Fleshed out get_filesystem_encoding_test thanks to Jonathan C

tests/functional/openlp_core_utils/test_utils.py

@@ -15,7 +15,30 @@ class TestUtils(TestCase):
         """
         Test the get_filesystem_encoding() function
         """
-        assert False, u'This test needs to be written'
+        with patch(u'sys.getfilesystemencoding') as mocked_getfilesystemencoding, \
+             patch(u'sys.getdefaultencoding') as mocked_getdefaultencoding:
+            # GIVEN: sys.getfilesystemencoding returns "cp1252"
+            mocked_getfilesystemencoding.return_value = u'cp1252'
+
+            # WHEN: get_filesystem_encoding() is called
+            result = get_filesystem_encoding()
+
+            # THEN: getdefaultencoding should have been called
+            mocked_getfilesystemencoding.assert_called_with()
+            assert not mocked_getdefaultencoding.called
+            assert result == u'cp1252', u'The result should be "cp1252"'
+
+            # GIVEN: sys.getfilesystemencoding returns None and sys.getdefaultencoding returns "utf-8"
+            mocked_getfilesystemencoding.return_value = None
+            mocked_getdefaultencoding.return_value = u'utf-8'
+
+            # WHEN: get_filesystem_encoding() is called
+            result = get_filesystem_encoding()
+
+            # THEN: getdefaultencoding should have been called
+            mocked_getfilesystemencoding.assert_called_with()
+            mocked_getdefaultencoding.assert_called_with()
+            assert result == u'utf-8', u'The result should be "utf-8"'
 
     def get_frozen_path_test(self):
         """