Node.js Event Emitters

In Node.js, the events module provides a way to implement event-driven architecture, where different parts of your application can communicate via emitting and listening to events.

🧵 When to Use

• Logging
• Messaging/event systems
• Async task management (e.g., background workers)
• Microservices event communication
• Streaming APIs
• Real-world use case - chat app, ticket system and logger

📚 Key Methods

• emitter.on(): Adds an event listener
• emitter.emit(): Triggers an event
• emitter.once(): Listens only for the first occurrence
• emitter.removeListener() / off(): Removes a listener
• emitter.removeAllListeners(): Clears all listeners for a given event

🚨 Tips

• Don’t forget to remove unused listeners to avoid memory leaks.
• You can increase the listener limit (default is 10):

🛠 Tech Stack

• Node.js
• Node.js events module

📦 Installation

# Clone the repo
git clone https://github.com/rupachowrasia/nodejs-event-emitter-for-pub-sub.git

# Move into the project directory
cd nodejs-event-emitter-for-pub-sub

# Install dependencies
npm install

# Run the app
npm run start