@azerothjs/store

@azerothjs/store

Overview

A small reactive state container for state that should be shared across components without prop drilling. createStore(factory) returns a useStore function; the factory runs once on first use and every later call returns the same instance.

import { createStore } from '@azerothjs/store';
import { createSignal } from '@azerothjs/reactivity';

const useCounter = createStore(() => {
    const [count, setCount] = createSignal(0);
    const increment = () => setCount(c => c + 1);
    return { count, increment };
});

// Anywhere in the app:
const { count, increment } = useCounter();

Architecture

The factory is a plain function whose return value is the store's public surface, so there is no schema, reducer protocol, or this. On the first useStore() call the factory runs inside a createRoot, which gives any createEffect, createMemo, or onRootDispose it sets up an ownership scope to live in. The result is cached, so the store is a lazy singleton: it is created on first use and shared from then on.

Instances are keyed by the active store scope. On the client there is one stable scope, so the store is an app-wide singleton; under SSR each request renders in its own scope (runInStoreScope) and gets an isolated instance, so concurrent requests never share state.

Stores compose: one store's factory can call another store's useStore().

Components

Building

npm run build -w @azerothjs/store

Examples

A store composed from another store:

import { createStore } from '@azerothjs/store';
import { createSignal, createMemo } from '@azerothjs/reactivity';

const useAuth = createStore(() => {
    const [user, setUser] = createSignal<string | null>(null);
    return { user, login: (name: string) => setUser(name) };
});

const useDashboard = createStore(() => {
    const auth = useAuth();                 // shares the same auth instance
    const greeting = createMemo(() => `Hello ${auth.user() ?? 'guest'}`);
    return { greeting };
});

Contributing

The package is intentionally minimal; keep it that way. State shape and update logic belong in the factory the caller writes, not in this package.