From 7e60264d44dd8660de400af5e84578cf378d3b55 Mon Sep 17 00:00:00 2001
From: Dave Liddament <dave@lampbristol.com>
Date: Sun, 9 Feb 2025 14:41:03 +0000
Subject: [PATCH] Update check for #[MustUseResult] on method definitions in
 interfaces and extended classes

---
 src/Rules/MustUseResultRule.php               | 31 +++++--
 tests/Rules/MustUseResultTest.php             | 10 +++
 .../mustUseResultOnExtendedClass.php          | 88 +++++++++++++++++++
 .../mustUseResultOnInterface.php              | 60 +++++++++++++
 4 files changed, 184 insertions(+), 5 deletions(-)
 create mode 100644 tests/Rules/data/mustUseResult/mustUseResultOnExtendedClass.php
 create mode 100644 tests/Rules/data/mustUseResult/mustUseResultOnInterface.php

diff --git a/src/Rules/MustUseResultRule.php b/src/Rules/MustUseResultRule.php
index dbfb31d..30e020e 100644
--- a/src/Rules/MustUseResultRule.php
+++ b/src/Rules/MustUseResultRule.php
@@ -7,6 +7,7 @@
 use DaveLiddament\PhpstanPhpLanguageExtensions\Helpers\Cache;
 use PhpParser\Node;
 use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\ClassReflection;
 use PHPStan\Reflection\ReflectionProvider;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
@@ -66,11 +67,8 @@ public function processNode(Node $node, Scope $scope): array
             if ($this->cache->hasEntry($fullMethodName)) {
                 $mustUseResult = $this->cache->getEntry($fullMethodName);
             } else {
-                $mustUseResult = AttributeFinder::hasAttributeOnMethod(
-                    $classReflection->getNativeReflection(),
-                    $methodName,
-                    MustUseResult::class,
-                );
+                $mustUseResult = $this->isMustUseResult($classReflection, $methodName);
+
                 $this->cache->addEntry($fullMethodName, $mustUseResult);
             }
 
@@ -85,4 +83,27 @@ public function processNode(Node $node, Scope $scope): array
 
         return [];
     }
+
+    private function isMustUseResult(ClassReflection $classReflection, string $methodName): bool
+    {
+        if (AttributeFinder::hasAttributeOnMethod(
+            $classReflection->getNativeReflection(),
+            $methodName,
+            MustUseResult::class,
+        )) {
+            return true;
+        }
+
+        foreach ($classReflection->getAncestors() as $parentClassReflection) {
+            if (AttributeFinder::hasAttributeOnMethod(
+                $parentClassReflection->getNativeReflection(),
+                $methodName,
+                MustUseResult::class,
+            )) {
+                return true;
+            }
+        }
+
+        return false;
+    }
 }
diff --git a/tests/Rules/MustUseResultTest.php b/tests/Rules/MustUseResultTest.php
index fd1585a..9652782 100644
--- a/tests/Rules/MustUseResultTest.php
+++ b/tests/Rules/MustUseResultTest.php
@@ -35,6 +35,16 @@ public function testMustUseWithParent(): void
         $this->assertIssuesReported(__DIR__.'/data/mustUseResult/mustUseResultWithParent.php');
     }
 
