refactor generator closures to private methods

Move inline closures to enable unit testing of methods.
Refactored additional code to enable future improvements of generated
comments.

Change-Id: I03e96b0ed10d5fcd2b61ee9cfcde4c0a34f78a54

2 files changed, 113 insertions, 29 deletions

diff --git a/oslo_config/generator.py b/oslo_config/generator.py
index 3e801d0..b00ac43 100644
--- a/oslo_config/generator.py
+++ b/oslo_config/generator.py
@@ -287,6 +287,36 @@ def on_load_failure_callback(*args, **kwargs):
     raise
 
 
+def _output_opts(f, group, namespaces):
+    f.format_group(group)
+    for (namespace, opts) in sorted(namespaces,
+                                    key=operator.itemgetter(0)):
+        f.write('\n#\n# From %s\n#\n' % namespace)
+        for opt in opts:
+            f.write('\n')
+            f.format(opt)
+
+
+def _get_group_name(item):
+    group = item[0]
+    # The keys of the groups dictionary could be an OptGroup. Otherwise the
+    # help text of an OptGroup wouldn't be part of the generated sample
+    # file. It could also be just a plain group name without any further
+    # attributes. That's the reason why we have to differentiate here.
+    return group.name if isinstance(group, cfg.OptGroup) else group
+
+
+def _get_groups(conf_ns):
+    groups = {'DEFAULT': []}
+    for namespace, listing in conf_ns:
+        for group, opts in listing:
+            if not opts:
+                continue
+            namespaces = groups.setdefault(group or 'DEFAULT', [])
+            namespaces.append((namespace, opts))
+    return groups
+
+
 def generate(conf):
     """Generate a sample config file.
 
@@ -303,39 +333,12 @@ def generate(conf):
     formatter = _OptFormatter(output_file=output_file,
                               wrap_width=conf.wrap_width)
 
-    groups = {'DEFAULT': []}
-    for namespace, listing in _list_opts(conf.namespace):
-        for group, opts in listing:
-            if not opts:
-                continue
-            namespaces = groups.setdefault(group or 'DEFAULT', [])
-            namespaces.append((namespace, opts))
-
-    def _output_opts(f, group, namespaces):
-        f.format_group(group)
-        for (namespace, opts) in sorted(namespaces,
-                                        key=operator.itemgetter(0)):
-            f.write('\n#\n# From %s\n#\n' % namespace)
-            for opt in opts:
-                f.write('\n')
-                f.format(opt)
-
-    def _get_group_name(item):
-        group = item[0]
-        # The keys of the groups dictionary could be an OptGroup. Otherwise the
-        # help text of an OptGroup wouldn't be part of the generated sample
-        # file. It could also be just a plain group name without any further
-        # attributes. That's the reason why we have to distinct this here.
-        if isinstance(group, cfg.OptGroup):
-            group_name = group.name
-        else:
-            group_name = group
-        return group_name
+    groups = _get_groups(_list_opts(conf.namespace))
 
     # Output the "DEFAULT" section as the very first section
     _output_opts(formatter, 'DEFAULT', groups.pop('DEFAULT'))
 
-    # output all other config sections with opts in alphabetical order
+    # output all other config sections with groups in alphabetical order
     for group, namespaces in sorted(groups.items(), key=_get_group_name):
         formatter.write('\n\n')
         _output_opts(formatter, group, namespaces)
diff --git a/oslo_config/tests/test_generator.py b/oslo_config/tests/test_generator.py
index 152c59a..ee94327 100644
--- a/oslo_config/tests/test_generator.py
+++ b/oslo_config/tests/test_generator.py
@@ -18,6 +18,7 @@ import fixtures
 import mock
 from oslotest import base
 from six import moves
+import tempfile
 import testscenarios
 
 from oslo_config import cfg
@@ -849,6 +850,86 @@ class IgnoreDoublesTestCase(base.BaseTestCase):
         self.assertEqual(len(config_opts), slurped_opts)
 
 
+class GeneratorAdditionalTestCase(base.BaseTestCase):
+
+    opts = [cfg.StrOpt('foo', help='foo option', default='fred'),
+            cfg.StrOpt('bar', help='bar option'),
+            cfg.StrOpt('foo_bar', help='foobar'),
+            cfg.StrOpt('str_opt', help='a string'),
+            cfg.BoolOpt('bool_opt', help='a boolean'),
+            cfg.IntOpt('int_opt', help='an integer')]
+
+    def test_get_group_name(self):
+        name = "group1"
+        item = [name]
+        self.assertEqual(name, generator._get_group_name(item))
+
+    def test_get_group_name_as_optgroup(self):
+        name = "group2"
+        item = [cfg.OptGroup(name)]
+        self.assertEqual(name, generator._get_group_name(item))
+
+    def test_get_groups_empty_ns(self):
+        groups = generator._get_groups([])
+        self.assertEqual({'DEFAULT': []}, groups)
+
+    def test_get_groups_single_ns(self):
+        config = [("namespace1", [
+                   ("beta", self.opts),
+                   ("alpha", self.opts)])]
+        groups = generator._get_groups(config)
+        self.assertEqual(['DEFAULT', 'alpha', 'beta'], sorted(groups))
+
+    def test_get_groups_multiple_ns(self):
+        config = [("namespace1", [
+                   ("beta", self.opts),
+                   ("alpha", self.opts)]),
+                  ("namespace2", [
+                   ("gamma", self.opts),
+                   ("alpha", self.opts)])]
+        groups = generator._get_groups(config)
+        self.assertEqual(['DEFAULT', 'alpha', 'beta', 'gamma'], sorted(groups))
+
+    def test_output_opts_empty_default(self):
+
+        config = [("namespace1", [
+                   ("alpha", [])])]
+        groups = generator._get_groups(config)
+
+        fd, tmp_file = tempfile.mkstemp()
+        f = open(tmp_file, 'w+')
+        formatter = generator._OptFormatter(output_file=f)
+        expected = '''[DEFAULT]
+'''
+        generator._output_opts(formatter, 'DEFAULT', groups.pop('DEFAULT'))
+        f.close()
+        content = open(tmp_file).read()
+        self.assertEqual(expected, content)
+
+    def test_output_opts_group(self):
+
+        config = [("namespace1", [
+                   ("alpha", [self.opts[0]])])]
+        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
+#
+
+# foo option (string value)
+#foo = fred
+'''
+        generator._output_opts(formatter, 'alpha', groups.pop('alpha'))
+        f.close()
+        content = open(tmp_file).read()
+        self.assertEqual(expected, content)
+
+
 class GeneratorRaiseErrorTestCase(base.BaseTestCase):
 
     def test_generator_raises_error(self):