Spoof Property

local spoofs = {}
local intentNull = newproxy()

local function spoofproperty(obj, prop, val)
    assert(typeof(obj) == "Instance", "spoofproperty argument 1 invalid type ("..typeof(obj)..", expected Instance)")
    assert(type(prop) == "string", "spoofproperty argument 2 invalid type ("..typeof(obj)..", expected string)")

    if not pcall(function() return obj[prop] end) then
        warn("spoofproperty: "..prop.." is not a valid property of "..obj:GetFullName())
    end

    if val == nil then
        val = intentNull
    end

    local props = spoofs[obj]
    if not props then
        props = {}
        spoofs[obj] = props
    end

    props[prop] = val
end

local function unspoofproperty(obj, prop)
    local props = spoofs[obj]
    if props then
        props[prop] = nil
    end
end

local getproperty; getproperty = hookmetamethod(game, "__index", function(self, index)
    local props = spoofs[self]
    local val = props and props[index]

    if val ~= nil then
        if val == intentNull then
            return nil
        end
        return val
    end

    return getproperty(self, index)
end)

getfenv(0).spoofproperty = spoofproperty
getfenv(0).unspoofproperty = unspoofproperty
getfenv(0).getproperty = getproperty