Proper way to remove middleware from the Express stack?

Question

Is there a canonical way to remove middleware added with app.use from the stack? It seems that it should be possible to just modify the app.stack array directly, but I am wondering if there is a documented method I should be considering first.

Answer 1

use actually comes from Connect (not Express), and all it really does is push the middleware function onto the app's stack.

So you should be just fine splicing the function out of the array.

However, keep in mind there is no documentation around app.stack nor is there a function to remove middleware. You run the risk of a future version of Connect making changes incompatible with your code.

Answer 2

There seems to be no built in way to do that, but you can manage to get the same result with a small trick. Create your own array of middleware (let's call it dynamicMiddleware) but don't push that into express, instead push just 1 middleware that will execute all the handlers in dynamicMiddleware asynchronously and in order.

const async = require('async')  // Middleware  const m1 = (req, res, next) => {     // do something here      next(); }  const m2 = (req, res, next) => {     // do something here      next(); }  const m3 = (req, res, next) => {     // do something here      next(); }  let dynamicMiddleware = [m1, m2, m3]  app.use((req, res, next) => {     // execute async handlers one by one     async.eachSeries(         // array to iterate over         dynamicMiddleware,          // iteration function         (handler, callback) => {             // call handler with req, res, and callback as next             handler(req, res, callback)         },          // final callback         (err) => {             if( err ) {             // handle error as needed              } else {                 // call next middleware                 next()             }         }     ); }) 

The code is a bit rough as I don't have a chance to test it right now, but the idea should be clear: wrap all dynamic handlers array in 1 middleware, that will loop through the array. And as you add or remove handlers to the array, only the ones left in the array will be called.