Refactor: extract method: driver_dict_from_config

Related to blueprint xenapi-volume-drivers

Extract method to create driver registries, so that it could be re-used
in xenapi for a similar purpose.

Change-Id: Ifd25d12335ac96a15dfea4c5ab7f315ff7ddfd8b

nova/tests/test_driver.py

@@ -0,0 +1,60 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (c) 2013 Citrix Systems, Inc.
+# Copyright 2013 OpenStack LLC.
+#
+#    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.
+
+from nova import test
+from nova.virt import driver
+
+
+class FakeDriver(object):
+    def __init__(self, *args, **kwargs):
+        self.args = args
+        self.kwargs = kwargs
+
+
+class FakeDriver2(FakeDriver):
+    pass
+
+
+class ToDriverRegistryTestCase(test.TestCase):
+
+    def assertDriverInstance(self, inst, class_, *args, **kwargs):
+        self.assertEquals(class_, inst.__class__)
+        self.assertEquals(args, inst.args)
+        self.assertEquals(kwargs, inst.kwargs)
+
+    def test_driver_dict_from_config(self):
+        drvs = driver.driver_dict_from_config(
+            [
+                'key1=nova.tests.test_driver.FakeDriver',
+                'key2=nova.tests.test_driver.FakeDriver2',
+            ], 'arg1', 'arg2', param1='value1', param2='value2'
+        )
+
+        self.assertEquals(
+            sorted(['key1', 'key2']),
+            sorted(drvs.keys())
+        )
+
+        self.assertDriverInstance(
+            drvs['key1'],
+            FakeDriver, 'arg1', 'arg2', param1='value1',
+            param2='value2')
+
+        self.assertDriverInstance(
+            drvs['key2'],
+            FakeDriver2, 'arg1', 'arg2', param1='value1',
+            param2='value2')