Migrate to app router (#2254)

lib/helpers/build-feed.ts

@@ -2,84 +2,58 @@ import { Feed } from "feed";
 import { getAllPosts } from "./posts";
 import config from "../config";
 import { meJpg } from "../config/favicons";
-import type { GetServerSideProps } from "next";
+import { metadata } from "../../app/layout";
 
-export type GetServerSideFeedProps = GetServerSideProps<Record<string, never>>;
-
-export type BuildFeedOptions = {
-  format: "rss" | "atom" | "json";
-};
-
-// handles literally *everything* about building the server-side rss/atom feeds and writing the response.
-// all the page needs to do is `return buildFeed(context, "rss")` from getServerSideProps.
-export const buildFeed = async (
-  context: Parameters<GetServerSideFeedProps>[0],
-  options: BuildFeedOptions
-): Promise<ReturnType<GetServerSideFeedProps>> => {
-  const { res } = context;
-  const baseUrl = process.env.NEXT_PUBLIC_BASE_URL || `https://${config.siteDomain}`;
+export const buildFeed = async (options: { type: "rss" | "atom" | "json" }): Promise<string> => {
+  const baseUrl = metadata.metadataBase?.href || `https://${config.siteDomain}/`;
 
   // https://github.com/jpmonette/feed#example
   const feed = new Feed({
-    id: `${baseUrl}/`,
-    link: `${baseUrl}/`,
+    id: baseUrl,
+    link: baseUrl,
     title: config.siteName,
     description: config.longDescription,
     copyright: config.licenseUrl,
     updated: new Date(process.env.RELEASE_DATE || Date.now()),
-    image: `${baseUrl}${meJpg.src}`,
+    image: new URL(meJpg.src, baseUrl).href,
     feedLinks: {
-      rss: `${baseUrl}/feed.xml`,
-      atom: `${baseUrl}/feed.atom`,
+      rss: new URL("feed.xml", baseUrl).href,
+      atom: new URL("feed.atom", baseUrl).href,
     },
     author: {
       name: config.authorName,
-      link: `${baseUrl}/`,
+      link: baseUrl,
       email: config.authorEmail,
     },
   });
 
   // add posts separately using their frontmatter
-  const posts = await getAllPosts();
-  posts.forEach((post) => {
+  (await getAllPosts()).forEach((post) => {
     feed.addItem({
       guid: post.permalink,
       link: post.permalink,
       title: post.title,
       description: post.description,
-      image: post.image && `${baseUrl}${post.image}`,
+      image: post.image || undefined,
       author: [
         {
           name: config.authorName,
-          link: `${baseUrl}/`,
+          link: baseUrl,
         },
       ],
       date: new Date(post.date),
     });
   });
 
-  // cache on edge for 24 hours by default
-  res.setHeader("cache-control", `public, max-age=0, s-maxage=86400, stale-while-revalidate`);
-
-  // generates RSS by default
-  if (options.format === "rss") {
-    res.setHeader("content-type", "application/rss+xml; charset=utf-8");
-    res.write(feed.rss2());
-  } else if (options.format === "atom") {
-    res.setHeader("content-type", "application/atom+xml; charset=utf-8");
-    res.write(feed.atom1());
-  } else if (options.format === "json") {
+  if (options.type === "rss") {
+    return feed.rss2();
+  } else if (options.type === "atom") {
+    return feed.atom1();
+  } else if (options.type === "json") {
     // rare but including as an option because why not...
     // https://www.jsonfeed.org/
-    res.setHeader("content-type", "application/feed+json; charset=utf-8");
-    res.write(feed.json1());
+    return feed.json1();
   } else {
-    throw new TypeError(`Invalid feed type "${options.format}", must be "rss", "atom", or "json".`);
+    throw new TypeError(`Invalid feed type "${options.type}", must be "rss", "atom", or "json".`);
   }
-
-  res.end();
-
-  return {
-    props: {},
-  };
 };