Node not redirecting to Page Not found 404

If I go to http://localhost:4000/asdfasd I should be seeing my page not found and my console.log in the server, but I don't see either or.

APP.JS

const EXPRESS = require('express');
const BODY_PARSER = require('body-parser');
const PATH = require('path');

const APP = EXPRESS();

const ADMIN_ROUTES = require('./routes/admin');
const SHOP_ROUTES = require('./routes/shop');

APP.use(BODY_PARSER.urlencoded({ extended: false }));

APP.use('/admin', ADMIN_ROUTES);
APP.use(SHOP_ROUTES);

APP.use((req, res, next) => {
  console.log('page not found');
  res
    .status(404)
    .sendFile(PATH.join(__dirname, '../', 'views', 'not-found.html'));
});

APP.listen(4000);

Solution

Example code

Express is not sending not-found.html because something higher up in your pipeline is handling your GET request to /asdfasd.

In your situation, APP.use(SHOP_ROUTES) is handling your request because all requests, excluding those that start with /admin, are first being sent to SHOP_ROUTES.

Here are some cases demonstrating why you do not see not-found.html:

Case 1: You are using router.use() in your shop router and it is handling the request.

In this example:

/routes/shop.js

router.use((req, res, next) => res.send('Something'))

A request to /asdfasd will display the word "Something" on the page. Express will not go further down the pipeline because the request has been handled already.

Case 2: You have an asynchronous function inside your shop router that does not use next().

For example, if you are making a call to some API:

/routes/shop.js

// request-promise is an HTTP request client that returns a promise
const rp = require('request-promise')

router.use((req, res, next) => {
    rp.get('https://myapi.com/users')
        .then(response => res.json(response))
        .catch()
})

and your API request returns a status code of 400+ or 500+, your request is essentially stuck inside of this router.use() because you did not tell Express how to handle bad requests.

You would have to use the next function as a callback inside of your .catch():

router.use((req, res, next) => {
    rp.get('https://myapi.com/users')
        .then(response => res.json(response))
        .catch(next)
})

Case 3: You have a dynamic route inside of your shop router, ex. /:word.

If in your SHOP_ROUTES, you have a dynamic route, like the one below:

/routes/shop.js

router.get('/:word', (req, res, next) => res.send(req.params.word))

Any request to / that is not already handled by a preceding route will be handled by this one.