From 81a27f861aadd8889793d85676a58058aacd33ad Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Tue, 8 Sep 2020 12:01:55 +0900
Subject: [PATCH] [Fix #8664] Fix a false positive for
 `Naming/BinaryOperatorParameterName`

Fixes #8664.

This PR fixes a false positive for `Naming/BinaryOperatorParameterName`
when naming multibyte character method name.
---
 CHANGELOG.md                                              | 1 +
 lib/rubocop/cop/naming/binary_operator_parameter_name.rb  | 2 +-
 .../cop/naming/binary_operator_parameter_name_spec.rb     | 8 ++++++++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f7f64c0b986..109fd81496c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@
 * [#8655](https://github.com/rubocop-hq/rubocop/pull/8655): Fix a false positive for `Style/ClassAndModuleChildren` when using cbase class name. ([@koic][])
 * [#8654](https://github.com/rubocop-hq/rubocop/pull/8654): Fix a false positive for `Style/SafeNavigation` when checking `foo&.empty?` in a conditional. ([@koic][])
 * [#8660](https://github.com/rubocop-hq/rubocop/pull/8660): Fix a false positive for `Style/ClassAndModuleChildren` when using cbase module name. ([@koic][])
+* [#8664](https://github.com/rubocop-hq/rubocop/issues/8664): Fix a false positive for `Naming/BinaryOperatorParameterName` when naming multibyte character method name. ([@koic][])
 
 ### Changes
 
diff --git a/lib/rubocop/cop/naming/binary_operator_parameter_name.rb b/lib/rubocop/cop/naming/binary_operator_parameter_name.rb
index 805a4c5b5e7..901ea982579 100644
--- a/lib/rubocop/cop/naming/binary_operator_parameter_name.rb
+++ b/lib/rubocop/cop/naming/binary_operator_parameter_name.rb
@@ -35,7 +35,7 @@ def on_def(node)
         def op_method?(name)
           return false if EXCLUDED.include?(name)
 
-          !/\A\w/.match?(name) || OP_LIKE_METHODS.include?(name)
+          !/\A[[:word:]]/.match?(name) || OP_LIKE_METHODS.include?(name)
         end
       end
     end
diff --git a/spec/rubocop/cop/naming/binary_operator_parameter_name_spec.rb b/spec/rubocop/cop/naming/binary_operator_parameter_name_spec.rb
index e3e35d068c9..4902e377e29 100644
--- a/spec/rubocop/cop/naming/binary_operator_parameter_name_spec.rb
+++ b/spec/rubocop/cop/naming/binary_operator_parameter_name_spec.rb
@@ -81,6 +81,14 @@ def ===(string)
     RUBY
   end
 
+  it 'does not register an offense for multibyte character method name' do
+    expect_no_offenses(<<~RUBY)
+      def ｄｏ＿ｓｏｍｅｔｈｉｎｇ(string)
+        string
+      end
+    RUBY
+  end
+
   it 'does not register an offense for non binary operators' do
     expect_no_offenses(<<~RUBY)
       def -@; end