Persistance not working on objects when adding properties using set method

[Pustelto]

Hi,

I have store where I store if some section in the UI is collapsed. It is and object indexed by id of the section. When I save these like this (for initial fetch), persistance works:

class UiStore {
  closedSections = {};

  toggleSection = (sectionId: string, newState?: boolean) => {
    if (newState === false) {
      // This works I have to get old sections and resave entire object again
      const oldSections = toJS(this.closedSections) || {};
      this.closedSections = { ...oldSections, [sectionId]: true };
    } else {
      remove(this.closedSections, sectionId);
    }
  };
}

decorate(UiStore, {
  closedSections: [persist('object'), observable],
  isClosed: observable,
  toggleSection: action,
  clearDataAfterLogout: action,
});

export default new UiStore();

but that is too tedious, I would prefer to use set mobx method. But that does not seems to work (see example below).

class UiStore {
  closedSections = {};

  toggleSection = (sectionId: string, newState?: boolean) => {
    if (newState === false) {
      // This does not work after rehdyratation closedSections is empty object
      set(this.closedSections, sectionId, true);
    } else {
      remove(this.closedSections, sectionId);
    }
  };
}

decorate(UiStore, {
  closedSections: [persist('object'), observable],
  isClosed: observable,
  toggleSection: action,
  clearDataAfterLogout: action,
});

export default new UiStore();

Any idea how to do it? Readme is not very clear about this. I also did not found any answer in the issues.

Thanks for help.