Issue #16997: unittest.TestCase now provides a subTest() context manager to procedurally generate, in an easy way, small test instances.

1 files changed, 16 insertions, 0 deletions

diff --git a/Lib/unittest/result.py b/Lib/unittest/result.py
index 97e5426927..eec4f21173 100644
--- a/Lib/unittest/result.py
+++ b/Lib/unittest/result.py
@@ -121,6 +121,22 @@ class TestResult(object):
         self.failures.append((test, self._exc_info_to_string(err, test)))
         self._mirrorOutput = True
 
+    @failfast
+    def addSubTest(self, test, subtest, err):
+        """Called at the end of a subtest.
+        'err' is None if the subtest ended successfully, otherwise it's a
+        tuple of values as returned by sys.exc_info().
+        """
+        # By default, we don't do anything with successful subtests, but
+        # more sophisticated test results might want to record them.
+        if err is not None:
+            if issubclass(err[0], test.failureException):
+                errors = self.failures
+            else:
+                errors = self.errors
+            errors.append((test, self._exc_info_to_string(err, test)))
+            self._mirrorOutput = True
+
     def addSuccess(self, test):
         "Called when a test has completed successfully"
         pass