bpo-22815: Print unexpected successes in summary in TextTestResult (GH-30138)

Lib/unittest/runner.py

@@ -142,6 +142,12 @@ def printErrors(self):
             self.stream.flush()
         self.printErrorList('ERROR', self.errors)
         self.printErrorList('FAIL', self.failures)
+        unexpectedSuccesses = getattr(self, 'unexpectedSuccesses', ())
+        if unexpectedSuccesses:
+            self.stream.writeln(self.separator1)
+            for test in unexpectedSuccesses:
+                self.stream.writeln(f"UNEXPECTED SUCCESS: {self.getDescription(test)}")
+            self.stream.flush()
 
     def printErrorList(self, flavour, errors):
         for test, err in errors:

Lib/unittest/test/test_program.py

@@ -61,6 +61,17 @@ def testPass(self):
             pass
         def testFail(self):
             raise AssertionError
+        def testError(self):
+            1/0
+        @unittest.skip('skipping')
+        def testSkipped(self):
+            raise AssertionError
+        @unittest.expectedFailure
+        def testExpectedFailure(self):
+            raise AssertionError
+        @unittest.expectedFailure
+        def testUnexpectedSuccess(self):
+            pass
 
     class FooBarLoader(unittest.TestLoader):
         """Test loader that returns a suite containing FooBar."""
@@ -111,9 +122,13 @@ def test_NonExit(self):
                                 testRunner=unittest.TextTestRunner(stream=stream),
                                 testLoader=self.FooBarLoader())
         self.assertTrue(hasattr(program, 'result'))
-        self.assertIn('\nFAIL: testFail ', stream.getvalue())
+        out = stream.getvalue()
-        self.assertTrue(stream.getvalue().endswith('\n\nFAILED (failures=1)\n'))
+        self.assertIn('\nFAIL: testFail ', out)
-
+        self.assertIn('\nERROR: testError ', out)
+        self.assertIn('\nUNEXPECTED SUCCESS: testUnexpectedSuccess ', out)
+        expected = ('\n\nFAILED (failures=1, errors=1, skipped=1, '
+                    'expected failures=1, unexpected successes=1)\n')
+        self.assertTrue(out.endswith(expected))
 
     def test_Exit(self):
         stream = BufferedWriter()
@@ -124,9 +139,13 @@ def test_Exit(self):
             testRunner=unittest.TextTestRunner(stream=stream),
             exit=True,
             testLoader=self.FooBarLoader())
-        self.assertIn('\nFAIL: testFail ', stream.getvalue())
+        out = stream.getvalue()
-        self.assertTrue(stream.getvalue().endswith('\n\nFAILED (failures=1)\n'))
+        self.assertIn('\nFAIL: testFail ', out)
-
+        self.assertIn('\nERROR: testError ', out)
+        self.assertIn('\nUNEXPECTED SUCCESS: testUnexpectedSuccess ', out)
+        expected = ('\n\nFAILED (failures=1, errors=1, skipped=1, '
+                    'expected failures=1, unexpected successes=1)\n')
+        self.assertTrue(out.endswith(expected))
 
     def test_ExitAsDefault(self):
         stream = BufferedWriter()
@@ -136,8 +155,13 @@ def test_ExitAsDefault(self):
             argv=["foobar"],
             testRunner=unittest.TextTestRunner(stream=stream),
             testLoader=self.FooBarLoader())
-        self.assertIn('\nFAIL: testFail ', stream.getvalue())
+        out = stream.getvalue()
-        self.assertTrue(stream.getvalue().endswith('\n\nFAILED (failures=1)\n'))
+        self.assertIn('\nFAIL: testFail ', out)
+        self.assertIn('\nERROR: testError ', out)
+        self.assertIn('\nUNEXPECTED SUCCESS: testUnexpectedSuccess ', out)
+        expected = ('\n\nFAILED (failures=1, errors=1, skipped=1, '
+                    'expected failures=1, unexpected successes=1)\n')
+        self.assertTrue(out.endswith(expected))
 
 
 class InitialisableProgram(unittest.TestProgram):

Misc/NEWS.d/next/Library/2021-12-16-12-54-21.bpo-22815.0NRH8s.rst

@@ -0,0 +1,2 @@
+Print unexpected successes together with failures and errors in summary in
+:class:`unittest.TextTestResult`.