Handle loading failure without overwriting progress

local ok, result = pcall(read)
if not ok then return { ok = false, reason = "unavailable" } end

A failed request is not evidence that a record is absent. Keep the operational outcome explicit.

New syntax: pcall, data-load, failure-policy

• persistent-state
• temporary-state
• schema
• nil
• guards

Main guided reference implementation; use the hierarchy’s stated Script or ModuleScript type.

local ProfileLoader = {}
function ProfileLoader.load(read)
    local ok, data = pcall(read)
    if not ok then return { ok = false, reason = "unavailable" } end
    if data == nil then return { ok = true, profile = { version = 1, completed = {}, soundEnabled = false } } end
    if type(data) ~= "table" or data.version ~= 1 or type(data.completed) ~= "table" or type(data.soundEnabled) ~= "boolean" then
        return { ok = false, reason = "invalid-schema" }
    end
    local completed = {}
    for _, id in ipairs(data.completed) do
        if type(id) ~= "string" then return { ok = false, reason = "invalid-schema" } end
        table.insert(completed, id)
    end
    return { ok = true, profile = { version = 1, completed = completed, soundEnabled = data.soundEnabled } }
end
return ProfileLoader

Local controlled read fixtures; no production datastore access.

local Loader = require(script.Parent.ProfileLoader)
local absent = Loader.load(function() return nil end)
assert(absent.ok and absent.profile.version == 1)
local failed = Loader.load(function() error("controlled read failure") end)
assert(not failed.ok and failed.profile == nil)
local valid = Loader.load(function() return { version = 1, completed = {"lamp"}, soundEnabled = false } end)
assert(valid.ok and valid.profile.completed[1] == "lamp")
local invalid = Loader.load(function() return { version = 99 } end)
assert(not invalid.ok and invalid.profile == nil)
print("Loading policies checked")

pcall returning false is distinct from pcall returning true,nil.

Validate persistent data even if an earlier version of your code wrote it.

This is a bounded learning lab. It has not been executed in an approved Roblox Studio environment by this website.

A checked checklist records your own review, not automated project competence or a community verification.

pcall runs a function and reports success plus its result or error. A successful nil result can mean no record; a failed call is an operational problem. These outcomes need different policies.

The Loader below accepts a read function so controlled tests can simulate failure without calling live storage. In a real server, the trusted read function can call GetAsync on a dedicated test store.

The lab returns ok=false and no profile on failure or unknown schema. It does not activate progression or permit saving fallback data after a failed load. Do not expose internal error strings to players.