WIP squash me [no ci]

need to rethink how ValidationErrors are raised when
hard_extended_due_date is patched to be before soft_extended_due_date.
Currently the API response will show that the error is from
soft_extended_due_date

autograder/rest_api/tests/test_views/test_group_views/test_group_views.py

@@ -484,9 +484,10 @@ def test_admin_update_group_deprecated_extended_due_date(self):
         group = obj_build.make_group(project=self.project)
 
         invalid_extended_due_date = "not a date"
-        self.do_patch_object_invalid_args_test(
+        response = self.do_patch_object_invalid_args_test(
             group, self.client, self.admin, self.group_url(group),
-            {'soft_extended_due_date': invalid_extended_due_date})
+            {'extended_due_date': invalid_extended_due_date})
+        self.assertIn('soft_extended_due_date', response.data)
 
         self.do_patch_object_test(
             group, self.client, self.admin, self.group_url(group),
@@ -505,15 +506,17 @@ def test_admin_update_soft_extended_due_date(self):
             project=self.project, hard_extended_due_date=self.new_due_date)
 
         invalid_soft_extended_due_date = "not a date"
-        self.do_patch_object_invalid_args_test(
+        response = self.do_patch_object_invalid_args_test(
             group, self.client, self.admin, self.group_url(group),
             {'soft_extended_due_date': invalid_soft_extended_due_date})
+        self.assertIn('soft_extended_due_date', response.data)
 
         # soft_extended_due_date can't be later than hard_extended_due_date
         invalid_soft_extended_due_date = self.new_due_date + datetime.timedelta(days=1)
-        self.do_patch_object_invalid_args_test(
+        response = self.do_patch_object_invalid_args_test(
             group, self.client, self.admin, self.group_url(group),
             {'soft_extended_due_date': invalid_soft_extended_due_date})
+        self.assertIn('soft_extended_due_date', response.data)
 
         valid_soft_extended_due_date = self.new_due_date - datetime.timedelta(days=1)
         self.do_patch_object_test(
@@ -532,15 +535,17 @@ def test_admin_update_hard_extended_due_date(self):
             project=self.project, soft_extended_due_date=self.new_due_date)
 
         invalid_hard_extended_due_date = "not a date"
-        self.do_patch_object_invalid_args_test(
+        response = self.do_patch_object_invalid_args_test(
             group, self.client, self.admin, self.group_url(group),
             {'hard_extended_due_date': invalid_hard_extended_due_date})
+        self.assertIn('hard_extended_due_date', response.data)
 
         # hard_extended_due_date can't be before soft_extended_due_date
         invalid_hard_extended_due_date = self.new_due_date - datetime.timedelta(days=1)
-        self.do_patch_object_invalid_args_test(
+        response = self.do_patch_object_invalid_args_test(
             group, self.client, self.admin, self.group_url(group),
             {'hard_extended_due_date': invalid_hard_extended_due_date})
+        self.assertIn('hard_extended_due_date', response.data)
 
         valid_hard_extended_due_date = self.new_due_date + datetime.timedelta(days=1)
         self.do_patch_object_test(
@@ -578,13 +583,6 @@ def test_admin_update_group_error_non_allowed_domain_guest(self):
             {'member_names': [allowed_guest.username, non_allowed_guest.username]})
         self.assertIn('members', response.data)
 
-    def test_admin_update_group_bad_date(self):
-        group = obj_build.make_group(project=self.project)
-        response = self.do_patch_object_invalid_args_test(
-            group, self.client, self.admin, self.group_url(group),
-            {'soft_extended_due_date': 'not a date'})
-        self.assertIn('soft_extended_due_date', response.data)
-
     def test_non_admin_update_group_permission_denied(self):
         group = obj_build.make_group(project=self.project)
         staff = obj_build.make_staff_user(self.course)