isfunctionhooked

function isfunctionhooked(target: function): boolean

local function foo()
    print("Hello, world!")
end

print("Before hooking:", isfunctionhooked(foo)) --> false

hookfunction(foo, function()
    print("Hello, new world!")
end)

print("After hooking:", isfunctionhooked(foo)) --> true

restorefunction(foo)
print("After restoring:", isfunctionhooked(foo)) --> false