react-speicher

A dead-simple state management library for React.

Inspired by Zustand. React-speicher is a tiny library, with a single dependency on use-sync-external-store.

API

createStore

Takes three arguments:

  • initialState – initial store state
  • actionsCreator – a function returning the actions to mutate the store
  • mapper (optional) – computes derived state

useStore

Hook to select the part of the store to use in your component

memoize

Utility function to wrap an expensive computation

shallow

Utility function to shallow compare the previous and next state

Examples

Basic example:

import { createStore, useStore } from 'react-store';

const store = createStore(
    { counter: 0 },
    ({ get, set }) => ({
        increment() {
            set((state) => ({ counter: state.counter + 1 }));
        }
    })
);

function MyComponent() {
    const counter = useStore(store, (state) => state.counter);
    return (
        <button onClick={() => {
            store.actions.increment();
        }}>
            Clicked {counter} times
        </button>
    );
}

Computed state:

import { createStore, memoize } from 'react-store';

const getTotalPrice = memoize((items) => {
    return items.reduce((acc, item) => acc + item.price, 0);
});

const store = createStore(
    { basket: [] },
    ({ get, set }) => ({
        addItem(item) {
            set((state) => ({
                basket: state.basket.concat([item])
            }));
        }
    }),
    (state) => ({
        ...state,
        // expensive computation
        totalPrice: getTotalPrice(state.basket)
    })
);

Why did you create this library?

After React 18 was released with the useSyncExternalStore hook, it has become easy to create new state-management libraries for React. This library is directly inspired by Zustand, but addresses the following issues with it’s API design:

  • State and actions are combined together.
    • Difficult to work with in TypeScript. You have to type all the actions in the State interface.
  • Need to use a custom middleware for computed/derived state

GitHub

View Github