process.cwd() instead of fs.readfileSync

fs.readfileSync() not working in vercel

During trainerlee_blog development, there was a issue where readfileSync does not read markdown files correctly, returning an error that the directory does not exist. However, the fs.readfileSync worked when I run npm run dev locally. This was the original version, where currentPostFull[0].link contained the path from root directory of the project to the markdown file.

const currentPostFull: QueryResultRow[]= await fetchPostFull(id);
const markdownContent = fs.readFileSync(currentPostFull[0].link, 'utf-8');

process.cwd()

On the official document of vercel, they recommend using process.cwd() when using fs.readFileSync. Vercel has a different way of determining the root directory, so process.cwd() determines the root directory. They say not to use __dirname.

Here is an example from vercel's official website.

import fs from 'fs';
import path from 'path';

export function GET(request) {
  let usersPath = path.join(process.cwd(), 'users.json');
  let file = fs.readFileSync(usersPath);
  return new Response(file);
}

Here is my example that works both locally and in vercel, but I changed the link to only include the name of the markdown file, instead of including the path as well. It seems that process.cwd() takes me to the root directory of the project.

const currentPostFull: QueryResultRow[]= await fetchPostFull(id);
const markdownContent = fs.readFileSync(process.cwd() + '/public/postmdfile/' + currentPostFull[0].link, 'utf-8');