test_visibility_enroll.py

from datetime import timedelta
import logging

from django.contrib.auth.models import User
from django.urls import reverse
from django.test import TestCase
from django.test.client import Client
from django.utils import timezone
from django.conf import settings

from course.models import Course, CourseInstance, CourseModule, \
    LearningObjectCategory
from exercise.exercise_models import BaseExercise, CourseChapter, LearningObject
from exercise.submission_models import Submission

class CourseVisibilityTest(TestCase):
    """Tests for course visibility and access control.
    There are also some tests about enrollment.
    """

    def setUp(self):
        self.user = User(username="testUser") # not enrolled in the course
        self.user.set_password("testUser")
        self.user.save()
        self.user.userprofile.student_id = '123456'
        self.user.userprofile.organization = settings.LOCAL_ORGANIZATION
        self.user.userprofile.save()

        self.student = User(username="student") # enrolled in the course
        self.student.set_password("student")
        self.student.save()
        self.student.userprofile.student_id = '654321'
        self.student.userprofile.organization = settings.LOCAL_ORGANIZATION
        self.student.userprofile.save()

        self.course = Course.objects.create(
            name="Test course",
            code="123456",
            url="Course-Url",
        )

        self.today = timezone.now()
        self.tomorrow = self.today + timedelta(days=1)
        self.two_days_from_now = self.tomorrow + timedelta(days=1)
        self.yesterday = self.today - timedelta(days=1)

        # course instances with different view_access_to settings
        self.public_course_instance = CourseInstance.objects.create(
            instance_name="Public",
            starting_time=self.yesterday,
            ending_time=self.tomorrow,
            course=self.course,
            url="public",
            view_content_to=CourseInstance.VIEW_ACCESS.PUBLIC,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.INTERNAL_USERS,
        )

        self.all_regist_course_instance = CourseInstance.objects.create(
            instance_name="All registered users",
            starting_time=self.yesterday,
            ending_time=self.tomorrow,
            course=self.course,
            url="allregistered",
            view_content_to=CourseInstance.VIEW_ACCESS.ALL_REGISTERED,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.INTERNAL_USERS,
        )

        self.enroll_audience_course_instance = CourseInstance.objects.create(
            instance_name="Enrollment audience",
            starting_time=self.yesterday,
            ending_time=self.two_days_from_now,
            course=self.course,
            url="enrollmentaudience",
            view_content_to=CourseInstance.VIEW_ACCESS.ENROLLMENT_AUDIENCE,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.INTERNAL_USERS,
        )

        self.enrolled_course_instance = CourseInstance.objects.create(
            instance_name="Enrolled",
            starting_time=self.yesterday,
            ending_time=self.two_days_from_now,
            course=self.course,
            url="enrolled",
            view_content_to=CourseInstance.VIEW_ACCESS.ENROLLED,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.INTERNAL_USERS,
        )
        self.course_instances = [self.public_course_instance, self.all_regist_course_instance,
            self.enroll_audience_course_instance, self.enrolled_course_instance]

        # enrollment
        for instance in self.course_instances:
            instance.enroll_student(self.student)

        # module/exercise round for each course instance
        self.course_modules = {}
        for instance in self.course_instances:
            self.course_modules[instance.id] = CourseModule.objects.create(
                name="Test module",
                url="test-module",
                points_to_pass=10,
                course_instance=instance,
                opening_time=self.today,
                closing_time=self.tomorrow,
            )

        # category
        self.categories = {}
        for instance in self.course_instances:
            self.categories[instance.id] = LearningObjectCategory.objects.create(
                name="Test category",
                course_instance=instance,
                points_to_pass=0,
            )

