Fixed memory leak for instances

tests/core/test_instances.py

@@ -129,9 +129,9 @@ class TestBaseInstance:
     assert instance.get_id() is not None
     assert instance.get_id().startswith("mf-base_instance-")
   
-  def test_i_can_get_prefix_from_class_name(self):
+  def test_i_can_get_prefix_from_class_name(self, session):
     """Test that get_prefix() returns the correct snake_case prefix."""
-    prefix = BaseInstance.get_prefix()
+    prefix = BaseInstance(None, session).get_prefix()
     
     assert prefix == "mf-base_instance"
 
@@ -182,7 +182,7 @@ class TestSingleInstance:
     instance = SingleInstance(parent=None, session=session)
     
     assert instance.get_id() == "mf-single_instance"
-    assert instance.get_id() == SingleInstance.get_prefix()
+    assert instance.get_prefix() == "mf-single_instance"
 
 
 class TestSingleInstanceSubclass:
@@ -249,6 +249,18 @@ class TestMultipleInstance:
     instance2 = MultipleInstance(parent=root_instance, session=session, _id=custom_id)
     
     assert instance1 is instance2
+  
+  def test_key_prefixed_by_underscore_uses_the_parent_id_as_prefix(self, root_instance):
+    """Test that key prefixed by underscore uses the parent id as prefix."""
+    instance = MultipleInstance(parent=root_instance, _id="-test_id")
+    
+    assert instance.get_id() == f"{root_instance.get_id()}-test_id"
+  
+  def test_no_parent_id_as_prefix_if_parent_is_none(self, session, root_instance):
+    """Test that key prefixed by underscore does not use the parent id as prefix if parent is None."""
+    instance = MultipleInstance(parent=None, session=session, _id="-test_id")
+    
+    assert instance.get_id() == "-test_id"
 
 
 class TestMultipleInstanceSubclass:
@@ -295,9 +307,9 @@ class TestMultipleInstanceSubclass:
     with pytest.raises(TypeError):
       MultipleInstance(parent=root_instance, _id=instance1.get_id())
   
-  def test_i_can_get_correct_prefix_for_multiple_subclass(self):
+  def test_i_can_get_correct_prefix_for_multiple_subclass(self, root_instance):
     """Test that subclass has correct auto-generated prefix."""
-    prefix = SubMultipleInstance.get_prefix()
+    prefix = SubMultipleInstance(root_instance).get_prefix()
     
     assert prefix == "mf-sub_multiple_instance"