[Fix #9429] Fix Style/NegatedIfElseCondition autocorrect to keep comments in correct branch

[tejasbubane]

Closes #9429

---

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• Added tests.
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[bbatsov]

@tejasbubane ping :-)

[tejasbubane]

@koic @bbatsov Fixed.

[koic]

Thank you for the fixing. There's one more thing. Can you add and pass the following test case ending in comments? (I think it's an edge case 😅 )

  it 'registers and corrects an offense when using negated condition and the end of branches are comment' do
     expect_offense(<<~RUBY)
       if !condition.nil?
       ^^^^^^^^^^^^^^^^^^ Invert the negated condition and swap the if-else branches.
         # part B
         # and foo is 39
         foo = 39
         # end of `then` body comment
       else
         # part A
         # and foo is 42
         foo = 42
         # end of `else` body comment
       end
     RUBY

     expect_correction(<<~RUBY)
       if condition.nil?
         # part A
         # and foo is 42
         foo = 42
         # end of `else` body comment
       else
         # part B
         # and foo is 39
         foo = 39
         # end of `then` body comment
       end
     RUBY
   end

[koic]

@tejasbubane Can you fix this issue with this PR? I think it's an edge case, so I think it can be merged and improved even at present if you don't have time for this case.

[tejasbubane]

@koic I tried handling this case but seems like this needs to be fixed at parser level. Below is output of processed_source.ast_with_comments. Note the comment just above else if taken as part of else statement. Is there any other rubocop API that I can use and I am unaware of?

irb(#<RuboCop::Cop::Style::NegatedIfElseCondition:0x00005588841deb30>):007:0> pp processed_source.ast_with_comments
{s(:lvasgn, :foo,
  s(:int, 39))=>
  [#<Parser::Source::Comment (string):2:3 "# part B">,
   #<Parser::Source::Comment (string):3:3 "# and foo is 39">],
 s(:lvasgn, :foo,
  s(:int, 42))=>
  [#<Parser::Source::Comment (string):5:3 "# end of `then` body comment">,
   #<Parser::Source::Comment (string):7:3 "# part A">,
   #<Parser::Source::Comment (string):8:3 "# and foo is 42">],
 s(:if,
  s(:send,
    s(:send,
      s(:send, nil, :condition), :nil?), :!),
  s(:lvasgn, :foo,
    s(:int, 39)),
  s(:lvasgn, :foo,
    s(:int, 42)))=>
  [#<Parser::Source::Comment (string):10:3 "# end of `else` body comment">]}

[koic]

Thank you for investigating. This issue may require deeper investigation to be resolved. And this PR has improved auto-correction, so let's merge it with the current status. Thank you again!