        # learning objects
        self.learning_objects = {}
        for instance in self.course_instances:
            lobjects = []
            chapter = CourseChapter.objects.create(
                name="Test chapter",
                course_module=self.course_modules[instance.id],
                category=self.categories[instance.id],
                url='chapter1',
            )
            lobjects.append(chapter)
            lobjects.append(BaseExercise.objects.create(
                name="Embedded exercise",
                parent=chapter,
                status=LearningObject.STATUS.UNLISTED,
                course_module=self.course_modules[instance.id],
                category=self.categories[instance.id],
                url='embedexercise',
                max_submissions=10,
                max_points=10,
                points_to_pass=0,
            ))
            lobjects.append(BaseExercise.objects.create(
                name="Normal exercise",
                course_module=self.course_modules[instance.id],
                category=self.categories[instance.id],
                url='normalexercise',
                max_submissions=10,
                max_points=10,
                points_to_pass=0,
            ))
            self.learning_objects[instance.id] = lobjects

        # submissions
        self.submissions = {}
        for course_instance_id, exercises in self.learning_objects.items():
            for exercise in exercises:
                if not exercise.is_submittable:
                    continue
                self.submissions[exercise.id] = []
                submission = Submission.objects.create(
                    exercise=exercise,
                )
                submission.submitters.add(self.student.userprofile)
                self.submissions[exercise.id].append(submission)

        # disable all logging
        logging.disable(logging.CRITICAL)

    def test_redirect_to_enroll(self):
        url = self.enrolled_course_instance.get_absolute_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)

        # unenrolled logged-in user should be redirected to the enroll page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertRedirects(response, self.enrolled_course_instance.get_url('enroll'))
        self.client.logout()

        # enrolled students should open the course front page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)

    def test_course_home(self):
        url = self.enroll_audience_course_instance.get_absolute_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should see the course home page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the course front page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # course instance: all registered/logged-in users may see the course
        url = self.all_regist_course_instance.get_absolute_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should see the course home page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the course front page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # public course instance
        url = self.public_course_instance.get_absolute_url()
        # anonymous user should see the course front page
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        # unenrolled logged-in user should see the course home page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the course front page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # course content visible to the enrollment audience, but user is
        # not in the enrollment audience
        ext_instance = CourseInstance.objects.create(
            instance_name="Enrollment audience external",
            starting_time=self.yesterday,
            ending_time=self.tomorrow,
            course=self.course,
            url="extaudience",
            view_content_to=CourseInstance.VIEW_ACCESS.ENROLLMENT_AUDIENCE,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.EXTERNAL_USERS,
        )
        url = ext_instance.get_absolute_url()
        self.assertTrue(self.client.login(username=self.user.username, password="testUser"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 403) # Forbidden
        response = self.client.get(ext_instance.get_url('enroll'))
        self.assertEqual(response.status_code, 200) # allowed to see the enrollment page
        response = self.client.post(ext_instance.get_url('enroll'))
        self.assertEqual(response.status_code, 403) # may not enroll
        self.client.logout()

        # course content visible to registered users (logged-in users), but user is
        # not in the enrollment audience
        ext_regist_instance = CourseInstance.objects.create(
            instance_name="Enrollment audience external - view registered users",
            starting_time=self.yesterday,
            ending_time=self.tomorrow,
            course=self.course,
            url="extaudience-registusers",
            view_content_to=CourseInstance.VIEW_ACCESS.ALL_REGISTERED,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.EXTERNAL_USERS,
        )
        url = ext_instance.get_absolute_url()
        self.assertTrue(self.client.login(username=self.user.username, password="testUser"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 403) # Forbidden
        response = self.client.get(ext_instance.get_url('enroll'))
        self.assertEqual(response.status_code, 200) # allowed to see the enrollment page
        response = self.client.post(ext_instance.get_url('enroll'))
        self.assertEqual(response.status_code, 403) # may not enroll
        self.client.logout()

