Add copy and deepcopy function to node class. (#800)

* Add copy and deepcopy function to node class. This function will only be used by nodes which can be converted to tree.
* Add test

bsb/config/_attrs.py

@@ -22,6 +22,7 @@
     compile_isc,
     compile_new,
     compile_postnew,
+    make_copyable,
     make_dictable,
     make_get_node_name,
     make_tree,
@@ -72,6 +73,7 @@ def node(node_cls, root=False, dynamic=False, pluggable=False):
     make_get_node_name(node_cls, root=root)
     make_tree(node_cls)
     make_dictable(node_cls)
+    make_copyable(node_cls)
 
     return node_cls
 

bsb/config/_make.py

@@ -584,6 +584,14 @@ def get_tree(instance):
     node_cls.__tree__ = get_tree
 
 
+def make_copyable(node_cls):
+    def loc_copy(instance, memo=None):
+        return type(instance)(instance.__tree__())
+
+    node_cls.__copy__ = loc_copy
+    node_cls.__deepcopy__ = loc_copy
+
+
 def walk_node_attributes(node):
     """
     Walk over all of the child configuration nodes and attributes of ``node``.

tests/test_configuration.py

@@ -1286,6 +1286,40 @@ class Test:
         self.assertEqual({"statement": "[1, 2, 3]"}, tree["a"])
 
 
+class TestCopy(unittest.TestCase):
+    def test_copy(self):
+        """
+        Check copy and deepcopy functions for the nodes.
+        """
+
+        @config.node
+        class SubClass:
+            c = config.attr(
+                required=False,
+                default=lambda: np.array([0, 0, 0], dtype=int),
+                call_default=True,
+                type=types.ndarray(),
+            )
+
+        @config.root
+        class MainClass:
+            a = config.attr(type=SubClass)
+            b = config.attr(default=5.0)
+
+        tab = np.array([1, 2, 3], dtype=int)
+        instance = MainClass({"a": {"c": tab}, "b": 3.0})
+        copied = instance.__copy__()
+        self.assertTrue(id(instance.a) != id(copied.a))
+        # check that the c arrays elements are equals
+        self.assertTrue(np.all(instance.a.c == copied.a.c))
+        self.assertEqual(instance.b, copied.b)
+        copied = instance.__deepcopy__()
+        self.assertTrue(id(instance.a) != id(copied.a))
+        # check that the c arrays elements are equals
+        self.assertTrue(np.all(instance.a.c == copied.a.c))
+        self.assertEqual(instance.b, copied.b)
+
+
 class TestDictScripting(unittest.TestCase):
     def test_add(self):
         netw = Scaffold()