diff --git a/tests/Serializer/StructuralElementDenormalizerTest.php b/tests/Serializer/StructuralElementDenormalizerTest.php
new file mode 100644
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--- /dev/null
+++ b/tests/Serializer/StructuralElementDenormalizerTest.php
@@ -0,0 +1,89 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2023 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace App\Tests\Serializer;
+
+use App\Entity\Parts\Category;
+use App\Serializer\StructuralElementDenormalizer;
+use PHPUnit\Framework\TestCase;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+
+class StructuralElementDenormalizerTest extends WebTestCase
+{
+
+    /** @var StructuralElementDenormalizer */
+    protected $service;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        //Get an service instance.
+        self::bootKernel();
+        $this->service = self::getContainer()->get(StructuralElementDenormalizer::class);
+    }
+
+    public function testHasCacheableSupportsMethod(): void
+    {
+        $this->assertFalse($this->service->hasCacheableSupportsMethod());
+    }
+
+    public function testSupportsDenormalization(): void
+    {
+        $this->assertFalse($this->service->supportsDenormalization('doesnt_matter', Category::class, 'json', ['groups' => ['import']]));
+        $this->assertFalse($this->service->supportsDenormalization(['name' => 'Test'], Category::class, 'json', ['groups' => ['simple']]));
+
+        //Denormalizer should only be active, when we use the import function
+        $this->assertTrue($this->service->supportsDenormalization(['name' => 'Test'], Category::class, 'json', ['groups' => ['import']]));
+    }
+
+    /**
+     * @group DB
+     */
+    public function testDenormalize(): void
+    {
+        //Check that we retrieve DB elements via the name
+        $data = ['name' => 'Node 1'];
+        $result = $this->service->denormalize($data, Category::class, 'json', ['groups' => ['import']]);
+        $this->assertInstanceOf(Category::class, $result);
+        $this->assertSame('Node 1', $result->getName());
+        $this->assertNotNull($result->getID()); //ID should be set, because we retrieved the element from the DB
+
+        //Check that we can retrieve nested DB elements
+        $data = ['name' => 'Node 1.1', 'parent' => ['name' => 'Node 1']];
+        $result = $this->service->denormalize($data, Category::class, 'json', ['groups' => ['import']]);
+        $this->assertInstanceOf(Category::class, $result);
+        $this->assertSame('Node 1.1', $result->getName());
+        $this->assertSame('Node 1', $result->getParent()->getName());
+        $this->assertNotNull($result->getID()); //ID should be set, because we retrieved the element from the DB
+        $this->assertNotNull($result->getParent()->getID()); //ID should be set, because we retrieved the element from the DB
+
+        //Check that we can create new elements
+        $data = ['name' => 'New Node 1.1', 'parent' => ['name' => 'New Node 1']];
+        $result = $this->service->denormalize($data, Category::class, 'json', ['groups' => ['import']]);
+        $this->assertInstanceOf(Category::class, $result);
+        $this->assertSame('New Node 1.1', $result->getName());
+        $this->assertSame('New Node 1', $result->getParent()->getName());
+        $this->assertNull($result->getID()); //ID should be null, because we created a new element
+
+        //Check that when we retrieve this element again, we get the same instance
+        $result2 = $this->service->denormalize($data, Category::class, 'json', ['groups' => ['import']]);
+        $this->assertSame($result, $result2);
+    }
+}