contentlayer.config.js

import { defineDocumentType, makeSource } from 'contentlayer/source-files';
import rehypePrettyCode from 'rehype-pretty-code';

export const Post = defineDocumentType(() => ({
  name: 'Post',
  filePathPattern: `**/*.mdx`,
  contentType: 'mdx',
  fields: {
    title: {
      type: 'string',
      required: true
    },
    description: {
      type: 'string',
      required: true
    },
    date: {
      type: 'date',
      required: true
    }
  },
  computedFields: {
    slug: {
      type: 'string',
      resolve: post => `${post._raw.flattenedPath}`
    }
  }
}));

export default makeSource({
  contentDirPath: 'posts',
  documentTypes: [Post],
  mdx: {
    rehypePlugins: [
      [
        rehypePrettyCode,
        {
          theme: 'github-dark',
          onVisitLine(node) {
            if (node.children.length === 0) {
              node.children = [{ type: 'text', value: ' ' }];
            }
          },
          onVisitHighlightedLine(node) {
            node.properties.className.push('line--highlighted');
          },
          onVisitHighlightedWord(node) {
            node.properties.className = ['word--highlighted'];
          }
        }
      ]
    ]
  }
});