Fix false positive comparing identical generic types below level 8

phpstan-baseline.neon

@@ -708,6 +708,12 @@ parameters:
 			count: 2
 			path: src/Rules/RuleErrorBuilder.php
 
+		-
+			rawMessage: Doing instanceof PHPStan\Type\Generic\GenericObjectType is error-prone and deprecated.
+			identifier: phpstanApi.instanceofType
+			count: 1
+			path: src/Rules/RuleLevelHelper.php
+
 		-
 			rawMessage: Doing instanceof PHPStan\Type\IntersectionType is error-prone and deprecated.
 			identifier: phpstanApi.instanceofType

src/Rules/RuleLevelHelper.php

@@ -6,11 +6,13 @@
 use PHPStan\Analyser\Scope;
 use PHPStan\DependencyInjection\AutowiredParameter;
 use PHPStan\DependencyInjection\AutowiredService;
+use PHPStan\Reflection\ParametersAcceptor;
 use PHPStan\Reflection\ReflectionProvider;
 use PHPStan\Type\BenevolentUnionType;
 use PHPStan\Type\CallableType;
 use PHPStan\Type\ClosureType;
 use PHPStan\Type\ErrorType;
+use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\Generic\TemplateMixedType;
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\MixedType;
@@ -49,6 +51,29 @@ public function __construct(
 	{
 	}
 
+	/**
+	 * @param callable(Type): Type $traverse
+	 */
+	private function traverseWithoutMapping(Type $type, ?Type $acceptingType, callable $traverse): Type
+	{
+		if ($type instanceof GenericObjectType && $acceptingType !== null) {
+			return $type->traverseSimultaneously($acceptingType, function (Type $type, Type $acceptingType) use ($traverse): Type {
+				if (
+					!$this->checkNullables
+					&& !$type instanceof BenevolentUnionType
+					&& TypeCombinator::containsNull($type)
+					&& !TypeCombinator::containsNull($acceptingType)
+				) {
+					return $traverse(TypeCombinator::removeNull($type));
+				}
+
+				return $type;
+			});
+		}
+
+		return $traverse($type);
+	}
+
 	/** @api */
 	public function isThis(Expr $expression): bool
 	{
@@ -93,9 +118,10 @@ private function transformAcceptedType(Type $acceptingType, Type $acceptedType):
 					return $acceptedType;
 				}
 
+				$acceptingReturnType = $acceptingType instanceof ParametersAcceptor ? $acceptingType->getReturnType() : null;
 				return new CallableType(
 					$acceptedType->getParameters(),
-					$traverse($acceptedType->getReturnType()),
+					$this->traverseWithoutMapping($acceptedType->getReturnType(), $acceptingReturnType, $traverse),
 					$acceptedType->isVariadic(),
 					$acceptedType->getTemplateTypeMap(),
 					$acceptedType->getResolvedTemplateTypeMap(),
@@ -109,9 +135,10 @@ private function transformAcceptedType(Type $acceptingType, Type $acceptedType):
 					return $acceptedType;
 				}
 
+				$acceptingReturnType = $acceptingType instanceof ParametersAcceptor ? $acceptingType->getReturnType() : null;
 				return new ClosureType(
 					$acceptedType->getParameters(),
-					$traverse($acceptedType->getReturnType()),
+					$this->traverseWithoutMapping($acceptedType->getReturnType(), $acceptingReturnType, $traverse),
 					$acceptedType->isVariadic(),
 					$acceptedType->getTemplateTypeMap(),
 					$acceptedType->getResolvedTemplateTypeMap(),
@@ -127,6 +154,10 @@ private function transformAcceptedType(Type $acceptingType, Type $acceptedType):
 				);
 			}
 
+			if ($acceptedType instanceof GenericObjectType) {
+				return $this->traverseWithoutMapping($acceptedType, $acceptingType, $traverse);
+			}
+
 			if (
 				!$this->checkNullables
 				&& !$acceptingType instanceof NullType

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -20,6 +20,8 @@
 class CallToFunctionParametersRuleTest extends RuleTestCase
 {
 
