[Python-checkins] bpo-46299: improve `test_descr.py` with stricter error handling (GH-30471)

[miss-islington]

https://github.com/python/cpython/commit/566d70a8d1c1afb8e770068f1686f762a1e343b9
commit: 566d70a8d1c1afb8e770068f1686f762a1e343b9
branch: 3.9
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2022-01-07T21:26:11-08:00
summary:

bpo-46299: improve `test_descr.py` with stricter error handling (GH-30471)

(cherry picked from commit e63066cfed27511c9b786d61761f87f7a532571a)

Co-authored-by: Nikita Sobolev <mail at sobolevn.me>

files:
M Lib/test/test_descr.py

diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 0e6a784c6c14b..e5e9f4939699e 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -2531,10 +2531,8 @@ def getdict(self):
         m2instance.b = 2
         m2instance.a = 1
         self.assertEqual(m2instance.__dict__, "Not a dict!")
-        try:
+        with self.assertRaises(TypeError):
             dir(m2instance)
-        except TypeError:
-            pass
 
         # Two essentially featureless objects, (Ellipsis just inherits stuff
         # from object.
@@ -4013,7 +4011,7 @@ class D(C):
         except TypeError:
             pass
         else:
-            assert 0, "best_base calculation found wanting"
+            self.fail("best_base calculation found wanting")
 
     def test_unsubclassable_types(self):
         with self.assertRaises(TypeError):
@@ -4399,6 +4397,8 @@ def __getattr__(self, attr):
             print("Oops!")
         except RuntimeError:
             pass
+        else:
+            self.fail("Didn't raise RuntimeError")
         finally:
             sys.stdout = test_stdout