config: Extract encode and decode helpers from String

mopidy/__main__.py

@@ -44,8 +44,12 @@ def main():
 
     extensions = []  # Make sure it is defined before the finally block
 
+    # TODO: figure out a way to make the boilerplate in this file reusable in
+    # scanner and other places we need it.
+
     try:
         create_file_structures()
+        # TODO: run raw logging config trough escape code etc, or just validate?
         logging_config = config_lib.load(config_files, config_overrides)
         log.setup_logging(
             logging_config, options.verbosity_level, options.save_debug_log)

mopidy/config/types.py

@@ -8,6 +8,21 @@ from mopidy.utils import path
 from mopidy.config import validators
 
 
+def decode(value):
+    if isinstance(value, unicode):
+        return value
+    # TODO: only unescape \n \t and \\?
+    return value.decode('string-escape').decode('utf-8')
+
+
+def encode(value):
+    if not isinstance(value, unicode):
+        return value
+    for char in ('\\', '\n', '\t'):  # TODO: more escapes?
+        value = value.replace(char, char.encode('unicode-escape'))
+    return value.encode('utf-8')
+
+
 class ConfigValue(object):
     """Represents a config key's value and how to handle it.
 
@@ -80,10 +95,7 @@ class String(ConfigValue):
     Supported kwargs: ``optional``, ``choices``, and ``secret``.
     """
     def deserialize(self, value):
-        if not isinstance(value, unicode):
-            # TODO: only unescape \n \t and \\?
-            value = value.decode('string-escape').decode('utf-8')
-        value = value.strip()
+        value = decode(value).strip()
         validators.validate_required(value, not self.optional)
         validators.validate_choice(value, self.choices)
         if not value:
@@ -91,11 +103,7 @@ class String(ConfigValue):
         return value
 
     def serialize(self, value):
-        if isinstance(value, unicode):
-            for char in ('\\', '\n', '\t'):  # TODO: more escapes?
-                value = value.replace(char, char.encode('unicode-escape'))
-            value = value.encode('utf-8')
-        return value
+        return encode(value)
 
 
 class Integer(ConfigValue):

tests/config/types_test.py

@@ -10,6 +10,8 @@ from mopidy.config import types
 
 from tests import unittest
 
+# TODO: DecodeTest and EncodeTest
+
 
 class ConfigValueTest(unittest.TestCase):
     def test_init(self):