Extract error message truncating into a method (unittest.TestCase._truncateMessage).
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index 7608e30..de58968 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -690,13 +690,15 @@
diffMsg = '\n' + '\n'.join(
difflib.ndiff(pprint.pformat(seq1).splitlines(),
pprint.pformat(seq2).splitlines()))
- if max_diff is None or len(diffMsg) <= max_diff:
- standardMsg += diffMsg
- else:
- standardMsg += diffMsg[:max_diff] + TRUNCATED_DIFF
+ standardMsg = self._truncateMessage(standardMsg, diffMsg, max_diff)
msg = self._formatMessage(msg, standardMsg)
self.fail(msg)
+ def _truncateMessage(self, message, diff, max_diff):
+ if max_diff is None or len(diff) <= max_diff:
+ return message + diff
+ return message + diff[:max_diff] + TRUNCATED_DIFF
+
def assertListEqual(self, list1, list2, msg=None):
"""A list-specific equality assertion.