test the jinja monkeypatch

apps/amo/tests/test_helpers.py

@@ -420,3 +420,11 @@ def test_site_nav():
     r = Mock()
     r.APP = amo.FIREFOX
     assert 'id="site-nav"' in helpers.site_nav({'request': r})
+
+
+def test_jinja_trans_monkeypatch():
+    # This tests the monkeypatch in manage.py that prevents localizers from
+    # taking us down.
+    render('{% trans come_on=1 %}% (come_on)s{% endtrans %}')
+    render('{% trans come_on=1 %}%(come_on){% endtrans %}')
+    render('{% trans come_on=1 %}%(come_on)z{% endtrans %}')