Merge pull request #10885 from dvandersluis/issue/10883

[Fix #10883] Fix `Style/RedundantParentheses` to be able to detect offenses and properly correct when the end parentheses and comma are on their own line

changelog/fix_fix_styleredundantparentheses_to_be_able.md

@@ -0,0 +1 @@
+* [#10883](https://github.com/rubocop/rubocop/issues/10883): Fix `Style/RedundantParentheses` to be able to detect offenses and properly correct when the end parentheses and comma are on their own line. ([@dvandersluis][])

lib/rubocop/cop/correctors/parentheses_corrector.rb

@@ -5,9 +5,13 @@ module Cop
     # This autocorrects parentheses
     class ParenthesesCorrector
       class << self
+        include RangeHelp
+
         def correct(corrector, node)
           corrector.remove(node.loc.begin)
           corrector.remove(node.loc.end)
+          handle_orphaned_comma(corrector, node)
+
           return unless ternary_condition?(node) && next_char_is_question_mark?(node)
 
           corrector.insert_after(node.loc.end, ' ')
@@ -22,6 +26,30 @@ def ternary_condition?(node)
         def next_char_is_question_mark?(node)
           node.loc.last_column == node.parent.loc.question.column
         end
+
+        def only_closing_paren_before_comma?(node)
+          source_buffer = node.source_range.source_buffer
+          line_range = source_buffer.line_range(node.loc.end.line)
+
+          line_range.source.start_with?(/\s*\)\s*,/)
+        end
+
+        # If removing parentheses leaves a comma on its own line, remove all the whitespace
+        # preceding it to prevent a syntax error.
+        def handle_orphaned_comma(corrector, node)
+          return unless only_closing_paren_before_comma?(node)
+
+          range = range_with_surrounding_space(
+            range: node.loc.end,
+            buffer: node.source_range.source_buffer,
+            side: :left,
+            newlines: true,
+            whitespace: true,
+            continuations: true
+          )
+
+          corrector.remove(range)
+        end
       end
     end
   end

lib/rubocop/cop/mixin/range_help.rb

@@ -54,11 +54,11 @@ def range_with_surrounding_comma(range, side = :both)
       NOT_GIVEN = Module.new
       def range_with_surrounding_space(range_positional = NOT_GIVEN, # rubocop:disable Metrics/ParameterLists
                                        range: NOT_GIVEN, side: :both, newlines: true,
-                                       whitespace: false, continuations: false)
+                                       whitespace: false, continuations: false,
+                                       buffer: @processed_source.buffer)
 
         range = range_positional unless range_positional == NOT_GIVEN
 
-        buffer = @processed_source.buffer
         src = buffer.source
 
         go_left, go_right = directions(side)

lib/rubocop/cop/style/redundant_parentheses.rb

@@ -57,7 +57,6 @@ def ignore_syntax?(node)
         def allowed_expression?(node)
           allowed_ancestor?(node) ||
             allowed_method_call?(node) ||
-            allowed_array_or_hash_element?(node) ||
             allowed_multiple_expression?(node) ||
             allowed_ternary?(node)
         end
@@ -167,26 +166,6 @@ def keyword_ancestor?(node)
           node.parent&.keyword?
         end
 
-        def allowed_array_or_hash_element?(node)
-          # Don't flag
-          # ```
-          # { a: (1
-          #      ), }
-          # ```
-          hash_or_array_element?(node) && only_closing_paren_before_comma?(node)
-        end
-
-        def hash_or_array_element?(node)
-          node.each_ancestor(:array, :hash).any?
-        end
-
-        def only_closing_paren_before_comma?(node)
-          source_buffer = node.source_range.source_buffer
-          line_range = source_buffer.line_range(node.loc.end.line)
-
-          /^\s*\)\s*,/.match?(line_range.source)
-        end
-
         def disallowed_literal?(begin_node, node)
           node.literal? && !node.range_type? && !raised_to_power_negative_numeric?(begin_node, node)
         end

spec/rubocop/cop/style/redundant_parentheses_spec.rb

@@ -218,25 +218,80 @@
     RUBY
   end
 
-  it_behaves_like 'plausible', "[(1\n),]"
-
-  it_behaves_like 'plausible', <<~RUBY
-    [
-      (
-        1
-      ),
-      2
-    ]
-  RUBY
-
-  it_behaves_like 'plausible', <<~RUBY
-    [
-      x = (
-        1
-      ),
-      y = 2
-    ]
-  RUBY
+  context 'literals in an array' do
+    context 'when there is a comma on the same line as the closing parentheses' do
+      it 'registers an offense and corrects when there is no subsequent item' do
+        expect_offense(<<~RUBY)
+          [
+            (
+            ^ Don't use parentheses around a literal.
+              1
+            )
+          ]
+        RUBY
+
+        expect_correction(<<~RUBY)
+          [
+          #{trailing_whitespace * 2}
+              1
+          #{trailing_whitespace * 2}
+          ]
+        RUBY
+      end
+
+      it 'registers an offense and corrects when there is a trailing comma' do
+        expect_offense(<<~RUBY)
+          [(1
+           ^^ Don't use parentheses around a literal.
+          ),]
+        RUBY
+
+        expect_correction(<<~RUBY)
+          [1,]
+        RUBY
+      end
+
+      it 'registers an offense and corrects when there is a subsequent item' do
+        expect_offense(<<~RUBY)
+          [
+            (
+            ^ Don't use parentheses around a literal.
+              1
+            ),
+            2
+          ]
+        RUBY
+
+        expect_correction(<<~RUBY)
+          [
+          #{trailing_whitespace * 2}
+              1,
+            2
+          ]
+        RUBY
+      end
+
+      it 'registers an offense and corrects when there is assignment' do
+        expect_offense(<<~RUBY)
+          [
+            x = (
+                ^ Don't use parentheses around a literal.
+              1
+            ),
+            y = 2
+          ]
+        RUBY
+
+        expect_correction(<<~RUBY)
+          [
+            x =#{trailing_whitespace}
+              1,
+            y = 2
+          ]
+        RUBY
+      end
+    end
+  end
 
   it 'registers an offense for parens around a literal hash value' do
     expect_offense(<<~RUBY)
@@ -262,7 +317,18 @@
     RUBY
   end
 
-  it_behaves_like 'plausible', "{a: (1\n),}"
+  it 'registers an offense and corrects for a parenthesized item in a hash where ' \
+     'the comma is on a line with the closing parens' do
+    expect_offense(<<~RUBY)
+      { a: (1
+           ^^ Don't use parentheses around a literal.
+      ),}
+    RUBY
+
+    expect_correction(<<~RUBY)
+      { a: 1,}
+    RUBY
+  end
 
   it 'registers an offense for parens around an integer exponentiation base' do
     expect_offense(<<~RUBY)
@@ -507,4 +573,24 @@ def x
       })
     RUBY
   end
+
+  it 'registers an offense and corrects when method arguments are unnecessarily parenthesized' do
+    expect_offense(<<~RUBY)
+      foo(
+        (
+        ^ Don't use parentheses around a literal.
+          1
+        ),
+        2
+      )
+    RUBY
+
+    expect_correction(<<~RUBY)
+      foo(
+      #{trailing_whitespace * 2}
+          1,
+        2
+      )
+    RUBY
+  end
 end