Symfony version(s) affected

6.4.2

Description

When using the cascade constraint on a class with a union typed property, the ClassMetadata will give an error:
Attempted to call an undefined method named 'getName' of class 'ReflectionUnionType'.

This is caused by ClassMetadata#L201 since $property->getType() returns an ReflectionUnionType.

How to reproduce

<?php

namespace Acme;

use Symfony\Component\Validator\Constraints as Assert;

#[Assert\Cascade]
class AnotherClass 
{
     private null|FirstClass|SecondClass $value = null;
}

<?php

namespace Acme;

use Symfony\Component\Validator\Constraints as Assert;

class FirstClass 
{
     #[Assert\NotBlank]
     private ?string $value = null;
}

<?php

namespace Acme;

use Symfony\Component\Validator\Constraints as Assert;

class SecondClass 
{
     #[Assert\NotBlank]
     private ?string $value = null;
}

Possible Solution

I think we can check if the property type is instance of ReflectionUnionType and if one of the types is an array or the defined class_exists the constraint could be added.

I am busy until end of next week, i can work on a PR.

Additional Context

No response