backport: #20145: assert[Raises|Warns]Regex now raise TypeError on bad regex.

Previously a non-string, non-regex second argument and missing callable
argument could cause the test to appear to always pass.

Initial patch by Kamilla Holanda.

1 files changed, 12 insertions, 0 deletions

diff --git a/Lib/unittest/test/test_case.py b/Lib/unittest/test/test_case.py
index 363390af09..49325784d2 100644
--- a/Lib/unittest/test/test_case.py
+++ b/Lib/unittest/test/test_case.py
@@ -1126,6 +1126,18 @@ test case
                 self.assertRaisesRegex, Exception, 'x',
                 lambda: None)
 
+    def testAssertRaisesRegexInvalidRegex(self):
+        # Issue 20145.
+        class MyExc(Exception):
+            pass
+        self.assertRaises(TypeError, self.assertRaisesRegex, MyExc, lambda: True)
+
+    def testAssertWarnsRegexInvalidRegex(self):
+        # Issue 20145.
+        class MyWarn(Warning):
+            pass
+        self.assertRaises(TypeError, self.assertWarnsRegex, MyWarn, lambda: True)
+
     def testAssertRaisesRegexMismatch(self):
         def Stub():
             raise Exception('Unexpected')