Merge "add hacking for assertIsNotNone"

HACKING.rst

@@ -16,6 +16,8 @@ Magnum Specific Commandments
   assertIsInstance(A, B).
 - [M318] Change assertEqual(A, None) or assertEqual(None, A) by optimal assert
   like assertIsNone(A)
+- [M319] Change assertNotEqual(A, None) or assertNotEqual(None, A)
+  by optimal assert like assertIsNotNone(A)
 - [M322] Method's default argument shouldn't be mutable.
 - [M323] Change assertEqual(True, A) or assertEqual(False, A) by optimal assert
   like assertTrue(A) or assertFalse(A)

magnum/hacking/checks.py

@@ -39,6 +39,10 @@ assert_equal_end_with_none_re = re.compile(
     r"(.)*assertEqual\((\w|\.|\'|\"|\[|\])+, None\)")
 assert_equal_start_with_none_re = re.compile(
     r"(.)*assertEqual\(None, (\w|\.|\'|\"|\[|\])+\)")
+assert_not_equal_end_with_none_re = re.compile(
+    r"(.)*assertNotEqual\((\w|\.|\'|\"|\[|\])+, None\)")
+assert_not_equal_start_with_none_re = re.compile(
+    r"(.)*assertNotEqual\(None, (\w|\.|\'|\"|\[|\])+\)")
 assert_equal_with_true_re = re.compile(
     r"assertEqual\(True,")
 assert_equal_with_false_re = re.compile(
@@ -66,6 +70,19 @@ def assert_equal_none(logical_line):
         yield (0, msg)
 
 
+def assert_not_equal_none(logical_line):
+    """Check for assertNotEqual(A, None) or assertNotEqual(None, A) sentences
+
+    M319
+    """
+    msg = ("M319: assertNotEqual(A, None) or assertNotEqual(None, A) "
+           "sentences not allowed")
+    res = (assert_not_equal_start_with_none_re.match(logical_line) or
+           assert_not_equal_end_with_none_re.match(logical_line))
+    if res:
+        yield (0, msg)
+
+
 def no_mutable_default_args(logical_line):
     msg = "M322: Method's default argument shouldn't be mutable!"
     if mutable_default_args.match(logical_line):
@@ -161,6 +178,7 @@ def no_log_warn(logical_line):
 def factory(register):
     register(no_mutable_default_args)
     register(assert_equal_none)
+    register(assert_not_equal_none)
     register(assert_equal_true_or_false)
     register(assert_equal_not_none)
     register(assert_true_isinstance)

magnum/tests/unit/test_hacking.py

@@ -130,6 +130,19 @@ class HackingTestCase(base.TestCase):
         code = "self.assertIsNone()"
         self._assert_has_no_errors(code, check)
 
+    def test_assert_not_equal_none(self):
+        errors = [(1, 0, "M319")]
+        check = checks.assert_not_equal_none
+
+        code = "self.assertNotEqual(A, None)"
+        self._assert_has_errors(code, check, errors)
+
+        code = "self.assertNotEqual(None, A)"
+        self._assert_has_errors(code, check, errors)
+
+        code = "self.assertIsNotNone()"
+        self._assert_has_no_errors(code, check)
+
     def test_assert_equal_true_or_false(self):
         errors = [(1, 0, "M323")]
         check = checks.assert_equal_true_or_false