From: "matz (Yukihiro Matsumoto)" <noreply@...>
Date: 2022-12-01T12:40:02+00:00
Subject: [ruby-core:111127] [Ruby master Bug#19047] DelegateClass displays "method redefined" warning when overriding methods

Issue #19047 has been updated by matz (Yukihiro Matsumoto).


For example, the example in #19079 does not give warning for overwriting the method `foo`.

Matz.


----------------------------------------
Bug #19047: DelegateClass displays "method redefined" warning when overriding methods
https://bugs.ruby-lang.org/issues/19047#change-100405

* Author: jonathanhefner (Jonathan Hefner)
* Status: Closed
* Priority: Normal
* ruby -v: ruby 3.1.2p20
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Perhaps this is not a bug, but it does seem unexpected.

When creating a `DelegateClass` class without an intervening ancestor, overriding a method displays "method redefined" warning:

```ruby
Base = Class.new do
  def foo
    "foo"
  end
end

Delegate1 = DelegateClass(Base) do
  def foo
    super + "1"
  end
end
# warning: method redefined; discarding old foo

Delegate2 = Class.new(DelegateClass(Base)) do
  def foo
    super + "2"
  end
end
# no warning

Delegate1.new(Base.new).foo
# => "foo1"

Delegate2.new(Base.new).foo
# => "foo2"
```

One possible solution would be to evaluate the `DelegateClass` block in a separate module, and prepend that module to the returned class.

Another possible solution would be to silence warnings around [when the block is evaluated](https://github.com/ruby/delegate/blob/df2283b8d8874446086b80355c586397f1b48d53/lib/delegate.rb#L442).

I would be happy to submit a PR to https://github.com/ruby/delegate if this is something we want to address.




-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
 ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/