Introduce class_implements dynamic return type

conf/config.neon

@@ -1637,6 +1637,11 @@ services:
 		tags:
 			- phpstan.typeSpecifier.functionTypeSpecifyingExtension
 
+	-
+		class: PHPStan\Type\Php\ClassImplementsFunctionReturnTypeExtension
+		tags:
+			- phpstan.broker.dynamicFunctionReturnTypeExtension
+
 	-
 		class: PHPStan\Type\Php\DefineConstantTypeSpecifyingExtension
 		tags:

resources/functionMap.php

@@ -948,9 +948,9 @@
 'chunk_split' => ['string', 'str'=>'string', 'chunklen='=>'positive-int', 'ending='=>'string'],
 'class_alias' => ['bool', 'user_class_name'=>'string', 'alias_name'=>'string', 'autoload='=>'bool'],
 'class_exists' => ['bool', 'classname'=>'string', 'autoload='=>'bool'],
-'class_implements' => ['array<string,class-string>|false', 'what'=>'object|string', 'autoload='=>'bool'],
+'class_implements' => ['array<string,interface-string>|false', 'what'=>'object|string', 'autoload='=>'bool'],
 'class_parents' => ['array<string,class-string>|false', 'instance'=>'object|string', 'autoload='=>'bool'],
-'class_uses' => ['array<string,string>|false', 'what'=>'object|string', 'autoload='=>'bool'],
+'class_uses' => ['array<string,trait-string>|false', 'what'=>'object|string', 'autoload='=>'bool'],
 'classkit_import' => ['array', 'filename'=>'string'],
 'classkit_method_add' => ['bool', 'classname'=>'string', 'methodname'=>'string', 'args'=>'string', 'code'=>'string', 'flags='=>'int'],
 'classkit_method_copy' => ['bool', 'dclass'=>'string', 'dmethod'=>'string', 'sclass'=>'string', 'smethod='=>'string'],

src/Type/Php/ClassImplementsFunctionReturnTypeExtension.php

@@ -0,0 +1,61 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Php;
+
+use PhpParser\Node\Expr\FuncCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\FunctionReflection;
+use PHPStan\Reflection\ParametersAcceptorSelector;
+use PHPStan\Type\ClassStringType;
+use PHPStan\Type\Constant\ConstantBooleanType;
+use PHPStan\Type\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\ObjectWithoutClassType;
+use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
+use PHPStan\Type\UnionType;
+use function count;
+use function in_array;
+
+class ClassImplementsFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
+{
+
+	public function isFunctionSupported(FunctionReflection $functionReflection): bool
+	{
+		return in_array(
+			$functionReflection->getName(),
+			['class_implements', 'class_uses', 'class_parents'],
+			true,
+		);
+	}
+
+	public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): ?Type
+	{
+		if (count($functionCall->getArgs()) < 1) {
+			return null;
+		}
+
+		$firstArgType = $scope->getType($functionCall->getArgs()[0]->value);
+		$autoload = !isset($functionCall->getArgs()[1])
+			|| $scope->getType($functionCall->getArgs()[1]->value)->equals(new ConstantBooleanType(true));
+
+		$isObject = (new ObjectWithoutClassType())->isSuperTypeOf($firstArgType);
+
+		$objectOrClassString = (new UnionType([new ObjectWithoutClassType(), new ClassStringType()]));
+		if (
+			$autoload && $objectOrClassString->isSuperTypeOf($firstArgType)->yes()
+			|| $isObject->yes()
+		) {
+			return TypeCombinator::remove(
+				ParametersAcceptorSelector::selectSingle($functionReflection->getVariants())->getReturnType(),
+				new ConstantBooleanType(false),
+			);
+		}
+
+		if ($isObject->no() && $firstArgType->isClassStringType()->no()) {
+			return new ConstantBooleanType(false);
+		}
+
+		return null;
+	}
+
+}

