fix: can create inversed one to one

[nikophil]

fixes #655

[nikophil]

I'm wondering if it is OK to return null here.
Can a "OneToOne" relationship be "not nullable" on the both sides of the relationship?

EDIT: I think it can:

#[Entity]
class Contact
{
    #[ORM\OneToOne(targetEntity: Address::class, inversedBy: 'contact')]
    #[ORM\JoinColumn(nullable: false)]
    public Address $address;

    public function __construct()
    {
        $this->address = new Address($this);
    }
}

#[Entity]
class Address
{
    public function __construct(
	    #[ORM\OneToOne(targetEntity: Contact::class, mappedBy: 'address')]
	    public Contact $contact;
    ) {}
}

and then, it would not be valid to return null here 🤷

[nikophil]

I think this very specific case, where both side of OneToOne are mandatory, could not be fixed : it is a circular dependency. Maybe we could find a way to emit a meaningful error for the user?

Also, maybe we could find a way to return something else than null here: in Foundry2, we used to return a PostPersistCallback which was not added to the normalized parameters. Maybe we could mimic this (but it would complexify the whole normalization phase)

BTW, I just figured out that you did notice this case was error prone: https://github.com/zenstruck/foundry/blob/2.x/tests/Integration/ORM/EntityFactoryRelationshipTestCase.php#L183

[kbond]

Yes, I don't remember the exact context of what happened but I think you're right, it's the circular dependency issue.

[nikophil]

need to fix this, to mimic how it is done with orm v3