@runicjs/runic/dist/utils/updateStatesWithProducer.js

A lightweight, type-safe vanilla JS state management library

/**
 * Takes a list of stores and a callback function that will be called with
 * a draft for each store.
 *
 * TODO: Having trouble making a types for this. Going to table it for now.
 *
 * Example:
 *   type NumState = { num: number };
 *   type NumsState = { nums: number[] };
 *
 *   const numStore1 = createStore<NumState>({ num: 1 });
 *   const numsStore = createStore<NumsState>({ nums: [2, 3, 4] });
 *   const numStore3 = createStore<NumState>({ num: 5 });
 *
 *   updateStates([numStore1, numsStore, numStore3], ([num1, nums, num3]) => {
 *     //          Draft<NumState>, Draft<NumsState>, Draft<NumState>
 *     console.log(num1,            nums,             num3);
 *   });
 */
export default function updateStatesWithProducer(stores, producer, // (state, (draft) => draft | undefined) => void
callback) {
    const drafts = [];
    const queue = stores.slice();
    function next() {
        if (queue.length === 0) {
            callback(drafts);
        }
        else {
            const store = queue.shift();
            const newState = producer(store.getState(), (draft) => {
                drafts.push(draft);
                next();
            });
            store.setState(newState);
        }
    }
    next();
}