Update CourseGradeFactory().iter() to return exception objects

lms/djangoapps/grades/new/course_grade_factory.py

@@ -18,7 +18,7 @@ class CourseGradeFactory(object):
     """
     Factory class to create Course Grade objects.
     """
-    GradeResult = namedtuple('GradeResult', ['student', 'course_grade', 'err_msg'])
+    GradeResult = namedtuple('GradeResult', ['student', 'course_grade', 'error'])
 
     def create(self, user, course=None, collected_block_structure=None, course_structure=None, course_key=None):
         """
@@ -108,7 +108,7 @@ class CourseGradeFactory(object):
                 try:
                     method = CourseGradeFactory().update if force_update else CourseGradeFactory().create
                     course_grade = method(user, course, course_data.collected_structure, course_structure, course_key)
-                    yield self.GradeResult(user, course_grade, "")
+                    yield self.GradeResult(user, course_grade, None)
 
                 except Exception as exc:  # pylint: disable=broad-except
                     # Keep marching on even if this student couldn't be graded for
@@ -119,7 +119,7 @@ class CourseGradeFactory(object):
                         course_data.course_key,
                         exc.message
                     )
-                    yield self.GradeResult(user, None, exc.message)
+                    yield self.GradeResult(user, None, exc)
 
     @staticmethod
     def _create_zero(user, course_data):

lms/djangoapps/grades/tests/test_grades.py

@@ -101,7 +101,7 @@ class TestGradeIteration(SharedModuleStoreTestCase):
         with self.assertNumQueries(4):
             all_course_grades, all_errors = self._course_grades_and_errors_for(self.course, self.students)
         self.assertEqual(
-            all_errors,
+            {student: all_errors[student].message for student in all_errors},
             {
                 student3: "Error for student3.",
                 student4: "Error for student4.",
@@ -130,10 +130,10 @@ class TestGradeIteration(SharedModuleStoreTestCase):
         students_to_course_grades = {}
         students_to_errors = {}
 
-        for student, course_grade, err_msg in CourseGradeFactory().iter(students, course):
+        for student, course_grade, error in CourseGradeFactory().iter(students, course):
             students_to_course_grades[student] = course_grade
-            if err_msg:
-                students_to_errors[student] = err_msg
+            if error:
+                students_to_errors[student] = error
 
         return students_to_course_grades, students_to_errors
 

lms/djangoapps/instructor_task/tasks_helper/grades.py

@@ -322,10 +322,10 @@ class CourseGradeReport(object):
         certificate_whitelist = CertificateWhitelist.objects.filter(course_id=context.course_id, whitelist=True)
         whitelisted_user_ids = [entry.user_id for entry in certificate_whitelist]
         success_rows, error_rows = [], []
-        for user, course_grade, err_msg in CourseGradeFactory().iter(users, course_key=context.course_id):
+        for user, course_grade, error in CourseGradeFactory().iter(users, course_key=context.course_id):
             if not course_grade:
                 # An empty gradeset means we failed to grade a student.
-                error_rows.append([user.id, user.username, err_msg])
+                error_rows.append([user.id, user.username, error.message])
             else:
                 success_rows.append(
                     [user.id, user.email, user.username] +
@@ -365,11 +365,12 @@ class ProblemGradeReport(object):
         current_step = {'step': 'Calculating Grades'}
 
         course = get_course_by_id(course_id)
-        for student, course_grade, err_msg in CourseGradeFactory().iter(enrolled_students, course):
+        for student, course_grade, error in CourseGradeFactory().iter(enrolled_students, course):
             student_fields = [getattr(student, field_name) for field_name in header_row]
             task_progress.attempted += 1
 
             if not course_grade:
+                err_msg = error.message
                 # There was an error grading this student.
                 if not err_msg:
                     err_msg = u'Unknown error'

lms/djangoapps/instructor_task/tests/test_tasks_helper.py

@@ -132,7 +132,7 @@ class TestInstructorGradeReport(InstructorGradeReportTestCase):
         progress dict and uploaded to the report store.
         """
         mock_grades_iter.return_value = [
-            (self.create_student('username', 'student@example.com'), None, 'Cannot grade student')
+            (self.create_student('username', 'student@example.com'), None, TypeError('Cannot grade student'))
         ]
         result = CourseGradeReport.generate(None, None, self.course.id, None, 'graded')
         self.assertDictContainsSubset({'attempted': 1, 'succeeded': 0, 'failed': 1}, result)
@@ -315,7 +315,7 @@ class TestInstructorGradeReport(InstructorGradeReportTestCase):
             (
                 self.create_student('username', 'student@example.com'),
                 mock_course_grade,
-                '',
+                None,
             )
         ]
         result = CourseGradeReport.generate(None, None, self.course.id, None, 'graded')
@@ -667,7 +667,7 @@ class TestProblemGradeReport(TestReportMixin, InstructorTaskModuleTestCase):
         """
         student = self.create_student(u'username', u'student@example.com')
         mock_grades_iter.return_value = [
-            (student, None, error_message)
+            (student, None, Exception(error_message))
         ]
         result = ProblemGradeReport.generate(None, None, self.course.id, None, 'graded')
         self.assertDictContainsSubset({'attempted': 1, 'succeeded': 0, 'failed': 1}, result)