feat: add option to drop decoy items from scores

Co-authored-by: Agrendalath <piotr@surowiec.it>

Author: pkulkark

Changelog.md

@@ -1,6 +1,16 @@
 Drag and Drop XBlock changelog
 ==============================
 
+Version 2.7.0 (2022-11-15)
+---------------------------
+
+* Add option to drop decoy items from scores
+
+Version 2.6.0 (2022-10-24)
+---------------------------
+
+* Add package publishing workflow.
+
 Version 2.5.0 (2022-10-13)
 ---------------------------
 

README.md

@@ -182,6 +182,15 @@ score would be `100%`:
 
     score = (3 + 1) / 4
 
+Optionally, there is an alternative grading that can be enabled, by setting the
+waffle flag `drag_and_drop_v2.grading_ignore_decoys`, which will drop
+the decoy items entirely from the score calculation. The formula will change to:
+
+    score = C / R
+
+Where *C* is the number of correctly placed regular items, *R* is the number of
+required regular items.
+
 Demo Course
 -----------
 

drag_and_drop_v2/compat.py

@@ -0,0 +1,32 @@
+"""
+Compatibility layer to isolate core-platform waffle flags from implementation.
+"""
+
+# Waffle flags configuration
+
+# Namespace
+WAFFLE_NAMESPACE = "drag_and_drop_v2"
+
+# Course Waffle Flags
+# .. toggle_name: drag_and_drop_v2.grading_ignore_decoys
+# .. toggle_implementation: CourseWaffleFlag
+# .. toggle_default: False
+# .. toggle_description: Enables alternative grading for the xblock
+#    that does not include decoy items in the score.
+# .. toggle_use_cases: open_edx
+# .. toggle_creation_date: 2022-11-10
+GRADING_IGNORE_DECOYS = 'grading_ignore_decoys'
+
+
+def get_grading_ignore_decoys_waffle_flag():
+    """
+    Import and return Waffle flag for enabling alternative grading for drag_and_drop_v2 Xblock.
+    """
+    # pylint: disable=import-error,import-outside-toplevel
+    from openedx.core.djangoapps.waffle_utils import CourseWaffleFlag
+    try:
+        # HACK: The base class of the `CourseWaffleFlag` was changed in Olive.
+        #  Ref: https://github.com/openedx/public-engineering/issues/28
+        return CourseWaffleFlag(WAFFLE_NAMESPACE, GRADING_IGNORE_DECOYS, __name__)
+    except ValueError:
+        return CourseWaffleFlag(f'{WAFFLE_NAMESPACE}.{GRADING_IGNORE_DECOYS}', __name__)

drag_and_drop_v2/drag_and_drop_v2.py

@@ -27,6 +27,7 @@
 from xblockutils.resources import ResourceLoader
 from xblockutils.settings import ThemableXBlockMixin, XBlockWithSettingsMixin
 
+from .compat import get_grading_ignore_decoys_waffle_flag
 from .default_data import DEFAULT_DATA
 from .utils import (
     Constants, SHOWANSWER, DummyTranslationService, FeedbackMessage,
@@ -1212,8 +1213,15 @@ def _get_item_stats(self):
         """
         items = self._get_item_raw_stats()
 
-        correct_count = len(items.correctly_placed) + len(items.decoy_in_bank)
-        total_count = len(items.required) + len(items.decoy)
+        correct_count = len(items.correctly_placed)
+        total_count = len(items.required)
+
+        if hasattr(self.runtime, 'course_id') and \
+                get_grading_ignore_decoys_waffle_flag().is_enabled(self.runtime.course_id):
+            return correct_count, total_count
+
+        correct_count += len(items.decoy_in_bank)
+        total_count += len(items.decoy)
 
         return correct_count, total_count
 

setup.py

@@ -23,7 +23,7 @@ def package_data(pkg, root_list):
 
 setup(
     name='xblock-drag-and-drop-v2',
-    version='2.5.0',
+    version='2.7.0',
     description='XBlock - Drag-and-Drop v2',
     packages=['drag_and_drop_v2'],
     install_requires=[

tests/unit/test_standard_mode.py

@@ -6,6 +6,7 @@
 import ddt
 
 from drag_and_drop_v2.utils import FeedbackMessages
+from mock import Mock, patch
 from tests.unit.test_fixtures import BaseDragAndDropAjaxFixture
 
