How to use the @xviz/schema.MessageTypes.ERROR function in @xviz/schema

test('sessionValidator#connect-start-error', t => {
  // Creation == connect
  const validator = new XVIZSessionValidator();

  validator.onConnect();
  validator.onStart({version: '3.0.0'});
  validator.onError({message: 'unsupported version'});

  const s = validator.stats;

  const e = {};
  e[MessageTypes.START] = 1;
  e[MessageTypes.ERROR] = 1;

  t.deepEqual(s.messages, e, 'got all messages');
  t.deepEqual(s.validationErrors, {}, 'all valid');
  t.deepEqual(s.stateErrors, {}, 'valid transitions');
  t.end();
});