Documentation for middleware with 4 arguments should be linked from "writing middleware" #1069
Description
Activity
Hey @denilsonsa!
That page should have a mention
PRs are welcome! Here is that page's source: https://github.com/expressjs/expressjs.com/blob/gh-pages/en/guide/writing-middleware.md
The error-handling middleware must be the last among other middleware and routes for it to function correctly.
This is not correct. I don't have time to dig into the article you posted, but my original skim leaves me with questions. Error handling middleware can be in many places and work correctly. The part where they state that gives no context for why they think that, so I cannot even guess at what they mean.
Hi. Can i work on this issue?
Hi. Can i work on this issue?
Sure, please, go ahead!
- locked and limited conversation to collaborators
on Aug 2, 2025
At http://expressjs.com/en/guide/writing-middleware.html, I see no mention of the error handling middleware, or even that 4-argument middleware exists. That page should have a mention (and a link to full documentation) just like how using middleware and app.use() already have.
Bonus feedback (that should probably be a separate issue anyway):
https://dev.to/nedsoft/central-error-handling-in-express-3aej - This third-party page notes that “The error-handling middleware must be the last among other middleware and routes for it to function correctly.”. If this note is so important, I think it should exist in the official documentation (or it should be more visible).
This was originally submitted as expressjs/express#4058