Refs #31811 -- Added optional timing outputs to the test runner.

tests/test_runner/test_discover_runner.py

@@ -8,7 +8,9 @@ from unittest import (
 from django.db import connections
 from django.test import SimpleTestCase
 from django.test.runner import DiscoverRunner
-from django.test.utils import captured_stderr, captured_stdout
+from django.test.utils import (
+    NullTimeKeeper, TimeKeeper, captured_stderr, captured_stdout,
+)
 from django.utils.version import PY37
 
 
@@ -324,6 +326,24 @@ class DiscoverRunnerTests(SimpleTestCase):
             DiscoverRunner(enable_faulthandler=False)
             mocked_enable.assert_not_called()
 
+    def test_timings_not_captured(self):
+        runner = DiscoverRunner(timing=False)
+        with captured_stderr() as stderr:
+            with runner.time_keeper.timed('test'):
+                pass
+            runner.time_keeper.print_results()
+        self.assertTrue(isinstance(runner.time_keeper, NullTimeKeeper))
+        self.assertNotIn('test', stderr.getvalue())
+
+    def test_timings_captured(self):
+        runner = DiscoverRunner(timing=True)
+        with captured_stderr() as stderr:
+            with runner.time_keeper.timed('test'):
+                pass
+            runner.time_keeper.print_results()
+        self.assertTrue(isinstance(runner.time_keeper, TimeKeeper))
+        self.assertIn('test', stderr.getvalue())
+
 
 class DiscoverRunnerGetDatabasesTests(SimpleTestCase):
     runner = DiscoverRunner(verbosity=2)