Be friendly, be cool 😎 show a message to your users to upgrade Node instead of a stacktrace

It's common for new Node users to miss the npm engines warning when installing a CLI. This package displays a beginner-friendly message if their Node version is below the one expected and it's just a few lines of JS code.

Example with hotel CLI:

$ node -v
0.12
$ hotel
hotel requires at least version 4 of Node, please upgrade

Install:

npm install please-upgrade-node

yarn add please-upgrade-node

Require please-upgrade-node before anything else:

// ./bin.js
// by default, will load ./package.json
require('please-upgrade-node')()

// The rest of your code...

In your package.json, define the required Node version:

{ 
  "name": "super-cli",
  "bin": "./bin.js",
  "engines": { "node": ">=6" }
}

Please note that >= is the only operator supported by please-upgrade-node (e.g. >=4, >=4.0, >=4.0.0). Now if your users install your super-cli project with an older Node version, they'll see:

$ npm install -g super-cli
# [...]
npm WARN engine [email protected]: : wanted: {"node":">=6"} (current: {"node":"4.8.3","npm":"2.15.11"})
# [...]

$ super-cli
super-cli requires at least version 6 of Node, please upgrade

pleaseUpgradeNode([pkgDir = '.'])

You can pass a pkgDir if your package.json is not at the same level:

// ./package.json
require('please-upgrade-node')()

// ../../package.json
require('please-upgrade-node')('../..')

Make sure when requiring please-upgrade-node to not use syntax that is only supported in recent versions of Node.

For example, if you use const instead of var, please-upgrade-node won't work with Node 0.12:

const pleaseUpgradeNode = require('please-upgrade-node') // ← Will fail and exit here with Node 0.12,
pleaseUpgradeNode() // Message won't be displayed

To avoid any issues, the recommended syntax is require('please-upgrade-node')().

• pkg-ok - 👌 Prevents publishing a module with bad paths
• husky - 🐶 Git hooks made easy

Thanks to zeit/serve for inspiring the error message.

MIT - Typicode 🌵 - Patreon