Files
edx-platform/common/djangoapps/course_groups/tests/test_views.py
2014-10-01 09:22:32 -04:00

805 lines
31 KiB
Python

import json
from django.test.client import RequestFactory
from django.test.utils import override_settings
from course_groups.tests.helpers import config_course_cohorts, CohortFactory
from collections import namedtuple
from django.http import Http404
from django.contrib.auth.models import User
from courseware.tests.tests import TEST_DATA_MIXED_MODULESTORE
from student.models import CourseEnrollment
from student.tests.factories import UserFactory
from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
from xmodule.modulestore.tests.factories import CourseFactory
from opaque_keys.edx.locations import SlashSeparatedCourseKey
from course_groups.models import CourseUserGroup
from course_groups.views import list_cohorts, add_cohort, users_in_cohort, add_users_to_cohort, remove_user_from_cohort
from course_groups.cohorts import get_cohort, CohortAssignmentType, get_cohort_by_name, DEFAULT_COHORT_NAME
@override_settings(MODULESTORE=TEST_DATA_MIXED_MODULESTORE)
class CohortViewsTestCase(ModuleStoreTestCase):
"""
Base class which sets up a course and staff/non-staff users.
"""
def setUp(self):
self.course = CourseFactory.create()
self.staff_user = UserFactory(is_staff=True, username="staff")
self.non_staff_user = UserFactory(username="nonstaff")
def _enroll_users(self, users, course_key):
"""Enroll each user in the specified course"""
for user in users:
CourseEnrollment.enroll(user, course_key)
def _create_cohorts(self):
"""Creates cohorts for testing"""
self.cohort1_users = [UserFactory() for _ in range(3)]
self.cohort2_users = [UserFactory() for _ in range(2)]
self.cohort3_users = [UserFactory() for _ in range(2)]
self.cohortless_users = [UserFactory() for _ in range(3)]
self.unenrolled_users = [UserFactory() for _ in range(3)]
self._enroll_users(
self.cohort1_users + self.cohort2_users + self.cohort3_users + self.cohortless_users,
self.course.id
)
self.cohort1 = CohortFactory(course_id=self.course.id, users=self.cohort1_users)
self.cohort2 = CohortFactory(course_id=self.course.id, users=self.cohort2_users)
self.cohort3 = CohortFactory(course_id=self.course.id, users=self.cohort3_users)
def _user_in_cohort(self, username, cohort):
"""
Return true iff a user with `username` exists in `cohort`.
"""
return username in [user.username for user in cohort.users.all()]
def _verify_non_staff_cannot_access(self, view, request_method, view_args):
"""
Verify that a non-staff user cannot access a given view.
`view` is the view to test.
`view_args` is a list of arguments (not including the request) to pass
to the view.
"""
if request_method == "GET":
request = RequestFactory().get("dummy_url")
elif request_method == "POST":
request = RequestFactory().post("dummy_url")
else:
request = RequestFactory().request()
request.user = self.non_staff_user
view_args.insert(0, request)
self.assertRaises(Http404, view, *view_args)
class ListCohortsTestCase(CohortViewsTestCase):
"""
Tests the `list_cohorts` view.
"""
def request_list_cohorts(self, course):
"""
Call `list_cohorts` for a given `course` and return its response as a
dict.
"""
request = RequestFactory().get("dummy_url")
request.user = self.staff_user
response = list_cohorts(request, course.id.to_deprecated_string())
self.assertEqual(response.status_code, 200)
return json.loads(response.content)
def verify_lists_expected_cohorts(self, expected_cohorts, response_dict=None):
"""
Verify that the server response contains the expected_cohorts.
If response_dict is None, the list of cohorts is requested from the server.
"""
if response_dict is None:
response_dict = self.request_list_cohorts(self.course)
self.assertTrue(response_dict.get("success"))
self.assertItemsEqual(
response_dict.get("cohorts"),
[
{
"name": cohort.name,
"id": cohort.id,
"user_count": cohort.user_count,
"assignment_type": cohort.assignment_type
}
for cohort in expected_cohorts
]
)
@staticmethod
def create_expected_cohort(cohort, user_count, assignment_type):
"""
Create a tuple storing the expected cohort information.
