Determine whether ActionScript method called using super

Question

I have a method which logs a message each time it is called. I would like this log message to indicate whether the method was called directly or invoked using super in a child class.

class DoerOfWork {
    public function doWork():void {
        var calledWithSuper:Boolean; 

        calledWithSuper = ???;

        trace("doWork called" + (calledWithSuper ? " (with super)." : "."));
    }
}

class SlowerDoerOfWork extends DoerOfWork {
    public override function doWork():void {
        for (var i:Number = 0; i < 321684; i++) {
            // wait a moment
        }
        super.doWork();
    }
}

I hoped it would be possible to determine whether the class of this had overridden the implementation of doWork by comparing this.doWork to DoerOfWork.prototype.doWork.

Unfortunately this isn't possible. Unbound methods are not accessible anywhere in ActionScript (the specification lists two types of functions: function closures and bound methods). There don't even to be any properties on instances on MethodClosure that could identify whether two are bound copies of the same method.

How can I check if a method has been overridden or use any other method to determine whether the currently-executing ActionScript method was called using super or called directly?

Answer 1

You can get a reference to the currently-executing function as arguments.callee. From the method this will be the MethodClosure of DoerOfWork().doWork() with this. If doWork() hasn't been overridden this will be equal to this.doWork.

class DoerOfWork {
    public function doWork():void {
        var calledWithSuper:Boolean; 

        calledWithSuper = this.doWork == arguments.callee;

        trace("doWork called" + (calledWithSuper ? " (with super)." : "."));
    }
}

If you're running in non-strict mode, apparently this will disable argument count checking for the current function. (I haven't checked this myself, I'm not even sure how to disable strict mode in IntelliJ.)