PromiseWithProgress.js

getPromiseWithProgress(resolver){

    return new (function PromiseWithProgress(){

        let observers = [],
        blockNotify = false,                
        notify = data => !blockNotify && observers.forEach(observer => observer(data)),                
        promise = new Promise((resolve, reject) => resolver(resolve, reject, notify))

        this.progress = function(observer){ typeof observer === 'function' && observers.push(observer); return this }
        this.then = function(){ promise.then(...arguments); return this }        
        this.catch = function(){ promise.catch(...arguments); return this }        
        this.finally = function(){ promise.finally(...arguments); return this }                

        promise.finally( () => blockNotify = true )

    })()

}