groupBy.js

 groupData = posts => {
    const array = Object.values(posts);

    const res = array.reduce((acc, curr) => {
      if (!acc[curr.data.subreddit]) {
        acc[curr.data.subreddit] = [];
      }
      // If this subreddit wasn't previously stored create an empty array

      acc[curr.data.subreddit].push(curr); // Add the post to group
      return acc;
    }, {});

    return Object.values(res); // convert to array and return
  };

// Group by key in data