findParentPackageJson.ts

/**
 * @description given the location of this file, find the package.json of the closest parent package
 * @async
 * @return {string} absolute path of parent packageJson file
 */
export function findParentPackageJson() {
  function parentDirOf(fileOrDir: string): string {
    return path.join(fileOrDir, '..')
  }
  async function packageJsonExists(dir: string): Promise<boolean> {
    const dirents = await fs.promises.readdir(dir, { withFileTypes: true })
    return dirents.some(dirent => dirent.isFile() && dirent.name === 'package.json')
  }

  // currentLocation could be a file or dir
  async function walkUp(currentLocation: string): Promise<string> {
    if (await packageJsonExists(currentLocation)) {
      return path.join(currentLocation, 'package.json')
    }
    else {
      const newLocation = parentDirOf(currentLocation)
      return walkUp(newLocation)
    }
  }

  // const currentFile = fileURLToPath(import.meta.url)
  const currentFile = __filename;
  const currentDir = parentDirOf(currentFile)
  return walkUp(currentDir)
}