Use assertIsInstance instead of assertTrue(isinstance(a, b))

Developer should use assertIsInstance to replace the
assertTrue(isinstance(a, b)).

Closes-Bug: #1510384
Change-Id: I70f68a5810a6797c7b7e112b46ef2463907bba3e

HACKING.rst

@@ -16,3 +16,5 @@ Magnum Specific Commandments
   like assertTrue(A) or assertFalse(A)
 - [M302] Change assertEqual(A is not None) by optimal assert like
   assertIsNotNone(A).
+- [M316] Change assertTrue(isinstance(A, B)) by optimal assert like
+  assertIsInstance(A, B).

magnum/hacking/checks.py

@@ -43,6 +43,9 @@ assert_equal_with_false_re = re.compile(
     r"assertEqual\(False,")
 asse_equal_with_is_not_none_re = re.compile(
     r"assertEqual\(.*?\s+is+\s+not+\s+None\)$")
+assert_true_isinstance_re = re.compile(
+    r"(.)*assertTrue\(isinstance\((\w|\.|\'|\"|\[|\])+, "
+    "(\w|\.|\'|\"|\[|\])+\)\)")
 
 
 def check_policy_enforce_decorator(logical_line,
@@ -94,9 +97,19 @@ def assert_equal_not_none(logical_line):
         yield (0, msg)
 
 
+def assert_true_isinstance(logical_line):
+    """Check for assertTrue(isinstance(a, b)) sentences
+
+    M316
+    """
+    if assert_true_isinstance_re.match(logical_line):
+        yield (0, "M316: assertTrue(isinstance(a, b)) sentences not allowed")
+
+
 def factory(register):
     register(check_policy_enforce_decorator)
     register(no_mutable_default_args)
     register(assert_equal_none)
     register(assert_equal_true_or_false)
     register(assert_equal_not_none)
+    register(assert_true_isinstance)

magnum/tests/unit/conductor/test_monitors.py

@@ -53,7 +53,7 @@ class MonitorsTestCase(base.TestCase):
         baymodel.coe = 'swarm'
         mock_baymodel_get_by_uuid.return_value = baymodel
         monitor = monitors.create_monitor(self.context, self.bay)
-        self.assertTrue(isinstance(monitor, monitors.SwarmMonitor))
+        self.assertIsInstance(monitor, monitors.SwarmMonitor)
 
     @mock.patch('magnum.objects.BayModel.get_by_uuid')
     def test_create_monitor_unsupported_coe(self, mock_baymodel_get_by_uuid):

magnum/tests/unit/test_hacking.py

@@ -127,3 +127,11 @@ class HackingTestCase(base.TestCase):
 
         self.assertEqual(0, len(list(checks.assert_equal_not_none(
             "self.assertIsNone()"))))
+
+    def test_assert_true_isinstance(self):
+        self.assertEqual(1, len(list(checks.assert_true_isinstance(
+            "self.assertTrue(isinstance(e, "
+            "exception.BuildAbortException))"))))
+
+        self.assertEqual(0, len(list(checks.assert_true_isinstance(
+            "self.assertTrue()"))))