+    public function testMustUseResultOnExtendedClass(): void
+    {
+        $this->assertIssuesReported(__DIR__.'/data/mustUseResult/mustUseResultOnExtendedClass.php');
+    }
+
+    public function testMustUseResultOnInterface(): void
+    {
+        $this->assertIssuesReported(__DIR__.'/data/mustUseResult/mustUseResultOnInterface.php');
+    }
+
     protected function getErrorFormatter(): string
     {
         return 'Result returned by method must be used';
diff --git a/tests/Rules/data/mustUseResult/mustUseResultOnExtendedClass.php b/tests/Rules/data/mustUseResult/mustUseResultOnExtendedClass.php
new file mode 100644
index 0000000..b163e0f
--- /dev/null
+++ b/tests/Rules/data/mustUseResult/mustUseResultOnExtendedClass.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace MustUseResultOnExtendedClass {
+
+
+    use DaveLiddament\PhpLanguageExtensions\MustUseResult;
+
+    abstract class BaseClass {
+
+        #[MustUseResult]
+        public function mustUseResult(): int
+        {
+            return 1;
+        }
+
+        #[MustUseResult]
+        abstract public function abstractMustUseResult(): int;
+
+        public function dontNeedToUseResult(): int
+        {
+            return 2;
+        }
+        
+        abstract function abstractDontNeedToUseResult(): int;
+
+    }
+
+    
+    class ExtendedOnce extends BaseClass 
+    {
+
+        public function mustUseResult(): int
+        {
+            return parent::mustUseResult();
+        }
+
+        public function dontNeedToUseResult(): int
+        {
+            return parent::dontNeedToUseResult();
+        }
+
+        public function abstractMustUseResult(): int
+        {
+            return 1;
+        }
+
+        public function abstractDontNeedToUseResult(): int
+        {
+            return 2;
+        }
+    }
+    
+    class ExtendedTwice extends ExtendedOnce 
+    {
+    }
+    
+    
+
+    $extendedOnce = new ExtendedOnce();
+
+    $extendedOnce->dontNeedToUseResult(); // OK
+
+    $extendedOnce->mustUseResult(); // ERROR
+
+    $extendedOnce->abstractMustUseResult(); // ERROR
+
+    $extendedOnce->abstractDontNeedToUseResult(); // OK
+
+    echo $extendedOnce->mustUseResult(); // OK;
+
+    $value = 1 + $extendedOnce->mustUseResult(); // OK
+
+
+
+    $extendedTwice = new ExtendedTwice();
+
+    $extendedTwice->dontNeedToUseResult(); // OK
+
+    $extendedTwice->mustUseResult(); // ERROR
+
+    $extendedTwice->abstractMustUseResult(); // ERROR
+
+    $extendedTwice->abstractDontNeedToUseResult(); // OK
+
+    echo $extendedTwice->mustUseResult(); // OK;
+
+    $value = 1 + $extendedTwice->mustUseResult(); // OK
+}
\ No newline at end of file
diff --git a/tests/Rules/data/mustUseResult/mustUseResultOnInterface.php b/tests/Rules/data/mustUseResult/mustUseResultOnInterface.php
new file mode 100644
index 0000000..416b784
--- /dev/null
+++ b/tests/Rules/data/mustUseResult/mustUseResultOnInterface.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace MustUseResultOnInterface {
+
+
+    use DaveLiddament\PhpLanguageExtensions\MustUseResult;
+
+    interface BaseClass {
+
+        #[MustUseResult]
+        public function mustUseResult(): int;
+
+        public function dontNeedToUseResult(): int;
+
+    }
+
+
+    class ExtendedOnce implements BaseClass
+    {
+
+        public function mustUseResult(): int
+        {
+            return 1;
+        }
+
+        public function dontNeedToUseResult(): int
+        {
+            return 2;
+        }
+
+    }
+
+    class ExtendedTwice extends ExtendedOnce
+    {
+    }
+
+
+
+    $extendedOnce = new ExtendedOnce();
+
+    $extendedOnce->dontNeedToUseResult(); // OK
+
+    $extendedOnce->mustUseResult(); // ERROR
+
+    echo $extendedOnce->mustUseResult(); // OK;
+
+    $value = 1 + $extendedOnce->mustUseResult(); // OK
+
+
+
+    $extendedTwice = new ExtendedTwice();
+
+    $extendedTwice->dontNeedToUseResult(); // OK
+
+    $extendedTwice->mustUseResult(); // ERROR
+
+    echo $extendedTwice->mustUseResult(); // OK;
+
+    $value = 1 + $extendedTwice->mustUseResult(); // OK
+}
\ No newline at end of file