Fix reparenting code

Author: daisylb

django_pgtree/models.py

@@ -33,11 +33,10 @@ def __init__(self, *args, parent=None, **kwargs):
     def parent(self):
         parent_path = self.tree_path[:-
                                      1]  # pylint: disable=unsubscriptable-object
-        print(parent_path)
         return self.__class__.objects.get(tree_path=parent_path)
 
     @parent.setter
-    def __set_parent(self, new_parent):
+    def parent(self, new_parent):
         if new_parent.tree_path is None:
             raise ValueError(
                 "Parent node must be saved before receiving children")
@@ -66,7 +65,7 @@ def save(self, *args, **kwargs):  # pylint: disable=arguments-differ
                 tree_path__descendant_of=self.__old_tree_path
             ).update(
                 tree_path=LtreeConcat(
-                    '.'.join(self.tree_path),
+                    models.Value('.'.join(self.tree_path)),
                     Subpath(models.F('tree_path'), len(self.__old_tree_path)),
                 )
             )

django_pgtree/tests.py

@@ -41,3 +41,14 @@ def test_family(animal):
     mammal = T.objects.get(name='Mammal')
     assert {x.name for x in mammal.family} == {
         'Animal', 'Mammal', 'Cat', 'Dog'}
+
+def test_reparent(animal):
+    marsupial = T.objects.get(name='Marsupial')
+    mammal = T.objects.get(name='Mammal')
+    marsupial.parent = mammal
+    marsupial.save()
+    assert marsupial.tree_path[:2] == mammal.tree_path
+    koala = T.objects.get(name='Koala')
+    assert koala.parent == marsupial
+    assert koala.tree_path[:2] == mammal.tree_path
+    assert mammal in koala.ancestors