Replace FakeObject with MagicMock[1/2]

FakeObject is used to set dynamic attributes to a fake class which
works in most cases but fails when an attribute is accessed which
is not defined/passed explicitly.
This causes failure of tests whenever a new attribute is accessed
and it's hard to maintain the set of attributes for every object
used.
MagicMock provides the same functionality with additional features
and handles the case effectively when an attribute is accessed
which is not explicitly defined in the tests.
This change will help safeguard against cases seen earlier in[1].
This patch replaces FakeObject with MagicMock in test_cinder_store.py

[1] https://review.opendev.org/c/openstack/glance/+/805974

Change-Id: Ifd0905b139cc90c2bd7444bc9e7638f3af6879a7

1 files changed, 49 insertions, 53 deletions

diff --git a/glance_store/tests/unit/test_cinder_store.py b/glance_store/tests/unit/test_cinder_store.py
index d59cf07..05eb7d0 100644
--- a/glance_store/tests/unit/test_cinder_store.py
+++ b/glance_store/tests/unit/test_cinder_store.py
@@ -44,12 +44,6 @@ sys.modules['glance_store.common.fs_mount'] = mock.Mock()
 from glance_store._drivers import cinder # noqa
 
 
-class FakeObject(object):
-    def __init__(self, **kwargs):
-        for name, value in kwargs.items():
-            setattr(self, name, value)
-
-
 class TestCinderStore(base.StoreBaseTest,
                       test_store_capabilities.TestStoreCapabilitiesChecking):
 
@@ -65,10 +59,10 @@ class TestCinderStore(base.StoreBaseTest,
                     u'endpoints_links': [],
                     u'name': u'cinder',
                     u'type': u'volumev3'}]
-        self.context = FakeObject(service_catalog=fake_sc,
-                                  user_id='fake_user',
-                                  auth_token='fake_token',
-                                  project_id='fake_project')
+        self.context = mock.MagicMock(service_catalog=fake_sc,
+                                      user_id='fake_user',
+                                      auth_token='fake_token',
+                                      project_id='fake_project')
         self.hash_algo = 'sha256'
         cinder._reset_cinder_session()
 
@@ -114,13 +108,13 @@ class TestCinderStore(base.StoreBaseTest,
 
     @mock.patch.object(time, 'sleep')
     def test_wait_volume_status(self, mock_sleep):
-        fake_manager = FakeObject(get=mock.Mock())
-        volume_available = FakeObject(manager=fake_manager,
-                                      id='fake-id',
-                                      status='available')
-        volume_in_use = FakeObject(manager=fake_manager,
-                                   id='fake-id',
-                                   status='in-use')
+        fake_manager = mock.MagicMock(get=mock.Mock())
+        volume_available = mock.MagicMock(manager=fake_manager,
+                                          id='fake-id',
+                                          status='available')
+        volume_in_use = mock.MagicMock(manager=fake_manager,
+                                       id='fake-id',
+                                       status='in-use')
         fake_manager.get.side_effect = [volume_available, volume_in_use]
         self.assertEqual(volume_in_use,
                          self.store._wait_volume_status(
@@ -130,10 +124,10 @@ class TestCinderStore(base.StoreBaseTest,
 
     @mock.patch.object(time, 'sleep')
     def test_wait_volume_status_unexpected(self, mock_sleep):
-        fake_manager = FakeObject(get=mock.Mock())
-        volume_available = FakeObject(manager=fake_manager,
-                                      id='fake-id',
-                                      status='error')
+        fake_manager = mock.MagicMock(get=mock.Mock())
+        volume_available = mock.MagicMock(manager=fake_manager,
+                                          id='fake-id',
+                                          status='error')
         fake_manager.get.return_value = volume_available
         self.assertRaises(exceptions.BackendException,
                           self.store._wait_volume_status,
@@ -142,10 +136,10 @@ class TestCinderStore(base.StoreBaseTest,
 