"""
cohort_tuple = namedtuple("Cohort", "name id user_count assignment_type")
return cohort_tuple(
name=cohort.name, id=cohort.id, user_count=user_count, assignment_type=assignment_type
)
def test_non_staff(self):
"""
Verify that we cannot access list_cohorts if we're a non-staff user.
"""
self._verify_non_staff_cannot_access(list_cohorts, "GET", [self.course.id.to_deprecated_string()])
def test_no_cohorts(self):
"""
Verify that no cohorts are in response for a course with no cohorts.
"""
self.verify_lists_expected_cohorts([])
def test_some_cohorts(self):
"""
Verify that cohorts are in response for a course with some cohorts.
"""
self._create_cohorts()
expected_cohorts = [
ListCohortsTestCase.create_expected_cohort(self.cohort1, 3, CohortAssignmentType.NONE),
ListCohortsTestCase.create_expected_cohort(self.cohort2, 2, CohortAssignmentType.NONE),
ListCohortsTestCase.create_expected_cohort(self.cohort3, 2, CohortAssignmentType.NONE),
]
self.verify_lists_expected_cohorts(expected_cohorts)
def test_auto_cohorts(self):
"""
Verify that auto cohorts are included in the response.
"""
config_course_cohorts(self.course, [], cohorted=True,
auto_cohort_groups=["AutoGroup1", "AutoGroup2"])
# Will create cohort1, cohort2, and cohort3. Auto cohorts remain uncreated.
self._create_cohorts()
# Get the cohorts from the course, which will cause auto cohorts to be created.
actual_cohorts = self.request_list_cohorts(self.course)
# Get references to the created auto cohorts.
auto_cohort_1 = get_cohort_by_name(self.course.id, "AutoGroup1")
auto_cohort_2 = get_cohort_by_name(self.course.id, "AutoGroup2")
expected_cohorts = [
ListCohortsTestCase.create_expected_cohort(self.cohort1, 3, CohortAssignmentType.NONE),
ListCohortsTestCase.create_expected_cohort(self.cohort2, 2, CohortAssignmentType.NONE),
ListCohortsTestCase.create_expected_cohort(self.cohort3, 2, CohortAssignmentType.NONE),
ListCohortsTestCase.create_expected_cohort(auto_cohort_1, 0, CohortAssignmentType.RANDOM),
ListCohortsTestCase.create_expected_cohort(auto_cohort_2, 0, CohortAssignmentType.RANDOM),
]
self.verify_lists_expected_cohorts(expected_cohorts, actual_cohorts)
def test_default_cohort(self):
"""
Verify that the default cohort is not created and included in the response until students are assigned to it.
"""
# verify the default cohort is not created when the course is not cohorted
self.verify_lists_expected_cohorts([])
# create a cohorted course without any auto_cohort_groups
config_course_cohorts(self.course, [], cohorted=True)
# verify the default cohort is not yet created until a user is assigned
self.verify_lists_expected_cohorts([])
# create enrolled users
users = [UserFactory() for _ in range(3)]
self._enroll_users(users, self.course.id)
# mimic users accessing the discussion forum
for user in users:
get_cohort(user, self.course.id)
# verify the default cohort is automatically created
default_cohort = get_cohort_by_name(self.course.id, DEFAULT_COHORT_NAME)
actual_cohorts = self.request_list_cohorts(self.course)
self.verify_lists_expected_cohorts(
[ListCohortsTestCase.create_expected_cohort(default_cohort, len(users), CohortAssignmentType.RANDOM)],
actual_cohorts,
)
# set auto_cohort_groups and verify the default cohort is no longer listed as RANDOM
config_course_cohorts(self.course, [], cohorted=True, auto_cohort_groups=["AutoGroup"])
actual_cohorts = self.request_list_cohorts(self.course)
auto_cohort = get_cohort_by_name(self.course.id, "AutoGroup")
self.verify_lists_expected_cohorts(
[
ListCohortsTestCase.create_expected_cohort(default_cohort, len(users), CohortAssignmentType.NONE),
ListCohortsTestCase.create_expected_cohort(auto_cohort, 0, CohortAssignmentType.RANDOM),
],
actual_cohorts,
)
class AddCohortTestCase(CohortViewsTestCase):
"""
Tests the `add_cohort` view.
