How to monkey patch a recursive function

I'm using a library (playcanvas) that exposes a function clone() that is called recursively for all the nodes in a hierarchy.

If I monkey patch the function to execute some additional code, this will be executed multiple times.

Instead, I need to execute my code at the end of the whole recursive calls, but I can't find a way to do it.

pc.Entity.prototype.clone = function() {
    ... some code
    // then for each child it calls itself
}

If I try this way I get "my stuff" executed multiple times.

pc.Entity.prototype.cloneOriginal = pc.Entity.prototype.clone;

pc.Entity.prototype.clone = function() {
    var c = this.cloneOriginal();
    // do my stuff
    return c;
}

I need to "override" the clone method so that after all its recursive calls, I can execute my code.

You can achieve that by temporarily restoring the original function before launching it. And when it is finished, you set your trap again, and perform your post processing:

const orig_clone = pc.Entity.prototype.clone; // Save original clone
// Set trap:
pc.Entity.prototype.clone = function patched_clone(...args) {
    pc.Entity.prototype.clone = orig_clone; // Restore original function
    let result = this.clone(...args); // Execute it
    // All is done, including recursion. 
    pc.Entity.prototype.clone = patched_clone; // Set trap again
    // Your code comes here
    console.log('post processing');
    return result;
}