Most efficient way to store domain state in Redux (Indexed Key-Value Store)

improved_cache.js

//After working on the backend for a while, I started to continue working on my front end, 
//I revisited my redux “cache” store and I made this improvement that made my life a lot easier.
//In my project for example, some collections i need to get the document by id, some by slug, some by username, and etc.

//If I need to account for those cases I had to make new action creators/types, for different entities.
//This is very frustrating as it makes the code less dry and leads to more boilerplate.

//Then what I realized was, I can just pass a “index” option for my insert action creators!(which defaults to “id")

//Actions
const actions = {
  INSERT_ONE:  'INSERT_ONE',
  INSERT_MANY: 'INSERT_MANY'
}

//Action Creators

export function insert(collection, payload, { index } = { index: 'id'}) {
  if(Array.isArray(doc)) {
    return {
      type: actions.INSERT_MANY,
      collection,
      docs: payload,
      index
    }
  } else {
    return {
      type: actions.INSERT_ONE,
      collection,
      doc: payload,
      index
    }
  }
}

//Reducer

const defaultState = {
  users: {},
  posts: {}
}

export default function cache(state = defaultState, action) {
  const { collection, index, doc } = action;
  switch(action.type) {
    default:
      return state;
    case actions.INSERT_ONE:
      return {
        ...state,
        [collection]: {
          ...state[collection],
          [doc[index]]: doc
        }
      };
    case actions.INSERT_MANY:
      const newDocs = {};
      docs.forEach(doc => {
       newDocs[ doc[index] ] = doc
      });
      return {
       ...state,
        [action.collection]: {
          ...state[action.collection],
          ...newDocs
        }
      }
  }
}

//How to insert

this.props.insert('users', user, {index: 'username'});
this.props.insert('posts', post, {index: 'slug'});
this.props.insert('posts', post); // index by "id"

// Now I can easily get document by the property I usually use for that type

const user = cache.users["some_username"]; //get using username
const post = cache.posts["some-title-slug"]; //get using slug
const post = cache.posts["234j2kl3j42h3j4l"] //get using id

//Joins in my components

const post = cache.posts["some-slug"];
post.user = cache.users[post.user_id];

//Easy peazy!