NPM Notes, Tips & Tricks

Just a fun trivia to begin with!

NPM downloads yesterday (23 Mar, 2017): 369 million.
NuGet downloads in the last week: 55 million.

Don't we love the Node Package Manager - NPM & Open Source Software in general?

This article focuses on some of the cool tips and tricks related to NPM and I hope you find it helpful.

Package vs. Module

A Package is a just a directory with one more files in it along with a package.json file that contains metadata about the package. A Module on the other hand... is just a simple file. Every file is treated as a separate module and in Node.js file:module is a 1:1 proposition.

Initialize > Install > Start

A typical flow for a Node.js application when you start from scratch is:

Initialize using npm init which in turn creates a package.json file.
Install dependencies using npm install or npm install --save or npm install --save-dev. --save switch will save the information about the package in dependencies section, whereas --save-dev switch saves it under devDependencies section.

Can you guess which switches have been used below?

[npm-demo] $ cat package.json 
{
  "name": "npm-demo",
  "version": "1.0.0",
  "summary": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.15.2",
    "lodash": "^4.17.4"
  },
  "devDependencies": {
    "underscore": "^1.8.3"
  }
}

Clone > Install > Start

Usually, you would clone a repository, install the dependencies and do an npm start like so:

Step 1: git clone https://github.com/TryGhost/Ghost.git (switch to the folder which has package.json)
Step 2: npm install to install dependencies.
Step 3: npm start to start the application.

This is pretty cool, no?

start, test, init

npm start: Starts your application based on scripts section in the package.json file.
npm test: Execute your tests.
npm init: Execute your initialization code.

Notice the presence of start, test and init in package.json for Ghost.

  "scripts": {
    "start": "node index",
    "test": "grunt validate --verbose",
    "init": "npm install -g knex-migrator ember-cli grunt-cli && npm install && grunt init"
  }

Getting Help

npm -h or npm -help: Shows brief help.
npm -h install: Shows brief help about a switch.
npm help install: Shows detailed help about a switch.
npm help-search remove: Searches for a keyword, in this case: remove, assuming you want to know which commands help you remove.

[Ghost] $ npm help-search remove
Top hits for "remove"
————————————————————————————————————————————————————————————————————————————————
npm help config                                                         remove:6
npm help unpublish                                                      remove:5
npm help uninstall                                                      remove:5
npm help index                                                          remove:4
npm help prune                                                          remove:4
npm help removing-npm                                                   remove:2
npm help bundle                                                         remove:2
npm help publish                                                        remove:1
npm help team                                                           remove:1
npm help owner                                                          remove:1
npm help package.json                                                   remove:1
npm help coding-style                                                   remove:1
npm help install                                                        remove:1
npm help disputes                                                       remove:1
npm help dist-tag                                                       remove:1
npm help access                                                         remove:1
————————————————————————————————————————————————————————————————————————————————
(run with -l or --long to see more context)

Now you can check the different commands like prune, unpublish, removing-npm, etc.

NPM Default Configuration

npm config list: List all configuration defaults.
npm config edit --global: View all the NPM configuration defaults.


;;;;
; npm userconfig file
; this is a simple ini-formatted file
; lines that start with semi-colons are comments.
; read `npm help config` for help on the various options
;;;;

//registry.npmjs.org/:_authToken=********

;;;;
; all options with default values
;;;;
; access=null
; always-auth=false
; also=null
; auth-type=legacy
; bin-links=true
; browser=null
; ca=null
; cafile=undefined
; cache=/Users/ rahul sonisoni/.npm
; cache-lock-stale=60000
; cache-lock-retries=10
; cache-lock-wait=10000
; cache-max=null
; cache-min=10
; cert=null
; color=true
; depth=null
; summary=true
; dev=false
; dry-run=false
; editor=vi
; engine-strict=false
; force=false
; fetch-retries=2
; fetch-retry-factor=10
; fetch-retry-mintimeout=10000
; fetch-retry-maxtimeout=60000
; git=git
; git-tag-version=true
; global=false
; globalconfig=/usr/local/etc/npmrc
; global-style=false
; group=20
; heading=npm
; if-present=false
; ignore-scripts=false
; init-module=/Users/ rahul sonisoni/.npm-init.js
; init-author-name=
; init-author-email=
; init-author-url=
; init-version=1.0.0
; init-license=ISC
; json=false
; key=null
; legacy-bundling=false
; link=false
; local-address=undefined
; loglevel=warn
; logs-max=10
; long=false
; maxsockets=50
; message=%s
; metrics-registry=null
; node-version=4.2.3
; onload-script=null
; only=null
; optional=true
; parseable=false
; prefix=/usr/local
; production=false
; progress=true
; proprietary-attribs=true
; proxy=null
; https-proxy=null
; user-agent=npm/{npm-version} node/{node-version} {platform} {arch}
; rebuild-bundle=true
; registry=https://registry.npmjs.org/
; rollback=true
; save=false
; save-bundle=false
; save-dev=false
; save-exact=false
; save-optional=false
; save-prefix=^
; scope=
; scripts-prepend-node-path=warn-only
; searchopts=
; searchexclude=null
; searchlimit=20
; searchstaleness=900
; send-metrics=false
; shell=/bin/bash
; shrinkwrap=true
; sign-git-tag=false
; sso-poll-frequency=500
; sso-type=oauth
; strict-ssl=true
; tag=latest
; tag-version-prefix=v
; tmp=/var/folders/w7/rcgmhk4j2sv1sxq5_dv1tr1c000ddd/T
; unicode=true
; unsafe-perm=true
; usage=false
; user=0
; userconfig=/Users/ rahul sonisoni/.npmrc
; umask=18
; version=false
; versions=false
; viewer=man
; _exit=true
; globalignorefile=/usr/local/etc/npmignore

npm config get userconfig: Gives you the path of the .npmrc file which contains all the configuration information.
npm config get maxsockets: Gives you details about maxsockets configuration inside of the .npmrc file. You can similarly get any key, or set it using npm config set command.

NPM Install

npm install lodash: Install the package called lodash.
npm install lodash -g: Install the package globally.
npm list: List the entire dependency tree of all the installed packages.
npm list -depth 1: Shows only the list of dependencies till depth 1.
npm list -depth 0 -dev: Shows only root level development dependencies.
npm list -g -depth 0: Shows the global dependencies.
npm list -g -depth 0 -long: Shows a lot more details about the installed dependencies.

Note:

You might need to use sudo to install with a -g switch.
You can use -D instead of --save-dev switch and -S for --save.

NPM Update

npm update: Updates all the dependencies.
npm update --dev -S: Updates all the dev dependencies.
npm update --prod -S: Updates all the prod dependencies.
npm update -g: Updates all the global dependencies.
npm install package@x.x.x - Install a specific version.

NPM Uninstall

npm uninstall package --save and npm uninstall package --save-dev uninstalls the package from your folder and updates the package.json file.
npm uninstall package -g uninstalls a global package.
npm cache clean: Cleans the npm cache.

I hope this helps. Do you know of a command that you use often or other tips that can help? Please post it in the comments section.

What next?

Well, stay tuned for upcoming articles. You may contact us at contact@attosol.com for your software and consultancy requirements.