@lena-inc/storage

zustand-x settings stores for Expo apps, persisted in expo-sqlite/kv-store.

import {
	createLenaStorage,
	createStore,
	useStoreValue
} from '@lena-inc/storage'
import { z } from 'zod'

const languageSchema = z.strictObject({
	preference: z.enum(['system', 'en', 'fr'])
})
const initialLanguage: z.output<typeof languageSchema> = {
	preference: 'system'
}

export const languageStore = createStore(initialLanguage, {
	name: 'my-app.language',
	mutative: true,
	persist: { enabled: true, storage: createLenaStorage(languageSchema) }
}).extendActions(({ set }) => ({
	setPreference: (value: unknown) => {
		set('preference', languageSchema.shape.preference.parse(value))
	}
}))

// In a component:
// const preference = useStoreValue(languageStore, 'preference')

One entry point. It re-exports zustand-x unchanged and adds createLenaStorage. React, Expo SQLite and zustand are host peers; zustand-x and mutative come with Lena. Apps own store names, schemas, initial state and actions.

• The store name is the kv key. The value is the store state as plain JSON with no persist wrapper, so keys written by defineStore in 0.2 load unchanged.
• Saved settings load synchronously while the store is created, so the first render already has them.
• Reads accept a partial object. A field added after the value was saved takes its initial value.
• Absent, malformed or schema-invalid saved JSON loads as the initial state. Reads never delete or rewrite saved bytes, but the next write saves the whole current state over them.
• Writes validate the whole state. An invalid state is never persisted and throws a safe TypeError, not raw Zod diagnostics. Expo I/O failures propagate.
• zustand's persist saves after the in-memory state changes, so a rejected or failed write leaves memory ahead of storage. Validate input in actions before calling set.
• The schema must be a Zod object without object-level refinements, because reads use its partial form. Keep cross-field rules in actions.
• Do not set a persist version or migrate. Saved bytes carry no version, so shape changes belong in the schema.

This is ordinary settings persistence, not encryption, SecureStore, backups, sync or a vault database. Never use it for secrets, canonical travel/journal data or access authority. A saved identifier remains a hint. The app's existing vault validation still owns all authority.

Migrating from 0.2

defineStore and the old useStoreValue(store) are removed. For each defineStore({ key, schema }):

1. Create createStore(initial, { name: key, mutative: true, persist: { enabled: true, storage: createLenaStorage(schema) } }), where initial is the default the app used for a null read. Model "not saved yet" as a nullable field in the state and schema.
2. Move read/write helpers into extendActions and derived values into extendSelectors.
3. Replace useStoreValue(store) ?? DEFAULT with useStoreValue(store, 'field') for each field a component reads, and store.read() with store.get('state').
4. Replace store.clear() with store.set('state', initial) followed by store.store.persist.clearStorage(), so memory resets and the key is removed.

Install zustand in the app. Every app in a repository must move to the same Lena version.

Tests mock expo-sqlite/kv-store at its owning module and replace the react-dom import of react-tracked's browser build. They do not prove native/device behavior.