fix up assertEqual(None...) check to catch more cases

To finally close out bug #1280522 it turned out that our hacking check
to eliminate assertEqual(None, ...) was pretty sub optimal. The
perfect fix would actually use the tokenizer, however this is a better
regex which catches a few more missing bits in our codebase. It's
probably close enough for most of what we need.

Fix the relevant tests that would fail the updating hacking check.

Change-Id: Ic8cb1192e001409d827c8da55fe536681895944b
Closes-Bug: #1280522

nova/hacking/checks.py

@@ -51,9 +51,9 @@ asse_equal_type_re = re.compile(
                        r"(.)*assertEqual\(type\((\w|\.|\'|\"|\[|\])+\), "
                        "(\w|\.|\'|\"|\[|\])+\)")
 asse_equal_end_with_none_re = re.compile(
-                           r"(.)*assertEqual\((\w|\.|\'|\"|\[|\])+, None\)")
+                           r"assertEqual\(.*?,\s+None\)$")
 asse_equal_start_with_none_re = re.compile(
-                           r"(.)*assertEqual\(None, (\w|\.|\'|\"|\[|\])+\)")
+                           r"assertEqual\(None,")
 conf_attribute_set_re = re.compile(r"CONF\.[a-z0-9_.]+\s*=\s*\w")
 log_translation = re.compile(
     r"(.)*LOG\.(audit|error|info|warn|warning|critical|exception)\(\s*('|\")")
@@ -250,8 +250,8 @@ def assert_equal_none(logical_line):
 
     N318
     """
-    res = (asse_equal_start_with_none_re.match(logical_line) or
+    res = (asse_equal_start_with_none_re.search(logical_line) or
-           asse_equal_end_with_none_re.match(logical_line))
+           asse_equal_end_with_none_re.search(logical_line))
     if res:
         yield (0, "N318: assertEqual(A, None) or assertEqual(None, A) "
                "sentences not allowed")

nova/tests/api/openstack/test_wsgi.py

@@ -125,7 +125,7 @@ class RequestTest(test.NoDBTestCase):
                 compute_nodes[1])
         self.assertEqual(request.get_db_compute_node('id2'),
                 compute_nodes[2])
-        self.assertEqual(request.get_db_compute_node('id3'), None)
+        self.assertIsNone(request.get_db_compute_node('id3'))
         self.assertEqual(request.get_db_compute_nodes(),
                 {'id0': compute_nodes[0],
                  'id1': compute_nodes[1],

nova/tests/network/test_api.py

@@ -517,9 +517,9 @@ class ApiTestCase(test.TestCase):
     @mock.patch('nova.objects.FixedIP.get_by_floating_address')
     def test_get_instance_by_floating_address_none(self, mock_get_by_floating):
         mock_get_by_floating.return_value = None
-        self.assertEqual(None,
+        self.assertIsNone(
-                         self.network_api.get_instance_id_by_floating_address(
+            self.network_api.get_instance_id_by_floating_address(
-                             self.context, mock.sentinel.floating))
+                self.context, mock.sentinel.floating))
         mock_get_by_floating.assert_called_once_with(self.context,
                                                      mock.sentinel.floating)
 

nova/tests/pci/test_pci_stats.py

@@ -237,7 +237,7 @@ class PciDeviceStatsWithTagsTestCase(test.NoDBTestCase):
         pci_dev_obj = objects.PciDevice.create(pci_dev)
         self.pci_stats.add_device(pci_dev_obj)
         # There should be no change
-        self.assertEqual(None,
+        self.assertIsNone(
             self.pci_stats._create_pool_keys_from_dev(pci_dev_obj))
         self._assertPools()
 
@@ -253,7 +253,7 @@ class PciDeviceStatsWithTagsTestCase(test.NoDBTestCase):
         pci_dev_obj = objects.PciDevice.create(pci_dev)
         self.pci_stats.remove_device(pci_dev_obj)
         # There should be no change
-        self.assertEqual(None,
+        self.assertIsNone(
             self.pci_stats._create_pool_keys_from_dev(pci_dev_obj))
         self._assertPools()
 

nova/tests/virt/libvirt/test_blockinfo.py

@@ -725,10 +725,10 @@ class LibvirtBlockInfoTest(test.TestCase):
         self.assertEqual('/dev/vda', blockinfo.get_device_name(driver_bdm))
 
         bdm_obj.device_name = None
-        self.assertEqual(None, blockinfo.get_device_name(bdm_obj))
+        self.assertIsNone(blockinfo.get_device_name(bdm_obj))
 
         driver_bdm = driver_block_device.DriverVolumeBlockDevice(bdm_obj)
-        self.assertEqual(None, blockinfo.get_device_name(driver_bdm))
+        self.assertIsNone(blockinfo.get_device_name(driver_bdm))
 
     @mock.patch('nova.virt.libvirt.blockinfo.find_disk_dev_for_disk_bus',
                 return_value='vda')

nova/tests/virt/libvirt/test_imagebackend.py

@@ -1287,6 +1287,6 @@ class UtilTestCase(test.NoDBTestCase):
     def test_get_hw_disk_discard(self):
         self.assertEqual('unmap', imagebackend.get_hw_disk_discard("unmap"))
         self.assertEqual('ignore', imagebackend.get_hw_disk_discard("ignore"))
-        self.assertEqual(None, imagebackend.get_hw_disk_discard(None))
+        self.assertIsNone(imagebackend.get_hw_disk_discard(None))
         self.assertRaises(RuntimeError, imagebackend.get_hw_disk_discard,
                           "fake")

nova/tests/virt/xenapi/test_volume_utils.py

@@ -37,9 +37,8 @@ class SROps(stubs.XenAPITestBaseNoDB):
         self.session = mock.Mock()
         self.session.XenAPI.Failure = UUIDException
         self.session.call_xenapi.side_effect = UUIDException
-        self.assertEqual(volume_utils.find_sr_by_uuid(self.session,
+        self.assertIsNone(
-                                                      'sr_uuid'),
+            volume_utils.find_sr_by_uuid(self.session, 'sr_uuid'))
-                         None)
 
     def test_find_sr_from_vdi(self):
         vdi_ref = 'fake-ref'
@@ -81,11 +80,9 @@ class ISCSIParametersTestCase(stubs.XenAPITestBaseNoDB):
                          'host')
 
         # There is no default value
-        self.assertEqual(volume_utils._get_target_host(':port'),
+        self.assertIsNone(volume_utils._get_target_host(':port'))
-                         None)
 
-        self.assertEqual(volume_utils._get_target_host(None),
+        self.assertIsNone(volume_utils._get_target_host(None))
-                         None)
 
     def test_target_port(self):
         self.assertEqual(volume_utils._get_target_port('host:port'),