Skip completion of non-default scorable blocks.

If a scorable block either has a custom completion strategy, or is
marked as excluded from completion, don't record a completion when its
score is updated.

lms/djangoapps/completion/handlers.py

@@ -7,8 +7,10 @@ from __future__ import absolute_import, division, print_function, unicode_litera
 from django.contrib.auth.models import User
 from django.dispatch import receiver
 
-from opaque_keys.edx.keys import CourseKey, UsageKey
 from lms.djangoapps.grades.signals.signals import PROBLEM_WEIGHTED_SCORE_CHANGED
+from opaque_keys.edx.keys import CourseKey, UsageKey
+from xblock.completable import XBlockCompletionMode
+from xblock.core import XBlock
 
 from .models import BlockCompletion
 from . import waffle
@@ -21,9 +23,14 @@ def scorable_block_completion(sender, **kwargs):  # pylint: disable=unused-argum
     """
     if not waffle.waffle().is_enabled(waffle.ENABLE_COMPLETION_TRACKING):
         return
-    user = User.objects.get(id=kwargs['user_id'])
     course_key = CourseKey.from_string(kwargs['course_id'])
     block_key = UsageKey.from_string(kwargs['usage_id'])
+    block_cls = XBlock.load_class(block_key.block_type)
+    if getattr(block_cls, 'completion_mode', XBlockCompletionMode.COMPLETABLE) != XBlockCompletionMode.COMPLETABLE:
+        return
+    if getattr(block_cls, 'has_custom_completion', False):
+        return
+    user = User.objects.get(id=kwargs['user_id'])
     if kwargs.get('score_deleted'):
         completion = 0.0
     else:

lms/djangoapps/completion/tests/test_handlers.py

@@ -10,6 +10,8 @@ from mock import patch
 from opaque_keys.edx.keys import CourseKey
 from pytz import utc
 import six
+from xblock.completable import XBlockCompletionMode
+from xblock.core import XBlock
 
 from lms.djangoapps.grades.signals.signals import PROBLEM_WEIGHTED_SCORE_CHANGED
 from student.tests.factories import UserFactory
@@ -19,6 +21,24 @@ from ..models import BlockCompletion
 from ..test_utils import CompletionWaffleTestMixin
 
 
+class CustomScorableBlock(XBlock):
+    """
+    A scorable block with a custom completion strategy.
+    """
+    has_score = True
+    has_custom_completion = True
+    completion_mode = XBlockCompletionMode.COMPLETABLE
+
+
+class ExcludedScorableBlock(XBlock):
+    """
+    A scorable block that is excluded from completion tracking.
+    """
+    has_score = True
+    has_custom_completion = False
+    completion_mode = XBlockCompletionMode.EXCLUDED
+
+
 @ddt.ddt
 class ScorableCompletionHandlerTestCase(CompletionWaffleTestMixin, TestCase):
     """
@@ -27,43 +47,79 @@ class ScorableCompletionHandlerTestCase(CompletionWaffleTestMixin, TestCase):
 
     def setUp(self):
         super(ScorableCompletionHandlerTestCase, self).setUp()
+        self.course_key = CourseKey.from_string('edx/course/beta')
+        self.scorable_block_key = self.course_key.make_usage_key(block_type='problem', block_id='red')
         self.user = UserFactory.create()
-        self.course_key = CourseKey.from_string("course-v1:a+valid+course")
-        self.block_key = self.course_key.make_usage_key(block_type="video", block_id="mah-video")
         self.override_waffle_switch(True)
 
-    @ddt.data(
-        ({'score_deleted': True}, 0.0),
-        ({'score_deleted': False}, 1.0),
-        ({}, 1.0),
-    )
-    @ddt.unpack
-    def test_handler_submits_completion(self, params, expected_completion):
+    def call_scorable_block_completion_handler(self, block_key, score_deleted=None):
+        """
+        Call the scorable completion signal handler for the specified block.
+
+        Optionally takes a value to pass as score_deleted.
+        """
+        if score_deleted is None:
+            params = {}
+        else:
+            params = {'score_deleted': score_deleted}
         handlers.scorable_block_completion(
             sender=self,
             user_id=self.user.id,
             course_id=six.text_type(self.course_key),
-            usage_id=six.text_type(self.block_key),
+            usage_id=six.text_type(block_key),
             weighted_earned=0.0,
             weighted_possible=3.0,
             modified=datetime.utcnow().replace(tzinfo=utc),
             score_db_table='submissions',
             **params
         )
-        completion = BlockCompletion.objects.get(user=self.user, course_key=self.course_key, block_key=self.block_key)
+
+    @ddt.data(
+        (True, 0.0),
+        (False, 1.0),
+        (None, 1.0),
+    )
+    @ddt.unpack
+    def test_handler_submits_completion(self, score_deleted, expected_completion):
+        self.call_scorable_block_completion_handler(self.scorable_block_key, score_deleted)
+        completion = BlockCompletion.objects.get(
+            user=self.user,
+            course_key=self.course_key,
+            block_key=self.scorable_block_key,
+        )
         self.assertEqual(completion.completion, expected_completion)
 
+    @XBlock.register_temp_plugin(CustomScorableBlock, 'custom_scorable')
+    def test_handler_skips_custom_block(self):
+        custom_block_key = self.course_key.make_usage_key(block_type='custom_scorable', block_id='green')
+        self.call_scorable_block_completion_handler(custom_block_key)
+        completion = BlockCompletion.objects.filter(
+            user=self.user,
+            course_key=self.course_key,
+            block_key=custom_block_key,
+        )
+        self.assertFalse(completion.exists())
+
+    @XBlock.register_temp_plugin(ExcludedScorableBlock, 'excluded_scorable')
+    def test_handler_skips_excluded_block(self):
+        excluded_block_key = self.course_key.make_usage_key(block_type='excluded_scorable', block_id='blue')
+        self.call_scorable_block_completion_handler(excluded_block_key)
+        completion = BlockCompletion.objects.filter(
+            user=self.user,
+            course_key=self.course_key,
+            block_key=excluded_block_key,
+        )
+        self.assertFalse(completion.exists())
+
     def test_signal_calls_handler(self):
         user = UserFactory.create()
-        course_key = CourseKey.from_string("course-v1:a+valid+course")
-        block_key = course_key.make_usage_key(block_type="video", block_id="mah-video")
 
         with patch('lms.djangoapps.completion.handlers.scorable_block_completion') as mock_handler:
             PROBLEM_WEIGHTED_SCORE_CHANGED.send_robust(
                 sender=self,
                 user_id=user.id,
-                course_id=six.text_type(course_key),
-                usage_id=six.text_type(block_key),
+                course_id=six.text_type(self.course_key),
+                usage_id=six.text_type(self.scorable_block_key),
                 weighted_earned=0.0,
                 weighted_possible=3.0,
                 modified=datetime.utcnow().replace(tzinfo=utc),