    def test_course_module(self):
        url = self.course_modules[self.enrolled_course_instance.id].get_absolute_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should be redirected to enrollment page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertRedirects(response, self.enrolled_course_instance.get_url('enroll'))
        self.client.logout()
        # enrolled students should open the course module page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # course instance: access to enrollment audience (logged-in internal users)
        url = self.course_modules[self.enroll_audience_course_instance.id].get_absolute_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should see the module page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the course module page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # course instance: access to registered users (any logged-in users)
        url = self.course_modules[self.all_regist_course_instance.id].get_absolute_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should see the module page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the course module page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # course instance: access to anyone (anonymous)
        url = self.course_modules[self.public_course_instance.id].get_absolute_url()
        # anonymous user can open the module page
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        # unenrolled logged-in user should see the module page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the course module page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # course content visible to the enrollment audience, but user is
        # not in the enrollment audience
        ext_instance = CourseInstance.objects.create(
            instance_name="Enrollment audience external",
            starting_time=self.yesterday,
            ending_time=self.tomorrow,
            course=self.course,
            url="extaudience",
            view_content_to=CourseInstance.VIEW_ACCESS.ENROLLMENT_AUDIENCE,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.EXTERNAL_USERS,
        )
        ext_module = CourseModule.objects.create(
            name="Test module",
            url="test-module",
            points_to_pass=10,
            course_instance=ext_instance,
            opening_time=self.today,
            closing_time=self.tomorrow,
        )
        url = ext_module.get_absolute_url()
        self.assertTrue(self.client.login(username=self.user.username, password="testUser"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 403) # Forbidden
        self.client.logout()

    def test_chapter_enrolled_only(self):
        url = self.learning_objects[self.enrolled_course_instance.id][0].get_display_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should be redirected to enrollment page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertRedirects(response, self.enrolled_course_instance.get_url('enroll'))
        self.client.logout()
        # enrolled students should open the chapter page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # chapter exercise
        chapter_exercise = self.learning_objects[self.enrolled_course_instance.id][1]
        url = '/Course-Url/enrolled/test-module/chapter1/embedexercise/plain/'
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should be redirected to enrollment page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertRedirects(response, self.enrolled_course_instance.get_url('enroll'))
        self.client.logout()
        # enrolled students should open the chapter page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # normal exercise (not inside chapter)
        exercise = self.learning_objects[self.enrolled_course_instance.id][2]
        url = reverse('exercise', kwargs={
            'exercise_path': exercise.url,
            'module_slug': exercise.course_module.url,
            'instance_slug': exercise.course_module.course_instance.url,
            'course_slug': exercise.course_module.course_instance.course.url,
        })
        self.assertEqual(url, '/Course-Url/enrolled/test-module/normalexercise/')
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should be redirected to enrollment page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertRedirects(response, self.enrolled_course_instance.get_url('enroll'))
        self.client.logout()
        # enrolled students should open the chapter page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

    def test_chapter_enroll_audience(self):
        url = self.learning_objects[self.enroll_audience_course_instance.id][0].get_display_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in internal user should see the chapter page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the chapter page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # chapter exercise
        chapter_exercise = self.learning_objects[self.enroll_audience_course_instance.id][1]
        url = '/Course-Url/enrollmentaudience/test-module/chapter1/embedexercise/plain/'
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in internal user should see the exercise
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the chapter page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # normal exercise (not inside chapter)
        exercise = self.learning_objects[self.enroll_audience_course_instance.id][2]
        url = reverse('exercise', kwargs={
            'exercise_path': exercise.url,
            'module_slug': exercise.course_module.url,
            'instance_slug': exercise.course_module.course_instance.url,
            'course_slug': exercise.course_module.course_instance.course.url,
        })
        self.assertEqual(url, '/Course-Url/enrollmentaudience/test-module/normalexercise/')
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should see the exercise
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the exercise page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # course content visible to the enrollment audience, but user is
        # not in the enrollment audience
        ext_instance = CourseInstance.objects.create(
            instance_name="Enrollment audience external",
            starting_time=self.yesterday,
            ending_time=self.tomorrow,
            course=self.course,
            url="extaudience",
            view_content_to=CourseInstance.VIEW_ACCESS.ENROLLMENT_AUDIENCE,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.EXTERNAL_USERS,
        )
        ext_module = CourseModule.objects.create(
            name="Test module",
            url="test-module",
            points_to_pass=10,
            course_instance=ext_instance,
            opening_time=self.today,
            closing_time=self.tomorrow,
        )
        ext_category = LearningObjectCategory.objects.create(
            name="External test category",
            course_instance=ext_instance,
            points_to_pass=0,
        )
        ext_chapter = CourseChapter.objects.create(
            name="External test chapter",
            course_module=ext_module,
            category=ext_category,
            url='extchapter1',
        )
        url = ext_chapter.get_display_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in internal user should NOT see the chapter page
        # (user is not external and the course is visible to external users only)
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 403)
        self.client.logout()

