node/express errors middleware (wip)

middleware-errors.js

var util = require('util');
var loggly = require('../services/loggly');

function middleware() {
  return function(err, req, res, next) {

    if (!util.isError(err)) {
      var error = new Error();
      if (typeof err === 'number') {
        error.status = err;
      } else {
        error.message = err;
      }
      err = error;
    }

    err.status = err.status || 500;

    res.status(err.status);

    var data = {
      message: err.message,
      stack: err.stack,
      status: err.status,
      user: req.user ? req.user.id : null,
      url: req.url,
      body: req.body,
    };

    if (req.app.get('env') === 'production') {
      loggly.log(data, ['server'], function(err, result) {
        if (err) console.error(err);
      });
    }

    if (err.status >= 500) {
      console.error(err.stack);
    }

    if (!req.accepts('html')) {
      res.json(toJSON(err));
      return;
    }

    res.locals.err = err;

    res
      .status(err.status)
      .render('error');

  };
}

function toJSON(err) {
  if (typeof err.message === 'object') return err.message;
  return { form: [err.message] };
}

function ahh(status, message) {
  var err = new Error();
  err.status = status;
  err.message = message;
  return err;
}

module.exports.middleware = middleware;
module.exports.ahh = ahh;