Rename notes from GitJournal Zettelkasten to Obsidian

rename.js

const { readdir, readFile, writeFile } = require('node:fs/promises');
const { spawn } = require('node:child_process');
const path = require('path');
const frontmatter = require('frontmatter');

let notedir = process.env.PWD;
if (process.argv.length > 2) {
  notedir = path.resolve(process.env.PWD, process.argv[2]);
}
const notesmap = {};
const titlemap = {};

readdir(notedir)
  .then((files) => files.filter((name) => name.indexOf('.md') !== -1))
  .then((notes) => {
    return notes.reduce((previousPromise, notefile) => {
      return previousPromise.then(() => {
        const filepath = path.resolve(notedir, notefile);
        return readFile(filepath, 'utf-8')
          .then((content) => {
            const parsed = frontmatter(content);
            let title;
            if (parsed.data.title) {
              title = parsed.data.title;
            } else {
              const matched = parsed.content.match(/^\# (.*)\n/m);
              if (matched.length) {
                title = matched[1];
              }
            }
            titlemap[notefile] = title;
          })
          .then(() => {
            if (!titlemap[notefile]) {
              // No title, ignore
              return Promise.resolve();
            }
            const newname = `${titlemap[notefile]}.md`;
            return new Promise((resolve, reject) => {
              console.log(`git mv ${notefile} ${newname}`);
              let err;
              const rename = spawn('git', [
                'mv',
                notefile,
                `${titlemap[notefile]}.md`
              ], {
                cwd: notedir,
            });
            rename.stderr.on('data', (d) => {
              err += d;
            });
            rename.on('close', (code) => {
              if (code !== 0) {
                reject(new Error(err));
                return;
              }
              notesmap[notefile] = newname;
              resolve();
            });
          });
        });
      });
    }, Promise.resolve());
  })
  .then(() => {
    // All files renamed, fix links
    return Promise.all(Object.keys(notesmap).map((notefile) => {
      const filepath = path.resolve(notedir, notesmap[notefile]);
      return readFile(filepath, 'utf-8')
        .then((content) => {
          let updated = content;
          Object.keys(notesmap).forEach((oldname) => {
            updated = updated.replace(oldname, encodeURI(notesmap[oldname]));
          });
          if (content === updated) {
            return Promise.resolve();
          }
          console.log(`Updated links in ${filepath}`);
          return writeFile(filepath, updated, 'utf-8');
        });
    }));
  })
  .then(() => {
    console.log(notesmap);
    process.exit(0);
  })
  .catch((e) => {
    console.error(e);
    process.exit(1);
  });