Description

I propose extending Property Accessor with an optional feature that could enable checking whether object setter has a non-nullable parameter and would call unset($object->parameter) instead of $object->setParameter($value) if $value is null and $object implements __unset() method.

If it makes sense I would create PR for this. I prototyped it and it works but I want to discuss the idea first before creating a full PR (with tests and everything).

Motivation

Form component could use this feature and reset non-nullable properties to uninitialized state when null value is submitted for a non-nullable property. Currently when a NotNull constraint is set on a property it is only evaluated for a new object (with uninitialized properties). Once the value for the property is set (for example through Doctrine hydration) and a user submits an empty/null value the constraint is never evaluated because execution fails on Property Accessor trying to call setter with non-nullable parameter.

Example

class User
{
    private string $name;

    public function setName(string $name)
    {
        $this->name = $name;
    }

    public function __unset($property)
    {
        unset($this->$property);
    }
}

$user = new User;

$propertyAccessor->setValue($user, 'name', 'John'); // $user->setName('John') is called
$propertyAccessor->setValue($user, 'name', null); // Fatal error: User::setName(): Argument #1 ($name) must be of type string, null given

$propertyAccessor = PropertyAccess::createPropertyAccessorBuilder()
    ->enableMagicUnset()
    ->getPropertyAccessor();

$propertyAccessor->setValue($user, 'name', null); // unset($user->name) is called