Zustand

Zustand — État global simple et performant

Bibliothèque légère (~1kb), sans boilerplate, qui évite les re-renders inutiles.

npm install zustand

Création d'un store

import { create } from 'zustand';

const useStore = create((set, get) => ({
  // State
  count: 0,
  user: null,

  // Actions
  increment: () => set(state => ({ count: state.count + 1 })),
  decrement: () => set(state => ({ count: state.count - 1 })),
  reset: () => set({ count: 0 }),

  setUser: (user) => set({ user }),
  logout: () => set({ user: null }),

  // Action async
  fetchUser: async (id) => {
    const user = await getUser(id);
    set({ user });
  },
}));

Utilisation dans les composants

function Compteur() {
  // Sélection précise = re-render SEULEMENT si count change
  const count = useStore(state => state.count);
  const increment = useStore(state => state.increment);

  return <button onClick={increment}>{count}</button>;
}

function Profil() {
  const { user, logout } = useStore(state => ({
    user: state.user,
    logout: state.logout
  }));

Zustand vs Context API