text: import { RECEIVE_TWEETS, TOGGLE_TWEET, ADD_TWEET } from '../actions/tweets';
  
  export default function tweets(state = {}, action) {
      switch (action.type) {
          case RECEIVE_TWEETS:
              return {
                  ...state,
                  ...action.tweets,
              };
          case TOGGLE_TWEET:
              return {
                  ...state,
                  [action.id]: {
                      ...state[action.id],
                      likes:
                          action.hasLiked === true
                              ? state[action.id].likes.filter(
                                    (uid) => uid !== action.authedUser
                                )
                              : state[action.id].likes.concat([
                                    action.authedUser,
                                ]),
                  },
              };
          case ADD_TWEET:
              const { tweet } = action;
  
              let replyingTo = {};
              if (tweet.replyingTo !== null) {
                  replyingTo = {
                      [tweet.replyingTo]: {
                          ...state[tweet.replyingTo],
                          replies: state[tweet.replyTo].replies.concat([
                              tweet.id,
                          ]),
                      },
                  };
              }
  
              return {
                  ...state,
                  [action.tweet.id]: action.tweet,
                  ...replyingTo,
              };
          default:
              return state;
      }
  }
  