Indieweb draft, creates per-tag RSS feeds.

src/lib/blog.ts

@@ -0,0 +1,22 @@
+import { type CollectionEntry, getCollection } from "astro:content";
+
+function publishedOnly(
+  p: CollectionEntry<"blog">,
+): p is CollectionEntry<"blog"> & { data: { pubDate: Date } } {
+  return p.data.pubDate !== undefined;
+}
+
+export async function getPublishedPosts(
+  tag?: string,
+): Promise<CollectionEntry<"blog">[]> {
+  const allPosts = (await getCollection("blog", publishedOnly)).sort(
+    (a, b) => b.data.pubDate.valueOf() - a.data.pubDate.valueOf(),
+  );
+  return tag ? allPosts.filter((p) => p.data.tags.includes(tag)) : allPosts;
+}
+
+export async function getAllTags(): Promise<string[]> {
+  const posts = await getCollection("blog", publishedOnly);
+
+  return posts.flatMap((p) => p.data.tags || []);
+}