project.test_views: test handling of invalid reference order.

Past bugs in the project editing forms have allowed project references to
be created with 'order=None', or with two references having the same
'order'.  Either situation should now prevent the project from being
submitted; check that this is the case.

ReferenceFormSet should allow these situations to be fixed manually:
if the confirm_reference_order checkbox is checked, then the 'order'
of all references should be updated; and if that box is not checked,
the 'order' of existing references should be untouched.  Check that
this works as expected.

physionet-django/project/test_views.py

@@ -1,5 +1,6 @@
 
 import base64
+import html.parser
 import os
 from http import HTTPStatus
 import json
@@ -41,6 +42,26 @@ def _basic_auth(username, password, encoding='UTF-8'):
     return 'Basic ' + token
 
 
+def _parse_html_form_fields(content):
+    """
+    Parse HTML and return all form fields as a dictionary.
+
+    Note that this currently only handles input elements, not other
+    form elements such as select or textarea.  It also makes no
+    distinction between multiple forms.
+    """
+    fields = {}
+
+    class Parser(html.parser.HTMLParser):
+        def handle_starttag(self, tag, attrs):
+            attrs = dict(attrs)
+            if tag == 'input' and 'name' in attrs:
+                fields[attrs['name']] = attrs.get('value', '')
+
+    Parser().feed(content)
+    return fields
+
+
 class TestAccessPresubmission(TestMixin):
     """
     Test that certain views or content in their various states can only
@@ -558,6 +579,55 @@ def test_content(self):
         project.refresh_from_db()
         self.assertFalse(project.is_submittable())
 
+    def test_reference_order(self):
+        """
+        Test handling of references with invalid order.
+        """
+        self.client.login(username=self.AUTHOR, password=self.PASSWORD)
+
+        project = ActiveProject.objects.get(title=self.PROJECT_TITLE)
+        self.assertEqual(project.references.count(), 0)
+        self.assertTrue(project.is_submittable())
+
+        # References with distinct order values are okay.
+        ref1 = project.references.create(description="asdf", order=1)
+        ref2 = project.references.create(description="ghjk", order=2)
+        self.assertTrue(project.is_submittable())
+
+        # Same order value for two references is an error.
+        ref1.order = 2
+        ref1.save()
+        self.assertFalse(project.is_submittable())
+
+        # Order value of None is an error.
+        ref2.order = None
+        ref2.save()
+        self.assertFalse(project.is_submittable())
+
+        content_url = reverse('project_content', args=(project.slug,))
+        response = self.client.get(content_url)
+        data = _parse_html_form_fields(response.content.decode())
+
+        # Try submitting form without confirm_reference_order.
+        # Existing order values should be unchanged.
+        data.pop('confirm_reference_order', None)
+        response = self.client.post(content_url, data=data)
+        ref1.refresh_from_db()
+        self.assertEqual(ref1.order, 2)
+        ref2.refresh_from_db()
+        self.assertEqual(ref2.order, None)
+        self.assertFalse(project.is_submittable())
+
+        # Try submitting form with confirm_reference_order.
+        # Order values should be unique.
+        data['confirm_reference_order'] = '1'
+        response = self.client.post(content_url, data=data)
+        ref1.refresh_from_db()
+        self.assertEqual(ref1.order, 1)
+        ref2.refresh_from_db()
+        self.assertEqual(ref2.order, 2)
+        self.assertTrue(project.is_submittable())
+
 
 class TestProjectTransfer(TestCase):
     """