Dependency injection in a revealing module

I usually create my javascript "controllers" in the following way:

var module = (function(){

    function init(someService){
        someService.doSomething();
    }

    return {
        init: init
    };

})();

module.init(SomeService);

I've just stumbled upon dependency injetion in javascript (e.g. JavaScript Dependency Injection).

What I would like to know is, from a testing point of view, is there any advantage using the Injector in my link to inject mocks and such, versus simply passing them do the init function like I do above.

To elaborate, I could just pass a SomeService mock when I initialize my tests today. So is there any point for me to use the Injector or something similar?