From cbd9ff1ca76f9dafcbaf30e87c2942f45f2441dc Mon Sep 17 00:00:00 2001
From: Tomas Votruba <tomas.vot@gmail.com>
Date: Wed, 2 Sep 2026 16:21:47 +0200
Subject: [PATCH] [DeadCode] Keep empty method when parent class or interface
 is out of analyzed scope

RemoveEmptyClassMethodRector removed an empty method whose abstract requirement
lives in a parent class or interface outside the analyzed paths, because the
reflection could not see it. Keep the method when the parent class cannot be
resolved (protected override) or an implemented interface is out of scope.

Fixes rectorphp/rector#9881

Claude-Session: https://claude.ai/code/session_01QswFbKfL2DRR9FTdAAKZPL
---
 .../skip_unresolvable_interface.php.inc       | 10 +++++++
 .../Fixture/skip_unresolvable_parent.php.inc  | 10 +++++++
 .../RemoveEmptyClassMethodRector.php          | 27 +++++++++++++++++++
 3 files changed, 47 insertions(+)
 create mode 100644 rules-tests/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector/Fixture/skip_unresolvable_interface.php.inc
 create mode 100644 rules-tests/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector/Fixture/skip_unresolvable_parent.php.inc

diff --git a/rules-tests/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector/Fixture/skip_unresolvable_interface.php.inc b/rules-tests/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector/Fixture/skip_unresolvable_interface.php.inc
new file mode 100644
index 00000000000..1eb02db29e7
--- /dev/null
+++ b/rules-tests/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector/Fixture/skip_unresolvable_interface.php.inc
@@ -0,0 +1,10 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\ClassMethod\RemoveEmptyClassMethodRector\Fixture;
+
+final class SkipUnresolvableInterface implements \App\OutOfScope\PostingInterface
+{
+    public function submitPosting(): void
+    {
+    }
+}
diff --git a/rules-tests/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector/Fixture/skip_unresolvable_parent.php.inc b/rules-tests/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector/Fixture/skip_unresolvable_parent.php.inc
new file mode 100644
index 00000000000..a17c11feaef
--- /dev/null
+++ b/rules-tests/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector/Fixture/skip_unresolvable_parent.php.inc
@@ -0,0 +1,10 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\ClassMethod\RemoveEmptyClassMethodRector\Fixture;
+
+final class SkipUnresolvableParent extends \App\OutOfScope\AbstractPosting
+{
+    protected function submitPosting(): void
+    {
+    }
+}
diff --git a/rules/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector.php b/rules/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector.php
index d7ef32dab1f..dbb60b459bd 100644
--- a/rules/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector.php
+++ b/rules/DeadCode/Rector/ClassMethod/RemoveEmptyClassMethodRector.php
@@ -156,6 +156,11 @@ private function shouldSkipClassMethod(Class_ $class, ClassMethod $classMethod):
             return true;
         }
 
+        // parent class or interface is out of analyzed scope, keep method as it may implement an abstract requirement
+        if ($this->hasUnresolvableParentOrInterface($class, $classMethod, $scope->getClassReflection())) {
+            return true;
+        }
+
         if ($this->paramAnalyzer->hasPropertyPromotion($classMethod->params)) {
             return true;
         }
@@ -184,6 +189,28 @@ private function shouldSkipClassMethod(Class_ $class, ClassMethod $classMethod):
         return $this->isAttributeMarkerConstructor($classMethod, $classReflection);
     }
 
+    private function hasUnresolvableParentOrInterface(
+        Class_ $class,
+        ClassMethod $classMethod,
+        ?ClassReflection $classReflection
+    ): bool {
+        if (! $classReflection instanceof ClassReflection) {
+            return false;
+        }
+
+        // a protected empty method only exists to override/implement a parent's method;
+        // if the parent is out of scope, keep it to avoid breaking an abstract requirement
+        if ($classMethod->isProtected() && $class->extends instanceof Name && ! $classReflection->getParentClass() instanceof ClassReflection) {
+            return true;
+        }
+
+        $interfaceNames = array_map(
+            static fn (ClassReflection $classReflection): string => $classReflection->getName(),
+            $classReflection->getInterfaces()
+        );
+        return array_any($class->implements, fn (Name $name): bool => ! in_array($this->getName($name), $interfaceNames, true));
+    }
+
     private function hasDeprecatedAnnotation(ClassMethod $classMethod): bool
     {
         $phpDocInfo = $this->phpDocInfoFactory->createFromNode($classMethod);