TASK: Simplify circularHierarchy check and improve errormessage and test

Author: Sebobo

Neos.Media/Classes/Domain/Model/AssetCollection.php

@@ -198,11 +198,13 @@ public function getParent(): ?self
     private function validateCircularHierarchy(): void
     {
         $parent = $this->parent;
-        $parents = [$parent];
         while ($parent !== null) {
             $parent = $parent->getParent();
-            if (in_array($parent, $parents, true)) {
-                throw new \InvalidArgumentException('Circular reference detected', 1680328041);
+            if ($parent === $this->parent) {
+                throw new \InvalidArgumentException(sprintf(
+                    'Circular reference detected, parent AssetCollection "%s" appeared twice in the hierarchy',
+                    $parent->getTitle()
+                ), 1680328041);
             }
         }
     }

Neos.Media/Tests/Functional/Domain/Model/AssetCollectionTest.php

@@ -73,19 +73,22 @@ public function parentChildrenRelation(): void
     }
 
     /**
+     * Verifies the following hierarchie throws an error:
+     *   first -> second -> third -> first
+     *
      * @test
      */
     public function circularParentChildrenRelationThrowsErrorWhenSettingParent(): void
     {
-        $child = new AssetCollection('child');
-        $childOfChild = new AssetCollection('childOfChild');
-        $parent = new AssetCollection('parent');
+        $firstCollection = new AssetCollection('first');
+        $secondCollection = new AssetCollection('second');
+        $thirdCollection = new AssetCollection('third');
 
-        $child->setParent($parent);
-        $childOfChild->setParent($child);
+        $secondCollection->setParent($firstCollection);
+        $thirdCollection->setParent($secondCollection);
 
         $this->expectException(\InvalidArgumentException::class);
-        $parent->setParent($childOfChild);
+        $firstCollection->setParent($thirdCollection);
     }
 
     /**