Preserve configuration when copying ConfigBox

AUTHORS.rst

@@ -98,3 +98,5 @@ Suggestions and bug reporting:
 - d00m514y3r
 - Sébastien Weber (seb5g)
 - Ward Loos (wrdls)
+
+- oyeong011

CHANGES.rst

@@ -1,6 +1,11 @@
 Changelog
 =========
 
+Unreleased
+----------
+
+* Preserve ConfigBox options when copying, including frozen_box and default_box.
+
 Version 7.4.1
 -------------
 

box/config_box.py

@@ -127,7 +127,12 @@ def __repr__(self):
         return f"{self.__class__.__name__}({str(self.to_dict())})"
 
     def copy(self):
-        return ConfigBox(super().copy())
+        config = {
+            key: value
+            for key, value in self._box_config.items()
+            if not key.startswith("__") and key != "box_namespace"
+        }
+        return ConfigBox(super().copy(), **config)
 
     def __copy__(self):
-        return ConfigBox(super().copy())
+        return ConfigBox.copy(self)

test/test_config_box.py

@@ -1,9 +1,13 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+from copy import copy
+
+import pytest
+
 from test.common import test_dict
 
-from box import Box, ConfigBox
+from box import Box, BoxError, ConfigBox
 
 
 class TestConfigBox:
@@ -49,3 +53,45 @@ def test_dir(self):
     def test_config_default(self):
         bx4 = Box(default_box=True, default_box_attr=ConfigBox)
         assert isinstance(bx4.bbbbb, ConfigBox)
+
+
+@pytest.mark.parametrize("copier", [copy, lambda value: value.copy()])
+def test_copy_preserves_frozen_config(copier):
+    original = ConfigBox(value=1, frozen_box=True)
+    copied = copier(original)
+    assert isinstance(copied, ConfigBox)
+    assert copied is not original
+    with pytest.raises(BoxError):
+        copied.value = 2
+
+
+@pytest.mark.parametrize("copier", [copy, lambda value: value.copy()])
+def test_copy_preserves_default_config(copier):
+    original = ConfigBox(default_box=True, default_box_attr=7)
+    copied = copier(original)
+    assert copied.missing == 7
+    assert "missing" not in original
+
+
+@pytest.mark.parametrize("copier", [copy, lambda value: value.copy()])
+@pytest.mark.parametrize("base", [Box, ConfigBox])
+def test_copy_preserves_base_type_for_subclass_with_required_argument(copier, base):
+    class CustomBox(base):
+        def __init__(self, required, **kwargs):
+            super().__init__(value=required, **kwargs)
+
+    original = CustomBox(1, frozen_box=True)
+    copied = copier(original)
+    assert type(copied) is base
+    assert copied.value == 1
+    assert copied is not original
+    with pytest.raises(BoxError):
+        copied.value = 2
+
+
+@pytest.mark.parametrize("copier", [copy, lambda value: value.copy()])
+def test_config_copy_detaches_namespace_and_hides_internal_config(copier):
+    original = ConfigBox(value=1, box_namespace=("parent",))
+    copied = copier(original)
+    assert copied == {"value": 1}
+    assert copied._box_config["box_namespace"] == ()