Install only one package from package.json? - npm

Question

Suppose that somewhere in my package.json I have:
"dependencies": {
"bower": "1.0.0",
// zillion other dependencies
}
Is there a way to make npm install only bower#1.0.0 from my package.json? Like so: npm install --only bower.
My goal is to make npm install and bower install run simultaneously.

Answer 1

As a workaround you may use something like:
$ node -pe "require('./package').dependencies.bower"
// → 1.0.0
$ npm install bower#$(node -pe "require('./package').dependencies.bower")
// npm install bower#1.0.0
// or with jq
$ npm install bower#$(< package.json jq -r '.dependencies.bower')
Where -e/--eval flag evaluates passed string and -p/--print prints result of eval.
💡 Please consider other answers as well since this one may be outdated.

Answer 2

As #atalantus noted in comment, the accepted answer doesn't work on newer version of NPM. Working solution for newer versions (verified on NPM 6.13.4) is:
npm install --no-package-lock --no-save bower#1.0.0
This will install bower and all its dependencies, but prevents installation of anything else you might have in package.json. It also doesn't create or modify existing package-lock.json.
From npm documentation:
The --no-package-lock argument will prevent npm from creating a package-lock.json file. When running with package-lock's disabled npm will not automatically prune your node modules when installing.
--no-save: Prevents saving to dependencies.
Combining this with Anton Rudeshko's approach to find out version in package.json, the final solution is:
VERSION_BOWER=`node -p -e "require('./package.json').dependencies.bower"`
npm install --no-package-lock --no-save bower#"$VERSION_BOWER"
Update 2023
Alternative solution I've just used is to temporarily modify package.json to only keep the dependency you need. That can be done quite easily with help of jq
Given package.json
{
"name": "sample",
"main": "src/index.js",
"dependencies": {
"bower": "1.0.0",
"foo": "^1.2.3",
"bar": "^4.5.6",
},
"devDependencies": {
"baz": "^10.20.30",
}
}
Let's first modify it with jq to only keep bower
cat package.json| jq 'del(.devDependencies) | .dependencies |= {bower:.bower}'
Gives us
{
"name": "sample",
"main": "src/index.js",
"dependencies": {
"bower": "1.0.0"
}
}
by deleting devDependencies completely and leaving only bower in dependencies.
Next up you would want to overwrite package.json with this new, version, but you can't do it directly like this
cat package.json | jq 'del(.devDependencies) | .dependencies |= {bower:.bower}' > package.json
because the file gets overwritten before it's fully read. Instead you need to buffer the output stream of jq command, simplest solution just storing it in variable, and then overwriting the original file
updated=`cat package.json | jq 'del(.devDependencies) | .dependencies |= {bower:.bower}'`
echo $updated > package.json
And package.json now reads:
cat package.json
{
"name": "sample",
"main": "src/index.js",
"dependencies": {
"bower": "1.0.0"
}
}
Run npm install now and you only install bower#1.0.0.
Obviously not always we can afford to modify the file, but you could also back-up the original file, etc. Main point is here how to easily modify json file thanks to jq rather than playing magic tricks with sed :-)

Answer 3

Seeing as with newer versions of NPM the previous solutions don't work anymore, I came up with this:
npm i -g --prefix=$(pwd) bower # $(pwd) = current directory, UNIX only
node bin/bower
Installing a package globally allows you to specify a "prefix" - a directory where the package will be installed. Here I just put the current directory as the folder I want the package to appear in. In CI, this will probably be your repo root.
Keep in mind this will ignore your package.json version and just download the latest one. If you need a specific version, just use bower#someversion instead.
An alternative solution is just rm package.json && npm i bower, or mv package.json _package.json && npm i bower if you want to restore it later