Add unit tests for get_local_key and get_natural_key.

tests/functional/openlp_core_utils/test_utils.py

@@ -5,7 +5,7 @@ from unittest import TestCase
 
 from mock import patch
 
-from openlp.core.utils import get_filesystem_encoding, _get_frozen_path
+from openlp.core.utils import get_filesystem_encoding, _get_frozen_path, get_local_key, get_natural_key
 
 class TestUtils(TestCase):
     """
@@ -56,3 +56,28 @@ class TestUtils(TestCase):
             # THEN: The frozen parameter is returned
             assert _get_frozen_path(u'frozen', u'not frozen') == u'frozen', u'Should return "frozen"'
 
+    def get_local_key_test(self):
+        """
+        Test the get_local_key(string) function
+        """
+        with patch(u'openlp.core.utils.languagemanager.LanguageManager.get_language') as mocked_get_language:
+            # GIVEN: The language is German
+            # 0x00C3 (A with diaresis) should be sorted as "A". 0x00DF (sharp s) should be sorted as "ss".
+            mocked_get_language.return_value = u'de'
+            unsorted_list = [u'Auszug', u'Aushang', u'\u00C4u\u00DFerung']
+            # WHEN: We sort the list and use get_locale_key() to generate the sorting keys
+            # THEN: We get a properly sorted list
+            assert sorted(unsorted_list, key=get_local_key) == [u'Aushang', u'\u00C4u\u00DFerung', u'Auszug'], u'Strings should be sorted properly'
+
+    def get_natural_key_test(self):
+        """
+        Test the get_natural_key(string) function
+        """
+        with patch(u'openlp.core.utils.languagemanager.LanguageManager.get_language') as mocked_get_language:
+            # GIVEN: The language is English (a language, which sorts digits before letters)
+            mocked_get_language.return_value = u'en'
+            unsorted_list = [u'item 10a', u'item 3b', u'1st item']
+            # WHEN: We sort the list and use get_natural_key() to generate the sorting keys
+            # THEN: We get a properly sorted list
+            assert sorted(unsorted_list, key=get_natural_key) == [u'1st item', u'item 3b', u'item 10a'], u'Numbers should be sortet naturally'
+