How can I specify the required Node.js version in package.json?

Question

I have a Node.js project that requires Node version 12 or higher. Is there a way to specify this in the packages.json file, so that the installer will automatically check and inform the users if they need to upgrade?

Solution 1

You can set the engines field in your package.json and set requirements for either node or npm versions or both:

  "engines" : { 
    "npm" : ">=7.0.0",
    "node" : ">=16.0.0"
  }

To enforce this via npm you need to create an .npmrc file (and commit it to the repository) and set the engines-strict option to true, which will cause npm commands such as npm install to fail if the required engine versions to not match:

# .npmrc
engine-strict=true

Without that file, every developer will need to run npm config set engine-strict true in their local workspace to switch on this option.

Original Answer

As you're saying your code definitely won't work with any lower versions, you probably want the "engineStrict" flag too:

{ "engineStrict" : true }

Documentation for the package.json file can be found on the npmjs site

Update

engineStrict is now deprecated, so this will only give a warning. It's now down to the user to run npm config set engine-strict true if they want this.

Update 2

As ben pointed out below, creating a .npmrc file at the root of your project (the same level as your package.json file) with the text engine-strict=true will force an error during installation if the Node version is not compatible.

Solution 2

Add the following to package.json:

  "engines": {
    "npm": ">=6.0.0",
    "node": ">=10.0.0"
  },

Add the following to .npmrc (same directory as package.json):

engine-strict=true

Solution 3

Just like said Ibam, engineStrict is now deprecated. But I've found this solution:

check-version.js:

import semver from 'semver';
import { engines } from './package';

const version = engines.node;
if (!semver.satisfies(process.version, version)) {
  console.log(`Required node version ${version} not satisfied with current version ${process.version}.`);
  process.exit(1);
}

package.json:

{
  "name": "my package",
  "engines": {
    "node": ">=50.9" // intentionally so big version number
  },
  "scripts": {
    "requirements-check": "babel-node check-version.js",
    "postinstall": "npm run requirements-check"
  }
}

Find out more here: https://medium.com/@adambisek/how-to-check-minimum-required-node-js-version-4a78a8855a0f#.3oslqmig4

.nvmrc

And one more thing. A dotfile '.nvmrc' can be used for requiring specific node version - https://github.com/creationix/nvm#nvmrc

But, it is only respected by npm scripts (and yarn scripts).

Solution 4

.nvmrc

If you are using NVM like this, which you likely should, then you can indicate the nodejs version required for given project in a git-tracked .nvmrc file:

node --version > .nvmrc

or:

echo v10.15.1 > .nvmrc

This does not take effect automatically on cd, which is sane: the user must then do a:

nvm use

and now that version of node will be used for the current shell.

You can list the versions of node that you have with:

nvm list

.nvmrc is documented at: https://github.com/creationix/nvm/tree/02997b0753f66c9790c6016ed022ed2072c22603#nvmrc

How to automatically select that node version on cd was asked at: Automatically switch to correct version of Node based on project

Tested with NVM 0.33.11.

.nvmrc vs package.json engines

What you might want to do is:

• use engines in package.json to give a "no known incompatibilities range"
• give the .nvmrc to set a "tested with"

much like package.json vs package-lock.json.

Heroku does respect package.json engines:

Worth mentioning, as documented here, Heroku does play it nice and obey the engines: entry e.g.:

  "engines": {
    "node": "14.17.0",
    "npm": "6.14.13"
  },

So you should Always, Always set that to what you are using locally.

This had been previously mentioned on this self deleted answer to this thread.

Solution 5

There's another, simpler way to do this:

1. npm install Node@8 (saves Node 8 as dependency in package.json)
2. Your app will run using Node 8 for anyone - even Yarn users!

This works because node is just a package that ships node as its package binary. It just includes as node_module/.bin which means it only makes node available to package scripts. Not main shell.

See discussion on Twitter here: https://twitter.com/housecor/status/962347301456015360

View more solutions

Comments

[Mike Stead]

github.com/npm/npm/blob/master/CHANGELOG.md#enginestrict "The rarely-used package.json option engineStrict has been deprecated for several months, producing warnings when it was used. Starting with npm@3, the value of the field is ignored, and engine violations will only produce warnings. If you, as a user, want strict engines field enforcement, just run npm config set engine-strict true"

[mlunoe]

Remember to cd .. && npm i <folder-name> in order to check for the project itself. However, this will trigger a whole build in it self.

[vasilakisfil]

why on earth they deprecated that.. it looses all its meaning then

[Brendan Hannemann]

I disagree, this would potentially hide the issue and would sideload a different version of node if it wasn't installed.

[ozanmuyes]

-1 because this is terrible (really terrible) idea. It's like saying that if you are unemployed you should fund a company first and you can start working there.

[ben]

Adding engine-strict=true to your .npmrc now has the same effect

[Jon]

Sounds like a great idea to me. Separate node versions for separate projects. Can safely upgrade one without upgrading the others. Only catch is have to run in .bin ./node node-sass rather than just node-sass. Not sure if same for all .bin files.

