eventEmitters.js

const EventEmitter = require('events')

class TestEmitter extends EventEmitter {
    constructor( opts = {} ) {
        super(opts)
        this.name = opts.name
        this.testFireIncrementer = 0
    }

    testFire() {
        this.testFireIncrementer+=1
        this.emit('testFire', this.testFireIncrementer)
    }
}

const emitter = new TestEmitter({ name: 'testEmitter' })


emitter.timedFire = function timedFire() {
    setTimeout(() => emitter.testFire(), 1000)
}

function listener_2(i) {
    console.log(`test fire again: ${i}`)
}

emitter.on('testFire', (i) => console.log(`test fire: ${i}`))
emitter.on('testFire', listener_2)

function main() {
    emitter.timedFire()
    setTimeout(() => emitter.removeListener('testFire', listener_2), 1000)
    setTimeout(emitter.timedFire, 1000)
}

main()