gistfile1.js

var server = nodeOauth2Server({
    model: modelHandlers,
    grants: ['password', 'refresh_token'],
    debug: false,
    refreshTokenLifetime: null, // never expire refresh token
    passthroughErrors: true
});

module.exports = {
  grantWrap: function oauthGrantWrap(req, res, next) {
    var grantInstace = server.grant();
    // hack to prevent ugly http error responses
    grantInstace(req, res, function grantErrorHandler(err) {
      if (err) {
        res.status(err.code || 500);
        res.json(err);
      }
    });
  },
  authoriseWrap: function oauthGrantWrap(req, res, next) {
    var authInstace = server.authorise();
    // hack to prevent ugly http error responses
    authInstace(req, res, function authErrorHandler(err) {
      if (err) {
        res.status(err.code || 500);
        res.json(err);
      }
    });
  }

}