Resource.error

luastra/resource

Resource.error(code: string, retryable: boolean, fields: { [string]: string }?): Error

Creates an admitted immutable error record with a stable uppercase code, an explicit retry decision, and optional field-specific codes. Bounds keep failure state safe to inspect and render without depending on provider messages.

Before you use it

Add luastra/resource to this module's dependencies in luastra.json, then import it with require("luastra/resource"). Create each controller once outside app.render. Record the exact ticket returned by begin, correlate it with the host RequestId, and settle only that ticket from app.resolve or another admitted completion boundary.

How it fits

Constructors and transitions are synchronous. begin creates a new generation ticket; resolve, reject, and cancel accept only the active ticket; snapshot returns the current frozen view used by render.

When to use it

Use Resource.error when rejecting a read or mutation ticket after translating transport, validation, or domain failure into application-owned codes. Do not copy credentials, raw response bodies, or human-readable provider messages into fields.

Parameters

Parameter	Type / values	Description
code	string	Checked code argument accepted by Resource.error.
retryable	boolean	Checked retryable argument accepted by Resource.error.
fields	{ [string]: string }?	Checked fields argument accepted by Resource.error.

Returns

Error — the exact Error value declared by the SDK contract.

What happens next

A reusable read or mutation controller whose snapshot represents loading, success, empty, stale failure, retry, cancellation, or submission state.

Failures and fixes

Invalid options and programmer contract violations fail immediately. A stale ticket returns false without overwriting current state. Translate provider failures to bounded Resource.Error codes and keep raw messages, payloads, tokens, and credentials outside the controller.

Availability

Public-source alpha state API in 0.5.0-alpha; host-independent and designed to compose with any asynchronous capability.

Focused example

local Resource = require("luastra/resource")

local profile = Resource.new {
    isEmpty = function(value: { name: string }): boolean
        return value.name == ""
    end,
}

local ticket = profile.begin(requestId, "load")
if result ~= nil then
    profile.resolve(ticket, result)
else
    profile.reject(ticket, Resource.error("NOT_FOUND", false))
end

local snapshot = profile.snapshot()

Complete inventory

View all pages in Asynchronous resources

Source alpha