Updating the require_course_staff decorator to work with json handler.

TNL-900

openassessment/xblock/staff_info_mixin.py

@@ -4,9 +4,11 @@ determine the flow of the problem.
 """
 import copy
 from functools import wraps
+import json
 import logging
 
 from xblock.core import XBlock
+import sys
 from openassessment.assessment.errors import (
     PeerAssessmentInternalError, PeerAssessmentWorkflowError,
 )
@@ -74,7 +76,10 @@ def require_course_staff(error_key, with_json_handler=False):
                 "STUDENT_INFO": xblock._(u"You do not have permission to access student information."),
 
             }
-            if (not xblock.is_course_staff and with_json_handler) or xblock.in_studio_preview:
+
+            if not xblock.is_course_staff and with_json_handler:
+                return {"success": False, "msg": permission_errors[error_key]}
+            elif not xblock.is_course_staff or xblock.in_studio_preview:
                 return xblock.render_error(permission_errors[error_key])
             else:
                 return func(xblock, *args, **kwargs)

openassessment/xblock/test/test_staff_info.py

@@ -520,8 +520,9 @@ class TestCourseStaff(XBlockHandlerTestCase):
     def test_cancel_submission_without_reason(self, xblock):
         # If we're not course staff, we shouldn't be able to see the
         # cancel submission option
-        xblock.xmodule_runtime = Mock(user_is_staff=False)
-        self.assertFalse(xblock.is_course_staff)
+        xblock.xmodule_runtime = self._create_mock_runtime(
+            xblock.scope_ids.usage_id, False, False, "Bob"
+        )
 
         resp = self.request(xblock, 'cancel_submission', json.dumps({}))
         self.assertIn("you do not have permission", resp.decode('utf-8').lower())