completed 4.5

parts/4/blogApp/src/utils.js

@@ -27,9 +27,25 @@ const totalLikes = (posts) => {
   return likeCount;
 };
 
+const favoritePost = (posts) => {
+  if (!posts || posts.length === 0) {
+    return null;
+  }
+
+  const highestLikes = posts.reduce(
+    (max, post) => (post.likes > max ? (max = post.likes) : max),
+    0
+  );
+
+  const favoritePost = posts.find((post) => post.likes == highestLikes);
+
+  return favoritePost;
+};
+
 module.exports = {
   reverse,
   average,
   listHelper,
   totalLikes,
+  favoritePost,
 };