Merge pull request #15961 from edx/ret/update-schedules-on-course-start-changes

Update Schedules when start date changes on non-live courses

lms/djangoapps/certificates/tests/test_signals.py

@@ -5,12 +5,12 @@ and disabling for instructor-paced courses.
 import mock
 
 from certificates import api as certs_api
-from certificates.models import \
-    CertificateGenerationConfiguration, \
-    CertificateWhitelist, \
-    GeneratedCertificate, \
-    CertificateStatuses
-from openedx.core.djangoapps.signals.handlers import _listen_for_course_pacing_changed
+from certificates.models import (
+    CertificateGenerationConfiguration,
+    CertificateWhitelist,
+    GeneratedCertificate,
+    CertificateStatuses,
+)
 from lms.djangoapps.grades.new.course_grade_factory import CourseGradeFactory
 from lms.djangoapps.grades.tests.utils import mock_passing_grade
 from lms.djangoapps.verify_student.models import SoftwareSecurePhotoVerification
@@ -25,12 +25,11 @@ class SelfGeneratedCertsSignalTest(ModuleStoreTestCase):
     """
     Tests for enabling/disabling self-generated certificates according to course-pacing.
     """
+    ENABLED_SIGNALS = ['course_published']
 
     def setUp(self):
         super(SelfGeneratedCertsSignalTest, self).setUp()
         SelfPacedConfiguration(enabled=True).save()
-        self.course = CourseFactory.create(self_paced=True)
-        # Enable the feature
         CertificateGenerationConfiguration.objects.create(enabled=True)
 
     def test_cert_generation_flag_on_pacing_toggle(self):
@@ -38,18 +37,15 @@ class SelfGeneratedCertsSignalTest(ModuleStoreTestCase):
         Verify that signal enables or disables self-generated certificates
         according to course-pacing.
         """
-        #self-generation of cert disables by default
+        self.course = CourseFactory.create(self_paced=False, emit_signals=True)
         self.assertFalse(certs_api.cert_generation_enabled(self.course.id))
 
-        _listen_for_course_pacing_changed('store', self.course.id, self.course.self_paced)
-        #verify that self-generation of cert is enabled for self-paced course
+        self.course.self_paced = True
+        self.store.update_item(self.course, self.user.id)
         self.assertTrue(certs_api.cert_generation_enabled(self.course.id))
 
         self.course.self_paced = False
         self.store.update_item(self.course, self.user.id)
-
-        _listen_for_course_pacing_changed('store', self.course.id, self.course.self_paced)
-        # verify that self-generation of cert is disabled for instructor-paced course
         self.assertFalse(certs_api.cert_generation_enabled(self.course.id))
 
 

lms/djangoapps/certificates/tests/test_webview_views.py

@@ -12,8 +12,8 @@ from django.conf import settings
 from django.core.urlresolvers import reverse
 from django.test.client import Client, RequestFactory
 from django.test.utils import override_settings
+from freezegun import freeze_time
 from util.date_utils import strftime_localized
-from django.utils.translation import ugettext as _
 from mock import patch
 from nose.plugins.attrib import attr
 
@@ -795,6 +795,7 @@ class CertificatesViewsTests(CommonCertificatesTestCase):
         self.assertIn('course_title_0', response.content)
         self.assertIn('Signatory_Title 0', response.content)
 
+    @freeze_time('2017-09-10 00:00:00Z')
     @override_settings(FEATURES=FEATURES_WITH_CERTS_ENABLED)
     @ddt.data(
         (datetime.datetime.now() - datetime.timedelta(days=1), True),

openedx/core/djangoapps/content/course_overviews/signals.py

@@ -4,6 +4,7 @@ Signal handler for invalidating cached course overviews
 from django.dispatch.dispatcher import receiver
 
 from .models import CourseOverview
+from openedx.core.djangoapps.signals.signals import COURSE_PACING_CHANGED, COURSE_START_DATE_CHANGED
 from xmodule.modulestore.django import SignalHandler
 
