From 0f550d7c79249900c7f23fdd53723a1f2443e01d Mon Sep 17 00:00:00 2001
From: Eric Brown <browne@vmware.com>
Date: Thu, 5 Mar 2015 02:05:23 -0800
Subject: [PATCH] Generate help text indicating possible values

Since the introduction of choices, the help text does not indicate
possible values of these choices.  This patch adds to the help a
list of all values that are accepted.

Change-Id: I68edda59ad7a690918f8e45abe2b3b56cd01ada7
Closes-Bug: 1427913
---
 oslo_config/generator.py            |  4 ++++
 oslo_config/tests/test_generator.py | 16 ++++++++++++++++
 tests/test_generator.py             | 16 ++++++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/oslo_config/generator.py b/oslo_config/generator.py
index 17977c21..0a4f7ce5 100644
--- a/oslo_config/generator.py
+++ b/oslo_config/generator.py
@@ -193,6 +193,10 @@ def format(self, opt):
             help_text = u'(%s)' % opt_type
         lines = self._format_help(help_text)
 
+        if getattr(opt.type, 'choices', None):
+            choices_text = ', '.join(opt.type.choices)
+            lines.append('# Allowed values: %s\n' % choices_text)
+
         for d in opt.deprecated_opts:
             lines.append('# Deprecated group/name - [%s]/%s\n' %
                          (d.group or 'DEFAULT', d.name or opt.dest))
diff --git a/oslo_config/tests/test_generator.py b/oslo_config/tests/test_generator.py
index 5922fb41..afd500f3 100644
--- a/oslo_config/tests/test_generator.py
+++ b/oslo_config/tests/test_generator.py
@@ -48,6 +48,10 @@ class GeneratorTestCase(base.BaseTestCase):
                                      'cupidatat non proident, sunt in culpa '
                                      'qui officia deserunt mollit anim id est '
                                      'laborum.'),
+        'choices_opt': cfg.StrOpt('choices_opt',
+                                  default='a',
+                                  choices=('a', 'b', 'c'),
+                                  help='a string with choices'),
         'deprecated_opt': cfg.StrOpt('bar',
                                      deprecated_name='foobar',
                                      help='deprecated'),
@@ -280,6 +284,18 @@ class GeneratorTestCase(base.BaseTestCase):
 '(string value)'
 '''
 #long_help = <None>
+''')),
+        ('choices_opt',
+         dict(opts=[('test', [(None, [opts['choices_opt']])])],
+              expected='''[DEFAULT]
+
+#
+# From test
+#
+
+# a string with choices (string value)
+# Allowed values: a, b, c
+#choices_opt = a
 ''')),
         ('deprecated',
          dict(opts=[('test', [('foo', [opts['deprecated_opt']])])],
diff --git a/tests/test_generator.py b/tests/test_generator.py
index 6717da08..41ddfec3 100644
--- a/tests/test_generator.py
+++ b/tests/test_generator.py
@@ -52,6 +52,10 @@ class GeneratorTestCase(base.BaseTestCase):
                                      'cupidatat non proident, sunt in culpa '
                                      'qui officia deserunt mollit anim id est '
                                      'laborum.'),
+        'choices_opt': cfg.StrOpt('choices_opt',
+                                  default='a',
+                                  choices=('a', 'b', 'c'),
+                                  help='a string with choices'),
         'deprecated_opt': cfg.StrOpt('bar',
                                      deprecated_name='foobar',
                                      help='deprecated'),
@@ -295,6 +299,18 @@ class GeneratorTestCase(base.BaseTestCase):
 '(string value)'
 '''
 #long_help = <None>
+''')),
+        ('choices_opt',
+         dict(opts=[('test', [(None, [opts['choices_opt']])])],
+              expected='''[DEFAULT]
+
+#
+# From test
+#
+
+# a string with choices (string value)
+# Allowed values: a, b, c
+#choices_opt = a
 ''')),
         ('deprecated',
          dict(opts=[('test', [('foo', [opts['deprecated_opt']])])],