From e0ec69bb8706acbbd4e1600f382b126e0287e3d0 Mon Sep 17 00:00:00 2001
From: Koichi ITO <koic.ito@gmail.com>
Date: Sun, 14 Mar 2021 14:22:12 +0900
Subject: [PATCH] Fix a false positive for
 `Style/RedundantEqualityComparisonBlock`

This PR fixes a false positive for `Style/RedundantEqualityComparisonBlock`
when using one argument with comma separator in block argument.
---
 CHANGELOG.md                                       |  1 +
 .../redundant_equality_comparison_block.rb         |  7 ++++++-
 .../redundant_equality_comparison_block_spec.rb    | 14 ++++++++++----
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 584898a884..2e3e3d26a8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 
 * [#162](https://github.com/rubocop/rubocop-performance/issues/162): Fix a false positive for `Performance/RedundantBlockCall` when an optional block that is overridden by block variable. ([@koic][])
 * [#36](https://github.com/rubocop/rubocop-performance/issues/36): Fix a false positive for `Performance/ReverseEach` when `each` is called on `reverse` and using the result value. ([@koic][])
+* [#224](https://github.com/rubocop/rubocop-performance/pull/224): Fix a false positive for `Style/RedundantEqualityComparisonBlock` when using one argument with comma separator in block argument. ([@koic][])
 
 ## 1.10.1 (2021-03-02)
 
diff --git a/lib/rubocop/cop/performance/redundant_equality_comparison_block.rb b/lib/rubocop/cop/performance/redundant_equality_comparison_block.rb
index 0e91f808f5..de13587c14 100644
--- a/lib/rubocop/cop/performance/redundant_equality_comparison_block.rb
+++ b/lib/rubocop/cop/performance/redundant_equality_comparison_block.rb
@@ -35,7 +35,8 @@ class RedundantEqualityComparisonBlock < Base
         IS_A_METHODS = %i[is_a? kind_of?].freeze
 
         def on_block(node)
-          return unless TARGET_METHODS.include?(node.method_name) && node.arguments.one?
+          return unless TARGET_METHODS.include?(node.method_name)
+          return unless one_block_argument?(node.arguments)
 
           block_argument = node.arguments.first
           block_body = node.body
@@ -53,6 +54,10 @@ def on_block(node)
 
         private
 
+        def one_block_argument?(block_arguments)
+          block_arguments.one? && !block_arguments.source.include?(',')
+        end
+
         def use_equality_comparison_block?(block_body)
           block_body.send_type? && COMPARISON_METHODS.include?(block_body.method_name)
         end
diff --git a/spec/rubocop/cop/performance/redundant_equality_comparison_block_spec.rb b/spec/rubocop/cop/performance/redundant_equality_comparison_block_spec.rb
index f9a5c4d9e7..a23ec9663d 100644
--- a/spec/rubocop/cop/performance/redundant_equality_comparison_block_spec.rb
+++ b/spec/rubocop/cop/performance/redundant_equality_comparison_block_spec.rb
@@ -59,13 +59,13 @@
       RUBY
     end
 
-    it 'does not register and corrects an offense when using `all?` without `===` comparison block' do
+    it 'does not register an offense when using `all?` without `===` comparison block' do
       expect_no_offenses(<<~RUBY)
         items.all?(other)
       RUBY
     end
 
-    it 'does not register and corrects an offense when using multiple block arguments' do
+    it 'does not register an offense when using multiple block arguments' do
       expect_no_offenses(<<~RUBY)
         items.all? { |key, _value| key == other }
       RUBY
@@ -83,13 +83,19 @@
       RUBY
     end
 
-    it 'does not register and corrects an offense when using block argument is not used as it is' do
+    it 'does not register an offense when using block argument is not used as it is' do
       expect_no_offenses(<<~RUBY)
         items.all? { |item| item.do_something == other }
       RUBY
     end
 
-    it 'does not register and corrects an offense when using not target methods with `===` comparison block' do
+    it 'does not register an offense when using one argument with comma separator in block argument' do
+      expect_no_offenses(<<~RUBY)
+        items.all? { |item,| item == other }
+      RUBY
+    end
+
+    it 'does not register an offense when using not target methods with `===` comparison block' do
       expect_no_offenses(<<~RUBY)
         items.do_something { |item| item == other }
       RUBY