 
@@ -13,7 +14,9 @@ def _listen_for_course_publish(sender, course_key, **kwargs):  # pylint: disable
     Catches the signal that a course has been published in Studio and
     updates the corresponding CourseOverview cache entry.
     """
-    CourseOverview.load_from_module_store(course_key)
+    previous_course_overview = CourseOverview.get_from_ids_if_exists([course_key]).get(course_key)
+    updated_course_overview = CourseOverview.load_from_module_store(course_key)
+    _check_for_course_changes(previous_course_overview, updated_course_overview)
 
 
 @receiver(SignalHandler.course_deleted)
@@ -27,3 +30,27 @@ def _listen_for_course_delete(sender, course_key, **kwargs):  # pylint: disable=
     from cms.djangoapps.contentstore.courseware_index import CourseAboutSearchIndexer
     # Delete course entry from Course About Search_index
     CourseAboutSearchIndexer.remove_deleted_items(course_key)
+
+
+def _check_for_course_changes(previous_course_overview, updated_course_overview):
+    if previous_course_overview:
+        _check_for_course_date_changes(previous_course_overview, updated_course_overview)
+        _check_for_pacing_changes(previous_course_overview, updated_course_overview)
+
+
+def _check_for_course_date_changes(previous_course_overview, updated_course_overview):
+    if previous_course_overview.start != updated_course_overview.start:
+        COURSE_START_DATE_CHANGED.send(
+            sender=None,
+            updated_course_overview=updated_course_overview,
+            previous_start_date=previous_course_overview.start,
+        )
+
+
+def _check_for_pacing_changes(previous_course_overview, updated_course_overview):
+    if previous_course_overview.self_paced != updated_course_overview.self_paced:
+        COURSE_PACING_CHANGED.send(
+            sender=None,
+            updated_course_overview=updated_course_overview,
+            previous_self_paced=previous_course_overview.self_paced,
+        )

openedx/core/djangoapps/content/course_overviews/tests/test_course_overviews.py

@@ -33,7 +33,7 @@ from xmodule.error_module import ErrorDescriptor
 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, check_mongo_calls, check_mongo_calls_range
+from xmodule.modulestore.tests.factories import CourseFactory, check_mongo_calls_range
 
 from ..models import CourseOverview, CourseOverviewImageSet, CourseOverviewImageConfig
 
@@ -270,56 +270,6 @@ class CourseOverviewTestCase(ModuleStoreTestCase):
         course = CourseFactory.create(default_store=modulestore_type, run="TestRun", **kwargs)
         self.check_course_overview_against_course(course)
 
-    @ddt.data(ModuleStoreEnum.Type.mongo, ModuleStoreEnum.Type.split)
-    def test_course_overview_cache_invalidation(self, modulestore_type):
-        """
-        Tests that when a course is published or deleted, the corresponding
-        course_overview is removed from the cache.
-
-        Arguments:
-            modulestore_type (ModuleStoreEnum.Type): type of store to create the
-                course in.
-        """
-        with self.store.default_store(modulestore_type):
-
-            # Create a course where mobile_available is True.
-            course = CourseFactory.create(mobile_available=True, default_store=modulestore_type)
-            course_overview_1 = CourseOverview.get_from_id(course.id)
-            self.assertTrue(course_overview_1.mobile_available)
-
-            # Set mobile_available to False and update the course.
-            # This fires a course_published signal, which should be caught in signals.py, which should in turn
-            # delete the corresponding CourseOverview from the cache.
-            course.mobile_available = False
-            with self.store.branch_setting(ModuleStoreEnum.Branch.draft_preferred):
-                self.store.update_item(course, ModuleStoreEnum.UserID.test)
-
-            # Make sure that when we load the CourseOverview again, mobile_available is updated.
-            course_overview_2 = CourseOverview.get_from_id(course.id)
-            self.assertFalse(course_overview_2.mobile_available)
-
-            # Verify that when the course is deleted, the corresponding CourseOverview is deleted as well.
-            with self.assertRaises(CourseOverview.DoesNotExist):
-                self.store.delete_course(course.id, ModuleStoreEnum.UserID.test)
-                CourseOverview.get_from_id(course.id)
-
-    @ddt.data(ModuleStoreEnum.Type.mongo, ModuleStoreEnum.Type.split)
-    def test_course_overview_caching(self, modulestore_type):
-        """
-        Tests that CourseOverview structures are actually getting cached.
-
-        Arguments:
-            modulestore_type (ModuleStoreEnum.Type): type of store to create the
-                course in.
-        """
-
-        # Creating a new course will trigger a publish event and the course will be cached
-        course = CourseFactory.create(default_store=modulestore_type, emit_signals=True)
-
-        # The cache will be hit and mongo will not be queried
-        with check_mongo_calls(0):
-            CourseOverview.get_from_id(course.id)
-
     @ddt.data(ModuleStoreEnum.Type.split, ModuleStoreEnum.Type.mongo)
     def test_get_non_existent_course(self, modulestore_type):
         """