"""
def request_add_cohort(self, cohort_name, course):
"""
Call `add_cohort` and return its response as a dict.
"""
request = RequestFactory().post("dummy_url", {"name": cohort_name})
request.user = self.staff_user
response = add_cohort(request, course.id.to_deprecated_string())
self.assertEqual(response.status_code, 200)
return json.loads(response.content)
def verify_contains_added_cohort(self, response_dict, cohort_name, expected_error_msg=None):
"""
Check that `add_cohort`'s response correctly returns the newly added
cohort (or error) in the response. Also verify that the cohort was
actually created/exists.
"""
if expected_error_msg is not None:
self.assertFalse(response_dict.get("success"))
self.assertEqual(
response_dict.get("msg"),
expected_error_msg
)
else:
self.assertTrue(response_dict.get("success"))
self.assertEqual(
response_dict.get("cohort").get("name"),
cohort_name
)
self.assertIsNotNone(get_cohort_by_name(self.course.id, cohort_name))
def test_non_staff(self):
"""
Verify that non-staff users cannot access add_cohort.
"""
self._verify_non_staff_cannot_access(add_cohort, "POST", [self.course.id.to_deprecated_string()])
def test_new_cohort(self):
"""
Verify that we can add a new cohort.
"""
cohort_name = "New Cohort"
self.verify_contains_added_cohort(
self.request_add_cohort(cohort_name, self.course),
cohort_name,
)
def test_no_cohort(self):
"""
Verify that we cannot explicitly add no cohort.
"""
response_dict = self.request_add_cohort("", self.course)
self.assertFalse(response_dict.get("success"))
self.assertEqual(response_dict.get("msg"), "No name specified")
def test_existing_cohort(self):
"""
Verify that we cannot add a cohort with the same name as an existing
cohort.
"""
self._create_cohorts()
cohort_name = self.cohort1.name
self.verify_contains_added_cohort(
self.request_add_cohort(cohort_name, self.course),
cohort_name,
expected_error_msg="You cannot create two cohorts with the same name"
)
class UsersInCohortTestCase(CohortViewsTestCase):
"""
Tests the `users_in_cohort` view.
"""
def request_users_in_cohort(self, cohort, course, requested_page, should_return_bad_request=False):
"""
Call `users_in_cohort` for a given cohort/requested page, and return
its response as a dict. When `should_return_bad_request` is True,
verify that the response indicates a bad request.
"""
request = RequestFactory().get("dummy_url", {"page": requested_page})
request.user = self.staff_user
response = users_in_cohort(request, course.id.to_deprecated_string(), cohort.id)
if should_return_bad_request:
self.assertEqual(response.status_code, 400)
return
self.assertEqual(response.status_code, 200)
return json.loads(response.content)
def verify_users_in_cohort_and_response(self, cohort, response_dict, expected_users, expected_page,
expected_num_pages):
"""
Check that the `users_in_cohort` response contains the expected list of
users, page number, and total number of pages for a given cohort. Also
verify that those users are actually in the given cohort.
"""
self.assertTrue(response_dict.get("success"))
self.assertEqual(response_dict.get("page"), expected_page)
self.assertEqual(response_dict.get("num_pages"), expected_num_pages)
returned_users = User.objects.filter(username__in=[user.get("username") for user in response_dict.get("users")])
self.assertItemsEqual(returned_users, expected_users)
self.assertTrue(set(returned_users).issubset(cohort.users.all()))
def test_non_staff(self):
"""
Verify that non-staff users cannot access `check_users_in_cohort`.
"""
cohort = CohortFactory(course_id=self.course.id, users=[])
self._verify_non_staff_cannot_access(users_in_cohort, "GET", [self.course.id.to_deprecated_string(), cohort.id])
def test_no_users(self):
"""
Verify that we don't get back any users for a cohort with no users.
"""
cohort = CohortFactory(course_id=self.course.id, users=[])
response_dict = self.request_users_in_cohort(cohort, self.course, 1)
self.verify_users_in_cohort_and_response(
cohort,
response_dict,
expected_users=[],
expected_page=1,
expected_num_pages=1
)
def test_few_users(self):
"""
Verify that we get back all users for a cohort when the cohort has
<=100 users.
