Fix ReflectionClassIsSubclassOfTypeSpecifyingExtension

Author: ondrejmirtes

src/Type/Php/ReflectionClassIsSubclassOfTypeSpecifyingExtension.php

@@ -12,6 +12,7 @@
 use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\MethodTypeSpecifyingExtension;
 use PHPStan\Type\ObjectWithoutClassType;
+use PHPStan\Type\TypeCombinator;
 use ReflectionClass;
 
 final class ReflectionClassIsSubclassOfTypeSpecifyingExtension implements MethodTypeSpecifyingExtension, TypeSpecifierAwareExtension
@@ -46,20 +47,11 @@ public function specifyTypes(MethodReflection $methodReflection, MethodCall $nod
 
 		$valueType = $scope->getType($node->getArgs()[0]->value);
 		$objectType = $valueType->getClassStringObjectType();
-		$narrowingType = new GenericObjectType(ReflectionClass::class, [$objectType]);
 
-		if (!$reflectionType->isSuperTypeOf($objectType)->yes()) {
-			// cause "always false" error
-			return $this->typeSpecifier->create(
-				$node->var,
-				$narrowingType,
-				$context,
-				$scope,
-			);
-		}
+		$intersected = TypeCombinator::intersect($reflectionType, $objectType);
+		$narrowingType = new GenericObjectType(ReflectionClass::class, [$intersected]);
 
-		if ($objectType->isSuperTypeOf($reflectionType)->yes()) {
-			// cause "always true" error
+		if ($reflectionType->isSuperTypeOf($objectType)->no()) {
 			return $this->typeSpecifier->create(
 				$node->var,
 				$narrowingType,

tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeMethodCallRuleTest.php

@@ -259,21 +259,21 @@ public function testBug12473(): void
 		$this->treatPhpDocTypesAsCertain = true;
 		$tip = 'Because the type is coming from a PHPDoc, you can turn off this check by setting <fg=cyan>treatPhpDocTypesAsCertain: false</> in your <fg=cyan>%configurationFile%</>.';
 		$this->analyse([__DIR__ . '/data/bug-12473.php'], [
-			[
+			/*[
 				'Call to method ReflectionClass<Bug12473\\Picture>::isSubclassOf() with \'Bug12473\\\\Picture\' will always evaluate to true.',
 				39,
 				$tip,
-			],
+			],*/
 			[
 				'Call to method ReflectionClass<Bug12473\\PictureUser>::isSubclassOf() with \'Bug12473\\\\PictureProduct\' will always evaluate to false.',
 				49,
 				$tip,
 			],
-			[
+			/*[
 				'Call to method ReflectionClass<Bug12473\\PictureUser>::isSubclassOf() with \'Bug12473\\\\PictureUser\' will always evaluate to true.',
 				59,
 				$tip,
-			],
+			],*/
 		]);
 	}
 

tests/PHPStan/Rules/Comparison/data/bug-12473.php

@@ -60,3 +60,14 @@ function doFoo3(string $a): void {
 
 	}
 }
+
+/**
+ * @param ReflectionClass<object> $a
+ * @param class-string<object> $b
+ * @return void
+ */
+function doFoo4(ReflectionClass $a, string $b): void {
+	if ($a->isSubclassOf($b)) {
+
+	}
+};