Fix help message in case of microversions

novaclient should display help message of the proper versioned method
(based on api_version value).

Closes-Bug: #1523649
Closes-Bug: #1523651

Change-Id: I67f7fc2befde9d312400e9a1569e590bd763156e

novaclient/api_versions.py

@@ -343,7 +343,7 @@ def get_substitutions(func_name, api_version=None):
     if api_version and not api_version.is_null():
         return [m for m in substitutions
                 if api_version.matches(m.start_version, m.end_version)]
-    return substitutions
+    return sorted(substitutions, key=lambda m: m.start_version)
 
 
 def wraps(start_version, end_version=None):
@@ -368,9 +368,7 @@ def wraps(start_version, end_version=None):
                 raise exceptions.VersionNotFoundForAPIMethod(
                     obj.api_version.get_string(), name)
 
-            method = max(methods, key=lambda f: f.start_version)
-
-            return method.func(obj, *args, **kwargs)
+            return methods[-1].func(obj, *args, **kwargs)
 
         if hasattr(func, 'arguments'):
             for cli_args, cli_kwargs in func.arguments:

novaclient/shell.py

@@ -59,6 +59,9 @@ DEFAULT_OS_COMPUTE_API_VERSION = '2.latest'
 DEFAULT_NOVA_ENDPOINT_TYPE = 'publicURL'
 DEFAULT_NOVA_SERVICE_TYPE = "compute"
 
+HINT_HELP_MSG = (" [hint: use '--os-compute-api-version' flag to show help "
+                 "message for proper version]")
+
 logger = logging.getLogger(__name__)
 
 
@@ -466,19 +469,26 @@ class OpenStackComputeShell(object):
             callback = getattr(actions_module, attr)
             desc = callback.__doc__ or ''
             if hasattr(callback, "versioned"):
+                additional_msg = ""
                 subs = api_versions.get_substitutions(
                     utils.get_function_name(callback))
                 if do_help:
-                    desc += msg % {'start': subs[0].start_version.get_string(),
-                                   'end': subs[-1].end_version.get_string()}
-                else:
-                    for versioned_method in subs:
+                    additional_msg = msg % {
+                        'start': subs[0].start_version.get_string(),
+                        'end': subs[-1].end_version.get_string()}
+                    if version.is_latest():
+                        additional_msg += HINT_HELP_MSG
+                subs = [versioned_method for versioned_method in subs
                         if version.matches(versioned_method.start_version,
-                                           versioned_method.end_version):
-                            callback = versioned_method.func
-                            break
-                    else:
-                        continue
+                                           versioned_method.end_version)]
+                if subs:
+                    # use the "latest" substitution
+                    callback = subs[-1].func
+                else:
+                    # there is no proper versioned method
+                    continue
+                desc = callback.__doc__ or desc
+                desc += additional_msg
 
             action_help = desc.strip()
             arguments = getattr(callback, 'arguments', [])

novaclient/tests/unit/fake_actions_module.py

@@ -27,6 +27,11 @@ def do_fake_action():
     return 2
 
 
+@api_versions.wraps("2.0")
+def do_another_fake_action():
+    return 0
+
+
 @cliutils.arg(
     '--foo',
     start_version='2.1',

novaclient/tests/unit/test_shell.py

@@ -582,12 +582,27 @@ class TestLoadVersionedActions(utils.TestCase):
         shell = novaclient.shell.OpenStackComputeShell()
         shell.subcommands = {}
         shell._find_actions(subparsers, fake_actions_module,
-                            api_versions.APIVersion("2.10000"), True)
+                            api_versions.APIVersion("2.15"), True)
         self.assertIn('fake-action', shell.subcommands.keys())
-        expected_desc = ("(Supported by API versions '%(start)s' - "
+        expected_desc = (" (Supported by API versions '%(start)s' - "
                          "'%(end)s')") % {'start': '2.10', 'end': '2.30'}
-        self.assertIn(expected_desc,
-                      shell.subcommands['fake-action'].description)
+        self.assertEqual(expected_desc,
+                         shell.subcommands['fake-action'].description)
+
+    def test_load_versioned_actions_with_help_on_latest(self):
+        parser = novaclient.shell.NovaClientArgumentParser()
+        subparsers = parser.add_subparsers(metavar='<subcommand>')
+        shell = novaclient.shell.OpenStackComputeShell()
+        shell.subcommands = {}
+        shell._find_actions(subparsers, fake_actions_module,
+                            api_versions.APIVersion("2.latest"), True)
+        self.assertIn('another-fake-action', shell.subcommands.keys())
+        expected_desc = (" (Supported by API versions '%(start)s' - "
+                         "'%(end)s')%(hint)s") % {
+            'start': '2.0', 'end': '2.latest',
+            'hint': novaclient.shell.HINT_HELP_MSG}
+        self.assertEqual(expected_desc,
+                         shell.subcommands['another-fake-action'].description)
 
     @mock.patch.object(novaclient.shell.NovaClientArgumentParser,
                        'add_argument')
@@ -641,7 +656,6 @@ class TestLoadVersionedActions(utils.TestCase):
         shell._find_actions(subparsers, fake_actions_module,
                             api_versions.APIVersion("2.4"), True)
         mock_add_arg.assert_has_calls([
-            mock.call('-h', '--help', action='help', help='==SUPPRESS=='),
             mock.call('-h', '--help', action='help', help='==SUPPRESS=='),
             mock.call('--foo',
                       help=" (Supported by API versions '2.1' - '2.2')"),