"""
users = [UserFactory() for _ in range(5)]
cohort = CohortFactory(course_id=self.course.id, users=users)
response_dict = self.request_users_in_cohort(cohort, self.course, 1)
self.verify_users_in_cohort_and_response(
cohort,
response_dict,
expected_users=users,
expected_page=1,
expected_num_pages=1
)
def test_many_users(self):
"""
Verify that pagination works correctly for cohorts with >100 users.
"""
users = [UserFactory() for _ in range(101)]
cohort = CohortFactory(course_id=self.course.id, users=users)
response_dict_1 = self.request_users_in_cohort(cohort, self.course, 1)
response_dict_2 = self.request_users_in_cohort(cohort, self.course, 2)
self.verify_users_in_cohort_and_response(
cohort,
response_dict_1,
expected_users=users[:100],
expected_page=1,
expected_num_pages=2
)
self.verify_users_in_cohort_and_response(
cohort,
response_dict_2,
expected_users=users[100:],
expected_page=2,
expected_num_pages=2
)
def test_out_of_range(self):
"""
Verify that we get a blank page of users when requesting page 0 or a
page greater than the actual number of pages.
"""
users = [UserFactory() for _ in range(5)]
cohort = CohortFactory(course_id=self.course.id, users=users)
response = self.request_users_in_cohort(cohort, self.course, 0)
self.verify_users_in_cohort_and_response(
cohort,
response,
expected_users=[],
expected_page=0,
expected_num_pages=1
)
response = self.request_users_in_cohort(cohort, self.course, 2)
self.verify_users_in_cohort_and_response(
cohort,
response,
expected_users=[],
expected_page=2,
expected_num_pages=1
)
def test_non_positive_page(self):
"""
Verify that we get a `HttpResponseBadRequest` (bad request) when the
page we request isn't a positive integer.
"""
users = [UserFactory() for _ in range(5)]
cohort = CohortFactory(course_id=self.course.id, users=users)
self.request_users_in_cohort(cohort, self.course, "invalid", should_return_bad_request=True)
self.request_users_in_cohort(cohort, self.course, -1, should_return_bad_request=True)
class AddUsersToCohortTestCase(CohortViewsTestCase):
"""
Tests the `add_users_to_cohort` view.
"""
def setUp(self):
super(AddUsersToCohortTestCase, self).setUp()
self._create_cohorts()
def request_add_users_to_cohort(self, users_string, cohort, course, should_raise_404=False):
"""
Call `add_users_to_cohort` for a given cohort, course, and list of
users, returning its response as a dict. When `should_raise_404` is
True, verify that the request raised a Http404.
"""
request = RequestFactory().post("dummy_url", {"users": users_string})
request.user = self.staff_user
if should_raise_404:
self.assertRaises(
Http404,
lambda: add_users_to_cohort(request, course.id.to_deprecated_string(), cohort.id)
)
else:
response = add_users_to_cohort(request, course.id.to_deprecated_string(), cohort.id)
self.assertEqual(response.status_code, 200)
return json.loads(response.content)
def verify_added_users_to_cohort(self, response_dict, cohort, course, expected_added, expected_changed,
expected_present, expected_unknown):
"""
Check that add_users_to_cohort returned the expected response and has
the expected side effects.
`expected_added` is a list of users
`expected_changed` is a list of (user, previous_cohort) tuples
`expected_present` is a list of (user, email/username) tuples where
email/username corresponds to the input
`expected_unknown` is a list of strings corresponding to the input
"""
self.assertTrue(response_dict.get("success"))
self.assertItemsEqual(
response_dict.get("added"),
[
{"username": user.username, "name": user.profile.name, "email": user.email}
for user in expected_added
]
)
self.assertItemsEqual(
response_dict.get("changed"),
[
{
"username": user.username,
"name": user.profile.name,
"email": user.email,
"previous_cohort": previous_cohort
}
for (user, previous_cohort) in expected_changed
]
)
self.assertItemsEqual(
response_dict.get("present"),
[username_or_email for (_, username_or_email) in expected_present]
)
self.assertItemsEqual(response_dict.get("unknown"), expected_unknown)
for user in expected_added + [user for (user, _) in expected_changed + expected_present]:
self.assertEqual(
CourseUserGroup.objects.get(
course_id=course.id,
group_type=CourseUserGroup.COHORT,
users__id=user.id
),
cohort
)
def test_non_staff(self):
"""
Verify that non-staff users cannot access `check_users_in_cohort`.
