Rubocop Style/RedundantSelf changes the semantics of breakouted method arguments when autocorrecting

[takayamaki]

Hi.

I encounted similer case of #5581.

I'm workaround it with a disable comment now.

Thank you.

Minimum example

before

def sample_method((a, b)) # This method expects Array that has 2 elements as argument.
  self.a = a
  self.b.some_method_call b
end

after

def sample_method((a, b))
  self.a = a
  b.some_method_call b
end

Concrete example

I read an example of Shrine gem documentation and tried this.

[7, 16] in /home/user_name/github/foo_app/app/controllers/file_uploads_controller.rb
    7: 
    8:   private
    9: 
   10:   def use_rack_response((status, headers, body))
   11:     self.status = status
   12:     headers.merge! headers
   13:     self.response_body = body
   14:     byebug
=> 15:   end
   16: end
(byebug) headers
{"Content-Type"=>"application/json; charset=utf-8", "Cache-Control"=>"no-store", "Content-Length"=>"753"}
(byebug) self.headers
{"X-Frame-Options"=>"SAMEORIGIN", "X-XSS-Protection"=>"1; mode=block", "X-Content-Type-Options"=>"nosniff", "X-Download-Options"=>"noopen", "X-Permitted-Cross-Domain-Policies"=>"none", "Referrer-Policy"=>"strict-origin-when-cross-origin"}
(byebug)

Expected behavior

RuboCop auto correction should not change the semantics of the code sample.

Actual behavior

RuboCop auto correction changes the semantics of the code sample.

Steps to reproduce the problem

~/tmp$ bundle ex rubocop -V
1.11.0 (using Parser 3.0.0.0, rubocop-ast 1.4.1, running on ruby 3.0.0 x86_64-linux)
~/tmp$ cat sample.rb
# frozen_string_literal: true

def sample_method((a, b))
  self.a = a
  self.b.some_method_call b
end

~/tmp$ bundle ex rubocop -a sample.rb 
Inspecting 1 file
C

Offenses:

sample.rb:5:3: C: [Corrected] Style/RedundantSelf: Redundant self detected.
  self.b.some_method_call b
  ^^^^^^

1 file inspected, 1 offense detected, 1 offense corrected

Tip: Based on detected gems, the following RuboCop extension libraries might be helpful:
  * rubocop-rspec (http://github.com/rubocop/rubocop-rspec)

You can opt out of this message by adding the following to your config (see https://docs.rubocop.org/rubocop/extensions.html#extension-suggestions for more options):
  AllCops:
    SuggestExtensions: false
~/tmp$ 

RuboCop version

~/tmp$ bundle ex rubocop -V
1.11.0 (using Parser 3.0.0.0, rubocop-ast 1.4.1, running on ruby 3.0.0 x86_64-linux)