get blog-post with sort date for next js

blog-post-data.js

import fs from 'fs'
import matter from 'gray-matter'
import { DateTime } from 'luxon'

export default function getBlogPostData(count = 999) {
  const files = fs.readdirSync(`${process.cwd()}/content/posts`)

  const posts = files.map((filename) => {
    const markdownWithMetadata = fs
      .readFileSync(`content/posts/${filename}`)
      .toString()

    const { data } = matter(markdownWithMetadata)
    const formattedDate = data.date.toLocaleDateString()

    const frontmatter = {
      ...data,
      date: formattedDate
    }

    return {
      slug: filename.replace('.md', ''),
      frontmatter
    }
  })

  const postDataSortByDate = posts.sort((a, b) => {
    const beforeDate = DateTime.fromFormat(a.frontmatter.date, 'M/d/yyyy')
    const afterDate = DateTime.fromFormat(b.frontmatter.date, 'M/d/yyyy')
    return afterDate - beforeDate
  })

  return {
    props: {
      posts: postDataSortByDate.splice(0, count)
    }
  }
}