gatsby rss feed + sanity

gatsby-config.js

const PortableText = require('@sanity/block-content-to-html')
const imageUrlBuilder = require('@sanity/image-url')

const { isFuture, parseISO } = require('date-fns')
const clientConfig = require('./client-config')
const {
  getBlogUrl,
  filterOutDocsPublishedInTheFuture
} = require('./nodeHelpers.js')

const h = PortableText.h
const isProd = process.env.NODE_ENV === 'production'
const imageUrlFor = source => imageUrlBuilder(clientConfig.sanity).image(source)


{
  resolve: `gatsby-plugin-feed`,
  options: {
    query: `
    {
      site {
        siteMetadata {
          title
          description
          siteUrl
          site_url: siteUrl
        }
      }
    }
    `,
    feeds: [
      {
        serialize: ({ query: { site, allSanityPost = [] } }) => {
          return allSanityPost.edges
            .filter(({ node }) => filterOutDocsPublishedInTheFuture(node))
            .filter(({ node }) => node.slug)
            .map(({ node }) => {
              const { title, publishedAt, slug, _rawBody } = node
              const url =
                site.siteMetadata.siteUrl +
                getBlogUrl(publishedAt, slug.current)
              return {
                title: title,
                date: publishedAt,
                url,
                guid: url,
                custom_elements: [
                  {
                    'content:encoded': PortableText({
                      blocks: _rawBody,
                      serializers: {
                        types: {
                          code: ({ node }) =>
                            h(
                              'pre',
                              h('code', { lang: node.language }, node.code)
                            ),
                          mainImage: ({ node }) =>
                            h('img', {
                              src: imageUrlFor(node.asset).url()
                            }),
                          twitter: ({ node }) =>
                            h(
                              'p',
                              {},
                              h('a', {
                                href: node.url,
                                innerHTML: 'Look at the tweet.'
                              })
                            )
                        }
                      }
                    })
                  }
                ]
              }
            })
        },
        query: `{
          allSanityPost(sort: {fields: publishedAt, order: DESC}) {
            edges {
              node {
                _rawExcerpt
                _rawBody(resolveReferences: {maxDepth: 10})
                title
                publishedAt
                slug {
                  current
                }
              }
            }
          }
        }
        `,
        output: '/rss.xml',
        title: 'Knut Melvær'
        // optional configuration to insert feed reference in pages:
        // if `string` is used, it will be used to create RegExp and then test if pathname of
        // current page satisfied this regular expression;
        // if not provided or `undefined`, all pages will have feed reference inserted
      }
    ]
  }
}