openedx/core/djangoapps/content/course_overviews/tests/test_signals.py

+import datetime
+import ddt
+from mock import patch
+from nose.plugins.attrib import attr
+
+from xmodule.modulestore import ModuleStoreEnum
+from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
+from xmodule.modulestore.tests.factories import CourseFactory, check_mongo_calls
+
+from ..models import CourseOverview
+
+
+@ddt.ddt
+@attr(shard=3)
+class CourseOverviewSignalsTestCase(ModuleStoreTestCase):
+    """
+    Tests for CourseOverview signals.
+    """
+    ENABLED_SIGNALS = ['course_deleted', 'course_published']
+    TODAY = datetime.datetime.utcnow()
+    NEXT_WEEK = TODAY + datetime.timedelta(days=7)
+
+    @ddt.data(ModuleStoreEnum.Type.mongo, ModuleStoreEnum.Type.split)
+    def test_caching(self, modulestore_type):
+        """
+        Tests that CourseOverview structures are actually getting cached.
+
+        Arguments:
+            modulestore_type (ModuleStoreEnum.Type): type of store to create the
+                course in.
+        """
+        # Creating a new course will trigger a publish event and the course will be cached
+        course = CourseFactory.create(default_store=modulestore_type, emit_signals=True)
+
+        # The cache will be hit and mongo will not be queried
+        with check_mongo_calls(0):
+            CourseOverview.get_from_id(course.id)
+
+    @ddt.data(ModuleStoreEnum.Type.mongo, ModuleStoreEnum.Type.split)
+    def test_cache_invalidation(self, modulestore_type):
+        """
+        Tests that when a course is published or deleted, the corresponding
+        course_overview is removed from the cache.
+
+        Arguments:
+            modulestore_type (ModuleStoreEnum.Type): type of store to create the
+                course in.
+        """
+        with self.store.default_store(modulestore_type):
+
+            # Create a course where mobile_available is True.
+            course = CourseFactory.create(mobile_available=True, default_store=modulestore_type)
+            course_overview_1 = CourseOverview.get_from_id(course.id)
+            self.assertTrue(course_overview_1.mobile_available)
+
+            # Set mobile_available to False and update the course.
+            # This fires a course_published signal, which should be caught in signals.py, which should in turn
+            # delete the corresponding CourseOverview from the cache.
+            course.mobile_available = False
+            with self.store.branch_setting(ModuleStoreEnum.Branch.draft_preferred):
+                self.store.update_item(course, ModuleStoreEnum.UserID.test)
+
+            # Make sure that when we load the CourseOverview again, mobile_available is updated.
+            course_overview_2 = CourseOverview.get_from_id(course.id)
+            self.assertFalse(course_overview_2.mobile_available)
+
+            # Verify that when the course is deleted, the corresponding CourseOverview is deleted as well.
+            with self.assertRaises(CourseOverview.DoesNotExist):
+                self.store.delete_course(course.id, ModuleStoreEnum.UserID.test)
+                CourseOverview.get_from_id(course.id)
+
+    def assert_changed_signal_sent(self, field_name, initial_value, changed_value, mock_signal):
+        course = CourseFactory.create(emit_signals=True, **{field_name: initial_value})
+
+        # changing display name doesn't fire the signal
+        course.display_name = course.display_name + u'changed'
+        self.store.update_item(course, ModuleStoreEnum.UserID.test)
+        self.assertFalse(mock_signal.called)
+
+        # changing the given field fires the signal
+        setattr(course, field_name, changed_value)
+        self.store.update_item(course, ModuleStoreEnum.UserID.test)
+        self.assertTrue(mock_signal.called)
+
+    @patch('openedx.core.djangoapps.signals.signals.COURSE_START_DATE_CHANGED.send')
+    def test_start_changed(self, mock_signal):
+        self.assert_changed_signal_sent('start', self.TODAY, self.NEXT_WEEK, mock_signal)
+
+    @patch('openedx.core.djangoapps.signals.signals.COURSE_PACING_CHANGED.send')
+    def test_pacing_changed(self, mock_signal):
+        self.assert_changed_signal_sent('self_paced', True, False, mock_signal)

