from-relative-to-absolute-imports.js

let glob = require('fast-glob');
let fs = require('fs').promises;
let path = require('path');

let RELATIVE_IMPORT_ABOVE_FILE = /^import .+? '((\.\.\/)+)/;
let isRelativeImportAboveFile = line => RELATIVE_IMPORT_ABOVE_FILE.test(line);
let asAbsoluteImport = line =>
  line.replace(line.match(RELATIVE_IMPORT_ABOVE_FILE)[1], '');

async function run() {
  let files = await glob(path.join(process.cwd(), 'src', '**/*.js'));

  await Promise.all(
    files.map(async file => {
      let source = await fs.readFile(file, 'utf8');
      source = source
        .split('\n')
        .map(line =>
          isRelativeImportAboveFile(line) ? asAbsoluteImport(line) : line
        )
        .join('\n');

      await fs.writeFile(file, source, 'utf8');
    })
  );
}

run();