createResolvers.js

const unified = require('unified')
const remarkParse = require('remark-parse')
const remarkHtml = require('remark-html')

exports.createResolvers = ({
  createResolvers,
}) => {
  const toHTML = async (source) => {
    const vfile = await unified()
      .use(remarkParse)
      .use(remarkHtml)
      .process(source)

    return vfile.contents
  }

  const resolvers = {
    MarkdownRemarkFrontmatter: {
      text: {
        resolve: async (source) => {
          const html = await toHTML(source.text)
          return html
        },
      },
    },
  }
  return createResolvers(resolvers)
}

Hey there! No problem at all. I did manage to infer part of this myself, but I was using onCreateNode instead. This actually seems cleaner though, so thanks for that!