"""
cohort = CohortFactory(course_id=self.course.id, users=[])
self._verify_non_staff_cannot_access(
add_users_to_cohort,
"POST",
[self.course.id.to_deprecated_string(), cohort.id]
)
def test_empty(self):
"""
Verify that adding an empty list of users to a cohort has no result.
"""
response_dict = self.request_add_users_to_cohort("", self.cohort1, self.course)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=[],
expected_changed=[],
expected_present=[],
expected_unknown=[]
)
def test_only_added(self):
"""
Verify that we can add users to their first cohort.
"""
response_dict = self.request_add_users_to_cohort(
",".join([user.username for user in self.cohortless_users]),
self.cohort1,
self.course
)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=self.cohortless_users,
expected_changed=[],
expected_present=[],
expected_unknown=[]
)
def test_only_changed(self):
"""
Verify that we can move users to a different cohort.
"""
response_dict = self.request_add_users_to_cohort(
",".join([user.username for user in self.cohort2_users + self.cohort3_users]),
self.cohort1,
self.course
)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=[],
expected_changed=(
[(user, self.cohort2.name) for user in self.cohort2_users] +
[(user, self.cohort3.name) for user in self.cohort3_users]
),
expected_present=[],
expected_unknown=[]
)
def test_only_present(self):
"""
Verify that we can 'add' users to their current cohort.
"""
usernames = [user.username for user in self.cohort1_users]
response_dict = self.request_add_users_to_cohort(
",".join(usernames),
self.cohort1,
self.course
)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=[],
expected_changed=[],
expected_present=[(user, user.username) for user in self.cohort1_users],
expected_unknown=[]
)
def test_only_unknown(self):
"""
Verify that non-existent users are not added.
"""
usernames = ["unknown_user{}".format(i) for i in range(3)]
response_dict = self.request_add_users_to_cohort(
",".join(usernames),
self.cohort1,
self.course
)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=[],
expected_changed=[],
expected_present=[],
expected_unknown=usernames
)
def test_all(self):
"""
Test all adding conditions together.
"""
unknowns = ["unknown_user{}".format(i) for i in range(3)]
response_dict = self.request_add_users_to_cohort(
",".join(
unknowns +
[
user.username
for user in self.cohortless_users + self.cohort1_users + self.cohort2_users + self.cohort3_users
]
),
self.cohort1,
self.course
)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=self.cohortless_users,
expected_changed=(
[(user, self.cohort2.name) for user in self.cohort2_users] +
[(user, self.cohort3.name) for user in self.cohort3_users]
),
expected_present=[(user, user.username) for user in self.cohort1_users],
expected_unknown=unknowns
)
def test_emails(self):
"""
Verify that we can use emails to identify users.
"""
unknown = "unknown_user@example.com"
response_dict = self.request_add_users_to_cohort(
",".join([
self.cohort1_users[0].email,
self.cohort2_users[0].email,
self.cohortless_users[0].email,
unknown
]),
self.cohort1,
self.course
)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=[self.cohortless_users[0]],
expected_changed=[(self.cohort2_users[0], self.cohort2.name)],
expected_present=[(self.cohort1_users[0], self.cohort1_users[0].email)],
expected_unknown=[unknown]
)
def test_delimiters(self):
"""
Verify that we can use different types of whitespace to delimit
usernames in the user string.
"""
unknown = "unknown_user"
response_dict = self.request_add_users_to_cohort(
" {} {}\t{}, \r\n{}".format(
unknown,
self.cohort1_users[0].username,
self.cohort2_users[0].username,
self.cohortless_users[0].username
),
self.cohort1,
self.course
)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=[self.cohortless_users[0]],
expected_changed=[(self.cohort2_users[0], self.cohort2.name)],
expected_present=[(self.cohort1_users[0], self.cohort1_users[0].username)],
expected_unknown=[unknown]
)
def test_can_cohort_unenrolled_users(self):
"""
Verify that users can be added to a cohort of a course they're not
enrolled in. This feature is currently used to pre-cohort users that
are expected to enroll in a course.