+	private bool $checkNullables = true;
+
 	private bool $checkExplicitMixed = false;
 
 	private bool $checkImplicitMixed = false;
@@ -32,7 +34,7 @@ protected function getRule(): Rule
 			new FunctionCallParametersCheck(
 				new RuleLevelHelper(
 					$broker,
-					checkNullables: true,
+					checkNullables: $this->checkNullables,
 					checkThisOnly: false,
 					checkUnionTypes: true,
 					checkExplicitMixed: $this->checkExplicitMixed,
@@ -3109,4 +3111,16 @@ public function testBug15168(): void
 		$this->analyse([__DIR__ . '/data/bug-15168.php'], []);
 	}
 
+	public function testBug9377(): void
+	{
+		$this->checkNullables = false;
+		$this->analyse([__DIR__ . '/data/bug-9377.php'], []);
+	}
+
+	public function testBug11041(): void
+	{
+		$this->checkNullables = false;
+		$this->analyse([__DIR__ . '/data/bug-11041.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Functions/ClosureReturnTypeRuleTest.php

@@ -13,12 +13,14 @@
 class ClosureReturnTypeRuleTest extends RuleTestCase
 {
 
+	private bool $checkNullables = true;
+
 	protected function getRule(): Rule
 	{
 		return new ClosureReturnTypeRule(new FunctionReturnTypeCheck(
 			new RuleLevelHelper(
 				self::createReflectionProvider(),
-				checkNullables: true,
+				checkNullables: $this->checkNullables,
 				checkThisOnly: false,
 				checkUnionTypes: true,
 				checkExplicitMixed: false,
@@ -154,4 +156,10 @@ public function testBug14914(): void
 		$this->analyse([__DIR__ . '/data/bug-14914.php'], []);
 	}
 
+	public function testBug12008(): void
+	{
+		$this->checkNullables = false;
+		$this->analyse([__DIR__ . '/data/bug-12008.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Functions/data/bug-11041.php

@@ -0,0 +1,41 @@
+<?php // lint >= 7.4
+
+declare(strict_types = 1);
+
+namespace Bug11041;
+
+/**
+ * @template TKey
+ * @template TValue
+ */
+class Collection
+{
+
+	/** @var array<TKey, TValue> */
+	private array $items;
+
+	/** @param array<TKey, TValue> $items */
+	public function __construct(array $items)
+	{
+		$this->items = $items;
+	}
+
+	/**
+	 * @param TKey $key
+	 * @return TValue
+	 */
+	public function get($key)
+	{
+		return $this->items[$key];
+	}
+
+}
+
+/** @param Collection<int, string|null> $collection */
+function testFunc(Collection $collection): void
+{
+}
+
+$collection = new Collection([0 => 'foo', 1 => 'bar', 2 => null, 3 => 'baz']);
+
+testFunc($collection);

tests/PHPStan/Rules/Functions/data/bug-12008.php

@@ -0,0 +1,54 @@
+<?php // lint >= 8.2
+
+declare(strict_types = 1);
+
+namespace Bug12008;
+
+use Closure;
+
+interface ProductOverview
+{
+
+	public function getId(): ?int;
+
+}
+
+/**
+ * @template T
+ */
+readonly class Pagination
+{
+
+	/**
+	 * @param iterable<T> $records
+	 */
+	public function __construct(
+		public iterable $records,
+	)
+	{
+	}
+
+}
+
+class HelloWorld
+{
+
+	private function respondToApiRequest(Closure|null $data): never
+	{
+		exit;
+	}
+
+	/** @param list<ProductOverview> $products */
+	public function run(array $products): never
+	{
+		$this->respondToApiRequest(function () use ($products) {
+			return new Pagination(array_map(
+				fn (ProductOverview $product) => [
+					'id' => $product->getId(),
+				],
+				$products,
+			));
+		});
+	}
+
+}

tests/PHPStan/Rules/Functions/data/bug-9377.php

@@ -0,0 +1,26 @@
+<?php declare(strict_types = 1);
+
+namespace Bug9377;
+
+/**
+ * @template T
+ */
+class HelloWorld
+{
+
+}
+
+/** @param HelloWorld<array{id: int|null}> $foo */
+function foo($foo): void
+{
+}
+
+/** @return HelloWorld<array{id: int|null}> */
+function bar(): HelloWorld
+{
+	return new HelloWorld();
+}
+
+$a = bar();
+
+foo($a);

tests/PHPStan/Rules/Methods/CallMethodsRuleTest.php

@@ -3023,6 +3023,42 @@ public function testCallablesWithoutCheckNullables(bool $checkNullables, bool $c
 		$this->analyse([__DIR__ . '/data/callables-without-check-nullables.php'], $expectedErrors);
 	}
 