openedx/core/djangoapps/models/course_details.py

@@ -9,7 +9,6 @@ from django.conf import settings
 from xmodule.fields import Date
 from xmodule.modulestore.exceptions import ItemNotFoundError
 from openedx.core.djangoapps.self_paced.models import SelfPacedConfiguration
-from openedx.core.djangoapps.signals.signals import COURSE_PACING_CHANGE
 from openedx.core.lib.courses import course_image_url
 from xmodule.modulestore.django import modulestore
 
@@ -190,7 +189,6 @@ class CourseDetails(object):
         descriptor = module_store.get_course(course_key)
 
         dirty = False
-        is_pacing_changed = False
 
         # In the descriptor's setter, the date is converted to JSON
         # using Date's to_json method. Calling to_json on something that
@@ -283,15 +281,10 @@ class CourseDetails(object):
                 and jsondict['self_paced'] != descriptor.self_paced):
             descriptor.self_paced = jsondict['self_paced']
             dirty = True
-            is_pacing_changed = True
 
         if dirty:
             module_store.update_item(descriptor, user.id)
 
-        # fires a signal indicating that the course pacing has changed
-        if is_pacing_changed:
-            COURSE_PACING_CHANGE.send(sender=None, course_key=course_key, course_self_paced=descriptor.self_paced)
-
         # NOTE: below auto writes to the db w/o verifying that any of
         # the fields actually changed to make faster, could compare
         # against db or could have client send over a list of which

openedx/core/djangoapps/schedules/models.py

-from collections import namedtuple
-
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 from django_extensions.db.models import TimeStampedModel

openedx/core/djangoapps/schedules/signals.py

@@ -3,13 +3,18 @@ import logging
 
 from django.db.models.signals import post_save
 from django.dispatch import receiver
+from django.utils import timezone
 
 from course_modes.models import CourseMode
 from courseware.models import DynamicUpgradeDeadlineConfiguration, CourseDynamicUpgradeDeadlineConfiguration
+from edx_ace.utils import date
+from openedx.core.djangoapps.signals.signals import COURSE_START_DATE_CHANGED
 from openedx.core.djangoapps.theming.helpers import get_current_site
 from openedx.core.djangoapps.waffle_utils import WaffleFlagNamespace, CourseWaffleFlag
 from student.models import CourseEnrollment
 from .models import Schedule, ScheduleConfig
+from .tasks import update_course_schedules
+
 
 log = logging.getLogger(__name__)
 
@@ -45,39 +50,11 @@ def create_schedule(sender, **kwargs):
         log.debug('Schedules: Creation only enabled for self-paced courses')
         return
 
-    delta = None
-    global_config = DynamicUpgradeDeadlineConfiguration.current()
-    if global_config.enabled:
-        # Use the default from this model whether or not the feature is enabled
-        delta = global_config.deadline_days
-
-    # Check if the course has a deadline override
-    course_config = CourseDynamicUpgradeDeadlineConfiguration.current(enrollment.course_id)
-    if course_config.enabled:
-        delta = course_config.deadline_days
-
-    upgrade_deadline = None
-
     # This represents the first date at which the learner can access the content. This will be the latter of
     # either the enrollment date or the course's start date.
     content_availability_date = max(enrollment.created, enrollment.course_overview.start)
 
