Function hookSetting

src/common/hook-setting.js:15–23

(key, update)

});

export default function hookSetting(key, update) {
  options.ready.then(() => update(options.get(key)));
  const list = hooks[key] || (hooks[key] = []);
  list.push(update);
  return () => {
    const i = list.indexOf(update);
    if (i >= 0) list.splice(i, 1);
  };
}