def handle(self, *args, **options):
"""
Execute the command. Since this is designed to fix any issues cause by running pre-CohortMembership code
with the database already migrated to post-CohortMembership state, we will use the pre-CohortMembership
table CourseUserGroup as the canonical source of truth. This way, changes made in the window are persisted.
"""
commit = 'commit' in options
memberships_to_delete = 0
memberships_to_add = 0
# Begin by removing any data in CohortMemberships that does not match CourseUserGroups data
for membership in CohortMembership.objects.all():
try:
CourseUserGroup.objects.get(
group_type=CourseUserGroup.COHORT,
users__id=membership.user.id,
course_id=membership.course_id,
id=membership.course_user_group.id
)
except CourseUserGroup.DoesNotExist:
memberships_to_delete += 1
if commit:
membership.delete()
# Now we can add any CourseUserGroup data that is missing a backing CohortMembership
for course_group in CourseUserGroup.objects.filter(group_type=CourseUserGroup.COHORT):
for user in course_group.users.all():
try:
CohortMembership.objects.get(
user=user,
course_id=course_group.course_id,
course_user_group_id=course_group.id
)
except CohortMembership.DoesNotExist:
memberships_to_add += 1
if commit:
membership = CohortMembership(
course_user_group=course_group,
user=user,
course_id=course_group.course_id
)
try:
membership.save()
except IntegrityError: # If the user is in multiple cohorts, we arbitrarily choose between them
# In this case, allow the pre-existing entry to be "correct"
course_group.users.remove(user)
user.course_groups.remove(course_group)
print '{} CohortMemberships did not match the CourseUserGroup table and will be deleted'.format(
memberships_to_delete
)
print '{} CourseUserGroup users do not have a CohortMembership; one will be added if it is valid'.format(
memberships_to_add
)
if commit:
print 'Changes have been made and saved.'
else:
print 'Dry run, changes have not been saved. Run again with "commit" argument to save changes'
def test_post_cohortmembership_fix(self):
"""
Test that changes made *after* migration, but *before* turning on new code are handled properly
"""
# First, we're going to simulate some problem states that can arise during this window
config_course_cohorts(self.course1, is_cohorted=True, auto_cohorts=["Course1AutoGroup1", "Course1AutoGroup2"])
# Get the cohorts from the courses, which will cause auto cohorts to be created
cohort_handler(self.request, unicode(self.course1.id))
course_1_auto_cohort_1 = get_cohort_by_name(self.course1.id, "Course1AutoGroup1")
course_1_auto_cohort_2 = get_cohort_by_name(self.course1.id, "Course1AutoGroup2")
# When migrations were first run, the users were assigned to CohortMemberships correctly
membership1 = CohortMembership(
course_id=course_1_auto_cohort_1.course_id,
user=self.user1,
course_user_group=course_1_auto_cohort_1
)
membership1.save()
membership2 = CohortMembership(
course_id=course_1_auto_cohort_1.course_id,
user=self.user2,
course_user_group=course_1_auto_cohort_1
)
membership2.save()
# But before CohortMembership code was turned on, some changes were made:
course_1_auto_cohort_2.users.add(self.user1) # user1 is now in 2 cohorts in the same course!
course_1_auto_cohort_2.users.add(self.user2)
course_1_auto_cohort_1.users.remove(self.user2) # and user2 was moved, but no one told CohortMembership!
# run the post-CohortMembership command, dry-run
call_command('post_cohort_membership_fix')
