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

1 files changed, 31 insertions, 7 deletions

diff --git a/Lib/unittest/test/support.py b/Lib/unittest/test/support.py
index dbe4ddc..02e8f3a 100644
--- a/Lib/unittest/test/support.py
+++ b/Lib/unittest/test/support.py
@@ -41,7 +41,7 @@ class TestHashing(object):
                 self.fail("Problem hashing %s and %s: %s" % (obj_1, obj_2, e))
 
 
-class LoggingResult(unittest.TestResult):
+class _BaseLoggingResult(unittest.TestResult):
     def __init__(self, log):
         self._events = log
         super().__init__()
@@ -52,7 +52,7 @@ class LoggingResult(unittest.TestResult):
 
     def startTestRun(self):
         self._events.append('startTestRun')
-        super(LoggingResult, self).startTestRun()
+        super().startTestRun()
 
     def stopTest(self, test):
         self._events.append('stopTest')
@@ -60,7 +60,7 @@ class LoggingResult(unittest.TestResult):
 
     def stopTestRun(self):
         self._events.append('stopTestRun')
-        super(LoggingResult, self).stopTestRun()
+        super().stopTestRun()
 
     def addFailure(self, *args):
         self._events.append('addFailure')
@@ -68,7 +68,7 @@ class LoggingResult(unittest.TestResult):
 
     def addSuccess(self, *args):
         self._events.append('addSuccess')
-        super(LoggingResult, self).addSuccess(*args)
+        super().addSuccess(*args)
 
     def addError(self, *args):
         self._events.append('addError')
@@ -76,15 +76,39 @@ class LoggingResult(unittest.TestResult):
 
     def addSkip(self, *args):
         self._events.append('addSkip')
-        super(LoggingResult, self).addSkip(*args)
+        super().addSkip(*args)
 
     def addExpectedFailure(self, *args):
         self._events.append('addExpectedFailure')
-        super(LoggingResult, self).addExpectedFailure(*args)
+        super().addExpectedFailure(*args)
 
     def addUnexpectedSuccess(self, *args):
         self._events.append('addUnexpectedSuccess')
-        super(LoggingResult, self).addUnexpectedSuccess(*args)
+        super().addUnexpectedSuccess(*args)
+
+
+class LegacyLoggingResult(_BaseLoggingResult):
+    """
+    A legacy TestResult implementation, without an addSubTest method,
+    which records its method calls.
+    """
+
+    @property
+    def addSubTest(self):
+        raise AttributeError
+
+
+class LoggingResult(_BaseLoggingResult):
+    """
+    A TestResult implementation which records its method calls.
+    """
+
+    def addSubTest(self, test, subtest, err):
+        if err is None:
+            self._events.append('addSubTestSuccess')
+        else:
+            self._events.append('addSubTestFailure')
+        super().addSubTest(test, subtest, err)
 
 
 class ResultWithNoStartTestRunStopTestRun(object):