tests: skip test if function is not implemented

This allows to skip certain tests if the feature is not implemented in
the driver if it raises NotImplementedError.

Change-Id: Id9848381c0ac053cb061d5557f468d336b997103

tooz/tests/__init__.py

@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+#
+#    Copyright (C) 2014 eNovance Inc. All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import functools
+
+import six
+from testtools import testcase
+
+
+def _skip_decorator(func):
+    @functools.wraps(func)
+    def skip_if_not_implemented(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except NotImplementedError as e:
+            raise testcase.TestSkipped(str(e))
+    return skip_if_not_implemented
+
+
+class SkipNotImplementedMeta(type):
+    def __new__(cls, name, bases, local):
+        for attr in local:
+            value = local[attr]
+            if callable(value) and (
+                    attr.startswith('test_') or attr == 'setUp'):
+                local[attr] = _skip_decorator(value)
+        return type.__new__(cls, name, bases, local)
+
+
+@six.add_metaclass(SkipNotImplementedMeta)
+class TestCaseSkipNotImplemented(testcase.TestCase):
+    pass

tooz/tests/test_coordination.py

@@ -22,6 +22,7 @@ import testscenarios
 from testtools import testcase
 
 import tooz.coordination
+from tooz import tests
 from zake import fake_storage
 
 # Real ZooKeeper server scenario
@@ -35,7 +36,8 @@ fake_zookeeper_tests = ('fake_zookeeper_tests', {'backend': 'zake',
                                                             fake_storage}})
 
 
-class TestAPI(testscenarios.TestWithScenarios, testcase.TestCase):
+class TestAPI(testscenarios.TestWithScenarios,
+              tests.TestCaseSkipNotImplemented):
 
     scenarios = [
         zookeeper_tests,