Clarify dangerous use of exceptions in unit tests

Also, update unit tests to use more specific exception where possible
to make auditing easier in the future.

Change-Id: I4906e2f8e3ebacf0587f1471ca8dd46c73edc17a

3 files changed, 7 insertions, 12 deletions

diff --git a/nova/tests/api/openstack/test_common.py b/nova/tests/api/openstack/test_common.py
index 250a199e8..4ebd49ca2 100644
--- a/nova/tests/api/openstack/test_common.py
+++ b/nova/tests/api/openstack/test_common.py
@@ -290,10 +290,8 @@ class MiscFunctionsTest(test.TestCase):
         try:
             common.raise_http_conflict_for_instance_invalid_state(exc,
                     'meow')
-        except Exception, e:
-            self.assertTrue(isinstance(e, webob.exc.HTTPConflict))
-            msg = str(e)
-            self.assertEqual(msg,
+        except webob.exc.HTTPConflict as e:
+            self.assertEqual(unicode(e),
                 "Cannot 'meow' while instance is in fake_attr fake_state")
         else:
             self.fail("webob.exc.HTTPConflict was not raised")
@@ -303,10 +301,8 @@ class MiscFunctionsTest(test.TestCase):
         try:
             common.raise_http_conflict_for_instance_invalid_state(exc,
                     'meow')
-        except Exception, e:
-            self.assertTrue(isinstance(e, webob.exc.HTTPConflict))
-            msg = str(e)
-            self.assertEqual(msg,
+        except webob.exc.HTTPConflict as e:
+            self.assertEqual(unicode(e),
                 "Instance is in an invalid state for 'meow'")
         else:
             self.fail("webob.exc.HTTPConflict was not raised")
diff --git a/nova/tests/compute/test_compute.py b/nova/tests/compute/test_compute.py
index 63af33153..747774fa4 100644
--- a/nova/tests/compute/test_compute.py
+++ b/nova/tests/compute/test_compute.py
@@ -2264,7 +2264,7 @@ class ComputeTestCase(BaseTestCase):
 
         try:
             raise NotImplementedError('test')
-        except Exception:
+        except NotImplementedError:
             exc_info = sys.exc_info()
 
         self.stubs.Set(nova.db, 'instance_fault_create', fake_db_fault_create)
@@ -2292,7 +2292,7 @@ class ComputeTestCase(BaseTestCase):
 
         try:
             raise user_exc
-        except Exception:
+        except exception.Invalid:
             exc_info = sys.exc_info()
 
         self.stubs.Set(nova.db, 'instance_fault_create', fake_db_fault_create)
diff --git a/nova/tests/test_db_api.py b/nova/tests/test_db_api.py
index 641c7c8cd..e434faaad 100644
--- a/nova/tests/test_db_api.py
+++ b/nova/tests/test_db_api.py
@@ -46,11 +46,10 @@ class DbApiTestCase(test.TestCase):
         return db.instance_create(self.context, args)
 
     def test_ec2_ids_not_found_are_printable(self):
-
         def check_exc_format(method):
             try:
                 method(self.context, 'fake')
-            except Exception as exc:
+            except exception.NotFound as exc:
                 self.assertTrue('fake' in unicode(exc))
 
         check_exc_format(db.get_ec2_volume_id_by_uuid)