Prevents students from accidentally changing their enrollment on login (LMS-2773)

skip tests if not run in lms

common/djangoapps/student/tests/tests.py

@@ -430,6 +430,88 @@ class EnrollInCourseTest(TestCase):
         self.assert_enrollment_event_was_emitted(user, course_id)
 
 
+@override_settings(MODULESTORE=TEST_DATA_MIXED_MODULESTORE)
+@unittest.skipUnless(settings.ROOT_URLCONF == 'lms.urls', 'Test only valid in lms')
+class ChangeEnrollmentViewTest(ModuleStoreTestCase):
+    """Tests the student.views.change_enrollment view"""
+
+    def setUp(self):
+        super(ChangeEnrollmentViewTest, self).setUp()
+        self.course = CourseFactory.create()
+        self.user = UserFactory.create(password='secret')
+        self.client.login(username=self.user.username, password='secret')
+        self.url = reverse('change_enrollment')
+
+    def enroll_through_view(self, course):
+        response = self.client.post(
+            reverse('change_enrollment'), {
+                'course_id': course.id.to_deprecated_string(),
+                'enrollment_action': 'enroll'
+            }
+        )
+        return response
+
+    def test_enroll_as_honor(self):
+        """Tests that a student can successfully enroll through this view"""
+        response = self.enroll_through_view(self.course)
+        self.assertEqual(response.status_code, 200)
+        enrollment_mode, is_active = CourseEnrollment.enrollment_mode_for_user(
+            self.user, self.course.id
+        )
+        self.assertTrue(is_active)
+        self.assertEqual(enrollment_mode, u'honor')
+
+    def test_cannot_enroll_if_already_enrolled(self):
+        """
+        Tests that a student will not be able to enroll through this view if
+        they are already enrolled in the course
+        """
+        CourseEnrollment.enroll(self.user, self.course.id)
+        self.assertTrue(CourseEnrollment.is_enrolled(self.user, self.course.id))
+        # now try to enroll that student
+        response = self.enroll_through_view(self.course)
+        self.assertEqual(response.status_code, 400)
+
+    def test_change_to_honor_if_verified(self):
+        """
+        Tests that a student that is a currently enrolled verified student cannot
+        accidentally change their enrollment to verified
+        """
+        CourseEnrollment.enroll(self.user, self.course.id, mode=u'verified')
+        self.assertTrue(CourseEnrollment.is_enrolled(self.user, self.course.id))
+        # now try to enroll the student in the honor mode:
+        response = self.enroll_through_view(self.course)
+        self.assertEqual(response.status_code, 400)
+        enrollment_mode, is_active = CourseEnrollment.enrollment_mode_for_user(
+            self.user, self.course.id
+        )
+        self.assertTrue(is_active)
+        self.assertEqual(enrollment_mode, u'verified')
+
+    def test_change_to_honor_if_verified_not_active(self):
+        """
+        Tests that one can renroll for a course if one has already unenrolled
+        """
+        # enroll student
+        CourseEnrollment.enroll(self.user, self.course.id, mode=u'verified')
+        # now unenroll student:
+        CourseEnrollment.unenroll(self.user, self.course.id)
+        # check that they are verified but inactive
+        enrollment_mode, is_active = CourseEnrollment.enrollment_mode_for_user(
+            self.user, self.course.id
+        )
+        self.assertFalse(is_active)
+        self.assertEqual(enrollment_mode, u'verified')
+        # now enroll them through the view:
+        response = self.enroll_through_view(self.course)
+        self.assertEqual(response.status_code, 200)
+        enrollment_mode, is_active = CourseEnrollment.enrollment_mode_for_user(
+            self.user, self.course.id
+        )
+        self.assertTrue(is_active)
+        self.assertEqual(enrollment_mode, u'honor')
+
+
 @override_settings(MODULESTORE=TEST_DATA_MIXED_MODULESTORE)
 class PaidRegistrationTest(ModuleStoreTestCase):
     """

common/djangoapps/student/views.py

@@ -613,6 +613,12 @@ def change_enrollment(request):
         if is_course_full:
             return HttpResponseBadRequest(_("Course is full"))
 
+        # check to see if user is currently enrolled in that course
+        if CourseEnrollment.is_enrolled(user, course_id):
+            return HttpResponseBadRequest(
+                _("Student is already enrolled")
+            )
+
         # If this course is available in multiple modes, redirect them to a page
         # where they can choose which mode they want.
         available_modes = CourseMode.modes_for_course(course_id)