exercise 4.6 completed

parts/4/blogApp/src/utils.js

@@ -42,10 +42,30 @@ const favoritePost = (posts) => {
   return favoritePost;
 };
 
+const mostPosts = (posts) => {
+  if (!posts || posts.length === 0) {
+    return null;
+  }
+
+  const countMap = posts.reduce((acc, post) => {
+    acc[post.author] = (acc[post.author] || 0) + 1;
+    return acc;
+  }, {});
+
+  // Use Object.entries to find the top author
+  const [author, postsCount] = Object.entries(countMap).reduce(
+    (max, entry) => (entry[1] > max[1] ? entry : max),
+    ['', 0]
+  );
+
+  return { author, posts: postsCount };
+};
+
 module.exports = {
   reverse,
   average,
   listHelper,
   totalLikes,
   favoritePost,
+  mostPosts,
 };