1 files changed, 40 insertions, 0 deletions
diff --git a/tests/test_interfaces.py b/tests/test_interfaces.py
new file mode 100644
index 00000000..e8e97022
--- /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)