-    if delta is not None:
-        upgrade_deadline = content_availability_date + datetime.timedelta(days=delta)
-
-        course_upgrade_deadline = None
-        try:
-            verified_mode = CourseMode.verified_mode_for_course(enrollment.course_id)
-        except CourseMode.DoesNotExist:
-            pass
-        else:
-            if verified_mode:
-                course_upgrade_deadline = verified_mode.expiration_datetime
-
-        if course_upgrade_deadline is not None and upgrade_deadline is not None:
-            # The content availability-based deadline should never occur after the verified mode's
-            # expiration date, if one is set.
-            upgrade_deadline = min(upgrade_deadline, course_upgrade_deadline)
+    upgrade_deadline = _calculate_upgrade_deadline(enrollment.course_id, content_availability_date)
 
     Schedule.objects.create(
         enrollment=enrollment,
@@ -87,3 +64,60 @@ def create_schedule(sender, **kwargs):
 
     log.debug('Schedules: created a new schedule starting at %s with an upgrade deadline of %s',
               content_availability_date, upgrade_deadline)
+
+
+@receiver(COURSE_START_DATE_CHANGED, dispatch_uid="update_schedules_on_course_start_changed")
+def update_schedules_on_course_start_changed(sender, updated_course_overview, previous_start_date, **kwargs):
+    """
+    Updates all course schedules if course hasn't started yet.
+    """
+    if previous_start_date > timezone.now():
+        upgrade_deadline = _calculate_upgrade_deadline(
+            updated_course_overview.id,
+            content_availability_date=updated_course_overview.start,
+        )
+        update_course_schedules.apply_async(
+            kwargs=dict(
+                course_id=unicode(updated_course_overview.id),
+                new_start_date_str=date.serialize(updated_course_overview.start),
+                new_upgrade_deadline_str=date.serialize(upgrade_deadline),
+            ),
+        )
+
+
+def _calculate_upgrade_deadline(course_id, content_availability_date):
+    upgrade_deadline = None
+
+    delta = _get_upgrade_deadline_delta_setting(course_id)
+    if delta is not None:
+        upgrade_deadline = content_availability_date + datetime.timedelta(days=delta)
+        if upgrade_deadline is not None:
+            # The content availability-based deadline should never occur
+            # after the verified mode's expiration date, if one is set.
+            try:
+                verified_mode = CourseMode.verified_mode_for_course(course_id)
+            except CourseMode.DoesNotExist:
+                pass
+            else:
+                if verified_mode:
+                    course_mode_upgrade_deadline = verified_mode.expiration_datetime
+                    if course_mode_upgrade_deadline is not None:
+                        upgrade_deadline = min(upgrade_deadline, course_mode_upgrade_deadline)
+
+    return upgrade_deadline
+
+
+def _get_upgrade_deadline_delta_setting(course_id):
+    delta = None
+
+    global_config = DynamicUpgradeDeadlineConfiguration.current()
+    if global_config.enabled:
+        # Use the default from this model whether or not the feature is enabled
+        delta = global_config.deadline_days
+
+    # Check if the course has a deadline
+    course_config = CourseDynamicUpgradeDeadlineConfiguration.current(course_id)
+    if course_config.enabled:
+        delta = course_config.deadline_days
+
+    return delta

openedx/core/djangoapps/schedules/tasks.py

@@ -5,19 +5,47 @@ from urlparse import urlparse
 from celery.task import task
 from django.conf import settings
 from django.contrib.sites.models import Site
+from django.core.exceptions import ValidationError
 from django.core.urlresolvers import reverse
+from django.db.utils import DatabaseError
 from django.utils.http import urlquote
 
+from logging import getLogger
+
 from edx_ace import ace
 from edx_ace.message import MessageType, Message
 from edx_ace.recipient import Recipient
 from edx_ace.utils.date import deserialize
-
 from edxmako.shortcuts import marketing_link
+from opaque_keys.edx.keys import CourseKey
 from openedx.core.djangoapps.schedules.models import Schedule, ScheduleConfig
 
