just some refactoring

lib/helpers/build-feed.ts

@@ -0,0 +1,72 @@
+import { Feed } from "feed";
+import { getAllNotes } from "./parse-notes";
+import * as config from "../config";
+import type { GetServerSidePropsContext, PreviewData } from "next";
+import type { ParsedUrlQuery } from "querystring";
+
+// 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, { format: "rss" })` from getServerSideProps.
+
+export const buildFeed = (
+  context: GetServerSidePropsContext<ParsedUrlQuery, PreviewData>,
+  options?: { type: "rss" | "atom" }
+): { props: Record<string, unknown> } => {
+  const { res } = context;
+
+  // https://github.com/jpmonette/feed#example
+  const feed = new Feed({
+    id: `${config.baseUrl}/`,
+    link: `${config.baseUrl}/`,
+    title: config.siteName,
+    description: config.longDescription,
+    copyright: "https://creativecommons.org/licenses/by/4.0/",
+    updated: new Date(),
+    image: `${config.baseUrl}/static/images/me.jpg`,
+    feedLinks: {
+      rss: `${config.baseUrl}/feed.xml`,
+      atom: `${config.baseUrl}/feed.atom`,
+    },
+    author: {
+      name: config.authorName,
+      link: `${config.baseUrl}/`,
+      email: config.authorEmail,
+    },
+  });
+
+  // add notes separately using their frontmatter
+  const notes = getAllNotes();
+  notes.forEach((note) => {
+    feed.addItem({
+      guid: note.permalink,
+      link: note.permalink,
+      title: note.title,
+      description: note.description,
+      image: note.image ? `${config.baseUrl}${note.image}` : "",
+      author: [
+        {
+          name: config.authorName,
+          link: config.baseUrl,
+        },
+      ],
+      date: new Date(note.date),
+    });
+  });
+
+  // cache on edge for one hour
+  res.setHeader("cache-control", "s-maxage=3600, stale-while-revalidate");
+
+  // generates RSS by default
+  if (options?.type === "atom") {
+    res.setHeader("content-type", "application/atom+xml; charset=utf-8");
+    res.write(feed.atom1());
+  } else {
+    res.setHeader("content-type", "application/rss+xml; charset=utf-8");
+    res.write(feed.rss2());
+  }
+
+  res.end();
+
+  return {
+    props: {},
+  };
+};