diff --git a/application/src/Domain/SourceManagement/TreeSourceService.php b/application/src/Domain/SourceManagement/TreeSourceService.php
index 77b0e7a..c207170 100644
--- a/application/src/Domain/SourceManagement/TreeSourceService.php
+++ b/application/src/Domain/SourceManagement/TreeSourceService.php
@@ -41,6 +41,7 @@ final class TreeSourceService extends AbstractSourceService implements TreeSourc
         $this->source = $source;
         $this->branches = new ArrayCollection();
         $this->leaves = new ArrayCollection();
+        $this->basicSort();
     }
 
     private function sortMember(SourceInterface $member): bool
diff --git a/application/tests/Unit/Domain/TreeSourceServiceTest.php b/application/tests/Unit/Domain/TreeSourceServiceTest.php
new file mode 100644
index 0000000..1638f33
--- /dev/null
+++ b/application/tests/Unit/Domain/TreeSourceServiceTest.php
@@ -0,0 +1,35 @@
+<?php
+namespace Tests\Unit\Domain;
+
+use PHPUnit\Framework\TestCase;
+use App\Entity\Source\Collection\TreeCollectionSourceInterface;
+use App\Entity\Source\Collection\TreeCollectionSource;
+use App\Entity\Source\SourceInterface;
+use Doctrine\Common\Collections\ArrayCollection;
+use App\Domain\SourceManagement\TreeSourceServiceInterface;
+use App\Domain\SourceManagement\TreeSourceService;
+
+class TreeSourceServiceTest extends TestCase
+{
+    /**
+     * 
+     * @var TreeSourceServiceInterface
+     */
+    protected $treeService;
+    
+    public function setUp():void {
+        $tree1 = new TreeCollectionSource();
+        $tree2 = new TreeCollectionSource();
+        $tree3 = new TreeCollectionSource();
+        $leave1 = $this->createMock(SourceInterface::class);
+        $leave2 = $this->createMock(SourceInterface::class);
+        $collection = new ArrayCollection([$tree2,$tree3,$leave1,$leave2]);
+        $tree1->setCollection($collection);
+        $this->treeService = new TreeSourceService($tree1);
+    }
+    
+    public function testGetLeaves():void{
+        $this->assertEquals(2, $this->treeService->getLeaves()->count());
+    }
+}
+