 
+log = getLogger(__name__)
+
+
 ROUTING_KEY = getattr(settings, 'ACE_ROUTING_KEY', None)
+KNOWN_RETRY_ERRORS = (  # Errors we expect occasionally that could resolve on retry
+    DatabaseError,
+    ValidationError,
+)
+
+
+@task(bind=True, default_retry_delay=30, routing_key=ROUTING_KEY)
+def update_course_schedules(self, **kwargs):
+    course_key = CourseKey.from_string(kwargs['course_id'])
+    new_start_date = deserialize(kwargs['new_start_date_str'])
+    new_upgrade_deadline = deserialize(kwargs['new_upgrade_deadline_str'])
+
+    try:
+        Schedule.objects.filter(enrollment__course_id=course_key).update(
+            start=new_start_date,
+            upgrade_deadline=new_upgrade_deadline
+        )
+    except Exception as exc:  # pylint: disable=broad-except
+        if not isinstance(exc, KNOWN_RETRY_ERRORS):
+            log.exception("Unexpected failure: task id: %s, kwargs=%s".format(self.request.id, kwargs))
+        raise self.retry(kwargs=kwargs, exc=exc)
 
 
 class RecurringNudge(MessageType):

openedx/core/djangoapps/schedules/tests/test_signals.py

@@ -9,7 +9,9 @@ from openedx.core.djangoapps.schedules.signals import SCHEDULE_WAFFLE_FLAG
 from openedx.core.djangoapps.site_configuration.tests.factories import SiteFactory
 from openedx.core.djangoapps.waffle_utils.testutils import override_waffle_flag
 from openedx.core.djangolib.testing.utils import skip_unless_lms
+from student.models import CourseEnrollment
 from student.tests.factories import CourseEnrollmentFactory
+from xmodule.modulestore import ModuleStoreEnum
 from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory
 from ..models import Schedule
@@ -21,13 +23,13 @@ from ..tests.factories import ScheduleConfigFactory
 class CreateScheduleTests(SharedModuleStoreTestCase):
 
     def assert_schedule_created(self):
-        course = create_course_run(self_paced=True)
+        course = _create_course_run(self_paced=True)
         enrollment = CourseEnrollmentFactory(course_id=course.id, mode=CourseMode.AUDIT)
         self.assertIsNotNone(enrollment.schedule)
         self.assertIsNone(enrollment.schedule.upgrade_deadline)
 
     def assert_schedule_not_created(self):
-        course = create_course_run(self_paced=True)
+        course = _create_course_run(self_paced=True)
         enrollment = CourseEnrollmentFactory(course_id=course.id, mode=CourseMode.AUDIT)
         with self.assertRaises(Schedule.DoesNotExist):
             enrollment.schedule
@@ -70,19 +72,64 @@ class CreateScheduleTests(SharedModuleStoreTestCase):
         site = SiteFactory.create()
         mock_get_current_site.return_value = site
         ScheduleConfigFactory.create(site=site, enabled=True, create_schedules=True)
-        course = create_course_run(self_paced=False)
+        course = _create_course_run(self_paced=False)
         enrollment = CourseEnrollmentFactory(course_id=course.id, mode=CourseMode.AUDIT)
         with self.assertRaises(Schedule.DoesNotExist):
             enrollment.schedule
 
 
-def create_course_run(self_paced=True):
+@skip_unless_lms
+class UpdateScheduleTests(SharedModuleStoreTestCase):
+    ENABLED_SIGNALS = ['course_published']
+    VERIFICATION_DEADLINE_DAYS = 14
+
+    def setUp(self):
+        super(UpdateScheduleTests, self).setUp()
+        self.site = SiteFactory.create()
+        ScheduleConfigFactory.create(site=self.site)
+        DynamicUpgradeDeadlineConfiguration.objects.create(enabled=True, deadline_days=self.VERIFICATION_DEADLINE_DAYS)
+
+    def assert_schedule_dates(self, schedule, expected_start):
+        self.assertEquals(_strip_secs(schedule.start), _strip_secs(expected_start))
+        self.assertEquals(
+            _strip_secs(schedule.upgrade_deadline),
+            _strip_secs(expected_start) + datetime.timedelta(days=self.VERIFICATION_DEADLINE_DAYS),
+        )
+
+    @patch('openedx.core.djangoapps.schedules.signals.get_current_site')
+    def test_schedule_updated(self, mock_get_current_site):
+        mock_get_current_site.return_value = self.site
+
+        course = _create_course_run(self_paced=True, start_day_offset=5)
+        enrollment = CourseEnrollmentFactory(course_id=course.id, mode=CourseMode.AUDIT)
+
+        self.assert_schedule_dates(enrollment.schedule, enrollment.course_overview.start)
+        course.start = course.start + datetime.timedelta(days=3)
+        self.store.update_item(course, ModuleStoreEnum.UserID.test)
+        enrollment = CourseEnrollment.objects.get(id=enrollment.id)
+        self.assert_schedule_dates(enrollment.schedule, course.start)
+
+    @patch('openedx.core.djangoapps.schedules.signals.get_current_site')
+    def test_schedule_not_updated(self, mock_get_current_site):
+        mock_get_current_site.return_value = self.site
+
+        course = _create_course_run(self_paced=True, start_day_offset=-5)
+        enrollment = CourseEnrollmentFactory(course_id=course.id, mode=CourseMode.AUDIT)
+        self.assert_schedule_dates(enrollment.schedule, enrollment.created)
+
+        course.start = course.start + datetime.timedelta(days=3)
+        self.store.update_item(course, ModuleStoreEnum.UserID.test)
+        self.assert_schedule_dates(enrollment.schedule, enrollment.created)
+
+
+def _create_course_run(self_paced=True, start_day_offset=-1):
     """ Create a new course run and course modes.
 
