'git try': a) Give users help when they ask for it, b) Don't start try job if...

trychange.py

 #!/usr/bin/python
 # Copyright (c) 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.
 """Client-side script to send a try job to the try server. It communicates to
 the try server by either writting to a svn repository or by directly connecting
 to the server by HTTP.
 """
 
 import datetime
@@ skipping 582 matching lines @@
                    const=_SendChangeSVN,
                    dest="send_patch",
                    help="Use SVN to talk to the try server")
   group.add_option("-S", "--svn_repo",
                    metavar="SVN_URL",
                    help="SVN url to use to write the changes in; --use_svn is "
                         "implied when using --svn_repo")
   parser.add_option_group(group)
 
   options, args = parser.parse_args(argv)
-  if len(args) == 1 and args[0] == 'help':
+
+  # Note that the args array includes the script name, so
+  # a single argument results in len(args) == 2.

[Evan Martin, 2010/07/29 23:36:19]

Wow, I have probably written the same bug a million times then!  :(

I knew that argv included the script name, but it seems totally busted to me
that optparse also gives it to you.  :(

+
+  # If they've asked for help, give it to them
+  if len(args) == 2 and args[1] == 'help':
     parser.print_help()
+    return 0
+
+  # If they've said something confusing, don't spawn a try job until you
+  # understand what they want.
+  if len(args) > 1:
+    plural = ""
+    if len(args) > 2:
+      plural = "s"
+    print "Argument%s \"%s\" not understood" % (plural, " ".join(args[1:]))
+    parser.print_help()
+    return 1
 
   LOG_FORMAT = '%(levelname)s %(filename)s(%(lineno)d): %(message)s'
   if not swallow_exception:
     if options.verbose == 0:
       logging.basicConfig(level=logging.WARNING, format=LOG_FORMAT)
     elif options.verbose == 1:
       logging.basicConfig(level=logging.INFO, format=LOG_FORMAT)
     elif options.verbose > 1:
       logging.basicConfig(level=logging.DEBUG, format=LOG_FORMAT)
 
@@ skipping 121 matching lines @@
   except (InvalidScript, NoTryServerAccess), e:
     if swallow_exception:
       return 1
     print e
     return 1
   return 0
 
 
 if __name__ == "__main__":
   sys.exit(TryChange(None, [], False))