Add missing RegisterState Attribute

src/Attributes/AttributeLoader.php

@@ -35,7 +35,17 @@ public function load(StateConfig $stateConfig): StateConfig
 
             $stateConfig->default($defaultStateAttribute->defaultStateClass);
         }
-
-        return $stateConfig;
+
+	    $registerStateAttributes = $this->reflectionClass->getAttributes(RegisterState::class);
+
+		foreach($registerStateAttributes as $attribute) {
+			/** @var \Spatie\ModelStates\Attributes\RegisterState $registerStateAttribute */
+			$registerStateAttribute = $attribute->newInstance();
+
+			$stateConfig->registerState($registerStateAttribute->stateClass);
+		}
+
+
+	    return $stateConfig;
     }
 }

src/Attributes/RegisterState.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Spatie\ModelStates\Attributes;
+
+use Attribute;
+use JetBrains\PhpStorm\Immutable;
+
+#[Attribute(Attribute::TARGET_CLASS | Attribute::IS_REPEATABLE)]
+class RegisterState
+{
+    public function __construct(
+        #[Immutable] public string|array $stateClass,
+    ) {
+    }
+}

tests/AttributeSateTest.php → tests/AttributeStateTest.php

@@ -2,12 +2,15 @@
 
 namespace Spatie\ModelStates\Tests;
 
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory\AttributeStateC;
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory\AttributeStateD;
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory\AttributeStateE;
 use Spatie\ModelStates\Tests\Dummy\AttributeState\AttributeStateA;
 use Spatie\ModelStates\Tests\Dummy\AttributeState\AttributeStateB;
 use Spatie\ModelStates\Tests\Dummy\AttributeState\AttributeStateTransition;
 use Spatie\ModelStates\Tests\Dummy\AttributeState\TestModelWithAttributeState;
 
-class AttributeSateTest extends TestCase
+class AttributeStateTest extends TestCase
 {
     /** @test */
     public function test_default()
@@ -39,4 +42,25 @@ public function test_allowed_transition()
         $this->assertTrue($model->state->equals(AttributeStateB::class));
         $this->assertTrue(AttributeStateTransition::$transitioned);
     }
+
+	/** @test */
+	public function test_registered_states()
+	{
+		if (PHP_VERSION_ID < 80000) {
+			$this->markTestSkipped('Not PHP 8');
+
+			return;
+		}
+
+		$model = new TestModelWithAttributeState();
+
+		$this->assertSame([AttributeStateC::class, AttributeStateD::class, AttributeStateE::class], AttributeStateA::config()->registeredStates);
+		$this->assertSame([AttributeStateC::class, AttributeStateD::class, AttributeStateE::class], AttributeStateC::config()->registeredStates);
+
+		$this->assertTrue($model->state->equals(AttributeStateA::class));
+
+		$model->state->transitionTo(AttributeStateC::class);
+
+		$this->assertTrue($model->state->equals(AttributeStateC::class));
+	}
 }

tests/Dummy/AttributeState/AnotherDirectory/AttributeStateC.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory;
+
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AttributeState;
+
+class AttributeStateC extends AttributeState
+{
+}

tests/Dummy/AttributeState/AnotherDirectory/AttributeStateD.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory;
+
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AttributeState;
+
+class AttributeStateD extends AttributeState
+{
+}

tests/Dummy/AttributeState/AnotherDirectory/AttributeStateE.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory;
+
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AttributeState;
+
+class AttributeStateE extends AttributeState
+{
+}

tests/Dummy/AttributeState/AnotherDirectory/AttributeStateF.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory;
+
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AttributeState;
+
+class AttributeStateF extends AttributeState
+{
+}

tests/Dummy/AttributeState/AttributeState.php

@@ -4,12 +4,19 @@
 
 use Spatie\ModelStates\Attributes\AllowTransition;
 use Spatie\ModelStates\Attributes\DefaultState;
+use Spatie\ModelStates\Attributes\RegisterState;
 use Spatie\ModelStates\State;
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory\AttributeStateC;
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory\AttributeStateD;
+use Spatie\ModelStates\Tests\Dummy\AttributeState\AnotherDirectory\AttributeStateE;
 
 #[
     AllowTransition(AttributeStateA::class, AttributeStateB::class, AttributeStateTransition::class),
     AllowTransition(AttributeStateB::class, AttributeStateA::class),
+    AllowTransition(AttributeStateA::class, AttributeStateC::class),
     DefaultState(AttributeStateA::class),
+	RegisterState(AttributeStateC::class),
+	RegisterState([AttributeStateD::class, AttributeStateE::class]),
 ]
 abstract class AttributeState extends State
 {