[Fix rubocop#11069] Fix an incorrect autocorrect for `Lint/RedundantC…

…opDisableDirective`

Fix rubocop#11069.

This PR fixes an incorrect autocorrect for `Lint/RedundantCopDisableDirective`
when disable directive contains free comment.

changelog/fix_an_error_for_lint_redundant_cop_disable_directive.md

@@ -0,0 +1 @@
+* [#11069](https://github.com/rubocop/rubocop/issues/11069): Fix an incorrect autocorrect for `Lint/RedundantCopDisableDirective` when disable directive contains free comment. ([@koic][])

lib/rubocop/cop/lint/redundant_cop_disable_directive.rb

@@ -209,7 +209,12 @@ def add_offense_for_entire_comment(comment, cops)
 
           add_offense(location, message: message(cop_names)) do |corrector|
             range = comment_range_with_surrounding_space(location, comment.loc.expression)
-            corrector.remove(range)
+
+            if leave_free_comment?(comment, range)
+              corrector.replace(range, ' # ')
+            else
+              corrector.remove(range)
+            end
           end
         end
 
@@ -227,6 +232,12 @@ def add_offense_for_some_cops(comment, cops)
           end
         end
 
+        def leave_free_comment?(comment, range)
+          free_comment = comment.text.gsub(range.source.strip, '')
+
+          !free_comment.empty? && !free_comment.start_with?('#')
+        end
+
         def cop_range(comment, cop)
           cop = remove_department_marker(cop)
           matching_range(comment.loc.expression, cop) ||

spec/rubocop/cop/lint/redundant_cop_disable_directive_spec.rb

@@ -581,6 +581,23 @@ def bar
         RUBY
       end
 
+      it 'removes cop duplicated by department and leaves free text as a comment' do
+        expect_offense(<<~RUBY)
+          # rubocop:disable Metrics
+          def bar
+            do_something # rubocop:disable Metrics/ClassLength - note
+                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Unnecessary disabling of `Metrics/ClassLength`.
+          end
+        RUBY
+
+        expect_correction(<<~RUBY)
+          # rubocop:disable Metrics
+          def bar
+            do_something # - note
+          end
+        RUBY
+      end
+
       it 'does not remove correct department' do
         expect_no_offenses(<<~RUBY)
           # rubocop:disable Metrics