Adding testing

certbot/tests/cli_test.py

@@ -882,6 +882,15 @@ class CLITest(unittest.TestCase):  # pylint: disable=too-many-public-methods
         mock_sys.exit.assert_called_with(''.join(
             traceback.format_exception_only(KeyboardInterrupt, interrupt)))
 
+        # Test dialog errors
+
+        import dialog
+        exception = dialog.error(message="test message")
+        main._handle_exception(
+                dialog.DialogError, exc_value=exception, trace=None, config=None)
+        error_msg = mock_sys.exit.call_args_list[-1][0][0]
+        self.assertTrue("test message" in error_msg)
+
     def test_read_file(self):
         rel_test_path = os.path.relpath(os.path.join(self.tmp_dir, 'foo'))
         self.assertRaises(