/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */

"use strict";

function registerStoreObserver(store, subscriber) {
  let oldState = store.getState();
  store.subscribe(() => {
    const state = store.getState();
    subscriber(state, oldState);
    oldState = state;
  });
}

exports.registerStoreObserver = registerStoreObserver;