diff options
Diffstat (limited to 'Lib/unittest/test/test_case.py')
| -rw-r--r-- | Lib/unittest/test/test_case.py | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Lib/unittest/test/test_case.py b/Lib/unittest/test/test_case.py index 1db433f32c..c74a539515 100644 --- a/Lib/unittest/test/test_case.py +++ b/Lib/unittest/test/test_case.py @@ -685,6 +685,42 @@ class Test_TestCase(unittest.TestCase, TestEquality, TestHashing): else: self.fail('assertMultiLineEqual did not fail') + def testAssertEqual_diffThreshold(self): + # check threshold value + self.assertEqual(self._diffThreshold, 2**16) + # disable madDiff to get diff markers + self.maxDiff = None + + # set a lower threshold value and add a cleanup to restore it + old_threshold = self._diffThreshold + self._diffThreshold = 2**8 + self.addCleanup(lambda: setattr(self, '_diffThreshold', old_threshold)) + + # under the threshold: diff marker (^) in error message + s = 'x' * (2**7) + with self.assertRaises(self.failureException) as cm: + self.assertEqual(s + 'a', s + 'b') + self.assertIn('^', str(cm.exception)) + self.assertEqual(s + 'a', s + 'a') + + # over the threshold: diff not used and marker (^) not in error message + s = 'x' * (2**9) + # if the path that uses difflib is taken, _truncateMessage will be + # called -- replace it with explodingTruncation to verify that this + # doesn't happen + def explodingTruncation(message, diff): + raise SystemError('this should not be raised') + old_truncate = self._truncateMessage + self._truncateMessage = explodingTruncation + self.addCleanup(lambda: setattr(self, '_truncateMessage', old_truncate)) + + s1, s2 = s + 'a', s + 'b' + with self.assertRaises(self.failureException) as cm: + self.assertEqual(s1, s2) + self.assertNotIn('^', str(cm.exception)) + self.assertEqual(str(cm.exception), '%r != %r' % (s1, s2)) + self.assertEqual(s + 'a', s + 'a') + def testAssertCountEqual(self): a = object() self.assertCountEqual([1, 2, 3], [3, 2, 1]) |