StackingWithReSelect.js

const stackedSubjectsSelector = createSelector(
    [state => state.list],
    list => stackAndGetTopLevelSubjects(list)
);

const bookListSelector = state => ({
    subjects: Object.assign({}, state.bookList.subjects, {list: stackedSubjectsSelector(state.bookList.subjects)}),
    books: Object.assign({}, state.bookList.books, {list: booksWithSubjectsSelector(state.bookList)}),
    filters: state.bookList.filters
});