NPM

What is NPM?

npm is the world’s largest software registry. Open source developers from every continent use npm to share and borrow packages, and many organizations use npm to manage private development as well.

See more details on About NPM

Installation

Install the npm with NodeJS by downloading it on the download page. It is strongly recommended to install Nodejs and npm with version manager like nvm

Check version

Once the npm is installed, check the version by running:

npm -v (or --version)

Check for hints of usage

npm help

Starting the package

Run npm init to start the use and it will create folder node_module and file called package.json. It will ask question in steps about the details. If you wish to use all defauylt options, add -y or --yes

npm init -y (or --yes)

The default package.json will look lik this:

  "name": "package-name",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "description": "",
  }
}

Then you can change the config details

Example

npm config set init-author-name "Irawan"
npm set init-license "MIT"

Then it will look like this:

  "name": "package-name",
  "version": "1.0.0",
  "main": "index.js",
   "scripts": {
    "test": "gulp test",
    "start": "gulp serve",
    "build": "gulp build"
  },
  "keywords": [],
  "author": "Irawan",
  "license": "MIT",
  "description": "",
  "dependencies": {
    "gulp": "^4.0.2",
    "lodash": "^4.17.3"
  }
}

check and remove default configuration

To check the configuration details, run the following:

npm config get init-author-name
npm get init-license

to remove details;

npm config delete init-author-name
npm delete init-license

Install package

Locally

E.g installing gulp-sass

npm install gulp gulp-sass --save-dev

Always use --save-dev to ensure that the changes is saved in the package.json file.

Install globally (in the machine and not only in current folder)

npm install -g nodemon
npm install -g live-server

Remove or uninstall module

npm uninstall gulp-sass --save-dev
# or
npm remove gulp --save-dev
#or
npm rm gulp-sass --save-dev

Install module with version and upate

npm install gulp-sas@5.5.5 --save

# to update
# UPDATE
npm update lodash --sav

To check the root folder of global install

npm root -g

Remove global package

npm remove -g gulp-sass

To show the installed packages

#Main modules only:
npm list

#result:

╰─ npm list                        
user@1.0.0 /Users/project-name
├── gulp-cli@2.3.0
├── gulp-sass@5.1.0
├── gulp@4.0.2
└── lodash@4.17.21

# Main modules with the direct dependencies:
npm list --depth 0

#Main modules with the dependencies next level 
npm list --depth 1

# the most important part of the package.json is the `scripts`
```json
  "scripts": {
    "test": "gulp test",
    "start": "gulp serve",
    "build": "gulp build"
  },

When you run the scripts e.g npm start it will run the module gulp serve