[Fix #10979] Fix a false positive for Style/Style/RedundantParentheses

changelog/fix_a_false_positive_for_style_redundant_parentheses.md

@@ -0,0 +1 @@
+* [#10979](https://github.com/rubocop/rubocop/issues/10979): Fix a false positive for `Style/RedundantParentheses` when using parentheses with pin operator except for variables. ([@Tietew][])

lib/rubocop/cop/style/redundant_parentheses.rb

@@ -29,6 +29,9 @@ class RedundantParentheses < Base
         # @!method rescue?(node)
         def_node_matcher :rescue?, '{^resbody ^^resbody}'
 
+        # @!method allowed_pin_operator?(node)
+        def_node_matcher :allowed_pin_operator?, '^(pin (begin !{lvar ivar cvar gvar}))'
+
         # @!method arg_in_call_with_block?(node)
         def_node_matcher :arg_in_call_with_block?, '^^(block (send _ _ equal?(%0) ...) ...)'
 
@@ -44,6 +47,7 @@ def parens_allowed?(node)
           empty_parentheses?(node) ||
             first_arg_begins_with_hash_literal?(node) ||
             rescue?(node) ||
+            allowed_pin_operator?(node) ||
             allowed_expression?(node)
         end
 

spec/rubocop/cop/style/redundant_parentheses_spec.rb

@@ -626,4 +626,49 @@ def x
       ]
     RUBY
   end
+
+  context 'pin operator', :ruby31 do
+    let(:target_ruby_version) { 3.1 }
+
+    shared_examples 'redundant parentheses' do |variable, description|
+      it "registers an offense and corrects #{description}" do
+        expect_offense(<<~RUBY, variable: variable)
+          var = 0
+          foo in { bar: ^(%{variable}) }
+                         ^^{variable}^ Don\x27t use parentheses around a variable.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          var = 0
+          foo in { bar: ^#{variable} }
+        RUBY
+      end
+    end
+
+    it_behaves_like 'redundant parentheses', 'var', 'a local variable'
+    it_behaves_like 'redundant parentheses', '@var', 'an instance variable'
+    it_behaves_like 'redundant parentheses', '@@var', 'a class variable'
+    it_behaves_like 'redundant parentheses', '$var', 'a global variable'
+
+    shared_examples 'allowed parentheses' do |expression, description|
+      it "accepts parentheses on #{description}" do
+        expect_no_offenses(<<~RUBY)
+          var = 0
+          foo in { bar: ^(#{expression}) }
+        RUBY
+      end
+    end
+
+    it_behaves_like 'allowed parentheses', 'meth', 'a function call with no arguments'
+    it_behaves_like 'allowed parentheses', 'meth(true)', 'a function call with arguments'
+    it_behaves_like 'allowed parentheses', 'var.to_i', 'a method call on a local variable'
+    it_behaves_like 'allowed parentheses', '@var.to_i', 'a method call on an instance variable'
+    it_behaves_like 'allowed parentheses', '@@var.to_i', 'a method call on a class variable'
+    it_behaves_like 'allowed parentheses', '$var.to_i', 'a method call on a global variable'
+    it_behaves_like 'allowed parentheses', 'var + 1', 'an expression'
+    it_behaves_like 'allowed parentheses', '[1, 2]', 'an array literal'
+    it_behaves_like 'allowed parentheses', '{ baz: 2 }', 'a hash literal'
+    it_behaves_like 'allowed parentheses', '1..2', 'a range literal'
+    it_behaves_like 'allowed parentheses', '1', 'an int literal'
+  end
 end