Fix Offline Grade Calculation

lms/djangoapps/instructor/offline_gradecalc.py

@@ -13,19 +13,20 @@ from json import JSONEncoder
 from courseware import grades, models
 from courseware.courses import get_course_by_id
 from django.contrib.auth.models import User
+from opaque_keys import OpaqueKey
+from opaque_keys.edx.keys import UsageKey
+from xmodule.graders import Score
 
 from instructor.utils import DummyRequest
 
 
 class MyEncoder(JSONEncoder):
-
-    def _iterencode(self, obj, markers=None):
-        if isinstance(obj, tuple) and hasattr(obj, '_asdict'):
-            gen = self._iterencode_dict(obj._asdict(), markers)
-        else:
-            gen = JSONEncoder._iterencode(self, obj, markers)
-        for chunk in gen:
-            yield chunk
+    """ JSON Encoder that can encode OpaqueKeys """
+    def default(self, obj):  # pylint: disable=method-hidden
+        """ Encode an object that the default encoder hasn't been able to. """
+        if isinstance(obj, OpaqueKey):
+            return unicode(obj)
+        return JSONEncoder.default(self, obj)
 
 
 def offline_grade_calculation(course_key):
@@ -50,9 +51,15 @@ def offline_grade_calculation(course_key):
         request.session = {}
 
         gradeset = grades.grade(student, request, course, keep_raw_scores=True)
-        gs = enc.encode(gradeset)
+        # Convert Score namedtuples to dicts:
+        totaled_scores = gradeset['totaled_scores']
+        for section in totaled_scores:
+            totaled_scores[section] = [score._asdict() for score in totaled_scores[section]]
+        gradeset['raw_scores'] = [score._asdict() for score in gradeset['raw_scores']]
+        # Encode as JSON and save:
+        gradeset_str = enc.encode(gradeset)
         ocg, _created = models.OfflineComputedGrade.objects.get_or_create(user=student, course_id=course_key)
-        ocg.gradeset = gs
+        ocg.gradeset = gradeset_str
         ocg.save()
         print "%s done" % student  	# print statement used because this is run by a management command
 
@@ -93,4 +100,17 @@ def student_grades(student, request, course, keep_raw_scores=False, use_offline=
             msg='Error: no offline gradeset available for {}, {}'.format(student, course.id)
         )
 
-    return json.loads(ocg.gradeset)
+    gradeset = json.loads(ocg.gradeset)
+    # Convert score dicts back to Score tuples:
+
+    def score_from_dict(encoded):
+        """ Given a formerly JSON-encoded Score tuple, return the Score tuple """
+        if encoded['module_id']:
+            encoded['module_id'] = UsageKey.from_string(encoded['module_id'])
+        return Score(**encoded)
+
+    totaled_scores = gradeset['totaled_scores']
+    for section in totaled_scores:
+        totaled_scores[section] = [score_from_dict(score) for score in totaled_scores[section]]
+    gradeset['raw_scores'] = [score_from_dict(score) for score in gradeset['raw_scores']]
+    return gradeset

