Merge pull request #7 from jedipi/feature/no-none-typing

don't try to type values as none

layeredconfig/dictsource.py

@@ -34,7 +34,7 @@ def subsection(self, key):
 
     def typed(self, key):
         # if we have it, we can type it
-        return key in self.source        
+        return key in self.source and self.source[key] is not None
 
     def has(self, key):
         # should has return true for types or only for real values?

tests/test_layeredconfig.py

@@ -1274,6 +1274,12 @@ def test_commandline_implicit_typing(self):
         cfg = LayeredConfig(Defaults({}), cmdlinesrc)
         self.assertEqual(cfg.force, True)
 
+    def test_layered_typing_for_none_values_in_lower_priority(self):
+        source1 = Defaults({'key': None})
+        source2 = Environment({'KEY': 3})
+        config = LayeredConfig(source1, source2)
+        self.assertEquals(config.key, 3)
+
 
 class TestTypingINIFile(TestINIFileHelper,
                         TestLayeredConfigHelper,