whoops, forgotten file
diff --git a/tests/test_interfaces.py b/tests/test_interfaces.py
new file mode 100644
index 0000000..e8e9702
--- /dev/null
+++ b/tests/test_interfaces.py
@@ -0,0 +1,40 @@
+import abc
+
+import pytest
+
+import six
+
+from cryptography.utils import (
+ InterfaceNotImplemented, register_interface, verify_interface
+)
+
+
+class TestVerifyInterface(object):
+ def test_verify_missing_method(self):
+ @six.add_metaclass(abc.ABCMeta)
+ class SimpleInterface(object):
+ @abc.abstractmethod
+ def method(self):
+ pass
+
+ @register_interface(SimpleInterface)
+ class NonImplementer(object):
+ pass
+
+ with pytest.raises(InterfaceNotImplemented):
+ verify_interface(SimpleInterface, NonImplementer)
+
+ def test_different_arguments(self):
+ @six.add_metaclass(abc.ABCMeta)
+ class SimpleInterface(object):
+ @abc.abstractmethod
+ def method(self, a):
+ pass
+
+ @register_interface(SimpleInterface)
+ class NonImplementer(object):
+ def method(self):
+ pass
+
+ with pytest.raises(InterfaceNotImplemented):
+ verify_interface(SimpleInterface, NonImplementer)