NodeJS package and module loading

// app.js

var pack = require('./pack/abc');
var pack1 = require('./pack1');
var pack2 = require('./pack2');

pack.info();
pack1.info();
pack2.info();

// pack/abc.js

exports.info = function () {
    console.log('module');
}

// pack1/index.js

exports.info = function () {
    console.log('pack1');
}

// pack2/abc.js

exports.info = function () {
    console.log('pack2');
}

// pack2/package.json

{
    "main": "./abc.js"
}