 
@@ -135,6 +136,53 @@ def mock_publish(_, event, params):
         self.assertEqual(1, self.block.raw_earned)
         self.assertEqual({'value': 1, 'max_value': 1, 'only_if_higher': None}, published_grades[-1])
 
+    @patch(
+        'drag_and_drop_v2.drag_and_drop_v2.get_grading_ignore_decoys_waffle_flag',
+        lambda: Mock(is_enabled=lambda _: True),
+    )
+    @ddt.data(*[random.randint(1, 50) for _ in range(5)])  # pylint: disable=star-args
+    def test_grading_ignore_decoy(self, weight):
+        self.block.weight = weight
+
+        published_grades = []
+
+        def mock_publish(_, event, params):
+            if event == 'grade':
+                published_grades.append(params)
+        self.block.runtime.publish = mock_publish
+
+        # Before the user starts working on the problem, grade should equal zero.
+        self.assertEqual(0, self.block.raw_earned)
+
+        # Drag the decoy item into one of the zones
+        self.call_handler(self.DROP_ITEM_HANDLER, {"val": 2, "zone": self.ZONE_1})
+
+        self.assertEqual(1, len(published_grades))
+        # Decoy items are not considered in the grading
+        self.assertEqual(0, self.block.raw_earned)
+        self.assertEqual(0, self.block.weighted_grade())
+        self.assertEqual({'value': 0, 'max_value': 1, 'only_if_higher': None}, published_grades[-1])
+
+        # Drag the first item into the correct zone.
+        self.call_handler(self.DROP_ITEM_HANDLER, {"val": 0, "zone": self.ZONE_1})
+
+        self.assertEqual(2, len(published_grades))
+        # The DnD test block has four items defined in the data fixtures:
+        # 1 item that belongs to ZONE_1, 1 item that belongs to ZONE_2, and two decoy items.
+        # After we drop the first item into ZONE_1, 1 out of 2 items are in the expected correct positions.
+        # The grade at this point is therefore 1/2 * weight.
+        self.assertEqual(0.5, self.block.raw_earned)
+        self.assertEqual(0.5 * self.block.weight, self.block.weighted_grade())
+        self.assertEqual({'value': 0.5, 'max_value': 1, 'only_if_higher': None}, published_grades[-1])
+
+        # Drag the second item into correct zone.
+        self.call_handler(self.DROP_ITEM_HANDLER, {"val": 1, "zone": self.ZONE_2})
+
+        self.assertEqual(3, len(published_grades))
+        # All items are now placed in the right place, the user therefore gets the full grade.
+        self.assertEqual(1, self.block.raw_earned)
+        self.assertEqual({'value': 1, 'max_value': 1, 'only_if_higher': None}, published_grades[-1])
+
     @ddt.data(True, False)
     def test_grading_deprecation(self, grade_below_one):
         self.assertFalse(self.block.has_submitted_answer())

tests/utils.py

@@ -4,7 +4,7 @@
 import random
 import re
 
-from mock import patch
+from mock import Mock, patch
 from six.moves import range
 from webob import Request
 from workbench.runtime import WorkbenchRuntime
@@ -30,6 +30,7 @@ def make_block():
     key_store = DictKeyValueStore()
     field_data = KvsFieldData(key_store)
     runtime = WorkbenchRuntime()
+    runtime.course_id = "dummy_course_id"
     def_id = runtime.id_generator.create_definition(block_type)
     usage_id = runtime.id_generator.create_usage(def_id)
     scope_ids = ScopeIds('user', block_type, def_id, usage_id)
@@ -64,6 +65,10 @@ def patch_workbench(self):
             lambda _, html: re.sub(r'"/static/([^"]*)"', r'"/course/test-course/assets/\1"', html),
             create=True,
         )
+        self.apply_patch(
+            'drag_and_drop_v2.drag_and_drop_v2.get_grading_ignore_decoys_waffle_flag',
+            lambda: Mock(is_enabled=lambda _: False),
+        )
 
     def apply_patch(self, *args, **kwargs):
         new_patch = patch(*args, **kwargs)