Is this possible? Would be very useful

Is it possible to create a function similar to what im about to describe below:

function UnitAddBuff takes integer buffType, unit whichUnit returns nothing

this function would get a buffID and add it upon a unit, basically without any real-game effects, in other words this would add the effect/buff-icon of a buff without the spell being cast. This would allow for showing the effects of jass-based abilities easier. There is of course work-arounds to this method but it would be by far easiest of them all upon completion.

the only other method i can think of is having seperate abilities that are based on something like purge and having them spawn the buff onto the unit with minimal effects, but this would require the creation of a seperate ability per buff and is not efficient. any help would be greatly appreciated.