In general should routes be placed before or after middleware?

Question

Oddly, when I moved my middleware in front of my routes, my routes stopped working. I got no error, on the client or the server.

My fetch() calls seemingly disappeared.

However when I put the routes before my middleware, the routes begin to work again.

I'm refactoring code and have no idea why this is happening.

// load middleware
const middleware = require(__dirname +'/middleware');
app.use(middleware.session.session);
...

// load routes
const routes = require(__dirname + '/routes');
app.use('/articles', routes.articles);
...

Answer 1

Routes and middleware should be placed in the order that you want them to be matched against the route and then to execute (if they match the incoming route). There is no absolute answer to which comes first as it really depends upon what you're trying to do. For example, you would put app.use(express.json()) before any route that wants to use a JSON formatted body. But, you would put the login page route handler BEFORE any middleware that checks to see if the user is authenticated (so that it can run for users that aren't yet authenticated).

If your code stops working when you put the middleware first, then there is probably something wrong with the implementation of the middleware. We can only help with that specific issue if you show us the actual code for that middleware. Perhaps you aren't calling next() to continue routing or you're sending a response in the middleware or there's a coding error in the middleware.