Add CheckChangeHasDescription.

presubmit_canned_checks.py

 #!/usr/bin/env python
 # Copyright (c) 2006-2009 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.
 
 """Generic presubmit checks that can be reused by other presubmit checks."""
 
 
 ### Description checks
 
@@ skipping 35 matching lines @@
   """Checks that the user didn't add 'DO NOT ' + 'SUBMIT' to the CL description.
   """
   keyword = 'DO NOT ' + 'SUBMIT'
   if keyword in input_api.change.DescriptionText():
     return [output_api.PresubmitError(
         keyword + " is present in the changelist description.")]
   else:
     return []
 
 
+def CheckChangeHasDescription(input_api, output_api):
+  """Checks the CL description is not empty."""
+  text = input_api.change.DescriptionText()
+  if text.strip() == '':
+    if input_api.is_committing:
+      return [output_api.PresubmitError("Add a description.")]
+    else:
+      return [output_api.PresubmitNotifyResult("Add a description.")]
+  return []
+
 ### Content checks
 
 def CheckDoNotSubmitInFiles(input_api, output_api):
   """Checks that the user didn't add 'DO NOT ' + 'SUBMIT' to any files."""
   keyword = 'DO NOT ' + 'SUBMIT'
   # We want to check every text files, not just source files.
   for f, line_num, line in input_api.RightHandSideLines(lambda x: x):
     if keyword in line:
       text = 'Found ' + keyword + ' in %s, line %s' % (f.LocalPath(), line_num)
       return [output_api.PresubmitError(text)]
@@ skipping 114 matching lines @@
                                   long_text=input_api.traceback.format_exc()))
 
   buffer = input_api.cStringIO.StringIO()
   results = input_api.unittest.TextTestRunner(stream=buffer, verbosity=0).run(
       input_api.unittest.TestSuite(tests_suite))
   if not results.wasSuccessful():
     outputs.append(message_type("%d unit tests failed." %
                                 (len(results.failures) + len(results.errors)),
                                 long_text=buffer.getvalue()))
   return outputs