CODEWITHSUNDEEP
node.jsexpresserror-handlingroutesmiddleware
James Harrington
James Harrington

Reputation: 3216

In express when i call next(err) the next tick/middleware does not get called/processed

This is a cool little middleware that returns a 405 error if the req.url matches one of the other routes connected to the same router object.

If it finds a match it will check to see if there is a matching http verb if there is no matching http verb it will set the flag to true and trigger the error.

My problem is that when next(err) gets called the next tick does not get processed. The server just blows up with an error as if i actually threw one.

I want the next tick to be processed (which is my error handeling middleware).

start.js

var express = require('express'),
    router = express.Router();

//Other routes

router.use( function(req, res, next) {

    var flag = false;
    for (var i = 0, rl = router.stack.length; i < rl; i++) {
      var route = router.stack[i].route;
      if (route && req.url.toLowerCase() === route.path.toLowerCase()) {
        for (var method in route.methods) {
          if (route.methods.hasOwnProperty(method)) {
            if(method.toLowerCase() !== req.method.toLowerCase()){
              flag = true;
            }
          }
        }
      }
    };
    if (flag) {
      var err = new Error('Method Not Allowed');
      err.status = 405;
      return next(err);
    }

    return next();
});
module.exports = router

EDIT:

routes.js

var express = require('express'),
    router = express.Router();


router.use(require('../middlewares/successHandler_logger'));

router.use('/start', require('./start/start'));
router.use('/login', require('./login/login'));

router.use(require('../middlewares/errorHandeling'));


module.exports = router

errorHandler.js 

var express = require('express'),
    router = express.Router();

router.use(function(err, req, res, next) {
  err.status = err.status || 500;
  if (!err.json) {
    err.json = {
      status:err.status,
      success: false,
      message: 'oops',
    }
  };


  res.status(err.status).json(err.json);

  console.log(err.stack);

});
module.exports = router

Upvotes: 1

Views: 694

Answers (1)

jfriend00
jfriend00

Reputation: 707188

I think the issue is that you have multiple routers and the error handling chaining you want does not work across routers.

I'd suggest you only create one router and share it. For example, in errorHandler.js, you can do this:

module.exports = function(err, req, res, next) {
  err.status = err.status || 500;
  if (!err.json) {
    err.json = {
      status:err.status,
      success: false,
      message: 'oops',
    }
  };


  res.status(err.status).json(err.json);

  console.log(err.stack);

});

And, then this will still work:

router.use(require('../middlewares/errorHandeling'));

You would then similarly have to use one common router in the other places.

Upvotes: 1

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