bpo-4080: unittest durations (#12271)

Lib/unittest/result.py

@@ -43,6 +43,7 @@ class TestResult(object):
         self.skipped = []
         self.expectedFailures = []
         self.unexpectedSuccesses = []
+        self.collectedDurations = []
         self.shouldStop = False
         self.buffer = False
         self.tb_locals = False
@@ -157,6 +158,12 @@ class TestResult(object):
         """Called when a test was expected to fail, but succeed."""
         self.unexpectedSuccesses.append(test)
 
+    def addDuration(self, test, elapsed):
+        """Called when a test finished to run, regardless of its outcome."""
+        # support for a TextTestRunner using an old TestResult class
+        if hasattr(self, "collectedDurations"):
+            self.collectedDurations.append((test, elapsed))
+
     def wasSuccessful(self):
         """Tells whether or not this result was a success."""
         # The hasattr check is for test_result's OldResult test.  That