Testing EMail sending in Django
===============================


    class TestOnboardingEmails(TestCase):
       MSG1 = 'Congratulations! You have now set your first '
           'assignment'
       MSG2 = 'You have been using product for a week now'

       def setUp(self):
           self.teacher = factories.TeacherFactory.create()
           self.teacher.email = 'test@test.domani.com'
           self.teacher.save()
           self.student = factories.StudentFactory.create()
           self.studentset = factories.StudentSetFactory.create(owner=self.teacher)
           self.studentset.join_student(self.student)
           self.studentset.join_teacher(self.teacher)
           self.quick = factories.QuickFactory.create()

           self.original_backend = settings.EMAIL_BACKEND
           settings.EMAIL_BACKEND = 'django.core.mail.backends.locmem.EmailBackend'

       def tearDown(self):
           settings.EMAIL_BACKEND = self.original_backend


       def test_new_assignment(self):
           aset = AssignmentSet.create(teacher=self.teacher,
                                       assign_date=datetime.now(),
                                       studentset=self.studentset,
                                       students_list=[self.student],
                                       content_list=[{'obj': self.quick,
                                                      'attempt_max':1}])
           cmd = process_events.Command()
           cmd.handle(no_celery=True, debug=False, name=None, date=None,
                      quiet=False)
           self.assertTrue(len(mail.outbox)==1)
           self.assertTrue(self.MSG1 in
                           mail.outbox[0].message().as_string())
           self.assertTrue(self.MSG2 not in
                           mail.outbox[0].message().as_string())

           after_1_week_plus = datetime.now() + relativedelta(days=8)

           cmd.handle(no_celery=True, debug=False, name=None,
                      date=after_1_week_plus.strftime(DATE_FORMAT),
                      quiet=False)
           self.assertTrue(len(mail.outbox)==2)
           self.assertTrue(self.MSG1 not in
                           mail.outbox[1].message().as_string())
           self.assertTrue(self.MSG2 in
                           mail.outbox[1].message().as_string())


    if __name__ == '__main__':
       unittest.main()

The important lines in setUp and tearDown:


     def setUp(self):
         self.original_backend = settings.EMAIL_BACKEND
         settings.EMAIL_BACKEND = 'django.core.mail.backends.locmem.EmailBackend'

     def tearDown(self):
         settings.EMAIL_BACKEND = self.original_backend