Add unit test for volume extensions client

This patch adds unit test for volume v2 extensions client.

Partially Implements: blueprint tempest-lib-missing-test-coverage

Change-Id: I5a614fb92f44f5960610dc39299c6effb979be9a

tempest/tests/lib/services/volume/v2/test_extensions_client.py

@@ -0,0 +1,70 @@
+# Copyright 2017 FiberHome Telecommunication Technologies CO.,LTD
+# 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.
+
+from tempest.lib.services.volume.v2 import extensions_client
+from tempest.tests.lib import fake_auth_provider
+from tempest.tests.lib.services import base
+
+
+class TestExtensionsClient(base.BaseServiceTest):
+
+    FAKE_EXTENSION_LIST = {
+        "extensions": [
+            {
+                "updated": "2012-03-12T00:00:00+00:00",
+                "name": "QuotaClasses",
+                "links": [],
+                "namespace": "fake-namespace-1",
+                "alias": "os-quota-class-sets",
+                "description": "Quota classes management support."
+            },
+            {
+                "updated": "2013-05-29T00:00:00+00:00",
+                "name": "VolumeTransfer",
+                "links": [],
+                "namespace": "fake-namespace-2",
+                "alias": "os-volume-transfer",
+                "description": "Volume transfer management support."
+            },
+            {
+                "updated": "2014-02-10T00:00:00+00:00",
+                "name": "VolumeManage",
+                "links": [],
+                "namespace": "fake-namespace-3",
+                "alias": "os-volume-manage",
+                "description": "Manage existing backend storage by Cinder."
+            }
+        ]
+    }
+
+    def setUp(self):
+        super(TestExtensionsClient, self).setUp()
+        fake_auth = fake_auth_provider.FakeAuthProvider()
+        self.client = extensions_client.ExtensionsClient(fake_auth,
+                                                         'volume',
+                                                         'regionOne')
+
+    def _test_list_extensions(self, bytes_body=False):
+        self.check_service_client_function(
+            self.client.list_extensions,
+            'tempest.lib.common.rest_client.RestClient.get',
+            self.FAKE_EXTENSION_LIST,
+            bytes_body)
+
+    def test_list_extensions_with_str_body(self):
+        self._test_list_extensions()
+
+    def test_list_extensions_with_bytes_body(self):
+        self._test_list_extensions(bytes_body=True)