No, as close as it gets is privacy.resistFingerprinting. Extensions shouldn’t even try to do this. (I’ve actually never heard of an extension that tries to do this.)

It has its own issues: https://news.ycombinator.com/item?id=25375709

Correct, and I’m taking those into account when saying “extensions shouldn’t even try to do this”.

> But IMHO it’s as close as it gets

How about replacing the original method (on the prototype) with a proxy to that method that intercepts apply?

wouldnt it make more sense to overwrite toString?

     original_functions[Function.prototype.toString.toString()] = originalToStringStr;

Yes, I’ve been doing this in the past elsewhere. Quite a messy affair, you have to overwrite `Function.prototype.toString` – meaning for all functions, no real way to do it for a single function. And then you have to be very careful because your overwritten functions runs in an environment you don’t control. Not sure whether implementing this in a completely tamper-proof way is possible.