Add solution to remove extra whitespaces from OL <lines> tag

Related to #550

openlp/plugins/songs/lib/importers/openlyrics.py

@@ -61,7 +61,15 @@ class OpenLyricsImport(SongImport):
                 # Pass a file object, because lxml does not cope with some
                 # special characters in the path (see lp:757673 and lp:744337).
                 parsed_file = etree.parse(file_path.open('rb'), parser)
-                xml = etree.tostring(parsed_file).decode()
+
+                # Remove whitespaces from <lines> tags and its descendants
+                root = parsed_file.getroot()
+                for elem in root.iter('{*}lines'):
+                    self._strip_whitespace(elem)
+                    for subelem in elem.iter('*'):
+                        self._strip_whitespace(subelem)
+
+                xml = etree.tostring(root).decode()
                 self.open_lyrics.xml_to_song(xml)
             except etree.XMLSyntaxError:
                 log.exception('XML syntax error in file {path}'.format(path=file_path))
@@ -71,3 +79,12 @@ class OpenLyricsImport(SongImport):
                                                                                             name=file_path,
                                                                                             text=exception.log_message))
                 self.log_error(file_path, exception.display_message)
+
+    def _strip_whitespace(self, elem):
+        """
+        Remove leading and trailing whitespace from the 'text' and 'tail' attributes of an etree._Element object
+        """
+        if elem.text is not None:
+            elem.text = elem.text.strip()
+        if elem.tail is not None:
+            elem.tail = elem.tail.strip()

tests/functional/openlp_plugins/songs/test_openlyricsimport.py

@@ -234,3 +234,31 @@ class TestOpenLyricsImport(TestCase, TestMixin):
             # THEN: add_songbook_entry should have been called twice
             assert mocked_song.method_calls[0][1][1] == '48'
             assert mocked_song.method_calls[1][1][1] == '445 A'
+
+    def test_leading_and_trailing_whitespaces_inside_lines_tags_are_removed(self):
+        """
+        Test that leading and trailing whitespace inside <lines> tags and its descendants are removed
+        """
+        # GIVEN: One OpenLyrics XML with extra whitespaces in <lines> tag (Amazing_Grace_1.xml)
+        # and a copy which only difference is that it lacks those whitespaces (Amazing_Grace_2.xml)
+        mocked_manager = MagicMock()
+        mocked_import_wizard = MagicMock()
+        importer = OpenLyricsImport(mocked_manager, file_paths=[])
+        importer.import_wizard = mocked_import_wizard
+        importer.open_lyrics = MagicMock()
+        importer.open_lyrics.xml_to_song = MagicMock()
+
+        # WHEN: Importing the file not having those whitespaces...
+        importer.import_source = [TEST_PATH / 'Amazing_Grace_2.xml']
+        importer.do_import()
+
+        # keep the parsed XML which is assumed to be the first positional argument of the xml_to_song() method
+        importer.open_lyrics.xml_to_song.assert_called()
+        no_whitespaces_xml = importer.open_lyrics.xml_to_song.call_args[0][0]
+
+        # ... and importing the file having those whitespaces
+        importer.import_source = [TEST_PATH / 'Amazing_Grace_1.xml']
+        importer.do_import()
+
+        # THEN: The last call of the xml_to_song() method should have got the same XML content as its first call
+        importer.open_lyrics.xml_to_song.assert_called_with(no_whitespaces_xml)

tests/resources/songs/openlyrics/Amazing_Grace_1.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<song xmlns="http://openlyrics.info/namespace/2009/song"
+      version="0.8"
+      createdIn="OpenLP 1.9.0"
+      modifiedIn="MyApp 0.0.1"
+      modifiedDate="2012-04-10T22:00:00+10:00">
+  <properties>
+    <titles>
+      <title>Amazing Grace</title>
+    </titles>
+  </properties>
+  <lyrics>
+    <verse name="v1">
+      <lines>
+        Amazing grace, how sweet the sound<br/>
+        That saved a wretch like me!<br/>
+        I once was lost, but now am found,<br/>
+        Was blind but now I see.
+      </lines>
+    </verse>
+  </lyrics>
+</song>

tests/resources/songs/openlyrics/Amazing_Grace_2.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<song xmlns="http://openlyrics.info/namespace/2009/song"
+      version="0.8"
+      createdIn="OpenLP 1.9.0"
+      modifiedIn="MyApp 0.0.1"
+      modifiedDate="2012-04-10T22:00:00+10:00">
+  <properties>
+    <titles>
+      <title>Amazing Grace</title>
+    </titles>
+  </properties>
+  <lyrics>
+    <verse name="v1">
+      <lines>Amazing grace, how sweet the sound<br/>That saved a wretch like me!<br/>I once was lost, but now am found,<br/>Was blind but now I see.</lines>
+    </verse>
+  </lyrics>
+</song>