fix: nullabe arrays of decoded ids were retrieved as [null]

src/Traits/HashIdTrait.php

@@ -143,6 +143,11 @@ private function locateAndDecodeIds($requestData, $key): mixed
      */
     private function processField($data, $keysTodo, $currentFieldName): mixed
     {
+        // is the current field a null?! we can give it back and chill out
+        if(is_null($data)) {
+             return $data;
+        }
+
         // check if there are no more fields to be processed
         if (empty($keysTodo)) {
             // there are no more keys left - so basically we need to decode this entry

tests/Unit/Traits/HashIdTraitTest.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Apiato\Core\Tests\Unit\Traits;
+
+use Apiato\Core\Tests\Unit\UnitTestCase;
+use Apiato\Core\Traits\HashIdTrait;
+use PHPUnit\Framework\Attributes\CoversClass;
+use ReflectionClass;
+
+#[CoversClass(HashIdTrait::class)]
+class HashIdTraitTest extends UnitTestCase
+{
+    private $trait;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        $this->trait = new class {
+            use HashIdTrait;
+        };
+    }
+
+    public function testProcessFieldShouldNotWrapANullInAnArray(): void
+    {
+        $data = null;
+        $keysTodo = ['*'];
+        $currentFieldName = null;
+        $reflection = new ReflectionClass($this->trait);
+        $method = $reflection->getMethod('processField');
+
+        $result = $method->invoke($this->trait, $data, $keysTodo, $currentFieldName);
+
+        $this->assertNull($result);
+    }
+}