@mock.patch.object(Site.objects, 'get_current')
    def test_watch_thread_then_reply(self, get_current):
        get_current.return_value.domain = 'testserver'

        t = ThreadFactory()
        f = t.forum
        poster = UserFactory()
        watcher = UserFactory()

        self._toggle_watch_thread_as(t, watcher, turn_on=True)
        self.client.login(username=poster.username, password='testpass')
        post(self.client, 'forums.reply', {'content': 'a post'},
             args=[t.forum.slug, t.id])

        p = Post.objects.all().order_by('-id')[0]
        attrs_eq(mail.outbox[0], to=[watcher.email],
                 subject=u'Re: {f} - {t}'.format(f=f, t=t))
        body = REPLY_EMAIL.format(
            username=poster.profile.name,
            forum_slug=f.slug,
            thread=t.title,
            thread_id=t.id,
            post_id=p.id)
        starts_with(mail.outbox[0].body, body)
The event fires and sends emails when watching a thread.
dataset/ETHPy150Open mozilla/kitsune/kitsune/forums/tests/test_notifications.py/NotificationsTests.test_watch_thread_then_reply