[8.x] Fix autoresolving model name from factory (#40616)

* Fix autoresolving model name from factory

* Reverse change to fallback factory

* Add test

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

@@ -686,12 +686,16 @@ public function newModel(array $attributes = [])
     public function modelName()
     {
         $resolver = static::$modelNameResolver ?: function (self $factory) {
+            $namespacedFactoryBasename = Str::replaceLast(
+                'Factory', '', Str::replaceFirst(static::$namespace, '', get_class($factory))
+            );
+
             $factoryBasename = Str::replaceLast('Factory', '', class_basename($factory));
 
             $appNamespace = static::appNamespace();
 
-            return class_exists($appNamespace.'Models\\'.$factoryBasename)
-                        ? $appNamespace.'Models\\'.$factoryBasename
+            return class_exists($appNamespace.'Models\\'.$namespacedFactoryBasename)
+                        ? $appNamespace.'Models\\'.$namespacedFactoryBasename
                         : $appNamespace.$factoryBasename;
         };
 

tests/Database/DatabaseEloquentFactoryTest.php

@@ -12,6 +12,7 @@
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Factories\Sequence;
 use Illuminate\Database\Eloquent\Model as Eloquent;
+use Illuminate\Tests\Database\Fixtures\Models\Money\Price;
 use Mockery;
 use PHPUnit\Framework\TestCase;
 
@@ -469,6 +470,18 @@ public function test_resolve_nested_model_factories()
         }
     }
 
+    public function test_resolve_nested_model_name_from_factory()
+    {
+        Container::getInstance()->instance(Application::class, $app = Mockery::mock(Application::class));
+        $app->shouldReceive('getNamespace')->andReturn('Illuminate\\Tests\\Database\\Fixtures\\');
+
+        Factory::useNamespace('Illuminate\\Tests\\Database\\Fixtures\\Factories\\');
+
+        $factory = Price::factory();
+
+        $this->assertSame(Price::class, $factory->modelName());
+    }
+
     public function test_resolve_non_app_nested_model_factories()
     {
         Container::getInstance()->instance(Application::class, $app = Mockery::mock(Application::class));

tests/Database/Fixtures/Factories/Money/PriceFactory.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Illuminate\Tests\Database\Fixtures\Factories\Money;
+
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class PriceFactory extends Factory
+{
+    public function definition()
+    {
+        return [
+            'name' => $this->faker->name,
+        ];
+    }
+}

tests/Database/Fixtures/Models/Money/Price.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Illuminate\Tests\Database\Fixtures\Models\Money;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Tests\Database\Fixtures\Factories\Money\PriceFactory;
+
+class Price extends Model
+{
+    use HasFactory;
+
+    protected $table = 'prices';
+
+    public static function factory()
+    {
+        return PriceFactory::new();
+    }
+}