Introduces UseFactory attribute

src/Illuminate/Database/Eloquent/Attributes/UseFactory.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Illuminate\Database\Eloquent\Attributes;
+
+use Attribute;
+
+#[Attribute(Attribute::TARGET_CLASS)]
+class UseFactory
+{
+    /**
+     * Create a new attribute instance.
+     *
+     * @param  string  $factoryClass
+     * @return void
+     */
+    public function __construct(public string $factoryClass) {}
+}

src/Illuminate/Database/Eloquent/Factories/HasFactory.php

@@ -1,6 +1,7 @@
 <?php
 
 namespace Illuminate\Database\Eloquent\Factories;
+use Illuminate\Database\Eloquent\Attributes\UseFactory;
 
 /**
  * @template TFactory of \Illuminate\Database\Eloquent\Factories\Factory
@@ -23,6 +24,24 @@ public static function factory($count = null, $state = [])
                     ->state(is_callable($count) || is_array($count) ? $count : $state);
     }
 
+    /**
+     * Get the factory from the UseFactory class attribute.
+     *
+     * @return TFactory|null
+     */
+    protected static function getUseFactoryAttribute()
+    {
+        $attributes = (new \ReflectionClass(static::class))
+            ->getAttributes(UseFactory::class);
+
+        if (!empty($attributes)) {
+            $useFactory = $attributes[0]->newInstance();
+            $factory = new $useFactory->factoryClass;
+            $factory->guessModelNamesUsing(fn() => static::class);
+            return $factory;
+        }
+    }
+
     /**
      * Create a new factory instance for the model.
      *
@@ -34,6 +53,10 @@ protected static function newFactory()
             return static::$factory::new();
         }
 
+        if($useFactory = static::getUseFactoryAttribute()) {
+            return $useFactory;
+        }
+
         return null;
     }
 }

tests/Database/DatabaseEloquentModelTest.php

@@ -17,6 +17,7 @@
 use Illuminate\Database\ConnectionResolverInterface as Resolver;
 use Illuminate\Database\Eloquent\Attributes\CollectedBy;
 use Illuminate\Database\Eloquent\Attributes\ObservedBy;
+use Illuminate\Database\Eloquent\Attributes\UseFactory;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Casts\ArrayObject;
 use Illuminate\Database\Eloquent\Casts\AsArrayObject;
@@ -30,6 +31,8 @@
 use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Database\Eloquent\Concerns\HasUlids;
 use Illuminate\Database\Eloquent\Concerns\HasUuids;
+use Illuminate\Database\Eloquent\Factories\Factory;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\JsonEncodingException;
 use Illuminate\Database\Eloquent\MassAssignmentException;
 use Illuminate\Database\Eloquent\MissingAttributeException;
@@ -51,6 +54,7 @@
 use ReflectionClass;
 use stdClass;
 
+
 include_once 'Enums.php';
 
 class DatabaseEloquentModelTest extends TestCase
@@ -3191,6 +3195,18 @@ public function testCollectedByAttribute()
 
         $this->assertInstanceOf(CustomEloquentCollection::class, $collection);
     }
+
+    public function testUseFactoryAttribute()
+    {
+        $model = new EloquentModelWithUseFactoryAttribute;
+        $instance = EloquentModelWithUseFactoryAttribute::factory()->make(['name' => 'test name']);
+        $factory = EloquentModelWithUseFactoryAttribute::factory();
+        $this->assertInstanceOf(EloquentModelWithUseFactoryAttribute::class, $instance);
+        $this->assertInstanceOf(EloquentModelWithUseFactoryAttributeFactory::class, $model::factory());
+        $this->assertInstanceOf(EloquentModelWithUseFactoryAttributeFactory::class, $model::newFactory());
+        $this->assertEquals(EloquentModelWithUseFactoryAttribute::class, $factory->modelName());
+        $this->assertEquals('test name', $instance->name); // Small smoke test to ensure the factory is working
+    }
 }
 
 class EloquentTestObserverStub
@@ -3990,3 +4006,18 @@ class EloquentModelWithCollectedByAttribute extends Model
 class CustomEloquentCollection extends Collection
 {
 }
+
+
+class EloquentModelWithUseFactoryAttributeFactory extends Factory
+{
+    public function definition()
+    {
+        return [];
+    }
+}
+
+#[UseFactory(EloquentModelWithUseFactoryAttributeFactory::class)]
+class EloquentModelWithUseFactoryAttribute extends Model
+{
+    use HasFactory;
+}