Global Middleware not being triggered

user_2054434 0
Viewed 47

Server.ts

import express, { Request, Response, NextFunction } from 'express'
import { router } from "./routes"
import { Database } from './Database/index'

const app = express()
const db = new Database()
db.connect()
app.use(router) // contains all my routes

// The middleware I'm trying to be fired
app.use((err: Error, req: Request, res: Response, next: NextFunction) => {
  if (err instanceof Error) {
    return res.status(400).json({
      error: err.message
    })
  }

  return res.status(500).json({
    status: 'error',
    message: 'Internal Server Error :('
  })
})

app.listen(3000, () => console.log('Server is running'))

According to Express4 Documentation

You define error-handling middleware last, after other app.use() and routes calls;

So I think it's right. But for some reason its NOT being called/triggered.

Why it's NOT working?

  • When I try to access an URL that doesn't exists inside routes.ts it gives a standard 404 error, but I want to get it from my middleware.

I want to use this Middleware for all errors, but most for when user makes a request for an endpoint that doesn't exists.

express node.js javascript
1 Answers

This is because in 404 is not an error. It just means there is no matching route.

From the docs:

In Express, 404 responses are not the result of an error, so the error-handler middleware will not capture them.

This is the default code from the docs. Add this at the bottom:

app.use(function (req, res, next) {
  res.status(404).send("Sorry can't find that!")
})
user_101401240
Related