is_a(): support class-string in parameter $class

Author: jiripudil

src/Type/Php/IsAFunctionTypeSpecifyingExtension.php

@@ -57,6 +57,9 @@ public function specifyTypes(FunctionReflection $functionReflection, FuncCall $n
 		} elseif ($classNameArgExprType instanceof ConstantStringType) {
 			$objectType = new ObjectType($classNameArgExprType->getValue());
 			$types = $this->typeSpecifier->create($node->args[0]->value, $objectType, $context);
+		} elseif ($classNameArgExprType instanceof GenericClassStringType) {
+			$objectType = $classNameArgExprType->getGenericType();
+			$types = $this->typeSpecifier->create($node->args[0]->value, $objectType, $context);
 		} elseif ($context->true()) {
 			$objectType = new ObjectWithoutClassType();
 			$types = $this->typeSpecifier->create($node->args[0]->value, $objectType, $context);

tests/PHPStan/Analyser/TypeSpecifierTest.php

@@ -17,7 +17,9 @@
 use PhpParser\Node\Scalar\String_;
 use PhpParser\Node\VarLikeIdentifier;
 use PHPStan\Type\ArrayType;
+use PHPStan\Type\ClassStringType;
 use PHPStan\Type\Constant\ConstantBooleanType;
+use PHPStan\Type\Generic\GenericClassStringType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\NullType;
 use PHPStan\Type\ObjectType;
@@ -57,6 +59,8 @@ protected function setUp(): void
 		$this->scope = $this->scope->assignVariable('stringOrFalse', new UnionType([new StringType(), new ConstantBooleanType(false)]));
 		$this->scope = $this->scope->assignVariable('array', new ArrayType(new MixedType(), new MixedType()));
 		$this->scope = $this->scope->assignVariable('foo', new MixedType());
+		$this->scope = $this->scope->assignVariable('classString', new ClassStringType());
+		$this->scope = $this->scope->assignVariable('genericClassString', new GenericClassStringType(new ObjectType('Bar')));
 	}
 
 	/**
@@ -437,6 +441,22 @@ public function dataCondition(): array
 				['$foo' => 'static(DateTime)'],
 				['$foo' => '~static(DateTime)'],
 			],
+			[
+				new FuncCall(new Name('is_a'), [
+					new Arg(new Variable('foo')),
+					new Arg(new Variable('classString')),
+				]),
+				['$foo' => 'object'],
+				[],
+			],
+			[
+				new FuncCall(new Name('is_a'), [
+					new Arg(new Variable('foo')),
+					new Arg(new Variable('genericClassString')),
+				]),
+				['$foo' => 'Bar'],
+				['$foo' => '~Bar'],
+			],
 			[
 				new FuncCall(new Name('is_a'), [
 					new Arg(new Variable('foo')),