     @mock.patch.object(time, 'sleep')
     def test_wait_volume_status_timeout(self, mock_sleep):
-        fake_manager = FakeObject(get=mock.Mock())
-        volume_available = FakeObject(manager=fake_manager,
-                                      id='fake-id',
-                                      status='available')
+        fake_manager = mock.MagicMock(get=mock.Mock())
+        volume_available = mock.MagicMock(manager=fake_manager,
+                                          id='fake-id',
+                                          status='available')
         fake_manager.get.return_value = volume_available
         self.assertRaises(exceptions.BackendException,
                           self.store._wait_volume_status,
@@ -161,7 +155,7 @@ class TestCinderStore(base.StoreBaseTest,
         fake_volume = mock.MagicMock(id=str(uuid.uuid4()), status='available',
                                      multiattach=multiattach)
         fake_volume.manager.get.return_value = fake_volume
-        fake_volumes = FakeObject(get=lambda id: fake_volume)
+        fake_volumes = mock.MagicMock(get=lambda id: fake_volume)
         fake_attachment_id = str(uuid.uuid4())
         fake_attachment_create = {'id': fake_attachment_id}
         if encrypted_nfs or qcow2_vol:
@@ -171,10 +165,10 @@ class TestCinderStore(base.StoreBaseTest,
         else:
             fake_attachment_update = mock.MagicMock(id=fake_attachment_id)
         fake_conn_info = mock.MagicMock(connector={})
-        fake_client = FakeObject(volumes=fake_volumes)
+        fake_client = mock.MagicMock(volumes=fake_volumes)
         _, fake_dev_path = tempfile.mkstemp(dir=self.test_dir)
         fake_devinfo = {'path': fake_dev_path}
-        fake_connector = FakeObject(
+        fake_connector = mock.MagicMock(
             connect_volume=mock.Mock(return_value=fake_devinfo),
             disconnect_volume=mock.Mock())
 
@@ -332,21 +326,21 @@ class TestCinderStore(base.StoreBaseTest,
 
         self.assertRaises(exceptions.BadStoreConfiguration,
                           self.store._check_context,
-                          FakeObject(service_catalog=None))
+                          mock.MagicMock(service_catalog=None))
 
-        self.store._check_context(FakeObject(service_catalog='fake'))
+        self.store._check_context(mock.MagicMock(service_catalog='fake'))
 
     def test_cinder_get(self):
         expected_size = 5 * units.Ki
         expected_file_contents = b"*" * expected_size
         volume_file = six.BytesIO(expected_file_contents)
-        fake_client = FakeObject(auth_token=None, management_url=None)
+        fake_client = mock.MagicMock(auth_token=None, management_url=None)
         fake_volume_uuid = str(uuid.uuid4())
         fake_volume = mock.MagicMock(id=fake_volume_uuid,
                                      metadata={'image_size': expected_size},
                                      status='available')
         fake_volume.manager.get.return_value = fake_volume
-        fake_volumes = FakeObject(get=lambda id: fake_volume)
+        fake_volumes = mock.MagicMock(get=lambda id: fake_volume)
 
         @contextlib.contextmanager
         def fake_open(client, volume, mode):
@@ -356,8 +350,8 @@ class TestCinderStore(base.StoreBaseTest,
         with mock.patch.object(cinder.Store, 'get_cinderclient') as mock_cc, \
                 mock.patch.object(self.store, '_open_cinder_volume',
                                   side_effect=fake_open):
-            mock_cc.return_value = FakeObject(client=fake_client,
-                                              volumes=fake_volumes)
+            mock_cc.return_value = mock.MagicMock(client=fake_client,
+                                                  volumes=fake_volumes)
             uri = "cinder://%s" % fake_volume_uuid
             loc = location.get_location_from_uri(uri, conf=self.conf)
             (image_file, image_size) = self.store.get(loc,
@@ -374,14 +368,14 @@ class TestCinderStore(base.StoreBaseTest,
             self.assertEqual(expected_file_contents, data)
 
     def test_cinder_get_size(self):
-        fake_client = FakeObject(auth_token=None, management_url=None)
+        fake_client = mock.MagicMock(auth_token=None, management_url=None)
         fake_volume_uuid = str(uuid.uuid4())
-        fake_volume = FakeObject(size=5, metadata={})
+        fake_volume = mock.MagicMock(size=5, metadata={})
         fake_volumes = {fake_volume_uuid: fake_volume}
 
         with mock.patch.object(cinder.Store, 'get_cinderclient') as mocked_cc:
-            mocked_cc.return_value = FakeObject(client=fake_client,
-                                                volumes=fake_volumes)
+            mocked_cc.return_value = mock.MagicMock(client=fake_client,
+                                                    volumes=fake_volumes)
 
