diff --git a/tests/Models/NullPromotionAttributeTest.php b/tests/Models/NullPromotionAttributeTest.php
new file mode 100644
index 0000000..921294b
--- /dev/null
+++ b/tests/Models/NullPromotionAttributeTest.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Jingga
+ *
+ * PHP Version 8.1
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 2.0
+ * @version   1.0.0
+ * @link      https://jingga.app
+ */
+declare(strict_types=1);
+
+namespace Modules\Marketing\tests\Models;
+
+use Modules\Marketing\Models\NullPromotionAttribute;
+
+/**
+ * @internal
+ */
+final class NullPromotionAttributeTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttribute
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\Marketing\Models\PromotionAttribute', new NullPromotionAttribute());
+    }
+
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttribute
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullPromotionAttribute(2);
+        self::assertEquals(2, $null->getId());
+    }
+
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttribute
+     * @group framework
+     */
+    public function testJsonSerialize() : void
+    {
+        $null = new NullPromotionAttribute(2);
+        self::assertEquals(['id' => 2], $null);
+    }
+}
diff --git a/tests/Models/NullPromotionAttributeTypeTest.php b/tests/Models/NullPromotionAttributeTypeTest.php
new file mode 100644
index 0000000..8f412cc
--- /dev/null
+++ b/tests/Models/NullPromotionAttributeTypeTest.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Jingga
+ *
+ * PHP Version 8.1
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 2.0
+ * @version   1.0.0
+ * @link      https://jingga.app
+ */
+declare(strict_types=1);
+
+namespace Modules\Marketing\tests\Models;
+
+use Modules\Marketing\Models\NullPromotionAttributeType;
+
+/**
+ * @internal
+ */
+final class NullPromotionAttributeTypeTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttributeType
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\Marketing\Models\PromotionAttributeType', new NullPromotionAttributeType());
+    }
+
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttributeType
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullPromotionAttributeType(2);
+        self::assertEquals(2, $null->getId());
+    }
+
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttributeType
+     * @group framework
+     */
+    public function testJsonSerialize() : void
+    {
+        $null = new NullPromotionAttributeType(2);
+        self::assertEquals(['id' => 2], $null);
+    }
+}
diff --git a/tests/Models/NullPromotionAttributeValueTest.php b/tests/Models/NullPromotionAttributeValueTest.php
new file mode 100644
index 0000000..4613ccc
--- /dev/null
+++ b/tests/Models/NullPromotionAttributeValueTest.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Jingga
+ *
+ * PHP Version 8.1
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 2.0
+ * @version   1.0.0
+ * @link      https://jingga.app
+ */
+declare(strict_types=1);
+
+namespace Modules\Marketing\tests\Models;
+
+use Modules\Marketing\Models\NullPromotionAttributeValue;
+
+/**
+ * @internal
+ */
+final class NullPromotionAttributeValueTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttributeValue
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\Marketing\Models\PromotionAttributeValue', new NullPromotionAttributeValue());
+    }
+
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttributeValue
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullPromotionAttributeValue(2);
+        self::assertEquals(2, $null->getId());
+    }
+
+    /**
+     * @covers Modules\Marketing\Models\NullPromotionAttributeValue
+     * @group framework
+     */
+    public function testJsonSerialize() : void
+    {
+        $null = new NullPromotionAttributeValue(2);
+        self::assertEquals(['id' => 2], $null);
+    }
+}
diff --git a/tests/Models/NullPromotionTest.php b/tests/Models/NullPromotionTest.php
new file mode 100644
index 0000000..466a227
--- /dev/null
+++ b/tests/Models/NullPromotionTest.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Jingga
+ *
+ * PHP Version 8.1
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 2.0
+ * @version   1.0.0
+ * @link      https://jingga.app
+ */
+declare(strict_types=1);
+
+namespace Modules\Marketing\tests\Models;
+
+use Modules\Marketing\Models\NullPromotion;
+
+/**
+ * @internal
+ */
+final class NullPromotionTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\Marketing\Models\NullPromotion
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\Marketing\Models\Promotion', new NullPromotion());
+    }
+
+    /**
+     * @covers Modules\Marketing\Models\NullPromotion
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullPromotion(2);
+        self::assertEquals(2, $null->getId());
+    }
+
+    /**
+     * @covers Modules\Marketing\Models\NullPromotion
+     * @group framework
+     */
+    public function testJsonSerialize() : void
+    {
+        $null = new NullPromotion(2);
+        self::assertEquals(['id' => 2], $null);
+    }
+}