Ensure stable ordering of attributes for tests

pyxform/survey.py

@@ -713,8 +713,20 @@ def date_stamp(self):
         """Returns a date string with the format of %Y_%m_%d."""
         return self._created.strftime("%Y_%m_%d")
 
-    def _to_ugly_xml(self):
-        return '<?xml version="1.0"?>' + self.xml().toxml()
+    def _to_testable_xml(self):
+        """Preserves attribute ordering across all Python versions.
+
+        See python_test_case.reorder_attributes for related code.
+        """
+        tree = ETree.fromstring(self.xml().toxml())
+        for el in tree.iter():
+            attrib = el.attrib
+            if len(attrib) > 1:
+                # adjust attribute order, e.g. by sorting
+                attribs = sorted(attrib.items())
+                attrib.clear()
+                attrib.update(attribs)
+        return ETree.tostring(tree, encoding="utf-8").decode("utf-8")
 
     def _to_pretty_xml(self):
         """

pyxform/tests_v1/pyxform_test_case.py

@@ -343,6 +343,8 @@ def reorder_attributes(root):
 
         See bottom of https://docs.python.org/3/library/xml.etree.elementtree.html#element-objects and 
         https://github.com/python/cpython/commit/a3697db0102b9b6747fe36009e42f9b08f0c1ea8 for more information.
+
+        See survey._to_testable_xml for related code.
         """
     for el in root.iter():
         attrib = el.attrib

pyxform/tests_v1/test_dynamic_default.py

@@ -40,7 +40,7 @@ def test_handling_dynamic_default(self):
             kwargs={"id_string": "id", "name": "dynamic", "title": "some-title"},
             autoname=False,
         )
-        survey_xml = survey._to_pretty_xml()
+        survey_xml = survey._to_testable_xml()
 
         self.assertContains(survey_xml, "<first_name/>", 1)
         self.assertContains(survey_xml, "<last_name>not_func$</last_name>", 1)
@@ -92,7 +92,7 @@ def test_handling_dynamic_default_in_repeat(self):
             kwargs={"id_string": "id", "name": "dynamic", "title": "some-title"},
             autoname=False,
         )
-        survey_xml = survey._to_pretty_xml()
+        survey_xml = survey._to_testable_xml()
 
         self.assertContains(survey_xml, "<feeling>not_func$</feeling>", 2)
         self.assertContains(survey_xml, "<age/>", 2)

pyxform/tests_v1/test_whitespace.py

@@ -30,6 +30,6 @@ def test_values_without_whitespaces_are_processed_successfully(self):
 
         survey = self.md_to_pyxform_survey(md_raw=md)
         expected = """<submission action="https://odk.ona.io/random_person/submission" base64RsaPublicKey="MIIB" method="post"/>"""
-        xml = survey._to_pretty_xml()
+        xml = survey._to_testable_xml()
         self.assertEqual(1, xml.count(expected))
         self.assertPyxformXform(md=md, xml__contains=expected, run_odk_validate=True)