perf: cache author for faster lookup

src/ts/app.ts

@@ -1,6 +1,7 @@
 import API from "./API";
 import UI from "./UI";
 import Input from "./Input";
+import Author from "./Author";
 
 const pkg = require("../../package.json");
 
@@ -35,12 +36,20 @@ declare const Prism: any;
 
     const blogPostContainer = UI.blogPostContainer;
     if (blogPostContainer) {
+        const authors = [];
         const template = Handlebars.compile(UI.blogPostTemplate.innerHTML);
         API.getBlogPostCount().then(async (count) => {
             for (let i = 0; i < count; i++) {
                 const posts = await API.getBlogPosts(i, 5);
                 for (const post of posts) {
-                    const author = await API.getAuthor(post.authorId);
+                    let author: Author;
+                    if (authors[post.authorId]) {
+                        author = authors[post.authorId];
+                    } else {
+                        author = await API.getAuthor(post.authorId);
+                        authors[post.authorId] = author;
+                    }
+
                     const card = UI.createBlogPostCard(template, post, author);
                     blogPostContainer.appendChild(card);
                     UI.updateUI(card);