config: Add LogLevel ConfigValue and tests.

mopidy/utils/config.py

@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 
+import logging
 import re
 
 
@@ -122,3 +123,19 @@ class List(ConfigValue):
 
     def serialize(self, value):
         return '\n  '.join(value)
+
+
+class LogLevel(ConfigValue):
+    levels = {'critical' : logging.CRITICAL,
+              'error' : logging.ERROR,
+              'warning' : logging.WARNING,
+              'info' : logging.INFO,
+              'debug' : logging.DEBUG}
+
+    def deserialize(self, value):
+        if value.lower() not in self.levels:
+            raise ValueError('%r must be one of %s.' % (value, ', '.join(self.levels)))
+        return self.levels.get(value.lower())
+
+    def serialize(self, value):
+        return dict((v, k) for k, v in self.levels.items()).get(value)

tests/utils/config_test.py

@@ -1,5 +1,7 @@
 from __future__ import unicode_literals
 
+import logging
+
 from mopidy.utils import config
 
 from tests import unittest
@@ -192,3 +194,34 @@ class ListTest(unittest.TestCase):
         value = config.List()
         self.assertRegexpMatches(value.serialize(['foo', 'bar', 'baz']),
                                                  r'foo\n\s*bar\n\s*baz')
+
+
+class BooleanTest(unittest.TestCase):
+    levels = {'critical' : logging.CRITICAL,
+              'error' : logging.ERROR,
+              'warning' : logging.WARNING,
+              'info' : logging.INFO,
+              'debug' : logging.DEBUG}
+
+    def test_deserialize_converts_to_numeric_loglevel(self):
+        value = config.LogLevel()
+        for name, level in self.levels.items():
+            self.assertEqual(level, value.deserialize(name))
+            self.assertEqual(level, value.deserialize(name.upper()))
+            self.assertEqual(level, value.deserialize(name.capitalize()))
+
+    def test_deserialize_fails_on_bad_data(self):
+        value = config.LogLevel()
+        with self.assertRaises(ValueError):
+            value.deserialize('nope')
+        with self.assertRaises(ValueError):
+            value.deserialize('sure')
+
+    def test_serialize_converts_to_string(self):
+        value = config.LogLevel()
+        for name, level in self.levels.items():
+            self.assertEqual(name, value.serialize(level))
+
+    def test_serialize_unknown_level(self):
+        value = config.LogLevel()
+        self.assertIsNone(value.serialize(1337))