simple event emitter implementation in nodejs

eventemitter.js

const process = require('process');

function Event() {
    this.events = [];
}

Event.prototype.emit = function(eventName) {
    process.nextTick(() => {
        const id = this.events.findIndex((event) => event.name === eventName);
        for (observer of this.events[id].observers) {
            observer();
        }
    });
}

Event.prototype.on = function(eventName, fn) {
    if (this.events.length) {
        const id = this.events.findIndex((event) => event.name === eventName);
        if (id >= 0) {
            this.events[id].observers.push(fn);
        } else {
            this.events.push({ name: eventName, observers: [fn] });
        }
    } else {
        this.events.push({ name: eventName, observers: [fn] });
    }
}


const e = new Event();
e.emit('Hello');
e.emit('bye');
e.on('Hello' , () => {
    console.log('Hello There');
    e.emit('inside');
});
e.on('Hello' , () => {
    console.log('Hello Here');
});
e.on('bye', () => {
    console.log('goodbye');
});
e.on('inside', () => {
    console.log('emitted from inside');
});