Fix tag detection. Fixes bug 1549549.

Fixes: https://launchpad.net/bugs/1549549

openlp/plugins/songs/lib/__init__.py

@@ -256,6 +256,7 @@ class VerseType(object):
         for num, translation in enumerate(VerseType.translated_names):
             if verse_name == translation.lower():
                 return num
+        return None
 
     @staticmethod
     def from_loose_input(verse_name, default=Other):
@@ -271,7 +272,7 @@ class VerseType(object):
             if verse_index is None:
                 verse_index = VerseType.from_string(verse_name, default)
         elif len(verse_name) == 1:
-            verse_index = VerseType.from_translated_tag(verse_name, default)
+            verse_index = VerseType.from_translated_tag(verse_name, None)
             if verse_index is None:
                 verse_index = VerseType.from_tag(verse_name, default)
         else:

tests/functional/__init__.py

@@ -26,12 +26,12 @@ import sys
 from PyQt5 import QtWidgets
 
 if sys.version_info[1] >= 3:
-    from unittest.mock import ANY, MagicMock, patch, mock_open, call
+    from unittest.mock import ANY, MagicMock, patch, mock_open, call, PropertyMock
 else:
-    from mock import ANY, MagicMock, patch, mock_open, call
+    from mock import ANY, MagicMock, patch, mock_open, call, PropertyMock
 
 # Only one QApplication can be created. Use QtWidgets.QApplication.instance() when you need to "create" a  QApplication.
 application = QtWidgets.QApplication([])
 application.setApplicationName('OpenLP')
 
-__all__ = ['ANY', 'MagicMock', 'patch', 'mock_open', 'call', 'application']
+__all__ = ['ANY', 'MagicMock', 'patch', 'mock_open', 'call', 'application', 'PropertyMock']

tests/functional/openlp_plugins/songs/test_lib.py

@@ -26,7 +26,7 @@ from unittest import TestCase
 
 from openlp.plugins.songs.lib import VerseType, clean_string, clean_title, strip_rtf
 from openlp.plugins.songs.lib.songcompare import songs_probably_equal, _remove_typos, _op_length
-from tests.functional import patch, MagicMock
+from tests.functional import patch, MagicMock, PropertyMock
 
 
 class TestLib(TestCase):
@@ -477,3 +477,27 @@ class TestVerseType(TestCase):
 
             # THEN: The result should be None
             self.assertIsNone(result, 'The result should be None, but was "%s"' % result)
+
+    @patch('openlp.plugins.songs.lib.VerseType.translated_tags', new_callable=PropertyMock, return_value=['x'])
+    def from_loose_input_with_invalid_input_test(self, mocked_translated_tags):
+        """
+        Test that the from_loose_input() method returns a sane default when passed an invalid tag and None as default.
+        """
+        # GIVEN: A mocked VerseType.translated_tags
+        # WHEN: We run the from_loose_input() method with an invalid verse type, we get the specified default back
+        result = VerseType.from_loose_input('m', None)
+
+        # THEN: The result should be None
+        self.assertIsNone(result, 'The result should be None, but was "%s"' % result)
+
+    @patch('openlp.plugins.songs.lib.VerseType.translated_tags', new_callable=PropertyMock, return_value=['x'])
+    def from_loose_input_with_valid_input_test(self, mocked_translated_tags):
+        """
+        Test that the from_loose_input() method returns valid output on valid input.
+        """
+        # GIVEN: A mocked VerseType.translated_tags
+        # WHEN: We run the from_loose_input() method with a valid verse type, we get the expected VerseType back
+        result = VerseType.from_loose_input('v')
+
+        # THEN: The result should be a Verse
+        self.assertEqual(result, VerseType.Verse, 'The result should be a verse, but was "%s"' % result)