Fix ImpossibleInstanceOfRule

Author: VincentLanglet

src/Rules/Classes/ImpossibleInstanceOfRule.php

@@ -9,10 +9,13 @@
 use PHPStan\Parser\LastConditionVisitor;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\Rules\RuleLevelHelper;
 use PHPStan\Type\Constant\ConstantBooleanType;
+use PHPStan\Type\ErrorType;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\ObjectWithoutClassType;
 use PHPStan\Type\StringType;
+use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
 use PHPStan\Type\VerbosityLevel;
 use function sprintf;
@@ -25,6 +28,7 @@ final class ImpossibleInstanceOfRule implements Rule
 {
 
 	public function __construct(
+		private RuleLevelHelper $ruleLevelHelper,
 		#[AutowiredParameter]
 		private bool $treatPhpDocTypesAsCertain,
 		#[AutowiredParameter]
@@ -42,11 +46,6 @@ public function getNodeType(): string
 
 	public function processNode(Node $node, Scope $scope): array
 	{
-		$instanceofType = $this->treatPhpDocTypesAsCertain ? $scope->getType($node) : $scope->getNativeType($node);
-		if (!$instanceofType instanceof ConstantBooleanType) {
-			return [];
-		}
-
 		if ($node->class instanceof Node\Name) {
 			$className = $scope->resolveName($node->class);
 			$classType = new ObjectType($className);
@@ -56,7 +55,13 @@ public function processNode(Node $node, Scope $scope): array
 				new StringType(),
 				new ObjectWithoutClassType(),
 			);
-			if (!$allowed->isSuperTypeOf($classType)->yes()) {
+			$typeResult = $this->ruleLevelHelper->findTypeToCheck(
+				$scope,
+				$node->class,
+				'',
+				static fn (Type $type): bool => !$allowed->isSuperTypeOf($type)->yes(),
+			);
+			if (!$typeResult->getType() instanceof ErrorType && !$allowed->isSuperTypeOf($typeResult->getType())->yes()) {
 				return [
 					RuleErrorBuilder::message(sprintf(
 						'Instanceof between %s and %s results in an error.',
@@ -67,6 +72,11 @@ public function processNode(Node $node, Scope $scope): array
 			}
 		}
 
+		$instanceofType = $this->treatPhpDocTypesAsCertain ? $scope->getType($node) : $scope->getNativeType($node);
+		if (!$instanceofType instanceof ConstantBooleanType) {
+			return [];
+		}
+
 		$addTip = function (RuleErrorBuilder $ruleErrorBuilder) use ($scope, $node): RuleErrorBuilder {
 			if (!$this->treatPhpDocTypesAsCertain) {
 				return $ruleErrorBuilder;

tests/PHPStan/Rules/Classes/ImpossibleInstanceOfRuleTest.php

@@ -3,6 +3,7 @@
 namespace PHPStan\Rules\Classes;
 
 use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleLevelHelper;
 use PHPStan\Testing\RuleTestCase;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\RequiresPhp;
@@ -19,7 +20,10 @@ class ImpossibleInstanceOfRuleTest extends RuleTestCase
 
 	protected function getRule(): Rule
 	{
+		$ruleLevelHelper = new RuleLevelHelper(self::createReflectionProvider(), true, false, true, false, false, false, true);
+
 		return new ImpossibleInstanceOfRule(
+			$ruleLevelHelper,
 			$this->treatPhpDocTypesAsCertain,
 			$this->reportAlwaysTrueInLastCondition,
 			true,
@@ -151,14 +155,14 @@ public function testInstanceof(): void
 					'Instanceof between ImpossibleInstanceOf\Bar and ImpossibleInstanceOf\BarGrandChild will always evaluate to false.',
 					322,
 				],
-				/*[
+				[
 					'Instanceof between mixed and int results in an error.',
 					353,
 				],
 				[
 					'Instanceof between mixed and ImpossibleInstanceOf\InvalidTypeTest|int results in an error.',
 					362,
-				],*/
+				],
 				[
 					'Instanceof between ImpossibleInstanceOf\Foo and ImpossibleInstanceOf\Foo will always evaluate to true.',
 					388,
@@ -496,6 +500,22 @@ public function testBug3632(): void
 		]);
 	}
 
+	public function testBug10036(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+
+		$this->analyse([__DIR__ . '/data/bug-10036.php'], [
+			[
+				'Instanceof between stdClass and string|null results in an error.',
+				11,
+			],
+			[
+				'Instanceof between stdClass and string|null results in an error.',
+				19,
+			],
+		]);
+	}
+
 	#[RequiresPhp('>= 8.0')]
 	public function testNewIsAlwaysFinalClass(): void
 	{

tests/PHPStan/Rules/Classes/data/bug-10036.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Bug10036;
+
+use stdClass;
+
+class HelloWorld
+{
+	public function sayHello(?string $class): void
+	{
+		var_dump(new stdClass instanceof $class);
+	}
+
+	/**
+	 * @param string|null $class
+	 */
+	public function sayWorld($class): void
+	{
+		var_dump(new stdClass instanceof $class);
+	}
+
+	public function sayString(string $class): void
+	{
+		var_dump(new stdClass instanceof $class);
+	}
+
+	public function sayMixed(mixed $class): void
+	{
+		var_dump(new stdClass instanceof $class);
+	}
+}