[DeadCode] Skip used by trait on RemoveUnusedPrivateMethodRector

rules-tests/DeadCode/Rector/ClassMethod/RemoveUnusedPrivateMethodRector/Fixture/skip_used_by_trait.php.inc

@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\ClassMethod\RemoveUnusedPrivateMethodRector\Fixture;
+
+use Rector\Tests\DeadCode\Rector\ClassMethod\RemoveUnusedPrivateMethodRector\Source\TraitConsumer;
+
+class SkipUsedByTrait
+{
+    use TraitConsumer;
+
+    private function run()
+    {
+    }
+}

rules-tests/DeadCode/Rector/ClassMethod/RemoveUnusedPrivateMethodRector/Fixture/skip_used_by_trait2.php.inc

@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\ClassMethod\RemoveUnusedPrivateMethodRector\Fixture;
+
+use Rector\Tests\DeadCode\Rector\ClassMethod\RemoveUnusedPrivateMethodRector\Source\TraitConsumer;
+
+class SkipUsedByTrait2
+{
+    use TraitConsumer;
+
+    private static function hello()
+    {
+    }
+}

rules-tests/DeadCode/Rector/ClassMethod/RemoveUnusedPrivateMethodRector/Source/TraitConsumer.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\DeadCode\Rector\ClassMethod\RemoveUnusedPrivateMethodRector\Source;
+
+trait TraitConsumer
+{
+    public function execute()
+    {
+        $this->run();
+    }
+
+    public static function helloExecute()
+    {
+        self::hello();
+    }
+}

rules/DeadCode/NodeAnalyzer/IsClassMethodUsedAnalyzer.php

@@ -4,13 +4,17 @@
 
 namespace Rector\DeadCode\NodeAnalyzer;
 
+use PhpParser\Node;
 use PhpParser\Node\Arg;
 use PhpParser\Node\Expr\Array_;
 use PhpParser\Node\Expr\ArrayItem;
+use PhpParser\Node\Expr\CallLike;
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\StaticCall;
+use PhpParser\Node\Name;
 use PhpParser\Node\Stmt\Class_;
 use PhpParser\Node\Stmt\ClassMethod;
+use PhpParser\Node\Stmt\Trait_;
 use PHPStan\Analyser\Scope;
 use PHPStan\Parser\ArrayMapArgVisitor;
 use PHPStan\Reflection\ClassReflection;
@@ -147,13 +151,59 @@ private function doesMethodExistInTrait(ClassMethod $classMethod, string $classM
         }
 
         $traits = $this->astResolver->parseClassReflectionTraits($classReflection);
+        $className = $classReflection->getName();
+
         foreach ($traits as $trait) {
-            $method = $trait->getMethod($classMethodName);
-            if (! $method instanceof ClassMethod) {
-                continue;
+            if ($this->isUsedByTrait($trait, $classMethodName, $className)) {
+                return true;
             }
+        }
 
-            return true;
+        return false;
+    }
+
+    private function isUsedByTrait(Trait_ $trait, string $classMethodName, string $className): bool
+    {
+        foreach ($trait->getMethods() as $classMethod) {
+            if ($classMethod->name->toString() === $classMethodName) {
+                return true;
+            }
+
+            /**
+             * Trait can't detect class type, so it rely on "this" or "self" or "static" or "ClassName::methodName()" usage...
+             */
+            $callMethod = $this->betterNodeFinder->findFirstInFunctionLikeScoped(
+                $classMethod,
+                function (Node $subNode) use ($className, $classMethodName): bool {
+                    if ($subNode instanceof MethodCall) {
+                        return $this->nodeNameResolver->isName(
+                            $subNode->var,
+                            'this'
+                        ) && $this->nodeNameResolver->isName(
+                            $subNode->name,
+                            $classMethodName
+                        );
+                    }
+
+                    if (! $subNode instanceof StaticCall) {
+                        return false;
+                    }
+
+                    if (! $subNode->class instanceof Name) {
+                        return false;
+                    }
+
+                    if ($subNode->class->isSpecialClassName() || $subNode->class->toString() === $className) {
+                        return $this->nodeNameResolver->isName($subNode->name, $classMethodName);
+                    }
+
+                    return false;
+                }
+            );
+
+            if ($callMethod instanceof CallLike) {
+                return true;
+            }
         }
 
         return false;