[NEW!] Roblox: Wait For Condition or Event w/ Timeout

local function waitUntil(eventOrCondition, timeout)
    local timedOut = Instance.new("BindableEvent")
    local result = nil

    local eventConn
    local waiting = true
    local function fireTimedOut(bool)
        timedOut:Fire(bool)
        timedOut:Destroy()
        waiting = false
    end

    if typeof(eventOrCondition) == "RBXScriptSignal" then
        eventConn = eventOrCondition:Connect(function(...)
            eventConn:Disconnect()
            result = {...}
            fireTimedOut(false)
        end)
    elseif typeof(eventOrCondition) == 'function' then
        task.spawn(function()
            while not eventOrCondition() and waiting do
                task.wait()
            end
            if waiting then
                result = {eventOrCondition()}
                fireTimedOut(false)
            end
        end)
    else
        local funcName = debug.info(1, 'n')
        local ts = "                "
        error("conditions must be wrapped in a function.\n"..ts.."Try:\n"
            ..ts.."  "..funcName..
            "(function()\n"..ts.."  ".."\treturn condition\n"..ts.."  ".."end, timeout)")
    end

    task.delay(timeout, function()
        if typeof(eventOrCondition) == "RBXScriptSignal" and eventConn.Connected then
            eventConn:Disconnect()
        end
        fireTimedOut(true)
    end)

    return timedOut.Event:Wait(), unpack(result or {})
end

-- Usage (doesn't timeout)
local condition = false
task.delay(2, function() condition = true end)
print("waiting...")
local timedOut = waitUntil(function() return condition end, 5)
print("done. timedOut =",timedOut)

-- Usage (times out)
condition = false
print("waiting...")
local timedOut = waitUntil(function() return condition end, 5)
print("done. timedOut =",timedOut)