[Fix #9387] Fix incorrect auto-correct for Style/NilComparison

Fixes #9387.

This PR fixes incorrect auto-correct for `Style/NilComparison` when using
`!x.nil?` and `EnforcedStyle: comparison`.

changelog/fix_incorrect_autocorrect_for_style_nil_comparison.md

@@ -0,0 +1 @@
+* [#9387](https://github.com/rubocop-hq/rubocop/issues/9387): Fix incorrect auto-correct for `Style/NilComparison` when using `!x.nil?` and `EnforcedStyle: comparison`. ([@koic][])

lib/rubocop/cop/style/nil_comparison.rb

@@ -50,6 +50,7 @@ def on_send(node)
                          end
 
               corrector.replace(node, new_code)
+              corrector.wrap(node, '(', ')') if node.parent&.method?(:!)
             end
           end
         end

spec/rubocop/cop/style/nil_comparison_spec.rb

@@ -40,5 +40,16 @@
         x == nil
       RUBY
     end
+
+    it 'registers and corrects an offense for `!x.nil?`' do
+      expect_offense(<<~RUBY)
+        !x.nil?
+           ^^^^ Prefer the use of the `==` comparison.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        !(x == nil)
+      RUBY
+    end
   end
 end