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -492,6 +492,7 @@ public function dataFileAsserts(): iterable
 		}
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/class-constant-types.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/class-implements.php');
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-3379.php');
 

tests/PHPStan/Analyser/data/class-implements.php

@@ -0,0 +1,128 @@
+<?php
+
+namespace ClassImplements;
+
+use function PHPStan\Testing\assertType;
+
+class ClassImplements
+{
+	/**
+	 * @param object|class-string $objectOrClassString
+	 * @param class-string $classString
+	 */
+	public function test(
+		object $object,
+		object|string $objectOrClassString,
+		object|string $objectOrString,
+		string $classString,
+		string $className,
+		bool $bool,
+		mixed $mixed,
+	): void {
+		assertType('array<string, class-string>', class_implements($object));
+		assertType('array<string, class-string>', class_implements($objectOrClassString));
+		assertType('array<string, class-string>|false', class_implements($objectOrString));
+		assertType('array<string, class-string>', class_implements($classString));
+		assertType('array<string, class-string>|false', class_implements($className));
+		assertType('false', class_implements('thisIsNotAClass'));
+
+		assertType('array<string, class-string>', class_implements($object, true));
+		assertType('array<string, class-string>', class_implements($objectOrClassString, true));
+		assertType('array<string, class-string>|false', class_implements($objectOrString, true));
+		assertType('array<string, class-string>', class_implements($classString, true));
+		assertType('array<string, class-string>|false', class_implements($className, true));
+		assertType('false', class_implements('thisIsNotAClass', true));
+
+		assertType('array<string, class-string>', class_implements($object, false));
+		assertType('array<string, class-string>|false', class_implements($objectOrClassString, false));
+		assertType('array<string, class-string>|false', class_implements($objectOrString, false));
+		assertType('array<string, class-string>|false', class_implements($classString, false));
+		assertType('array<string, class-string>|false', class_implements($className, false));
+		assertType('false', class_implements('thisIsNotAClass', false));
+
+		assertType('array<string, class-string>', class_implements($object, $bool));
+		assertType('array<string, class-string>|false', class_implements($objectOrClassString, $bool));
+		assertType('array<string, class-string>|false', class_implements($objectOrString, $bool));
+		assertType('array<string, class-string>|false', class_implements($classString, $bool));
+		assertType('array<string, class-string>|false', class_implements($className, $bool));
+		assertType('false', class_implements('thisIsNotAClass', $bool));
+
+		assertType('array<string, class-string>', class_implements($object, $mixed));
+		assertType('array<string, class-string>|false', class_implements($objectOrClassString, $mixed));
+		assertType('array<string, class-string>|false', class_implements($objectOrString, $mixed));
+		assertType('array<string, class-string>|false', class_implements($classString, $mixed));
+		assertType('array<string, class-string>|false', class_implements($className, $mixed));
+		assertType('false', class_implements('thisIsNotAClass', $mixed));
+
+		assertType('array<string, class-string>', class_uses($object));
+		assertType('array<string, class-string>', class_uses($objectOrClassString));
+		assertType('array<string, class-string>|false', class_uses($objectOrString));
+		assertType('array<string, class-string>', class_uses($classString));
+		assertType('array<string, class-string>|false', class_uses($className));
+		assertType('false', class_uses('thisIsNotAClass'));
+
+		assertType('array<string, class-string>', class_uses($object, true));
+		assertType('array<string, class-string>', class_uses($objectOrClassString, true));
+		assertType('array<string, class-string>|false', class_uses($objectOrString, true));
+		assertType('array<string, class-string>', class_uses($classString, true));
+		assertType('array<string, class-string>|false', class_uses($className, true));
+		assertType('false', class_uses('thisIsNotAClass', true));
+
+		assertType('array<string, class-string>', class_uses($object, false));
+		assertType('array<string, class-string>|false', class_uses($objectOrClassString, false));
