Skip to main content
In this lesson, we’ll explore Node.js—an open-source, cross-platform JavaScript runtime—and see how it powers custom GitHub Actions workflows. You’ll learn about its core features, the built-in package manager, and a typical project layout.

​
What Is Node.js?

Node.js is a JavaScript runtime built on Google’s high-performance V8 engine. It lets you run JavaScript outside the browser, so you can build server-side apps, CLI tools, and more—all with the same language you use in the browser. Node.js supports Windows, macOS, and Linux.
For production environments, use the Long-Term Support (LTS) version of Node.js. Manage multiple versions easily with tools like nvm.

​
Node Package Manager (npm)

When you install Node.js, you also get npm—the package manager that helps you discover, install, and manage JavaScript libraries and dependencies. With npm you can:
  • Share code with the community via the npm registry
  • Install and update packages with a single command
  • Define project scripts for testing, building, and running your app

​
Sample Node.js Project Structure

A minimal Node.js project often includes these three files:
FilePurpose
package.jsonMetadata (name, version) and dependency definitions
index.jsApplication entry point and core logic
test.jsAutomated tests for your code
To set up your project: 
# Install all dependencies listed in package.json
npm install
After installation, npm creates a node_modules folder with all packages you need.

​
Common npm Commands

CommandDescription
npm installInstall project dependencies
npm testRun tests defined in test.js
npm startLaunch the application (e.g., server)
# Verify your environment
$ node -v
v18.16.0
$ npm -v
9.8.1

# Install dependencies
$ npm install

# Run tests
$ npm test

# Start the application
$ npm start
App listening on port 3000
Once the application is running, open your browser and navigate to http://localhost:3000.

Watch Video