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Node.js

Node.js is an open-source, cross-platform, JavaScript runtime environment that executes JavaScript code outside of a browser.

Installation

NodeJS installation

Note: For instructions on how to install NodeJS on MX Linux, please check further down.

Node.js v14.x (check last version here):

Ubuntu
$ curl -sL https://deb.nodesource.com/setup_14.x | sudo -E bash -
$ sudo apt-get install -y nodejs
Debian, as root
# curl -sL https://deb.nodesource.com/setup_14.x | bash -
# apt-get install -y nodejs
Fedora, as root
# curl -sL https://rpm.nodesource.com/setup_14.x | bash -
$ sudo dnf install -y nodejs

How to install Node.js on MX Linux:

check_alt "MX" "patito feo" "Debian" "stretch"
check_alt "mx-linux" "patito feo" "Debian" "stretch"
  • Save the file as setup_14.x and make it ejecutable: chmod +x setup_14.x, then:
  • sudo ./setup_14.x
  • sudo apt install -y nodejs

Install the Yarn package manager (optional):

curl -sL https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt update && sudo apt install yarn

NPM

How to generate a package.json

npm init
or
npm init -y

How to install packages

# As normal dependency
npm i <package>
# As development dependency
npm i -D <package>
# Globally
npm i -g <package>

How to check for installed packages

# Globally installed
npm list -g --depth 0`
# Locally installed
npm list --depth 0

Troubleshooting

npm ERR! code ELIFECYCLE

If you get this error when npm start, follow these steps:

  1. $ npm cache clean --force
  2. $ rm -rf node_modules
  3. npm install

Dependencies

Nodemon, a useful dependency

  • nodemon: Tool that helps develop node.js based applications by automatically restarting the node application when file changes in the directory are detected.

Installation: npm i -D nodemon Usage: nodemon index.js

You can also install nodemon as a development dependency:

npm install --save-dev nodemon

With a local installation, nodemon will not be available in your system path. Instead, the local installation of nodemon can be run by calling it from within an npm script (such as npm start) or using npx nodemon.

Better usage

In the package.json created, we must modify some things. Within "scrips":, we remove "test": "echo \"Error: no test specified\" && exit 1", and add "start": and "dev":, so the "script": section ends up like this:

"scripts": {
    "start": "node server",
    "dev": "nodemon server"
  },

To run the app during development, we type: npm run dev

Other dependencies

  • socket.io: Nodejs realtime framework server for dealing with web sockets.
  • moment: A lightweight JavaScript date library for parsing, validating, manipulating, and formatting dates.
  • dotenv: Module that loads environment variables from a .env file into process.env.
  • bcrypt: Library to help you hash passwords for Node.js.
  • passport: Express-compatible authentication middleware for Node.js.
  • passport-local: Passport strategy for authenticating with a local username and password.
  • express-session: Simple session middleware for Express in a Node.js module.
  • express-flash: Flash Messages for your Express Application.
  • helmet: Helps secure Express/Connect apps with various HTTP headers.
  • body-parser: Node.js body parsing middleware (included in Express by default)
  • cors: node.js package for providing a Connect/Express middleware that can be used to enable CORS with various options.
  • compression: Node.js compression middleware.
  • morgan: HTTP request logger middleware for node.js.