Mutik – A tiny immutable state management library based on Immer

Nice work by Jared Palmer: a React State Management Library which uses Immer internally so you don’t have to worry about overwriting (unrelated) parts of your state whilst updating some value in it.

import React from 'react';
import { render } from 'react-dom';
import { createStore, Provider, useSelector } from 'mutik';
// Create a lil' store with some state
let store = createStore({
  count: 0,
// Pass the store to the Provider.
function App() {
  return (
    <Provider store={store}>
        <Label />
        <Buttons />
// You can mutate the store from anywhere you want to,
// even outside of React code. Mutate is based on immer.
function increment() {
  store.mutate(state => {
// Or you can update it like React.useState's update
function decrement() {
  store.set(prevState => ({
    count: state.count - 1
// You don't need to pass it down as props either,
// although you can if you need to.
function Buttons() {
  return (
      <button onClick={decrement}>-</button>
      <button onClick={increment}>+</button>
function Label() {
  // You can subcribe to "slices" of mutable state with useSelector
  // Note: be sure to memoize these with React.useCallback
  const selector = React.useCallback(state => state.count, []);
  const count = useSelector(selector);
  return <p>The count is {count}</p>;
render(<App />, window.root);

As you can see in the code example you can use store.set or leverage its power by calling store.mutate which takes an Immer-style updater function as its argument.

Installation per npm/Yarn

yarn add mutik

Mutik Source (GitHub) →
Mutik Demo →

⚠️ Mutik requires experimental builds of react/react-dom as it used the brand spanking new useMutableSource hook which landed only 5 days ago!

yarn add react@experimental react-dom@experimental

Published by Bramus!

Bramus is a frontend web developer from Belgium, working as a Chrome Developer Relations Engineer at Google. From the moment he discovered view-source at the age of 14 (way back in 1997), he fell in love with the web and has been tinkering with it ever since (more …)

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