hoelee-blog/src/pages/rss.xml.ts

import rss from '@astrojs/rss';
import { getCollection } from 'astro:content';
import { SITE } from '../config';

export async function GET(context) {
  const posts = (await getCollection('posts', ({ data }) => !data.draft && data.lang === 'en'))
    .sort((a, b) => b.data.pubDate.valueOf() - a.data.pubDate.valueOf());

  return rss({
    title: SITE.name,
    description: SITE.description,
    site: context.site,
    items: posts.map((post) => ({
      title: post.data.title,
      description: post.data.description,
      pubDate: post.data.pubDate,
      link: `/posts/${post.slug}/`,
      categories: [post.data.category, ...post.data.tags],
    })),
    customData: `<language>${SITE.locale}</language>`,
  });
}