Replace assertEqual(None, *) with assertIsNone in tests

Replace assertEqual(None, *) with assertIsNone in tests to have more
clear messages in case of failure.

Change-Id: I74452af6d840bcf612fd3bb2521db9134460dd63
Closes-Bug: #1280522

taskflow/tests/unit/test_failure.py

@@ -64,7 +64,7 @@ class GeneralFailureObjTestsMixin(object):
 
     def test_check_str_not_there(self):
         val = 'ValueError'
-        self.assertEqual(None, self.fail_obj.check(val))
+        self.assertIsNone(self.fail_obj.check(val))
 
     def test_check_type(self):
         self.assertIs(self.fail_obj.check(RuntimeError), RuntimeError)
@@ -306,7 +306,7 @@ class WrappedFailureTestCase(test.TestCase):
         fail_obj = _captured_failure('Woot!')
         wf = exceptions.WrappedFailure([fail_obj])
         self.assertEqual(RuntimeError, wf.check(RuntimeError))
-        self.assertEqual(None, wf.check(ValueError))
+        self.assertIsNone(wf.check(ValueError))
 
     def test_two_failures(self):
         fls = [

taskflow/tests/unit/test_storage.py

@@ -179,7 +179,7 @@ class StorageTestMixin(object):
     def test_reset_unknown_task(self):
         s = self._get_storage()
         s.ensure_atom(test_utils.NoopTask('my task'))
-        self.assertEqual(None, s.reset('my task'))
+        self.assertIsNone(s.reset('my task'))
 
     def test_fetch_by_name(self):
         s = self._get_storage()
@@ -215,7 +215,7 @@ class StorageTestMixin(object):
         s = self._get_storage()
         s.ensure_atom(test_utils.NoopTask('my task'))
         self.assertEqual(0.0, s.get_task_progress('my task'))
-        self.assertEqual(None, s.get_task_progress_details('my task'))
+        self.assertIsNone(s.get_task_progress_details('my task'))
 
     def test_task_progress(self):
         s = self._get_storage()
@@ -248,7 +248,7 @@ class StorageTestMixin(object):
 
         s.set_task_progress('my task', 0.8, {})
         self.assertEqual(0.8, s.get_task_progress('my task'))
-        self.assertEqual(None, s.get_task_progress_details('my task'))
+        self.assertIsNone(s.get_task_progress_details('my task'))
 
     def test_fetch_result_not_ready(self):
         s = self._get_storage()

taskflow/tests/unit/test_utils.py

@@ -103,7 +103,7 @@ class CachedPropertyTest(test.TestCase):
             def b(self):
                 return 'b'
 
-        self.assertEqual(None, inspect.getdoc(A.b))
+        self.assertIsNone(inspect.getdoc(A.b))
 
     def test_threaded_access_property(self):
         called = collections.deque()
@@ -172,7 +172,7 @@ class UriParseTest(test.TestCase):
         url = "rsync://test@www.yahoo.com:873"
         parsed = misc.parse_uri(url)
         self.assertEqual('test', parsed.username)
-        self.assertEqual(None, parsed.password)
+        self.assertIsNone(parsed.password)
 
 
 class TestSequenceMinus(test.TestCase):

taskflow/tests/unit/worker_based/test_endpoint.py

@@ -80,4 +80,4 @@ class TestEndpoint(test.TestCase):
                                      progress_callback=None,
                                      result=self.task_result,
                                      failures={})
-        self.assertEqual(None, result)
+        self.assertIsNone(result)