     Both audit and verified `CourseMode` objects will be created for the course run.
     """
     now = datetime.datetime.now(utc)
-    course = CourseFactory.create(start=now + datetime.timedelta(days=-1), self_paced=self_paced)
+    start = now + datetime.timedelta(days=start_day_offset)
+    course = CourseFactory.create(start=start, self_paced=self_paced)
 
     CourseModeFactory(
         course_id=course.id,
@@ -95,3 +142,7 @@ def create_course_run(self_paced=True):
     )
 
     return course
+
+
+def _strip_secs(timestamp):
+    return timestamp.replace(second=0, microsecond=0)

openedx/core/djangoapps/signals/handlers.py

@@ -3,32 +3,28 @@ This module contains all general use or cross-use handlers.
 """
 import logging
 
-from celery.task import task
 from django.dispatch import receiver
 
 from certificates.models import CertificateGenerationCourseSetting
-from opaque_keys.edx.keys import CourseKey
-from signals import COURSE_PACING_CHANGE
+from signals import COURSE_PACING_CHANGED
 
 log = logging.getLogger(__name__)
 
 
-@receiver(COURSE_PACING_CHANGE, dispatch_uid="course_pacing_changed")
-def _listen_for_course_pacing_changed(sender, course_key, course_self_paced, **kwargs):  # pylint: disable=unused-argument
+@receiver(COURSE_PACING_CHANGED, dispatch_uid="update_cert_settings_on_pacing_change")
+def _update_cert_settings_on_pacing_change(sender, updated_course_overview, **kwargs):  # pylint: disable=unused-argument
     """
     Catches the signal that course pacing has changed and enable/disable
     the self-generated certificates according to course-pacing.
     """
-    toggle_self_generated_certs.delay(unicode(course_key), course_self_paced)
-    log.info(u'Certificate Generation Setting Toggled for {course} via pacing change'.format(
-        course=course_key
+    toggle_self_generated_certs(updated_course_overview.id, updated_course_overview.self_paced)
+    log.info(u'Certificate Generation Setting Toggled for {course_id} via pacing change'.format(
+        course_id=updated_course_overview.id
     ))
 
 
-@task
 def toggle_self_generated_certs(course_key, course_self_paced):
     """
     Enable or disable self-generated certificates for a course according to pacing.
     """
-    course_key = CourseKey.from_string(course_key)
     CertificateGenerationCourseSetting.set_enabled_for_course(course_key, course_self_paced)

openedx/core/djangoapps/signals/signals.py

@@ -23,4 +23,6 @@ COURSE_GRADE_NOW_PASSED = Signal(
 # Signal that indicates that a user has become verified
 LEARNER_NOW_VERIFIED = Signal(providing_args=['user'])
 
-COURSE_PACING_CHANGE = Signal(providing_args=["course_key", "course_self_paced"])
+COURSE_PACING_CHANGED = Signal(providing_args=["updated_course_overview", "previous_self_paced"])
+
+COURSE_START_DATE_CHANGED = Signal(providing_args=["updated_course_overview", "previous_start_date"])