Immer

import { createStore, immer } from '@sinuxjs/core';

const store = createStore(
  { items: [{ id: 1, text: 'Hello', done: false }] },
  {
    toggleItem: (state, id: number) => {
      // Mutate the draft directly -- immer makes it immutable
      const item = state.items.find(i => i.id === id);
      if (item) item.done = !item.done;
    },
  },
  [immer()]
);

• All signal handlers receive an Immer draft
• Mutate directly -- no spread operators needed
• Backward compatible: returning an object still works
• immer is a peer dependency -- install it separately: npm install immer