+	public static function dataGenericArgumentNullability(): iterable
+	{
+		yield [false, [
+			[
+				'Parameter #1 $collection of method GenericArgumentNullability\\Foo::acceptNullable() expects GenericArgumentNullability\\Collection<string, int|null>, GenericArgumentNullability\\Collection<string, int> given.',
+				75,
+				'Template type TValue on class GenericArgumentNullability\\Collection is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
+			],
+		]];
+		yield [true, [
+			[
+				'Parameter #1 $collection of method GenericArgumentNullability\\Foo::acceptPlain() expects GenericArgumentNullability\\Collection<string, int>, GenericArgumentNullability\\Collection<string, int|null> given.',
+				74,
+			],
+			[
+				'Parameter #1 $collection of method GenericArgumentNullability\\Foo::acceptNullable() expects GenericArgumentNullability\\Collection<string, int|null>, GenericArgumentNullability\\Collection<string, int> given.',
+				75,
+				'Template type TValue on class GenericArgumentNullability\\Collection is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
+			],
+			[
+				'Parameter #1 $collection of method GenericArgumentNullability\\Foo::acceptCovariantPlain() expects GenericArgumentNullability\\CovariantCollection<int>, GenericArgumentNullability\\CovariantCollection<int|null> given.',
+				76,
+			],
+		]];
+	}
+
+	/** @param list<array{0: string, 1: int, 2?: string|null}> $expectedErrors */
+	#[DataProvider('dataGenericArgumentNullability')]
+	public function testGenericArgumentNullability(bool $checkNullables, array $expectedErrors): void
+	{
+		$this->checkThisOnly = false;
+		$this->checkNullables = $checkNullables;
+		$this->checkUnionTypes = true;
+		$this->analyse([__DIR__ . '/data/generic-argument-nullability.php'], $expectedErrors);
+	}
+
 	#[RequiresPhp('>= 8.0.0')]
 	public function testBug8713(): void
 	{

tests/PHPStan/Rules/Methods/CallStaticMethodsRuleTest.php

@@ -25,6 +25,8 @@
 class CallStaticMethodsRuleTest extends RuleTestCase
 {
 
+	private bool $checkNullables = true;
+
 	private bool $checkThisOnly;
 
 	private bool $checkExplicitMixed = false;
@@ -36,7 +38,7 @@ protected function getRule(): Rule
 		$reflectionProvider = self::createReflectionProvider();
 		$ruleLevelHelper = new RuleLevelHelper(
 			$reflectionProvider,
-			checkNullables: true,
+			checkNullables: $this->checkNullables,
 			checkThisOnly: $this->checkThisOnly,
 			checkUnionTypes: true,
 			checkExplicitMixed: $this->checkExplicitMixed,
@@ -1084,4 +1086,11 @@ public function testBug12827(): void
 		]);
 	}
 
+	public function testBug10698(): void
+	{
+		$this->checkThisOnly = false;
+		$this->checkNullables = false;
+		$this->analyse([__DIR__ . '/data/bug-10698.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Methods/ReturnTypeRuleTest.php

@@ -16,6 +16,8 @@
 class ReturnTypeRuleTest extends RuleTestCase
 {
 
+	private bool $checkNullables = true;
+
 	private bool $checkExplicitMixed = false;
 
 	private bool $checkUnionTypes = true;
@@ -27,7 +29,7 @@ protected function getRule(): Rule
 		return new ReturnTypeRule(new FunctionReturnTypeCheck(
 			new RuleLevelHelper(
 				self::createReflectionProvider(),
-				checkNullables: true,
+				checkNullables: $this->checkNullables,
 				checkThisOnly: false,
 				checkUnionTypes: $this->checkUnionTypes,
 				checkExplicitMixed: $this->checkExplicitMixed,
@@ -1364,4 +1366,10 @@ public function testBug14893(): void
 		$this->analyse([__DIR__ . '/data/bug-14893.php'], []);
 	}
 
+	public function testBug12984(): void
+	{
+		$this->checkNullables = false;
+		$this->analyse([__DIR__ . '/data/bug-12984.php'], []);
+	}
+
 }