errorPageUtils.js

var ErrorPage = require("error-page"),
    errorConfig = require("./error-config.json")

module.exports = errorpage

function errorpage(req, res, status) {
    if (Array.isArray(status)) {
        var page = ErrorPage(req, res, errorConfig)
        page.apply(page, status)
    } else {
        ErrorPage(req, res, errorConfig)(status)
    }
}

usage.js

var RedSess = require("redsess"),
    errorPage = require("../../utils/errorPage")

module.exports = {
    isTutor: isTutor
}

function isTutor(req, res, next) {
    var session = RedSess(req, res)
    session.get("auth", handleAuth)

    function handleAuth(err, auth) {
        if (err) {
            return errorPage(req, res, [500, err])
        }
        if (!auth) {
            return errorPage(req, res, [500, new Error("not logged in")])
        }
        if (!auth.tutor_application) {
            return errorPage(req, res, [500, new Error("Not authorized")])
        }
        next()
    }
}