             uri = 'cinder://%s' % fake_volume_uuid
             loc = location.get_location_from_uri(uri, conf=self.conf)
@@ -389,16 +383,16 @@ class TestCinderStore(base.StoreBaseTest,
             self.assertEqual(fake_volume.size * units.Gi, image_size)
 
     def test_cinder_get_size_with_metadata(self):
-        fake_client = FakeObject(auth_token=None, management_url=None)
+        fake_client = mock.MagicMock(auth_token=None, management_url=None)
         fake_volume_uuid = str(uuid.uuid4())
         expected_image_size = 4500 * units.Mi
-        fake_volume = FakeObject(size=5,
-                                 metadata={'image_size': expected_image_size})
+        fake_volume = mock.MagicMock(
+            size=5, metadata={'image_size': expected_image_size})
         fake_volumes = {fake_volume_uuid: fake_volume}
 
         with mock.patch.object(cinder.Store, 'get_cinderclient') as mocked_cc:
-            mocked_cc.return_value = FakeObject(client=fake_client,
-                                                volumes=fake_volumes)
+            mocked_cc.return_value = mock.MagicMock(client=fake_client,
+                                                    volumes=fake_volumes)
 
             uri = 'cinder://%s' % fake_volume_uuid
             loc = location.get_location_from_uri(uri, conf=self.conf)
@@ -415,9 +409,10 @@ class TestCinderStore(base.StoreBaseTest,
                                 usedforsecurity=False).hexdigest()
         expected_multihash = hashlib.sha256(expected_file_contents).hexdigest()
         expected_location = 'cinder://%s' % fake_volume.id
-        fake_client = FakeObject(auth_token=None, management_url=None)
+        fake_client = mock.MagicMock(auth_token=None, management_url=None)
         fake_volume.manager.get.return_value = fake_volume
-        fake_volumes = FakeObject(create=mock.Mock(return_value=fake_volume))
+        fake_volumes = mock.MagicMock(create=mock.Mock(
+            return_value=fake_volume))
         self.config(cinder_volume_type='some_type')
 
         @contextlib.contextmanager
@@ -432,8 +427,8 @@ class TestCinderStore(base.StoreBaseTest,
                     cinder.Store, '_wait_resize_device') as mock_wait_resize:
             if fail_resize:
                 mock_wait_resize.side_effect = exceptions.BackendException()
-            mock_cc.return_value = FakeObject(client=fake_client,
-                                              volumes=fake_volumes)
+            mock_cc.return_value = mock.MagicMock(client=fake_client,
+                                                  volumes=fake_volumes)
             loc, size, checksum, multihash, _ = self.store.add(
                 expected_image_id, image_file, expected_size, self.hash_algo,
                 self.context, verifier)
@@ -478,13 +473,13 @@ class TestCinderStore(base.StoreBaseTest,
         fake_volume.delete.assert_called_once_with()
 
     def test_cinder_delete(self):
-        fake_client = FakeObject(auth_token=None, management_url=None)
+        fake_client = mock.MagicMock(auth_token=None, management_url=None)
         fake_volume_uuid = str(uuid.uuid4())
-        fake_volumes = FakeObject(delete=mock.Mock())
+        fake_volumes = mock.MagicMock(delete=mock.Mock())
 
         with mock.patch.object(cinder.Store, 'get_cinderclient') as mocked_cc:
-            mocked_cc.return_value = FakeObject(client=fake_client,
-                                                volumes=fake_volumes)
+            mocked_cc.return_value = mock.MagicMock(client=fake_client,
+                                                    volumes=fake_volumes)
 
             uri = 'cinder://%s' % fake_volume_uuid
             loc = location.get_location_from_uri(uri, conf=self.conf)
@@ -501,8 +496,9 @@ class TestCinderStore(base.StoreBaseTest,
                 raise cinder.cinder_exception.NotFound(code=404)
 
         with mock.patch.object(self.store, 'get_cinderclient') as mocked_cc:
-            mocked_cc.return_value = FakeObject(volume_types=FakeObject(
-                find=fake_volume_type))
+            mocked_cc.return_value = mock.MagicMock(
+                volume_types=mock.MagicMock(
+                    find=fake_volume_type))
             self.config(cinder_volume_type='some_type')
             # If volume type exists, no exception is raised
             self.store.configure_add()