New in Symfony 6.1: Improvements Related to Types

UIDs Controller Resolver

Contributed by
Thomas Calvet

in #44665.

Symfony provides argument value resolvers to transform certain arguments of
controller methods into other objects. That’s how you can get for example the
current request object just by typing any argument with the Response class.

In Symfony 6.1 we’re add a new resolver to transform UID values into UID objects.
For example, in previous Symfony versions you need to do this to get a UUID v4
from a controller argument:

#[Route(path: ‚/token/{token}‘)]
public function someControllerMethod(string $token): Response
$token = UuidV4::fromRfc4122($token);
// …

In Symfony 6.1 you can do the same type-hinting the controller argument with the
type of object you want to receive:

use SymfonyComponentUidUuidV4;

#[Route(path: ‚/token/{token}‘)]
public function someControllerMethod(UuidV4 $token): Response
// …

Support for Mutation of Constructor Promoted Properties

Contributed by
Raphaƫl Voisin

in #45062.

Starting from PHP 8.0, you can use constructor property promotion to declare
properties directly in the constructor signature. However, you can use PHPdoc
annotations to change the type of the properties. In Symfony 6.1 we’ve improved
the PropertyInfo component to take into account those PHPdoc modifications.

In the following example, the type of $someProperty will be reported as
string instead of mixed:

class SomeClass
* @param string $someProperty

public function __construct(private mixed $someProperty)

Backend Enums Controller Resolver

Contributed by
Maxime Steinhausser

in #44831.

Another controller argument resolver added in Symfony 6.1 allows to transform
arguments into backend enums cases. Take for example the well-known Suit
enum example:

namespace AppModel;

enum Suit: string
case Hearts = ‚H‘;
case Diamonds = ‚D‘;
case Clubs = ‚C‘;
case Spades = ‚S‘;

In Symfony 6.1 you can use Suit as the type of the controller argument. If
the route parameter matches any of the enum values, Symfony will inject the
enum case. Otherwise, it will return a 404 HTTP error:

class CardController
public function list(Suit $suit): Response
// …

PHPStan Pseudo-Types Support

Contributed by
Emil Masiakowski

in #44451.

Thanks to the popularity of static analyzers such as PHPStan, more and more
developers use pseudo-types that describe arguments and return values with more

For example, instead of string you can use non-empty-string; instead of
int you can use positiveInt; instead of int|float you can use number,
etc. In Symfony 6.1 we’ve improved the PropertyInfo to properly infer the right
PHP type of a variable described with these pseudo-types:

class SomeClass
/** @var negative-int */
public $property1;

/** @var non-empty-array */
public $property2;

/** @var non-empty-list */
public $property3;

/** @var non-empty-lowercase-string */
public $property4;

In Symfony 6.1, the PHP type of these properties will be correctly inferred as
integer, array, array and string respectively.

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