bpo-33718: regrtest: use format_duration() to display failed tests (GH-7686)

* Enhance also format_duration(): work on integers and rounds towards
  +infinity (math.ceil).
* Write unit tests on format_duration()

1 files changed, 25 insertions, 0 deletions

diff --git a/Lib/test/test_regrtest.py b/Lib/test/test_regrtest.py
index 1041152..af332ad 100644
--- a/Lib/test/test_regrtest.py
+++ b/Lib/test/test_regrtest.py
@@ -19,6 +19,7 @@ import threading
 import unittest
 from test import libregrtest
 from test import support
+from test.libregrtest import utils
 
 
 Py_DEBUG = hasattr(sys, 'getobjects')
@@ -980,5 +981,29 @@ class ArgsTestCase(BaseTestCase):
                                   failed=testname, rerun=testname)
 
 
+class TestUtils(unittest.TestCase):
+    def test_format_duration(self):
+        self.assertEqual(utils.format_duration(0),
+                         '0 ms')
+        self.assertEqual(utils.format_duration(1e-9),
+                         '1 ms')
+        self.assertEqual(utils.format_duration(10e-3),
+                         '10 ms')
+        self.assertEqual(utils.format_duration(1.5),
+                         '1 sec 500 ms')
+        self.assertEqual(utils.format_duration(1),
+                         '1 sec')
+        self.assertEqual(utils.format_duration(2 * 60),
+                         '2 min')
+        self.assertEqual(utils.format_duration(2 * 60 + 1),
+                         '2 min 1 sec')
+        self.assertEqual(utils.format_duration(3 * 3600),
+                         '3 hour')
+        self.assertEqual(utils.format_duration(3 * 3600  + 2 * 60 + 1),
+                         '3 hour 2 min')
+        self.assertEqual(utils.format_duration(3 * 3600 + 1),
+                         '3 hour 1 sec')
+
+
 if __name__ == '__main__':
     unittest.main()