A small events data type to handle paystack payments events

events.js

"use strict";

const EventEmitter = require('events').EventEmitter;
const util = require('util');

module.export = eventsCreator;

const eventNames;

function eventsCreator(object) {
	if(!object) throw new Error("Agent object not found!");

	if(!object.key) throw new Error("Please ensure that you've called the agent object");

	// cache quickly
	eventNames = object.events;

	events.bind(object);

	EventEmitter.call(events);

	util.inherits(events, EventEmitter)

	return events;
}

function events(req, res, next) {
	let body = req.body;
	let eventType = body.event;
	
	if(!eventNames) {
		if(process.NODE_ENV === "development") console.log("You are not listing the events you really want to listen to!") 
		
		if(!(eventType in eventNames)) {
			next(new Error("Event not supported!"));
		}
	}

	var hash = crypto.createHmac('sha512', secret).update(JSON.stringify(body)).digest('hex');

	if(hash === req.headers['x-paystack-signature']) {
		// Valid
		res.send(200);
		events.emit(eventType, req, next);
	}
}

events.setHandler = function(eventType, callback) {
	this.addListener(eventType, callback);
}

I recently published a package that takes care of Events Paystack-API.