aTestScript.jsx

/*needs som additional data from the outside*/
(function(thisObj){
fun();
function fun(){
app.beginUndoGroup("XXX");
var curComp = app.project.activeItem;
   if (!curComp || !(curComp instanceof CompItem)){
        alert("noComp");
        return;
    };
alert(info);
app.endUndoGroup();
}
})(this);