Using Lazy::whenLoaded with Larastan

[benbjurstrom]

Looking for some advice on using Lazy::whenLoaded with Larastan. Suppose I have a setup where blogposts belong to users and my BlogPostData class looks like this:

class BlogPostData extends Data
{
    public function __construct(
        public string $id,
        ...
        public Lazy|UserData $user,
    ){}

    public static function fromModel(BlogPost $bp): BlogPostData
    {
        return new self(
            id: $bp->id,
            ..
            user: Lazy::whenLoaded('user', $bp, fn() => UserData::fromModel($bp->user)),
        );
    }
}

Larastan gives the following error because $user is a non nullable parameter in my UserData::fromModel method.

 ------ ------------------------------------------------------------------------------------------------------------------------- 
  Line   Data/BlogPostData.php                                                                                                    
 ------ ------------------------------------------------------------------------------------------------------------------------- 
  41     Parameter #1 $user of static method App\Data\UserData::fromModel() expects App\Models\User, App\Models\User|null given.  
 ------ ------------------------------------------------------------------------------------------------------------------------- 

I could update UserData::fromModel() to accept a nullable param but then I'd have to throw an exception if it's not set.

    public static function fromModel(?User $user): UserData
    {
        if (!$user) {
            throw new Exception();
        }

        return new self(
            id: $user->id,

This works ok, but seems messy. Just wondering if there's a better way that I'm overlooking.
Thanks!

Edit:
Just thought of another way to tackle this by declaring a local variable in the Lazy::whenLoaded callback. Still kinda messy.

    public static function fromModel(BlogPost $bp): BlogPostData
    {
        return new self(
            id: $bp->id,
            user: Lazy::whenLoaded('user', $bp, function () use ($bp) {
                /** @var User $user */
                $user = $bp->user;
                return UserData::fromModel($user);
            }),

[Nir-An]

Hi @benbjurstrom

I think you should use from as a function to create an object because it is a magical-creation and not fromModel

this way it should handle with null value.

fn() => UserData::from($bp->user)

[benbjurstrom]

That worked, thank you!