# Verify nothing was changed in dry-run mode.
self.assertEqual(self.user1.course_groups.count(), 2) # CourseUserGroup has 2 entries for user1
self.assertEqual(CohortMembership.objects.get(user=self.user2).course_user_group.name, 'Course1AutoGroup1')
user2_cohorts = list(self.user2.course_groups.values_list('name', flat=True))
self.assertEqual(user2_cohorts, ['Course1AutoGroup2']) # CourseUserGroup and CohortMembership disagree
# run the post-CohortMembership command, and commit it
call_command('post_cohort_membership_fix', commit='commit')
# verify that both databases agree about the (corrected) state of the memberships
self.assertEqual(self.user1.course_groups.count(), 1)
self.assertEqual(CohortMembership.objects.filter(user=self.user1).count(), 1)
self.assertEqual(self.user2.course_groups.count(), 1)
self.assertEqual(CohortMembership.objects.filter(user=self.user2).count(), 1)
self.assertEqual(CohortMembership.objects.get(user=self.user2).course_user_group.name, 'Course1AutoGroup2')
user2_cohorts = list(self.user2.course_groups.values_list('name', flat=True))
self.assertEqual(user2_cohorts, ['Course1AutoGroup2'])
def test_post_cohortmembership_fix(self):
"""
Test that changes made *after* migration, but *before* turning on new code are handled properly
"""
# First, we're going to simulate some problem states that can arise during this window
config_course_cohorts(self.course1, is_cohorted=True, auto_cohorts=["Course1AutoGroup1", "Course1AutoGroup2"])
# Get the cohorts from the courses, which will cause auto cohorts to be created
cohort_handler(self.request, unicode(self.course1.id))
course_1_auto_cohort_1 = get_cohort_by_name(self.course1.id, "Course1AutoGroup1")
course_1_auto_cohort_2 = get_cohort_by_name(self.course1.id, "Course1AutoGroup2")
# When migrations were first run, the users were assigned to CohortMemberships correctly
membership1 = CohortMembership(
course_id=course_1_auto_cohort_1.course_id,
user=self.user1,
course_user_group=course_1_auto_cohort_1
)
membership1.save()
membership2 = CohortMembership(
course_id=course_1_auto_cohort_1.course_id,
user=self.user2,
course_user_group=course_1_auto_cohort_1
)
membership2.save()
# But before CohortMembership code was turned on, some changes were made:
course_1_auto_cohort_2.users.add(self.user1) # user1 is now in 2 cohorts in the same course!
course_1_auto_cohort_2.users.add(self.user2)
course_1_auto_cohort_1.users.remove(self.user2) # and user2 was moved, but no one told CohortMembership!
# run the post-CohortMembership command, dry-run
call_command('post_cohort_membership_fix')
# Verify nothing was changed in dry-run mode.
self.assertEqual(self.user1.course_groups.count(), 2) # CourseUserGroup has 2 entries for user1
self.assertEqual(CohortMembership.objects.get(user=self.user2).course_user_group.name, 'Course1AutoGroup1')
user2_cohorts = list(self.user2.course_groups.values_list('name', flat=True))
self.assertEqual(user2_cohorts, ['Course1AutoGroup2']) # CourseUserGroup and CohortMembership disagree
# run the post-CohortMembership command, and commit it
call_command('post_cohort_membership_fix', commit='commit')
# verify that both databases agree about the (corrected) state of the memberships
self.assertEqual(self.user1.course_groups.count(), 1)
self.assertEqual(CohortMembership.objects.filter(user=self.user1).count(), 1)
self.assertEqual(self.user2.course_groups.count(), 1)
self.assertEqual(CohortMembership.objects.filter(user=self.user2).count(), 1)
self.assertEqual(CohortMembership.objects.get(user=self.user2).course_user_group.name, 'Course1AutoGroup2')
user2_cohorts = list(self.user2.course_groups.values_list('name', flat=True))
self.assertEqual(user2_cohorts, ['Course1AutoGroup2'])
def handle(self, *args, **options):
"""
Execute the command. Since this is designed to fix any issues cause by running pre-CohortMembership code
with the database already migrated to post-CohortMembership state, we will use the pre-CohortMembership
table CourseUserGroup as the canonical source of truth. This way, changes made in the window are persisted.
"""
commit = options['commit']
memberships_to_delete = 0
memberships_to_add = 0
# Begin by removing any data in CohortMemberships that does not match CourseUserGroups data
for membership in CohortMembership.objects.all():
try:
CourseUserGroup.objects.get(group_type=CourseUserGroup.COHORT,
users__id=membership.user.id,
course_id=membership.course_id,
id=membership.course_user_group.id)
except CourseUserGroup.DoesNotExist:
memberships_to_delete += 1
if commit:
membership.delete()
# Now we can add any CourseUserGroup data that is missing a backing CohortMembership
for course_group in CourseUserGroup.objects.filter(
group_type=CourseUserGroup.COHORT):
for user in course_group.users.all():
try:
CohortMembership.objects.get(
user=user,
course_id=course_group.course_id,
course_user_group_id=course_group.id)
except CohortMembership.DoesNotExist:
memberships_to_add += 1
if commit:
membership = CohortMembership(
course_user_group=course_group,
user=user,
course_id=course_group.course_id)
try:
membership.save()
except IntegrityError: # If the user is in multiple cohorts, we arbitrarily choose between them
# In this case, allow the pre-existing entry to be "correct"
course_group.users.remove(user)
user.course_groups.remove(course_group)
print '{} CohortMemberships did not match the CourseUserGroup table and will be deleted'.format(
memberships_to_delete)
print '{} CourseUserGroup users do not have a CohortMembership; one will be added if it is valid'.format(
memberships_to_add)
if commit:
print 'Changes have been made and saved.'
else:
print 'Dry run, changes have not been saved. Run again with "commit" argument to save changes'