[jcollum]

This is the easiest solution that gives the end user a nice fat error about not having the right version of node when they run npm install; works with yarn as well

[craft]

This is the best answer in 2019, in light of set engine deprecation and the reality that many are (likely) encountering this due to switching versions with nvm.

[Adrian]

This seems to have no effect at all. I set up my package.json with an "engines" section similar to the above (11.13.0 and 6.7.0), and a .npmrc with nothing but content specified above. I had nvm switch me to an older node version, then ran npm install, but it just installs the dependencies and doesn't even mention the engine version mismatch.

[Joshua Pinter]

@ben Perfect, thank you! And this can be committed so that at least your entire team is required to adhere to the engine version requirements.

[Nathan Bedford]

This is a simple and elegant solution - as long as the team members working on the product know this is happening, I think it's a great answer. We are using this technique at a large company to deal with the variety of Node versions for a dozen web front-end products. Removes the need for constant switching with nvm when going back and forth between products.

[ivosh]

This solution has its own pros and cons. Node version encapsulation is potentially its biggest pro. The downside is bloated docker image size if you are going to deploy it this way.

[Ben G]

Should not be a unit test, use package.json /dotfiles

[Joe]

@MikeStead that deprecation is for the package.json directive engineStrict and not the user-configurable engine-strict setting for NPM

[Mike Stead]

@Joe erm yep I was replying to this answer (in 2015) which mentioned engineStrict specifically and my reply also mentioned the alternative engine-strict npm config option.

[Jamie Nicholl-Shelley]

But whhhhhhhy, a unit test is designed for this >.-

[ankhzet]

Because you need Node to run a unit test. If the node version present is too outdated, the tests will simply not run or they'll fail with syntax error or smth. similar, which defeats the point of unit testing. It's like hiding a password reset form behind an authorization form. If you can't remember the password, you need to use reset password function, but now you can't use it, because you don't remember the password.

[Christopher Camplin]

This assumes @babel/node is installed.

[Ini]

I dont't get a warning on windows when engine-strict=false and { "engineStrict" : true }

[chharvey]

Just to be clear, adding engine-strict=true to your own .npmrc file does not enforce anything for your end user, it only enforces you to use the right engine for the packages that you install. There’s nothing you can do to enforce that your end users use the right engine, short of you telling them to add the setting to their .npmrc file.

[chharvey]

Adding engine-strict=true to your .npmrc file only enforces you to use the right engine when you install packages. It does not enforce anything for your end user. If you want your users to use the engines listed under the "engines: {}" property in your package.json when they install it, you should tell them to add engine-strict=true to their .npmrc file.

[Aakash Verma]

nvm use doesn't pick up .nvmrc for nvm version 1.1.7

[Ciro Santilli OurBigBook.com]

@AakashVerma hmmm, on a quick look nvm only goes to version 0.37.2, and nvmrc is still documented on master: github.com/nvm-sh/nvm/tree/… let me know if you figure it out.

[Ciro Santilli OurBigBook.com]

@AakashVerma I'm guessing you're using github.com/coreybutler/nvm-windows/releases As mentioned on their README "The original nvm is a completely separate project for Mac/Linux only. This project uses an entirely different philosophy and is not just a clone of nvm" so it's not surprising. Consider opening a feature request on their tracker.

[Aakash Verma]

Seems there's a recent PR waiting for this github.com/coreybutler/nvm-windows/pull/594

[Jamie Nicholl-Shelley]

My assumption being there is at least a minimal packages installed. why else enforce a specific one.

[Mikel]

@chharvey you could add to the package.json the script "preinstall": "echo 'engine-strict=true' >> .npmrc"

[svandragt]

engine-strict usage in .npmrc is currently not supported by direnv's .envrc github.com/direnv/direnv/wiki/Node (Found '.nvmrc' with version engine-strict=trueN/A: version "engine-strict=true -> N/A" is not yet installed.

[rofrol]

npm install respects engine=strict but yarn install ignores it

[milahu]

must be >=12 not >=0.12

[olawalejuwonm]

how can i set this with yarn

[Abdennour TOUMI]

@JamieNicholl-Shelley Nooooo! unit-test not designed for that! Did you see how go.mod specify the version of go, ... pom.xml specify the version of java! we need the saaaame! got it?

[Jamie Nicholl-Shelley]

How so? It needs to execute and blocks the runtime if fail. PLus, I mean it's a node project, if you haven't got node installed.. well good luck to you

[Mocha]

But how do I know the minimum required node version of the node proejct I've made? Please let me know if anyone has a clue. thanks.

[Rajesh Swarnkar]

May I know what is the deal with node version in package.json shown as 0.10.0 but in CLI it says 10.0.x?

[Big Rich]

Am I misunderstanding something but, couldn't this be installed as a 'dev' dependency, so npm I -D Node@8, I'm guessing it wouldn't (shouldn't) then be bundled into a Docker image (or executable), which would simply provide it's own NodeJS runtime, right?

[hellopeach]

@Brendan Hannemann ，why would it not being installed? shouldn't you always run npm install at least once before running the app? This is the best solution IMHO as it's basically packaging a virtual environment with the app which means it will always run with exactly the same nodejs environment for everyone as long as npm install finished successfully.