    def test_chapter_all_registered(self):
        url = self.learning_objects[self.all_regist_course_instance.id][0].get_display_url()
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in internal user should see the chapter page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the chapter page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # chapter exercise
        chapter_exercise = self.learning_objects[self.all_regist_course_instance.id][1]
        url = '/Course-Url/allregistered/test-module/chapter1/embedexercise/plain/'
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in internal user should see the exercise
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the chapter page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # normal exercise (not inside chapter)
        exercise = self.learning_objects[self.all_regist_course_instance.id][2]
        url = reverse('exercise', kwargs={
            'exercise_path': exercise.url,
            'module_slug': exercise.course_module.url,
            'instance_slug': exercise.course_module.course_instance.url,
            'course_slug': exercise.course_module.course_instance.course.url,
        })
        self.assertEqual(url, '/Course-Url/allregistered/test-module/normalexercise/')
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should see the exercise
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the exercise page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

    def test_chapter_public(self):
        url = self.learning_objects[self.public_course_instance.id][0].get_display_url()
        # anonymous user can open the chapter
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        # unenrolled logged-in internal user should see the chapter page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the chapter page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # chapter exercise
        chapter_exercise = self.learning_objects[self.public_course_instance.id][1]
        url = '/Course-Url/public/test-module/chapter1/embedexercise/plain/'
        # anonymous user can open the chapter exercise
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        # unenrolled logged-in internal user should see the exercise
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the chapter exercise normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

        # normal exercise (not inside chapter)
        exercise = self.learning_objects[self.public_course_instance.id][2]
        url = reverse('exercise', kwargs={
            'exercise_path': exercise.url,
            'module_slug': exercise.course_module.url,
            'instance_slug': exercise.course_module.course_instance.url,
            'course_slug': exercise.course_module.course_instance.course.url,
        })
        self.assertEqual(url, '/Course-Url/public/test-module/normalexercise/')
        # anonymous user can open the exercise
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        # unenrolled logged-in user should see the exercise
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()
        # enrolled students should open the exercise page normally
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

    def test_submission(self):
        # submission in the chapter exercise
        chapter_exercise = self.learning_objects[self.enrolled_course_instance.id][1]
        submission = self.submissions[chapter_exercise.id][0]
        url = submission.get_absolute_url()
        self.assertEqual(url,
            '/Course-Url/enrolled/test-module/chapter1/embedexercise/submissions/{0}/'.format(
                submission.id))
        # should redirect to A+ login
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        # unenrolled logged-in user should be redirected to enrollment page
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertRedirects(response, self.enrolled_course_instance.get_url('enroll'))
        self.client.logout()
        # enrolled non-submitter user should not see the submission
        self.enrolled_course_instance.enroll_student(self.user)
        self.assertTrue(self.client.login(username=self.user.username, password='testUser'))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 403)
        self.client.logout()
        self.enrolled_course_instance.get_enrollment_for(self.user).delete()
        # the submitter should see her submission
        self.assertTrue(self.client.login(username=self.student.username, password="student"))
        response = self.client.get(url)
        self.assertEqual(response.status_code, 200)
        self.client.logout()

    def test_enroll(self):
        self.assertTrue(self.enrolled_course_instance.is_enrollable(self.user))
        self.assertTrue(self.enrolled_course_instance.is_enrollment_open())

        # course instance is hidden from students
        new_instance = CourseInstance.objects.create(
            instance_name="Hidden course instance",
            starting_time=self.yesterday,
            ending_time=self.tomorrow,
            course=self.course,
            url="hiddencourse",
            view_content_to=CourseInstance.VIEW_ACCESS.PUBLIC,
            enrollment_audience=CourseInstance.ENROLLMENT_AUDIENCE.INTERNAL_USERS,
            visible_to_students=False,
        )
        url = new_instance.get_url('enroll')
        # anonymous user accesses a hidden course: redirect to login
        response = self.client.post(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)
        response = self.client.get(url)
        self.assertRedirects(response, '/accounts/login/?next=' + url)

