From e1b1076b28b9fdcac56fcdfa20644990cad39ecd Mon Sep 17 00:00:00 2001
From: ydah <t.yudai92@gmail.com>
Date: Fri, 1 Mar 2024 23:13:52 +0900
Subject: [PATCH] Fix a false positive for `RSpec/RepeatedSubjectCall`

Fix: #1821
---
 CHANGELOG.md                                  |  2 ++
 docs/modules/ROOT/pages/cops_rspec.adoc       |  6 +++++
 .../cop/rspec/repeated_subject_call.rb        | 24 +++++++++++--------
 .../cop/rspec/repeated_subject_call_spec.rb   | 11 +++++++++
 4 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a8de0a471..6cda77667 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Master (Unreleased)
 
+- Fix a false positive for `RSpec/RepeatedSubjectCall` when `subject.method_call`. ([@ydah])
+
 ## 2.27.0 (2024-03-01)
 
 - Add new `RSpec/IsExpectedSpecify` cop. ([@ydah])
diff --git a/docs/modules/ROOT/pages/cops_rspec.adoc b/docs/modules/ROOT/pages/cops_rspec.adoc
index a818c0d94..c2fb78a3e 100644
--- a/docs/modules/ROOT/pages/cops_rspec.adoc
+++ b/docs/modules/ROOT/pages/cops_rspec.adoc
@@ -4921,6 +4921,12 @@ it do
   expect { my_method }.to change { A.count }
   expect { my_method }.to not_change { A.count }
 end
+
+# also good
+it do
+  expect { subject.a }.to change { A.count }
+  expect { subject.b }.to not_change { A.count }
+end
 ----
 
 === References
diff --git a/lib/rubocop/cop/rspec/repeated_subject_call.rb b/lib/rubocop/cop/rspec/repeated_subject_call.rb
index 8d2267e0e..faa430718 100644
--- a/lib/rubocop/cop/rspec/repeated_subject_call.rb
+++ b/lib/rubocop/cop/rspec/repeated_subject_call.rb
@@ -23,6 +23,12 @@ module RSpec
       #     expect { my_method }.to not_change { A.count }
       #   end
       #
+      #   # also good
+      #   it do
+      #     expect { subject.a }.to change { A.count }
+      #     expect { subject.b }.to not_change { A.count }
+      #   end
+      #
       class RepeatedSubjectCall < Base
         include TopLevelGroup
 
@@ -64,17 +70,15 @@ def on_top_level_group(node)
 
         private
 
-        def detect_offense(example_node, subject_node)
-          walker = subject_node
+        def detect_offense(subject_node)
+          return if subject_node.chained?
+          return unless (block_node = expect_block(subject_node))
 
-          while walker.parent? && walker.parent != example_node.body
-            walker = walker.parent
+          add_offense(block_node)
+        end
 
-            if walker.block_type? && walker.method?(:expect)
-              add_offense(walker)
-              return
-            end
-          end
+        def expect_block(node)
+          node.each_ancestor(:block).find { |block| block.method?(:expect) }
         end
 
         def detect_offenses_in_block(node, subject_names = [])
@@ -96,7 +100,7 @@ def detect_offenses_in_example(node, subject_names)
 
           subject_calls(node.body, Set[*subject_names, :subject]).each do |call|
             if subjects_used[call.method_name]
-              detect_offense(node, call)
+              detect_offense(call)
             else
               subjects_used[call.method_name] = true
             end
diff --git a/spec/rubocop/cop/rspec/repeated_subject_call_spec.rb b/spec/rubocop/cop/rspec/repeated_subject_call_spec.rb
index 883d955cf..514c9893c 100644
--- a/spec/rubocop/cop/rspec/repeated_subject_call_spec.rb
+++ b/spec/rubocop/cop/rspec/repeated_subject_call_spec.rb
@@ -102,4 +102,15 @@
       end
     RUBY
   end
+
+  it 'registers no offenses for `subject.method_call`' do
+    expect_no_offenses(<<~RUBY)
+      RSpec.describe Foo do
+        it do
+          expect { subject.a }.to change { A.count }
+          expect { subject.b }.to not_change { A.count }
+        end
+      end
+    RUBY
+  end
 end