+		assertType('array<string, class-string>|false', class_uses($objectOrString, false));
+		assertType('array<string, class-string>|false', class_uses($classString, false));
+		assertType('array<string, class-string>|false', class_uses($className, false));
+		assertType('false', class_uses('thisIsNotAClass', false));
+
+		assertType('array<string, class-string>', class_uses($object, $bool));
+		assertType('array<string, class-string>|false', class_uses($objectOrClassString, $bool));
+		assertType('array<string, class-string>|false', class_uses($objectOrString, $bool));
+		assertType('array<string, class-string>|false', class_uses($classString, $bool));
+		assertType('array<string, class-string>|false', class_uses($className, $bool));
+		assertType('false', class_uses('thisIsNotAClass', $bool));
+
+		assertType('array<string, class-string>', class_uses($object, $mixed));
+		assertType('array<string, class-string>|false', class_uses($objectOrClassString, $mixed));
+		assertType('array<string, class-string>|false', class_uses($objectOrString, $mixed));
+		assertType('array<string, class-string>|false', class_uses($classString, $mixed));
+		assertType('array<string, class-string>|false', class_uses($className, $mixed));
+		assertType('false', class_uses('thisIsNotAClass', $mixed));
+
+		assertType('array<string, class-string>', class_parents($object));
+		assertType('array<string, class-string>', class_parents($objectOrClassString));
+		assertType('array<string, class-string>|false', class_parents($objectOrString));
+		assertType('array<string, class-string>', class_parents($classString));
+		assertType('array<string, class-string>|false', class_parents($className));
+		assertType('false', class_parents('thisIsNotAClass', $className));
+
+		assertType('array<string, class-string>', class_parents($object, true));
+		assertType('array<string, class-string>', class_parents($objectOrClassString, true));
+		assertType('array<string, class-string>|false', class_parents($objectOrString, true));
+		assertType('array<string, class-string>', class_parents($classString, true));
+		assertType('array<string, class-string>|false', class_parents($className, true));
+		assertType('false', class_parents('thisIsNotAClass', true));
+
+		assertType('array<string, class-string>', class_parents($object, false));
+		assertType('array<string, class-string>|false', class_parents($objectOrClassString, false));
+		assertType('array<string, class-string>|false', class_parents($objectOrString, false));
+		assertType('array<string, class-string>|false', class_parents($classString, false));
+		assertType('array<string, class-string>|false', class_parents($className, false));
+		assertType('false', class_parents('thisIsNotAClass', false));
+
+		assertType('array<string, class-string>', class_parents($object, $bool));
+		assertType('array<string, class-string>|false', class_parents($objectOrClassString, $bool));
+		assertType('array<string, class-string>|false', class_parents($objectOrString, $bool));
+		assertType('array<string, class-string>|false', class_parents($classString, $bool));
+		assertType('array<string, class-string>|false', class_parents($className, $bool));
+		assertType('false', class_parents('thisIsNotAClass', $bool));
+
+		assertType('array<string, class-string>', class_parents($object, $mixed));
+		assertType('array<string, class-string>|false', class_parents($objectOrClassString, $mixed));
+		assertType('array<string, class-string>|false', class_parents($objectOrString, $mixed));
+		assertType('array<string, class-string>|false', class_parents($classString, $mixed));
+		assertType('array<string, class-string>|false', class_parents($className, $mixed));
+		assertType('false', class_parents('thisIsNotAClass', $mixed));
+	}
+
+}

tests/PHPStan/Rules/Arrays/IterableInForeachRuleTest.php

@@ -75,4 +75,9 @@ public function testBug6564(): void
 		$this->analyse([__DIR__ . '/data/bug-6564.php'], []);
 	}
 
+	public function testBug4335(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-4335.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Arrays/data/bug-4335.php

@@ -0,0 +1,19 @@
+<?php declare(strict_types = 1);
+
+namespace Bug4335;
+
+class HelloWorld
+{
+	public function sayHello(): void
+	{
+		foreach (class_implements($this) as $k => $v) {
+			var_dump($k, $v);
+		}
+		foreach (class_parents($this) as $k => $v) {
+			var_dump($k, $v);
+		}
+		foreach (class_uses($this) as $k => $v) {
+			var_dump($k, $v);
+		}
+	}
+}