Log exceptions that terminate CQ loop

tests/commit_queue_test.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unit tests for commit_queue.py."""
 
+import logging
 import os
 import StringIO
 import sys
 import time
+import traceback
 import unittest
 
 ROOT_DIR = os.path.dirname(os.path.abspath(__file__))
 sys.path.insert(0, os.path.join(ROOT_DIR, '..'))
 
 import commit_queue
 import context
 import creds
 
 from testing_support import auto_stub
@@ skipping 44 matching lines @@
     return '1%s1' % user
 
 
 class CommitQueueTest(auto_stub.TestCase):
   def setUp(self):
     super(CommitQueueTest, self).setUp()
     self.mock(sys, 'argv', ['commit_queue.py'])
     self.mock(sys, 'stdout', StringIO.StringIO())
     self.mock(sys, 'stderr', StringIO.StringIO())
     self.mock(commit_queue.projects, 'load_project', None)
+    self.mock(commit_queue, 'SetupLogging', lambda _: None)
+    # Setup logging attached to the mocked sys.stderr, printing
+    # only the exception name to make tests less fragile.
+    handler = logging.StreamHandler()
+    formatter = logging.Formatter()
+    formatter.formatException = lambda _: traceback.format_exc(0)
+    handler.setFormatter(formatter)
+    logging.getLogger().handlers = [handler]
     self._time = 1
     self.mock(time, 'time', self._get_time)
     self.mock(creds, 'Credentials', self._get_cred)
 
   def tearDown(self):
     try:
       if not self.has_failed():
         self._check('stdout', '')
         self._check('stderr', '')
     finally:
@@ skipping 49 matching lines @@
     self.assertEqual('chromium', calls[0][0])
     self.assertEqual('commit-bot@chromium.org', calls[0][1])
     self.assertEqual(
         os.path.join(os.path.dirname(ROOT_DIR), 'workdir'), calls[0][2])
     self.assertEqual(None, calls[0][4])
     self._check(
         'stdout',
         'Using read-only Rietveld\n'
         'Using read-only checkout\n'
         'Using read-only chromium-status interface\n')
-    self._check('stderr', 'Saving db...     \nDone!            \n')
+    self._check(
+        'stderr',
+        'CQ loop terminating\n'
+        'Traceback (most recent call last):\n'
+        'Stop\n\n'
+        'Saving db...\ndb save successful.\n')
 
   def testDryRun(self):
     sys.argv.extend(('--project', 'chromium'))
     pc = PendingManagerMock(self)
     self.mock(
         commit_queue.projects,
         'load_project',
         lambda *args: pc)
     try:
       commit_queue.main()
       self.fail()
     except Stop:
       pass
     self.assertEqual(
         'ReadOnlyCheckout', pc.context.checkout.__class__.__name__)
     # Ugh.
     self.assertEqual(
         'RietveldMock', pc.context.rietveld.__class__.__name__)
     self._check(
         'stdout',
         'Using read-only Rietveld\n'
         'Using read-only checkout\n'
         'Using read-only chromium-status interface\n')
-    self._check('stderr', 'Saving db...     \nDone!            \n')
+    self._check(
+        'stderr',
+        'CQ loop terminating\n'
+        'Traceback (most recent call last):\n'
+        'Stop\n\n'
+        'Saving db...\ndb save successful.\n')
 
 
 if __name__ == '__main__':
   unittest.main()