NodeJS AsyncEach for handling async.series-like control-flow on Array of items.

asynceach.js

const _ = require('lodash');
const trace = console.log.bind(console);

function AsyncEach(objList, funcList, cb) {
	this.objList = objList;
	this.funcList = _.isArray(funcList) ? funcList : [funcList];
	this.cb = cb;
	this._objID = -1;
	this._obj = null;
	this._funcID = -1;

	this._next = this.next.bind(this);
	this._each = this.each.bind(this);

	setTimeout(this._next, 1);
}

_.extend(AsyncEach.prototype, {
	next() {
		if((++this._objID) >= this.objList.length) {
			return this.cb();
		}

		this._obj = this.objList[this._objID];

		//Reset the callback ID before we start iterating on each one:
		this._funcID = -1;
		this._each();
	},

	each() {
		if((++this._funcID) >= this.funcList.length) {
			return this._next();
		}

		var func = this.funcList[this._funcID];

		func(this._each, this._obj, this._objID);
	}
});

AsyncEach.make = function(arr, onDone, onEach) {
	new AsyncEach(arr, onDone, onEach);
};

module.exports = AsyncEach;

////////////////////////////////////////////

AsyncEach.make(["bob", "foo", "bar"], [
	(step, item, id) => {
		trace(`test 1 ${item} #${id}`);

		setTimeout(step, 500);
	},
	(step, item, id) => {
		trace(`test 2 ${item} #${id}`);

		setTimeout(step, 250);
	}
], () => trace("DONE! Toute Finito!") );