        # enrollment closed
        new_instance.visible_to_students = True
        new_instance.enrollment_starting_time = self.yesterday
        new_instance.enrollment_ending_time = self.yesterday + timedelta(hours=1)
        new_instance.save()
        url = new_instance.get_url('enroll')
        self.assertTrue(new_instance.is_enrollable(self.user))
        self.assertFalse(new_instance.is_enrollment_open())
        self.assertTrue(self.client.login(username=self.user.username, password="testUser"))
        response = self.client.get(url)
        # can open the enrollment page
        self.assertEqual(response.status_code, 200)
        # can not enroll
        response = self.client.post(url)
        self.assertEqual(response.status_code, 403)
        self.client.logout()

    def test_enrollment_exercise(self):
        instance = self.enrolled_course_instance
        enroll_exercise = self.learning_objects[instance.id][2]
        enroll_exercise.status = LearningObject.STATUS.ENROLLMENT
        enroll_exercise.save()
        enroll_url = instance.get_url('enroll')
        exercise_url = reverse('exercise', kwargs={
            'exercise_path': enroll_exercise.url,
            'module_slug': enroll_exercise.course_module.url,
            'instance_slug': enroll_exercise.course_module.course_instance.url,
            'course_slug': enroll_exercise.course_module.course_instance.course.url,
        })

        # anonymous may not open the exercise nor enroll
        response = self.client.post(enroll_url)
        self.assertRedirects(response, '/accounts/login/?next=' + enroll_url)
        response = self.client.get(exercise_url)
        self.assertRedirects(response, '/accounts/login/?next=' + exercise_url)
        response = self.client.post(exercise_url)
        self.assertRedirects(response, '/accounts/login/?next=' + exercise_url)
        # the course has only one enrollment (made in setUp())
        self.assertEqual(instance.students.count(), 1)

        # logged-in user may open the exercise and submit
        self.assertTrue(self.client.login(username=self.user.username, password="testUser"))
        response = self.client.post(enroll_url)
        self.assertRedirects(response, exercise_url) # redirects to the enrollment exercise
        response = self.client.get(exercise_url)
        self.assertEqual(response.status_code, 200)
        # Since there is no exercise service running in the unit test environment,
        # we can not make test submissions to the exercise.
        success_flag, warnings, students = enroll_exercise.check_submission_allowed(self.user.userprofile)
        self.assertEqual(success_flag, BaseExercise.SUBMIT_STATUS.ALLOWED)
        self.assertEqual(len(warnings), 0)
        instance.enroll_student(self.user)
        self.assertEqual(instance.students.count(), 2)
        self.assertTrue(instance.is_student(self.user))
        self.client.logout()

    def test_enrollment_exercise_external_users(self):
        # only external users may enroll
        instance = self.enrolled_course_instance
        instance.enrollment_audience = CourseInstance.ENROLLMENT_AUDIENCE.EXTERNAL_USERS
        instance.save()

        enroll_exercise = self.learning_objects[instance.id][2]
        enroll_exercise.status = LearningObject.STATUS.ENROLLMENT_EXTERNAL
        enroll_exercise.save()
        enroll_url = instance.get_url('enroll')
        exercise_url = reverse('exercise', kwargs={
            'exercise_path': enroll_exercise.url,
            'module_slug': enroll_exercise.course_module.url,
            'instance_slug': enroll_exercise.course_module.course_instance.url,
            'course_slug': enroll_exercise.course_module.course_instance.course.url,
        })

        # internal user may not enroll
        self.assertTrue(self.client.login(username=self.user.username, password="testUser"))
        response = self.client.post(enroll_url)
        self.assertEqual(response.status_code, 403)
        response = self.client.get(exercise_url)
        self.assertEqual(response.status_code, 403)
        response = self.client.post(exercise_url)
        self.assertEqual(response.status_code, 403)
        self.assertFalse(instance.is_student(self.user))
        self.client.logout()

    def tearDown(self):
        # return previous logging settings
        logging.disable(logging.NOTSET)