Handle generics using AST instead of PHPStan

Author: Orest-Divintari

rules-tests/TypeDeclaration/Rector/ClassMethod/NarrowObjectReturnTypeRector/Fixture/narrow_with_generic_parent.php.inc

@@ -0,0 +1,39 @@
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\NarrowObjectReturnTypeRector\Fixture;
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\NarrowObjectReturnTypeRector\Source\AbstractGenericFactory;
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\NarrowObjectReturnTypeRector\Source\ConferenceTalk;
+
+/**
+ * @extends AbstractGenericFactory<ConferenceTalk>
+ */
+final class ConcreteGenericFactory extends AbstractGenericFactory
+{
+    public function build(): object
+    {
+        return new ConferenceTalk();
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\NarrowObjectReturnTypeRector\Fixture;
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\NarrowObjectReturnTypeRector\Source\AbstractGenericFactory;
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\NarrowObjectReturnTypeRector\Source\ConferenceTalk;
+
+/**
+ * @extends AbstractGenericFactory<ConferenceTalk>
+ */
+final class ConcreteGenericFactory extends AbstractGenericFactory
+{
+    public function build(): \Rector\Tests\TypeDeclaration\Rector\ClassMethod\NarrowObjectReturnTypeRector\Source\ConferenceTalk
+    {
+        return new ConferenceTalk();
+    }
+}
+
+?>

rules-tests/TypeDeclaration/Rector/ClassMethod/NarrowObjectReturnTypeRector/Source/AbstractGenericFactory.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\NarrowObjectReturnTypeRector\Source;
+
+/**
+ * @template T
+ */
+abstract class AbstractGenericFactory
+{
+    /**
+     * @return T
+     */
+    abstract public function build(): object;
+}

rules/TypeDeclaration/Rector/ClassMethod/NarrowObjectReturnTypeRector.php

@@ -10,6 +10,7 @@
 use PhpParser\Node\Stmt\ClassMethod;
 use PHPStan\Reflection\ClassReflection;
 use PHPStan\Type\ObjectType;
+use Rector\PhpParser\AstResolver;
 use Rector\PhpParser\Node\BetterNodeFinder;
 use Rector\Rector\AbstractRector;
 use Rector\Reflection\ReflectionResolver;
@@ -26,6 +27,7 @@ final class NarrowObjectReturnTypeRector extends AbstractRector
     public function __construct(
         private readonly BetterNodeFinder $betterNodeFinder,
         private readonly ReflectionResolver $reflectionResolver,
+        private readonly AstResolver $astResolver,
     ) {
     }
 
@@ -189,17 +191,18 @@ private function isNarrowingValid(string $declaredType, string $actualType): boo
     private function hasParentMethodWithNonObjectReturn(ClassMethod $classMethod): bool
     {
         $classReflection = $this->reflectionResolver->resolveClassReflection($classMethod);
+
         if (! $classReflection instanceof ClassReflection) {
             return false;
         }
 
         $ancestors = array_filter(
             $classReflection->getAncestors(),
-            fn (ClassReflection $ancestorClassReflection): bool =>
-            $classReflection->getName() !== $ancestorClassReflection->getName()
+            fn (ClassReflection $ancestorClassReflection): bool => $classReflection->getName() !== $ancestorClassReflection->getName()
         );
 
         $methodName = $this->getName($classMethod);
+
         foreach ($ancestors as $ancestor) {
             if ($ancestor->getFileName() === null) {
                 continue;
@@ -209,11 +212,19 @@ private function hasParentMethodWithNonObjectReturn(ClassMethod $classMethod): b
                 continue;
             }
 
-            $parentMethod = $ancestor->getNativeMethod($methodName);
-            $parentReturnType = $parentMethod->getVariants()[0]
-                ->getReturnType();
+            $parentClassMethod = $this->astResolver->resolveClassMethod($ancestor->getName(), $methodName);
+
+            if ($parentClassMethod === null) {
+                continue;
+            }
+
+            $parentReturnType = $parentClassMethod->returnType;
+
+            if ($parentReturnType === null) {
+                continue;
+            }
 
-            if ($parentReturnType->isObject()->yes() && $parentReturnType->getObjectClassNames() === []) {
+            if ($parentReturnType instanceof Identifier && $parentReturnType->name === 'object') {
                 continue;
             }