NPM Install add custom warning message - node.js

Question

How should I got about adding a warning message when a user tries to install a given version of a library?
For example, when you install babel-preset-es2015 you get the following warning:
🙌 Thanks for using Babel: we recommend using babel-preset-env now: please read babeljs.io/env to update!
By inspecting their code I saw they add a deprecated entry in their package.json as follows:
"deprecated": "🙌 Thanks for using Babel: we recommend using babel-preset-env now: please read babeljs.io/env to update! ",
I can easily add that, but I'm not actually deprecating anything. I just want to warn users that they are installing an alpha version and there may be changes in the API.
Question
Is there a similar entry to deprecated that can do the job?

Answer 1

There's not necessarily a way you can do that, or not with given fields like "deprecated"
What you can do, which is a little bit of a workaround, is adding a post-install script, that outputs a string to the console if you mark a version as alpha.
// package.json
{
"version": "1.2.3-alpha.2",
"scripts": {
"postinstall": "node postinstall.js"
}
}
// postinstall.js
const package = require('./package.json')
if (package.version.includes('alpha')) {
console.log('You are using an alpha version. Beware!')
}

Answer 2

Please check out belows:
https://docs.npmjs.com/cli/deprecate
https://docs.npmjs.com/deprecating-and-undeprecating-packages-or-package-versions
$ npm deprecate <pkg>[#<version>] <message>
Example:
$ npm deprecate some-lib#"< 1.0.0" "🙌 Thanks for using it. we recommend using new version, 1.x.x. Please check out https://example.com"
then,
$ yarn
yarn install v1.16.0
info No lockfile found.
[1/4] 🔍 Resolving packages...
warning some-lib#0.1.5: 🙌 Thanks for using it. we recommend using new version, 1.x.x. Please check out https://example.com
[2/4] 🚚 Fetching packages...
[3/4] 🔗 Linking dependencies...
[4/4] 🔨 Building fresh packages...
success Saved lockfile.
✨ Done in 5.25s.
Time: 0h:00m:06s