NodeJS Application Overview

In this guide, you’ll learn how to set up a basic Node.js project, install dependencies, run tests, and launch a simple web server. By the end, you’ll be ready to incorporate these steps into a custom GitHub Action workflow.

What Is Node.js?

Node.js is an open-source, event-driven JavaScript runtime built on Chrome’s V8 engine. It enables full-stack development in a single language by allowing JavaScript to run outside of the browser on Windows, macOS, and Linux environments. Installing Node.js also provides npm (Node Package Manager), which helps you discover, install, and manage JavaScript packages.

Note

For production applications, it’s recommended to use the latest LTS version of Node.js. Check Node.js Releases for details.

Checking Installed Versions

Before you begin, verify that both Node.js and npm are available:

node -v    # e.g., v18.16.0
npm -v     # e.g., 9.8.1

If these commands fail, download and install Node.js from the official website.

Sample Node.js Project Structure

A minimal Node.js application typically includes these items:

File/Directory	Purpose
package.json	Project metadata: name, version, dependencies, scripts
node_modules/	Installed packages after running `npm install`
index.js	Main application entry point
test.js	Contains unit or integration test cases

Installing Dependencies

All required libraries are defined under dependencies and devDependencies in package.json. To install them:

npm install

You should see output similar to:

added 58 packages and audited 59 packages in 5s

Running Tests

Most Node.js projects include a test script in package.json. To execute your test suite:

npm test

Example output:

> [email protected] test
> node test.js

Testing is successful

Warning

Ensure your tests cover edge cases and error paths. Incomplete test coverage can lead to undetected bugs in production.

Starting the Application

Launch your application using the predefined start script:

npm start

You’ll see:

> [email protected] start
> node index.js

App listening on port 3000

Accessing Your Application

Open your browser and navigate to:

http://localhost:3000

You should see the response defined in index.js, for example, “Hello, World!”.

Next Steps

Now that you can install, test, and run a Node.js app locally, you’re ready to:

Automate these steps in a GitHub Actions workflow
Containerize your application with Docker
Deploy to a cloud provider using Terraform or Kubernetes

References

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