Issue #11117 has been updated by Nobuyoshi Nakada.

Priority changed from High to Normal
Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN to 2.0.0: REQUIRED, 2.1: REQUIRED, 2.2: REQUIRED

----------------------------------------
Bug #11117: When you refine String with to_regexp, then it breaks Regexp.try_convert even when the refinement is not used
https://bugs.ruby-lang.org/issues/11117#change-52342

* Author: Jakub Jirutka
* Status: Closed
* Priority: Normal
* Assignee: 
* ruby -v: 2.2.2p95
* Backport: 2.0.0: REQUIRED, 2.1: REQUIRED, 2.2: REQUIRED
----------------------------------------
I”Ēve run into a very strange bug with refinements. Let me show you:

~~~ruby
module Ref
  refine String do
    def to_regexp
    end
  end
end

Regexp.try_convert('foo')
# or Regexp.union('foo', 'bar')
~~~

~~~
bug.rb:8:in `try_convert': undefined method `to_regexp' for "foo":String (NoMethodError)
	from test.rb:8:in `<main>'
~~~

Note that the refinement is not used (_using_), only declared, and yet it has affected behaviour of the refined class! This problem occurs only when the method is named `to_string`. It seems that there”Ēs some serious scoping issue with refinements.

I”Ēve reproduced this issue on MRI 2.2.2p95, 2.1.5p273, and 2.0.0p598.



-- 
https://bugs.ruby-lang.org/