Allow use of empty string as a value for a Attribute

tostr will always return a string regardless of input,
no check on value is needed as empty string is allowed.

suds/mx/appender.py

@@ -176,8 +176,7 @@ def append(self, parent, content):
         if content.tag.startswith('_') and isinstance(content.type, Attribute):
             attr = content.tag[1:]
             value = tostr(content.value)
-            if value:
-                parent.set(attr, value)
+            parent.set(attr, value)
         else:
             child = self.node(content)
             child.setText(tostr(content.value))
@@ -275,8 +274,7 @@ def append(self, parent, content):
         if content.tag.startswith('_') and isinstance(content.type, Attribute):
             attr = content.tag[1:]
             value = tostr(content.value)
-            if value:
-                parent.set(attr, value)
+            parent.set(attr, value)
         else:
             child = self.node(content)
             child.setText(content.value)

tests/test_mx_appender.py

@@ -0,0 +1,83 @@
+# -*- coding: utf-8 -*-
+
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the (LGPL) GNU Lesser General Public License as published by the
+# Free Software Foundation; either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU Library Lesser General Public License
+# for more details at ( http://www.gnu.org/licenses/lgpl.html ).
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+# written by: Jurko Gospodnetić ( jurko.gospodnetic@pke.hr )
+
+"""
+Suds MX appender unit tests.
+
+Implemented using the 'pytest' testing framework.
+
+"""
+
+if __name__ == "__main__":
+    import testutils
+    testutils.run_using_pytest(globals())
+
+from suds.mx.appender import PrimitiveAppender, TextAppender
+from suds.xsd.sxbasic import Attribute
+
+from unittest.mock import Mock, patch
+
+
+class MockContent:
+    def __init__(self, tag, value):
+        self.tag = tag
+        self.value = value
+        self.type = Mock(spec=Attribute)
+
+
+class TestPrimitiveAppender:
+
+    @patch("suds.mx.appender.Appender.__init__", return_value=None)
+    def test_append_string(self, _):
+        parent = Mock()
+        content = MockContent("_TEST_TAG", "")
+        primitive_appender = PrimitiveAppender()
+        primitive_appender.append(parent, content)
+        parent.set.assert_called_once_with(content.tag.lstrip("_"), content.value)
+
+    @patch("suds.mx.appender.Appender.__init__", return_value=None)
+    def test_append_string_to_child(self, _):
+        parent = Mock()
+        content = MockContent("TEST_TAG", "")
+        primitive_appender = PrimitiveAppender()
+        mock_node = Mock()
+        primitive_appender.node = Mock(return_value=mock_node)
+        primitive_appender.append(parent, content)
+        mock_node.setText.assert_called_once_with(content.value)
+        parent.append.assert_called_once_with(mock_node)
+
+
+class TestTextAppender:
+
+    @patch("suds.mx.appender.Appender.__init__", return_value=None)
+    def test_append_string(self, _):
+        parent = Mock()
+        content = MockContent("_TEST_TAG", "")
+        primitive_appender = TextAppender()
+        primitive_appender.append(parent, content)
+        parent.set.assert_called_once_with(content.tag.lstrip("_"), content.value)
+
+    @patch("suds.mx.appender.Appender.__init__", return_value=None)
+    def test_append_string_to_child(self, _):
+        parent = Mock()
+        content = MockContent("TEST_TAG", "")
+        primitive_appender = TextAppender()
+        mock_node = Mock()
+        primitive_appender.node = Mock(return_value=mock_node)
+        primitive_appender.append(parent, content)
+        mock_node.setText.assert_called_once_with(content.value)
+        parent.append.assert_called_once_with(mock_node)