jasmine - spy property into jquery.post callback

With Jasmine. I'm trying to assert if a property changed after a $.post, I mean in it's callback.

$.post(x,x,function(){ boolean = true; <--- need to assert this })

Because I don't really want my tests to be coupled to $ I can spyOn, something like.

spyOn($,'post')

This works BUT I'm overwriting my original callback and my boolean will never be change.

I could use ".CallThrough" but I don't want the REALLY do the post, it's a test.

Any idea how to solve it? I'm thinking it wrong ?

Thanks !!!