lms/djangoapps/instructor/tests/test_offline_gradecalc.py

@@ -0,0 +1,107 @@
+"""
+Tests for offline_gradecalc.py
+"""
+import json
+from mock import patch
+
+from courseware.models import OfflineComputedGrade
+from student.models import CourseEnrollment
+from student.tests.factories import UserFactory
+from xmodule.graders import Score
+from xmodule.modulestore import ModuleStoreEnum
+from xmodule.modulestore.django import modulestore
+from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
+from xmodule.modulestore.tests.factories import CourseFactory
+
+from ..offline_gradecalc import offline_grade_calculation, student_grades
+
+
+def mock_grade(_student, _request, course, **_kwargs):
+    """ Return some fake grade data to mock grades.grade() """
+    return {
+        'grade': u'Pass',
+        'totaled_scores': {
+            u'Homework': [
+                Score(earned=10.0, possible=10.0, graded=True, section=u'Subsection 1', module_id=None),
+            ]
+        },
+        'percent': 0.85,
+        'raw_scores': [
+            Score(
+                earned=5.0, possible=5.0, graded=True, section=u'Numerical Input',
+                module_id=course.id.make_usage_key('problem', 'problem1'),
+            ),
+            Score(
+                earned=5.0, possible=5.0, graded=True, section=u'Multiple Choice',
+                module_id=course.id.make_usage_key('problem', 'problem2'),
+            ),
+        ],
+        'section_breakdown': [
+            {'category': u'Homework', 'percent': 1.0, 'detail': u'Homework 1 - Test - 100% (10/10)', 'label': u'HW 01'},
+            {'category': u'Final Exam', 'prominent': True, 'percent': 0, 'detail': u'Final = 0%', 'label': u'Final'}
+        ],
+        'grade_breakdown': [
+            {'category': u'Homework', 'percent': 0.85, 'detail': u'Homework = 85.00% of a possible 85.00%'},
+            {'category': u'Final Exam', 'percent': 0.0, 'detail': u'Final Exam = 0.00% of a possible 15.00%'}
+        ]
+    }
+
+
+class TestOfflineGradeCalc(ModuleStoreTestCase):
+    """ Test Offline Grade Calculation with some mocked grades """
+    def setUp(self):
+        super(TestOfflineGradeCalc, self).setUp()
+
+        with modulestore().default_store(ModuleStoreEnum.Type.split):  # Test with split b/c old mongo keys are messy
+            self.course = CourseFactory.create()
+        self.user = UserFactory.create()
+        CourseEnrollment.enroll(self.user, self.course.id)
+
+        patcher = patch('courseware.grades.grade', new=mock_grade)
+        patcher.start()
+        self.addCleanup(patcher.stop)
+
+    def test_output(self):
+        offline_grades = OfflineComputedGrade.objects
+        self.assertEqual(offline_grades.filter(user=self.user, course_id=self.course.id).count(), 0)
+        offline_grade_calculation(self.course.id)
+        result = offline_grades.get(user=self.user, course_id=self.course.id)
+        decoded = json.loads(result.gradeset)
+        self.assertEqual(decoded['grade'], "Pass")
+        self.assertEqual(decoded['percent'], 0.85)
+        self.assertEqual(decoded['totaled_scores'], {
+            "Homework": [
+                {"earned": 10.0, "possible": 10.0, "graded": True, "section": "Subsection 1", "module_id": None}
+            ]
+        })
+        self.assertEqual(decoded['raw_scores'], [
+            {
+                "earned": 5.0,
+                "possible": 5.0,
+                "graded": True,
+                "section": "Numerical Input",
+                "module_id": unicode(self.course.id.make_usage_key('problem', 'problem1')),
+            },
+            {
+                "earned": 5.0,
+                "possible": 5.0,
+                "graded": True,
+                "section": "Multiple Choice",
+                "module_id": unicode(self.course.id.make_usage_key('problem', 'problem2')),
+            }
+        ])
+        self.assertEqual(decoded['section_breakdown'], [
+            {"category": "Homework", "percent": 1.0, "detail": "Homework 1 - Test - 100% (10/10)", "label": "HW 01"},
+            {"category": "Final Exam", "label": "Final", "percent": 0, "detail": "Final = 0%", "prominent": True}
+        ])
+        self.assertEqual(decoded['grade_breakdown'], [
+            {"category": "Homework", "percent": 0.85, "detail": "Homework = 85.00% of a possible 85.00%"},
+            {"category": "Final Exam", "percent": 0.0, "detail": "Final Exam = 0.00% of a possible 15.00%"}
+        ])
+
+    def test_student_grades(self):
+        """ Test that the data returned by student_grades() and grades.grade() match """
+        offline_grade_calculation(self.course.id)
+        with patch('courseware.grades.grade', side_effect=AssertionError('Should not re-grade')):
+            result = student_grades(self.user, None, self.course, use_offline=True)
+        self.assertEqual(result, mock_grade(self.user, None, self.course))