"""
unenrolled_usernames = [user.username for user in self.unenrolled_users]
response_dict = self.request_add_users_to_cohort(
",".join(unenrolled_usernames),
self.cohort1,
self.course
)
self.verify_added_users_to_cohort(
response_dict,
self.cohort1,
self.course,
expected_added=self.unenrolled_users,
expected_changed=[],
expected_present=[],
expected_unknown=[]
)
def test_non_existent_cohort(self):
"""
Verify that an error is raised when trying to add users to a cohort
which does not belong to the given course.
"""
users = [UserFactory(username="user{0}".format(i)) for i in range(3)]
usernames = [user.username for user in users]
wrong_course_key = SlashSeparatedCourseKey("some", "arbitrary", "course")
wrong_course_cohort = CohortFactory(name="wrong_cohort", course_id=wrong_course_key, users=[])
self.request_add_users_to_cohort(
",".join(usernames),
wrong_course_cohort,
self.course,
should_raise_404=True
)
class RemoveUserFromCohortTestCase(CohortViewsTestCase):
"""
Tests the `remove_user_from_cohort` view.
"""
def request_remove_user_from_cohort(self, username, cohort):
"""
Call `remove_user_from_cohort` with the given username and cohort.
"""
if username is not None:
request = RequestFactory().post("dummy_url", {"username": username})
else:
request = RequestFactory().post("dummy_url")
request.user = self.staff_user
response = remove_user_from_cohort(request, self.course.id.to_deprecated_string(), cohort.id)
self.assertEqual(response.status_code, 200)
return json.loads(response.content)
def verify_removed_user_from_cohort(self, username, response_dict, cohort, expected_error_msg=None):
"""
Check that `remove_user_from_cohort` properly removes a user from a
cohort and returns appropriate success. If the removal should fail,
verify that the returned error message matches the expected one.
"""
if expected_error_msg is None:
self.assertTrue(response_dict.get("success"))
self.assertIsNone(response_dict.get("msg"))
self.assertFalse(self._user_in_cohort(username, cohort))
else:
self.assertFalse(response_dict.get("success"))
self.assertEqual(response_dict.get("msg"), expected_error_msg)
def test_non_staff(self):
"""
Verify that non-staff users cannot access `check_users_in_cohort`.
"""
cohort = CohortFactory(course_id=self.course.id, users=[])
self._verify_non_staff_cannot_access(
remove_user_from_cohort,
"POST",
[self.course.id.to_deprecated_string(), cohort.id]
)
def test_no_username_given(self):
"""
Verify that we get an error message when omitting a username.
"""
cohort = CohortFactory(course_id=self.course.id, users=[])
response_dict = self.request_remove_user_from_cohort(None, cohort)
self.verify_removed_user_from_cohort(
None,
response_dict,
cohort,
expected_error_msg='No username specified'
)
def test_user_does_not_exist(self):
"""
Verify that we get an error message when the requested user to remove
does not exist.
"""
username = "bogus"
cohort = CohortFactory(course_id=self.course.id, users=[])
response_dict = self.request_remove_user_from_cohort(
username,
cohort
)
self.verify_removed_user_from_cohort(
username,
response_dict,
cohort,
expected_error_msg='No user \'{0}\''.format(username)
)
def test_can_remove_user_not_in_cohort(self):
"""
Verify that we can "remove" a user from a cohort even if they are not a
member of that cohort.
"""
user = UserFactory()
cohort = CohortFactory(course_id=self.course.id, users=[])
response_dict = self.request_remove_user_from_cohort(user.username, cohort)
self.verify_removed_user_from_cohort(user.username, response_dict, cohort)
def test_can_remove_user_from_cohort(self):
"""
Verify that we can remove a user from a cohort.
"""
user = UserFactory()
cohort = CohortFactory(course_id=self.course.id, users=[user])
response_dict = self.request_remove_user_from_cohort(user.username, cohort)
self.verify_removed_user_from_cohort(user.username, response_dict, cohort)