generator: format string default value for List type properlymitaka-eolstable/mitaka

List type allows to pass string values as default values, which are then
handled by splitting on commas. For formatting matters, if the default
value is of string type, there is no special conversion needed, and we
can reuse the value as-is.

Change-Id: Ie9ecdfc064e886f6138b1fa9e839d8f95a7df339
Closes-Bug: #1586366
(cherry picked from commit 75e1c306630378673861d52a34de51e869183062)

2 files changed, 31 insertions, 0 deletions

diff --git a/oslo_config/tests/test_generator.py b/oslo_config/tests/test_generator.py
index 72ae1d3..4ea7100 100644
--- a/oslo_config/tests/test_generator.py
+++ b/oslo_config/tests/test_generator.py
@@ -939,6 +939,35 @@ class GeneratorAdditionalTestCase(base.BaseTestCase):
         content = open(tmp_file).read()
         self.assertEqual(expected, content)
 
+    def _test_output_default_list_opt_with_string_value(self, default):
+        opt = cfg.ListOpt('list_opt', help='a list', default=default)
+        config = [("namespace1", [
+                   ("alpha", [opt])])]
+        groups = generator._get_groups(config)
+
+        fd, tmp_file = tempfile.mkstemp()
+        f = open(tmp_file, 'w+')
+        formatter = generator._OptFormatter(output_file=f)
+        expected = '''[alpha]
+
+#
+# From namespace1
+#
+
+# a list (list value)
+#list_opt = %(default)s
+''' % {'default': default}
+        generator._output_opts(formatter, 'alpha', groups.pop('alpha'))
+        f.close()
+        content = open(tmp_file).read()
+        self.assertEqual(expected, content)
+
+    def test_output_default_list_opt_with_string_value_multiple_entries(self):
+        self._test_output_default_list_opt_with_string_value('foo,bar')
+
+    def test_output_default_list_opt_with_string_value_single_entry(self):
+        self._test_output_default_list_opt_with_string_value('foo')
+
 
 class GeneratorMutableOptionTestCase(base.BaseTestCase):
 
diff --git a/oslo_config/types.py b/oslo_config/types.py
index 2464c5c..71d7817 100644
--- a/oslo_config/types.py
+++ b/oslo_config/types.py
@@ -447,6 +447,8 @@ class List(ConfigType):
         )
 
     def _formatter(self, value):
+        if isinstance(value, six.string_types):
+            return value
         return ','.join(value)