svelte-ux/stores/changeStore.js

- Increment version in `package.json` and commit as `Version bump to x.y.z` - `npm run publish`

import { derived } from 'svelte/store';
function changeStore(store, onChange) {
    let previous = undefined;
    return derived(store, ($store) => {
        const value = { previous, current: $store };
        if (previous === undefined) {
            // First update
        }
        else if (onChange) {
            onChange(value);
        }
        previous = $store;
        return value;
    });
}
export default changeStore;