Larastan: Support for states on new Laravel 8 factories

[JeroenVanOort]

• Larastan Version: 0.6.4
• --level used: max

Description

It's seems that states on the new factories that came with Laravel 8 are not yet supported.

It would be nice if we could deduct the return type of the Model::factory() method, added by the HasFactory trait.

Laravel code where the issue was found

User::factory()->expired()->create();

I would love to help out, but I haven't got a clue where to start. If anyone could guide me, I'm very much willing to put some time and effort into this.

[Daanra]

I would love to help out, but I haven't got a clue where to start. If anyone could guide me, I'm very much willing to put some time and effort into this.

One way of doing this would be to write a DynamicStaticMethodReturnTypeExtension.

Here's an example of one https://github.com/nunomaduro/larastan/blob/master/src/ReturnTypes/StorageDynamicStaticMethodReturnTypeExtension.php

See also: https://phpstan.org/developing-extensions/dynamic-return-type-extensions

The class could look something like this:

public function getClass(): string
{
     return Model::class;
}

public function isStaticMethodSupported(MethodReflection $methodReflection): bool
{
     return $methodReflection->getName() === 'factory';
}

public function getTypeFromStaticMethodCall(
    MethodReflection $methodReflection,
    StaticCall $methodCall,
    Scope $scope
): Type {
    $modelName = $methodReflection->getDeclaringClass()->getName();
    // Here you have to determine $factoryName from $modelName
    return new ObjectType($factoryName);
}

I haven't worked a lot with the new factories yet, so I'm not sure if there are any caveats, but I think this should be enough to make it work.

[robbplo]

I've been spending some time on this, I've got the return type resolving the correct factory but it's still in a union type with the base factory. When i have more time I'll try to fix this.

[mrsamse]

For all those who currently have this problem: I solved it by specifying the static method factory with a specified return value in the PHPDoc:

/**
 * @method static UserFactory factory(mixed $parameters)
 */
class User extends Model
{
    use HasFactory;
}