Bug #18799: Refinement#import_methods vs attr_reader

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.1.1p18 (2022-02-18 revision 53f5fc4236) [x86_64-darwin21]
• Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN

[palkan (Vladimir Dementyev)]

Currently, it's not possible to import methods defined as attr_{reader, accessor,writer}:

module M
  attr_reader :fuu
end

module R
  refine Object do
    import_methods M
  end
end

#=> Can't import method which is not defined with Ruby code: M#fuu (ArgumentError)

Is that a known/intentional limitation or a bug? From the error message it might seem that this is a bug (since attr_smth is a Ruby code).

[palkan (Vladimir Dementyev)]

UPD: looks like define_method is not supported, too:

module M
  define_method(:fuu) { }
end

module R
  refine Object do
    import_methods M
  end
end

#=> Can't import method which is not defined with Ruby code: M#fuu (ArgumentError)

[Eregon (Benoit Daloze)]

is not defined with Ruby code

It means the method's body is not Ruby code. And indeed, attr_* defines methods which are not defined in/with Ruby code.

So this seems expected.

Same for define_method, which has some internal wrapper around the given block and so cannot easily be import-ed.

[shugo (Shugo Maeda)]

As eregon stated, it's an intended limitation.

It's possible to allow importing C methods without refinements activation.
It may be helpful for attr_*, but not for define_method.

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Closed