year ago Today's findings:
The Marshal dumps are different because some otherwise equal objects objects have different ordering of instance variables, namely in VolumeSpecification objects. Why, yes, I did spend a stupid amount of time to find the reason for this difference. Unsuccessfully.
My plan is to accept the reality of the nondeterministic ordering and instead remove the gorilla from the room: Marshal. We are using it because ProposalSettings#== does not work properly
WIP:
irb(main):001:0> class C; def initialize(attrs); attrs.each { |a| instance_variable_set(a.to_sym, a.to_s) } ; end ; end
=> :initialize
irb(main):004:0> a = C.new([])
=> #<C:0x0000563aa62d27b0>
irb(main):005:0> b = C.new([])
=> #<C:0x0000563aa618b848>
irb(main):006:0> a == b
=> false
irb(main):007:0> module EqualByIVs; def ==(other); return if other.class != self.class; instance_variables.all? { |iv| instance_variable_get(iv) == other.instance_variable_get(iv) }; end; end
=> :==
irb(main):008:0> class C; include EqualByIVs; end
=> C
irb(main):009:0> a == b
=> true
coveralls
yast-bot
Problem
Ruby 3.2 yast2-storage-ng sometimes fails to build, diff in Marshal.dump
The failing test means to check that a new
ProposalSettingsis in fact equal to the original one, and does so by dumping and reloading the two objects withMarshal. It fails in case the two objects differ in the order in which their instance variables were assigned.Solution
Instead of using
Marshal, addProposalSettings#==.Do it by introducing a simple module,
EqualByInstanceVariables, including it in that class and a couple of others that are used by it.Gory details: everything I've learned about equality in Ruby along the way, very messy so far: https://gist.github.com/mvidner/eb10bf4d70f0df5c1073a2229fd4491e
Testing
Screenshots
N/A