Node.js 21: "[DEP0040] DeprecationWarning: The `punycode` module is deprecated." about serve

[MikeMcC399]

The serve dependency fast-url-parser can be patched as a temporary measure. Starting with the following:

mkdir serve-test
cd serve-test
npm init -y
npm install serve
export NODE_OPTIONS='--trace-deprecation'
npx serve -v

Workaround

Use npm module patch-package

npm install patch-package

add script to package.json

"postinstall": "patch-package"

Edit node_modules\fast-url-parser\src\urlparser.js
Line 401

Change

var punycode = require("punycode");

to

var punycode = require("punycode/");

then execute

npx patch-package fast-url-parser

To verify, execute again:

npx serve -v

There should be no deprecation message, even when running under Node.js 21.x.

For package managers other than npm, see README of patch-package.

[tik9]

Should I execute the code on top mkdir serve-test.. and then execute the workaround?

[MikeMcC399]

@tik9

Should I execute the code on top mkdir serve-test.. and then execute the workaround?

You would replace serve-test with the name of your existing repository. Sorry if that was not clear. I just used the name serve-test to demonstrate the principal of patching. You wouldn't normally be creating a new directory if you already have a repository that you are going to patch.