MessageBroker NPM Package Documentation

Overview

The MessageBroker package provides an abstraction layer over RabbitMQ, enabling easy message publishing, consuming, and RPC request-response communication. This package simplifies interaction with RabbitMQ using TypeScript and amqplib.

Installation

To install the package, run:

npm install message-broker-util

Importing

import MessageBroker, { MessageBrokerConfig } from "message-broker-util";

Configuration

The MessageBroker class requires a configuration object of type MessageBrokerConfig:

interface MessageBrokerConfig {
  url: string; // RabbitMQ connection URL
  exchangeName: string; // Exchange name
  queueName: string; // Queue name
}

Example configuration:

const config: MessageBrokerConfig = {
  url: "amqp://localhost",
  exchangeName: "my_exchange",
  queueName: "my_queue",
};

Usage

1. Initializing the Message Broker

const broker = new MessageBroker(config);
await broker.initialize();

2. Publishing Messages

await broker.publishMessage("routing_key", { message: "Hello, RabbitMQ!" });

3. Subscribing to Messages

await broker.subscribeMessage("routing_key", (msg) => {
  if (msg) {
    console.log("Received:", msg.content.toString());
  }
});

4. Request-Response (RPC) Pattern

a. Sending an RPC Request

const response = await broker.requestData("rpc_queue", {
  data: "Request Data",
});
console.log("Response:", response);

b. Observing RPC Requests

await broker.observeRequest("rpc_queue", async (requestPayload) => {
  return { response: "Processed " + requestPayload.data };
});

5. Closing the Connection

await broker.close();

Error Handling

The package includes robust error handling. If a connection or operation fails, an error message is logged to the console, and an exception is thrown.

License

MIT License

Author

Rajesh Singha Mahapatra

Contributions

Contributions are welcome! Feel free to submit a PR or open an issue.

This documentation provides a structured guide on how to use your package efficiently. Let me know if you need any refinements!