Replace assert* with more suitable asserts in tests

The following replacements were done in unit tests to
 have clearer messages in case of failure:
- assertTrue(a == b or a == c) with assertIn(a, [b, c])
- assertTrue(type(a) == dict) with assertIsInstance(a, dict)
- assertTrue(type(a) == int) with assertIsInstance(a, int)

Also assertTrue with several conditions was splitted.

Change-Id: Id6e5db9ead8d8dceb9f416c1b55280855d25e604

nova/tests/api/ec2/test_cinder_cloud.py

@@ -815,8 +815,7 @@ class CinderCloudTestCase(test.TestCase):
 
         self.assertEqual(len(vols), 2)
         for vol in vols:
-            self.assertTrue(str(vol['id']) == str(vol1_uuid) or
-                str(vol['id']) == str(vol2_uuid))
+            self.assertIn(str(vol['id']), [str(vol1_uuid), str(vol2_uuid)])
             if str(vol['id']) == str(vol1_uuid):
                 self.volume_api.attach(self.context, vol['id'],
                                        instance_uuid, '/dev/sdb')
@@ -847,10 +846,8 @@ class CinderCloudTestCase(test.TestCase):
         vols = [v for v in vols if v['instance_uuid'] == instance_uuid]
         self.assertEqual(len(vols), 2)
         for vol in vols:
-            self.assertTrue(str(vol['id']) == str(vol1_uuid) or
-                            str(vol['id']) == str(vol2_uuid))
-            self.assertTrue(vol['mountpoint'] == '/dev/sdb' or
-                            vol['mountpoint'] == '/dev/sdc')
+            self.assertIn(str(vol['id']), [str(vol1_uuid), str(vol2_uuid)])
+            self.assertIn(vol['mountpoint'], ['/dev/sdb', '/dev/sdc'])
             self.assertEqual(vol['instance_uuid'], instance_uuid)
             self.assertEqual(vol['status'], "in-use")
             self.assertEqual(vol['attach_status'], "attached")

nova/tests/virt/hyperv/test_hypervapi.py

@@ -853,9 +853,9 @@ class HyperVAPITestCase(HyperVAPIBaseTestCase):
                             func_call_matcher.call)
         self._mox.VerifyAll()
 
-        self.assertTrue(self._image_metadata and
-                        "disk_format" in self._image_metadata and
-                        self._image_metadata["disk_format"] == "vhd")
+        self.assertTrue(self._image_metadata)
+        self.assertIn("disk_format", self._image_metadata)
+        self.assertEqual("vhd", self._image_metadata["disk_format"])
 
         # Assert states changed in correct order
         self.assertIsNone(func_call_matcher.match())

nova/tests/virt/libvirt/test_driver.py

@@ -4020,7 +4020,7 @@ class LibvirtConnTestCase(test.TestCase):
         self.mox.ReplayAll()
         ret = conn.check_can_live_migrate_source(self.context, instance_ref,
                                                  dest_check_data)
-        self.assertTrue(type(ret) == dict)
+        self.assertIsInstance(ret, dict)
         self.assertIn('is_shared_storage', ret)
 
     def test_check_can_live_migrate_source_vol_backed_w_disk_raises(self):

nova/tests/virt/libvirt/test_fakelibvirt.py

@@ -276,7 +276,7 @@ class FakeLibvirtTests(test.NoDBTestCase):
 
     def test_getVersion(self):
         conn = self.get_openAuth_curry_func()('qemu:///system')
-        self.assertTrue(type(conn.getVersion()) is int)
+        self.assertIsInstance(conn.getVersion(), int)
 
     def test_getCapabilities(self):
         conn = self.get_openAuth_curry_func()('qemu:///system')