CraftFast Immutable State

import { craft } from "@sylphx/craft";

const baseState = {
  user: { name: "Alice", age: 25 },
  todos: [
    { id: 1, text: "Learn Craft", done: false },
    { id: 2, text: "Use Craft", done: false },
  ],
};

const nextState = craft(baseState, (draft) => {
  draft.user.age = 26;
  draft.todos[0].done = true;
  draft.todos.push({ id: 3, text: "Master Craft", done: false });
});

// Original is unchanged
console.log(baseState.user.age); // 25

// New state has the updates
console.log(nextState.user.age); // 26
console.log(nextState.todos.length); // 3

// Structural sharing - unchanged parts are the same reference
console.log(baseState.todos[1] === nextState.todos[1]); // true

// ❌ Manual (error-prone, verbose, slow)
const nextState = {
  ...state,
  user: {
    ...state.user,
    profile: {
      ...state.user.profile,
      age: state.user.profile.age + 1,
    },
  },
};

// ✅ Craft (simple, safe, fast)
const nextState = craft(state, (draft) => {
  draft.user.profile.age++;
});