replace assertNotEqual(*,None) to assertIsNotNone

replace assertNotEqual(*, None) with assertIsNotNone in tests to have
more clear messages in case of failure.add hacking for assertNotEqual
(*, None) and unit hacking unittest.

Change-Id: I16607be4830e39cc26a5d2cb3c12a0c41fa1d599

tests/hacking/README.rst

@@ -21,6 +21,7 @@ Rally Specific Commandments
  * [N322] - Ensure that ``assertEqual(A, None)`` and ``assertEqual(None, A)`` are not used
  * [N323] - Ensure that ``assertTrue/assertFalse(A in/not in B)`` are not used with collection contents
  * [N324] - Ensure that ``assertEqual(A in/not in B, True/False)`` and ``assertEqual(True/False, A in/not in B)`` are not used with collection contents
+ * [N325] - Ensure that ``assertNotEqual(A, None)`` and ``assertNotEqual(None, A)`` are not used
 * [N340] - Ensure that we are importing always ``from rally import objects``
 * [N341] - Ensure that we are importing oslo_xyz packages instead of deprecated oslo.xyz ones
 * [N350] - Ensure that single quotes are not used

tests/hacking/checks.py

@@ -36,6 +36,9 @@ re_assert_equal_type = re.compile(
     r"(\w|\.|\'|\"|\[|\])+\)")
 re_assert_equal_end_with_none = re.compile(r"assertEqual\(.*?,\s+None\)$")
 re_assert_equal_start_with_none = re.compile(r"assertEqual\(None,")
+re_assert_not_equal_end_with_none = re.compile(
+    r"assertNotEqual\(.*?,\s+None\)$")
+re_assert_not_equal_start_with_none = re.compile(r"assertNotEqual\(None,")
 re_assert_true_false_with_in_or_not_in = re.compile(
     r"assert(True|False)\("
     r"(\w|[][.'\"])+( not)? in (\w|[][.'\",])+(, .*)?\)")
@@ -277,6 +280,20 @@ def assert_equal_in(logical_line, physical_line, filename):
                   "collection contents.")
 
 
+@skip_ignored_lines
+def assert_not_equal_none(logical_line, physical_line, filename):
+    """Check for assertNotEqual(A, None) or assertEqual(None, A) sentences
+
+    N325
+    """
+    res = (re_assert_not_equal_start_with_none.search(logical_line) or
+           re_assert_not_equal_end_with_none.search(logical_line))
+    if res:
+        yield (0, "N325 assertNotEqual(A, None) or assertNotEqual(None, A) "
+                  "sentences not allowed, you should use assertIsNotNone(A) "
+                  "instead.")
+
+
 @skip_ignored_lines
 def check_no_direct_rally_objects_import(logical_line, physical_line,
                                          filename):

tests/unit/test_hacking.py

@@ -170,6 +170,17 @@ class HackingTestCase(test.TestCase):
         self.assertEqual(
             len(list(checks.assert_equal_none(line, line, "f"))), result)
 
+    @ddt.data(
+        {"line": "self.assertNotEqual(A, None)", "result": 1},
+        {"line": "self.assertNotEqual(None, A)", "result": 1},
+        {"line": "self.assertIsNotNone()", "result": 0}
+    )
+    @ddt.unpack
+    def test_assert_not_equal_none(self, line, result):
+
+        self.assertEqual(
+            len(list(checks.assert_not_equal_none(line, line, "f"))), result)
+
     def test_assert_true_or_false_with_in_or_not_in(self):
         good_lines = [
             "self.assertTrue(any(A > 5 for A in B))",