Symfony version(s) affected

5.3.x

Description

Java Bean validation can be applied on method argument in a MVC Controller or other Jakarta EE components, but this does not work in Symfony.

I got the following exception when adding attributes on method arguments of a Controller.

 Uncaught Error: Attribute "Symfony\Component\Validator\Constraints\PositiveOrZero" cannot target parameter (allowed targets: method, prop
erty)

How to reproduce

Create a method like this.

  #[Route(path: "", name: "all", methods: ["GET"])]
  function all(string $keyword, #[PositiveOrZero] int $offset = 0, #[Positive] int $limit = 20): Response
  {
      $data = $this->posts->findByKeyword($keyword||'', $offset, $limit);
      return $this->json($data);
  }

Possible Solution

Make it work, and if validation failed throws an ContraintsVoilationException.

Additional Context

Add a built-in EventListener to handle this exception by default.