Fix context sensitive help for info and tempurl

Make it so that swift <cmd> --help will print the info
subcommand help for info and tempurl just like all the
other subcommands.

Also add unit tests to verify subcommand help.

Change-Id: Id3666dcf72a9727fbfda2f74c23293ada1c53aa0

Author: Alistair Coles

swiftclient/shell.py

@@ -46,6 +46,8 @@
 
 BASENAME = 'swift'
 POLICY = 'X-Storage-Policy'
+commands = ('delete', 'download', 'list', 'post',
+            'stat', 'upload', 'capabilities', 'info', 'tempurl')
 
 
 def get_conn(options):
@@ -1244,7 +1246,7 @@ def _upload_dir(path, object_queue, object_name):
 
 Optional positional arguments:
   <proxy_url>           Proxy URL of the cluster to retrieve capabilities.
-'''
+'''.strip('\n')
 st_info_help = st_capabilities_help
 
 
@@ -1344,6 +1346,12 @@ def parse_args(parser, args, enforce_requires=True):
         args = ['-h']
     (options, args) = parser.parse_args(args)
 
+    if len(args) > 1 and args[1] == '--help':
+        _help = globals().get('st_%s_help' % args[0],
+                              "no help for %s" % args[0])
+        print(_help)
+        exit()
+
     # Short circuit for tempurl, which doesn't need auth
     if len(args) > 0 and args[0] == 'tempurl':
         return options, args
@@ -1371,25 +1379,6 @@ def parse_args(parser, args, enforce_requires=True):
         'region_name': options.os_region_name,
     }
 
-    if len(args) > 1 and args[1] == '--help':
-        if args[0] == 'capabilities':
-            print(st_capabilities_help)
-        elif args[0] == 'delete':
-            print(st_delete_help)
-        elif args[0] == 'download':
-            print(st_download_help)
-        elif args[0] == 'list':
-            print(st_list_help)
-        elif args[0] == 'post':
-            print(st_post_help)
-        elif args[0] == 'stat':
-            print(st_stat_help)
-        elif args[0] == 'upload':
-            print(st_upload_help)
-        else:
-            print("no help for %s" % args[0])
-        exit()
-
     if len(args) > 1 and args[0] == "capabilities":
         return options, args
 
@@ -1588,8 +1577,6 @@ def main(arguments=None):
     (options, args) = parse_args(parser, argv[1:], enforce_requires=False)
     parser.enable_interspersed_args()
 
-    commands = ('delete', 'download', 'list', 'post',
-                'stat', 'upload', 'capabilities', 'info', 'tempurl')
     if not args or args[0] not in commands:
         parser.print_usage()
         if args:

tests/unit/test_shell.py

@@ -356,3 +356,25 @@ def test_capabilities(self, connection):
         connection.return_value.get_capabilities.return_value = {'swift': None}
         swiftclient.shell.main(argv)
         connection.return_value.get_capabilities.assert_called_with(None)
+
+
+class TestSubcommandHelp(unittest.TestCase):
+
+    def test_subcommand_help(self):
+        for command in swiftclient.shell.commands:
+            help_var = 'st_%s_help' % command
+            self.assertTrue(help_var in vars(swiftclient.shell))
+            out = six.StringIO()
+            with mock.patch('sys.stdout', out):
+                argv = ['', command, '--help']
+                self.assertRaises(SystemExit, swiftclient.shell.main, argv)
+            expected = vars(swiftclient.shell)[help_var]
+            self.assertEqual(out.getvalue().strip('\n'), expected)
+
+    def test_no_help(self):
+        out = six.StringIO()
+        with mock.patch('sys.stdout', out):
+            argv = ['', 'bad_command', '--help']
+            self.assertRaises(SystemExit, swiftclient.shell.main, argv)
+        expected = 'no help for bad_command'
+        self.assertEqual(out.getvalue().strip('\n'), expected)