You don't see it bugged because you don't make use of it
Even when the devs uses it, they have it also buggy because when they write
Lua Code:
function ChatContainer:UpdateScrollVisibility()
local visible = self.currentBuffer:GetNumVisibleLines()
local history = self.currentBuffer:GetNumHistoryLines()
local hide = history <= visible
self.scrollbar:SetHidden(hide)
self.scrollUpButton:SetHidden(hide)
self.scrollDownButton:SetHidden(hide)
self.scrollEndButton:SetHidden(hide)
end
You will notice the visibility of the slider update perfectly if no lines are wrapped, but as soon as you have many wrapped lines, the slider will be hidden when it should be visible or vice versa
The same code the devs are using works perfectly in Wow because the GetNumHistoryLines() is very well implemented under wow
In Eso they just workaround this weakness by adding a larger value to the slider bar so you can slide at a larger value than what is inside the textbuffer but that's just an ugly workaround they made