Merge pull request #167 from janluke/fix/constraint-cannot-be-copied

Fix: `Constraint.__getattr__` was returning `None` instead of raising `AttributeError`

cloup/constraints/_core.py

@@ -52,12 +52,14 @@ def must_check_consistency(ctx: click.Context) -> bool:
     def __getattr__(self, attr: str) -> Any:
         removed_attrs = ('toggle_consistency_checks', 'consistency_checks_toggled')
         if attr in removed_attrs:
-            raise Exception(
+            raise AttributeError(
                 f'attribute `{attr}` was removed in v0.9. You can now enable/disable '
                 f'consistency checks using the `click.Context` parameter '
                 f'`check_constraints_consistency`. '
                 f'Pass it as part of your `context_settings`.'
             )
+        else:
+            raise AttributeError(attr)
 
     @abc.abstractmethod
     def help(self, ctx: click.Context) -> str:

tests/constraints/test_constraints.py

@@ -20,7 +20,7 @@
 )
 from cloup.constraints.exceptions import ConstraintViolated, UnsatisfiableConstraint
 from tests.util import (
-    make_context, make_fake_context, make_options, parametrize, should_raise
+    make_context, make_fake_context, make_options, parametrize, should_raise,
 )
 
 
@@ -31,8 +31,10 @@ class FakeConstraint(Constraint):
 
     to create a test double with characteristics of both a mock and a fake."""
 
-    def __init__(self, satisfied=True, consistent=True, help='help',
-                 error='error', inconsistency_reason='consistency_error'):
+    def __init__(
+        self, satisfied=True, consistent=True, help='help',
+        error='error', inconsistency_reason='consistency_error'
+    ):
         self.satisfied = satisfied
         self.consistent = consistent
         self._help = help
@@ -349,3 +351,9 @@ def test_check_consistency_doesnt_raise_if_wrapped_constraint_doesnt_raise(self)
         params = make_options('abc')
         with pytest.raises(UnsatisfiableConstraint):
             rephraser.check_consistency(params)
+
+
+def test_a_constraint_can_be_copied_and_deep_copied():
+    import copy
+    copy.copy(RequireAtLeast(1))
+    copy.deepcopy(RequireAtLeast(1))