const { posix, win32 } = require('node:path');

function assertEqual(actual, expected, message) {
  if (actual !== expected) {
    throw new Error(`${message}: expected ${JSON.stringify(expected)}, got ${JSON.stringify(actual)}`);
  }
}

const parsedBasename = posix.parse('file.txt');
assertEqual(parsedBasename.dir, '', 'basename-only parse dir');
assertEqual(posix.format(parsedBasename), 'file.txt', 'format(parse(path))');
assertEqual(posix.format({ dir: '', root: '/', base: 'file' }), '/file', 'empty dir should fall back to root');
assertEqual(posix.format({ dir: '/x', base: '', name: 'file', ext: '.js' }), '/x/file.js', 'empty base should fall back to name and ext');
assertEqual(posix.format({ dir: '', root: '/', base: '', name: 'file', ext: 'js' }), '/file.js', 'name and ext fallback should add a missing dot');
assertEqual(win32.format({ dir: '', root: 'C:\\', base: 'file' }), 'C:\\file', 'empty win32 dir should fall back to root');
assertEqual(win32.format({ dir: 'D:\\work', root: 'C:\\', base: 'file' }), 'D:\\work\\file', 'non-empty win32 dir should override root');

console.log('path parse/format empty fields ok');