renderRSSFeedToString.js

import { Feed } from 'feed'
import { crawl, resolve } from 'navi'
import path from 'path'
import React from 'react'
import ReactDOMServer from 'react-dom/server'
import siteMetadata from './siteMetadata'

async function renderRSSFeed({ routes }) {
  let publicURL = process.env.PUBLIC_URL || '/'
  let { paths } = await crawl({
    routes,
    root: '/posts',
  })

  const feed = new Feed({
    title: siteMetadata.title,
    description: siteMetadata.description,
    id: publicURL,
    // TODO: set this based on the siteMap slugs
    // updated: new Date(),
    link: publicURL,
    author: {
      name: siteMetadata.author,
    },
  });

  for (let pathname of paths.sort()) {
    let route = await resolve({
      routes,
      url: pathname,
    })
    let meta = route.data || {}
    let link = path.join(publicURL, pathname)

    // Each post's content is just an MDX component, which can be rendered
    // independently of the rest of the app.
    let content = ReactDOMServer.renderToStaticMarkup(
      React.createElement(route.views[route.views.length - 1].MDXComponent)
    )

    // todo: add a date
    feed.addItem({
      title: route.title,
      id: link,
      link: link,
      description: meta.spoiler,
      content,
      author: {
        name: siteMetadata.author,
      }
    })
  }

  return feed.rss2();
}

export default renderRSSFeed