Question

I am trying to build some sort of logger functionality in javascript. Is there any API for a script to get its own filename?

Answer 1

This should work:
(new Error).fileName

Or you can try this:

var filepath;
(function(){ 
    var scripts = document.getElementsByTagName('script'); 
    filepath = scripts[ scripts.length-1 ].src; 
}());

The second option gives you the path of your script file.