From b79367b4cb912060067cef35442018639f395d9c Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Mon, 12 Jul 2021 10:53:58 +0900
Subject: [PATCH] Fix an incorrect auto-correct for `Style/SingleLineMethods`

Fixes https://github.com/testdouble/standard/issues/309.

This PR fixes an incorrect auto-correct for `Style/SingleLineMethods`
when method body is enclosed in parentheses.
---
 ...tocorrect_for_style_single_line_methods.md |  1 +
 lib/rubocop/cop/style/single_line_methods.rb  | 23 +++++++++++--------
 .../cop/style/single_line_methods_spec.rb     | 13 +++++++++++
 3 files changed, 28 insertions(+), 9 deletions(-)
 create mode 100644 changelog/fix_incorrect_autocorrect_for_style_single_line_methods.md

diff --git a/changelog/fix_incorrect_autocorrect_for_style_single_line_methods.md b/changelog/fix_incorrect_autocorrect_for_style_single_line_methods.md
new file mode 100644
index 00000000000..5e6e09297b9
--- /dev/null
+++ b/changelog/fix_incorrect_autocorrect_for_style_single_line_methods.md
@@ -0,0 +1 @@
+* [#9926](https://github.com/rubocop/rubocop/pull/9926): Fix an incorrect auto-correct for `Style/SingleLineMethods` when method body is enclosed in parentheses. ([@koic][])
diff --git a/lib/rubocop/cop/style/single_line_methods.rb b/lib/rubocop/cop/style/single_line_methods.rb
index 098dd7c4d7f..5e0f2a9bf68 100644
--- a/lib/rubocop/cop/style/single_line_methods.rb
+++ b/lib/rubocop/cop/style/single_line_methods.rb
@@ -72,17 +72,15 @@ def correct_to_endless?(body_node)
         end
 
         def correct_to_multiline(corrector, node)
-          each_part(node.body) do |part|
-            LineBreakCorrector.break_line_before(
-              range: part, node: node, corrector: corrector,
-              configured_width: configured_indentation_width
-            )
+          if (body = node.body) && body.begin_type? && body.parenthesized_call?
+            break_line_before(corrector, node, body)
+          else
+            each_part(body) do |part|
+              break_line_before(corrector, node, part)
+            end
           end
 
-          LineBreakCorrector.break_line_before(
-            range: node.loc.end, node: node, corrector: corrector,
-            indent_steps: 0, configured_width: configured_indentation_width
-          )
+          break_line_before(corrector, node, node.loc.end, indent_steps: 0)
 
           move_comment(node, corrector)
         end
@@ -96,6 +94,13 @@ def correct_to_endless(corrector, node)
           corrector.replace(node, replacement)
         end
 
+        def break_line_before(corrector, node, range, indent_steps: 1)
+          LineBreakCorrector.break_line_before(
+            range: range, node: node, corrector: corrector,
+            configured_width: configured_indentation_width, indent_steps: indent_steps
+          )
+        end
+
         def each_part(body)
           return unless body
 
diff --git a/spec/rubocop/cop/style/single_line_methods_spec.rb b/spec/rubocop/cop/style/single_line_methods_spec.rb
index 96b4c57d7aa..de3899ef801 100644
--- a/spec/rubocop/cop/style/single_line_methods_spec.rb
+++ b/spec/rubocop/cop/style/single_line_methods_spec.rb
@@ -32,6 +32,19 @@ def @table.columns;#{trailing_whitespace}
     RUBY
   end
 
+  it 'registers an offense for a single-line method and method body is enclosed in parentheses' do
+    expect_offense(<<~RUBY)
+      def foo() (do_something) end
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Avoid single-line method definitions.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      def foo()#{trailing_whitespace}
+        (do_something)#{trailing_whitespace}
+      end
+    RUBY
+  end
+
   context 'when AllowIfMethodIsEmpty is disabled' do
     let(:cop_config) { { 'AllowIfMethodIsEmpty' => false } }