JS Construtor

var Foo = function (callback) {
    var lol = 123;
    this.bar = function () {
        console.log(lol)
    };
    this.text = "se fude";
    callback.call(this);
};

Foo.prototype = function () {
    return this;
};

new Foo(function () {
    console.log(this);
    this.bar();
});