Node.js / npm mini cheatsheet

Just some really basic commands, but paradoxically they’re not always obvious to find so hopefully they’ll help some newcomers

Running a script with Node.js:
node myscript.js

Initializing a Node app/package:
Move to the target folder (where you want to place your code) and npm init

Installing dependencies (listed in package.json) for the current package:
npm install

Updating dependencies:
1) Quick and dirty: edit package.json and replace version numbers for the dependencies you want to update with "*", then run
npm install --save, or npm install --save-dev for the devDependencies
2) Normal way: for each package, one by one, run:
npm install package-name --save (or --save-dev)
It happened to me in the past that dependencies wouldn’t update when I ran that, in which case you can try to change their version number as described in 1), only one by one, and you could also try deleting your package-lock.json file. You can also force a version number, for instance npm install –save package-name@^2.
3) npm update is also supposed to update dependencies, in the same way as 1) I remember it failing more often than succeeding, but last time I tried it worked nicely
4) My new favorite way: cf later in this post the section about npm-check-updates

Removing some dependencies:
Remove their entries from package.json, then run npm prune

Updating global librairies/packages:
npm update -g

Removing a global package:
npm uninstall -g [package name]

Finding the version of a currently installed global package:
npm list -g [package name]
Note that it may allow you to notice that a package is installed with multiple, different versions, manually and as a dependency of other packages

Checking for updates for all your packages:
There’s a package for that called npm-check-updates (beware, it has tons of dependencies, over 250).
npm i -g npm-check-updates
Then, ncu for the dependencies of a project of ncu -g for global dependencies. There is also a command to update your package.json (then you can run npm i to udpate): ncu -u.

Listing globally installed packages, but only those that you actually installed (not their dependencies, which are probably huge):
npm list -g --depth 0

Sources:
https://www.themarketingtechnologist.co/how-to-update-an-out-of-date-package-json/
http://www.kubilayerdogan.net/node-js-1-initialize-a-node-js-project-with-dependencies/

Update 2021-09-21: finding the npmrc files

A tiny number of damn important Node settings are located in those hard to find, multiple files. Here’s the documentation on where to find them, and here is where I found them in my case:

• C:\Program Files\nodejs\node_modules\npm\.npmrc => empty
• C:\Program Files\nodejs\node_modules\npm\npmrc => very same folder but just a removed dot in the name… how fucked up. Anyway, this one was very important as I had to put prefix=${APPDATA}\npm inside of it after some Node upgrade (I believe it was from Node 12 to 14), otherwise global package installation was completely messed up
• %appdata%\npm\etc\npmrc => not empty but unmodified for almost 4 years… My guess is that’s an ancient location that’s not used anymore?