Introduces UseFactory attribute

[christopherarter]

Description

This PR introduces a new UseFactory attribute that provides a more elegant way to associate model factories with Eloquent models using PHP 8.0+ attributes. This is especially useful for factory registration for models that are outside of the typical App\Models namespace and improves code readability (in my opinion).

Usage

<?php

namespace App\SomeFeatureDomain\Models\Comment;

use Database\Factories\CommentFactory;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Attributes\UseFactory;

#[UseFactory(CommentFactory::class)]
class Comment extends Model
{
    use HasFactory;
    // ...
}

Instead of defining a new method for newFactory(), we can simply allow developers to add the Attribute.

Automatic inverse detection

When using this attribute, the factory for the given model will automatically be set, so there is no need to define a protected $model = \App\SomeFeatureDomain\Models\Comment::class from our example above.

Completely Optional & Fully backwards compatible

This logic only runs on classes that implement this attribute. Developers are still free to define static newFactory methods as they have before.

Priority Order

The factory resolution follows this priority:

1. Static $factory property if defined
2. UseFactory attribute if present
3. Convention-based factory resolution

Requirements

• PHP 8.0+ (required for attributes support)

Testing

This PR includes tests that verify:

• Proper factory instantiation via attribute
• Automatic model name resolution

[taylorotwell]

I think I'm on board overall. Any reason you didn't just choose Factory as the attribute name? 👀

[christopherarter]

@taylorotwell No particular reason other than for an explicit name to tell the developer exactly what it does, and to follow a more action-focused naming convention of the other attributes, e.g. ScopedBy, ObservedBy. But, it's a very loosely held opinion.

Also, probably just React leaking into my brain 😅

[shaedrich]

One might name it FakeWith() or the like but neither do I think, "factory" can be made into a useful participle (FactoriedBy wouldn't be proper English and FactorizedBy sounds too complicated for what it does) nor will the alternative (e.g. FakeWith/FakedBy) be 100% intuitive and fitting.

[christopherarter]

@taylorotwell Would you like me to change to Factory instead? No biggie.

[taylorotwell]

Hmm, got it. Good point on ScopedBy, etc. I would probably name this HasFactory then @christopherarter ... errr nvm that probably isn't possible due to already having a HasFactory trait.

[shaedrich]

Hmm, got it. Good point on ScopedBy, etc. I would probably name this HasFactory then @christopherarter ... errr nvm that probably isn't possible due to already having a HasFactory trait.

Well, it's possible—it could just end up being a PITA to keep in mind to alias one of them 😂

[christopherarter]

@taylorotwell Yeah that was my conclusion as well. Which, is how I arrived at UseFactory, since it's descriptive & phrased as an action to follow that convention, and will likely seem familiar or intuitive from React pervading throughout the dev ecosystem.

Naming is hard!

[Rizky92]

I was thinking it could be named as CreateFactoryUsing since some parts use this naming terse within Laravel, albeit in methods.

<?php

namespace App\SomeFeatureDomain\Models\Comment;

use Database\Factories\CommentFactory;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Attributes\CreateFactoryUsing;

#[CreateFactoryUsing(CommentFactory::class)]
class Comment extends Model
{
    use HasFactory;
    // ...
}

[christopherarter]

@Rizky92 another good suggestion!

Just waiting to see where we land from the maintainers, and I'll be happy to update the name to whatever we land on. This will be my first contribution to core so, hoping it gets in 🤞🥹

[laserhybiz]

How about getting rid of the trait call as well? why should we need to define both the trait and the attribute

[raz-iacob]

I noticed that I still need to add
/** @use HasFactory<\Database\Factories\CommentFactory> */
for phpstan. Is this a larastan issue?

[stsepelin]

Hello,

I also noticed that PhpStorm is complaining that the factory class couldn't be found if getting rid of protected $model = \App\SomeFeatureDomain\Models\Comment::class in the factory class.

[christopherarter]

@raz-iacob @stsepelin Noted, I'll try and reproduce and fix stan 👍

[JeffreyDavidson]

@christopherarter Is there an update for this with phpstan/larastan?

[alexkart]

Hello,

I also noticed that PhpStorm is complaining that the factory class couldn't be found if getting rid of protected $model = \App\SomeFeatureDomain\Models\Comment::class in the factory class.

It's the Laravel Idea issue laravel-idea/plugin#1220