Question

Is this even possible?

function foo() {
    // do stuff
}
foo.prototype = {
    // stuff...
    bar: function() {
        // do some things with this, where this refers to foo
    },
    bar.prototype: {
        // set some definitions for bar to work with.
        // Where does "this" go and what does it refer to?
    }
}

Answer 1

No. You’d need to use

function bar() {...}
bar.prototype = {...};
function foo() {...}
foo.prototype.bar = bar;

Although this won’t work. There is no reason to put the bar constructor on foos prototype, because when instantiating bar objects by using new ((new foo()).bar)(), there will be no reference to the foo instance. You could equally use new foo.prototype.bar().