What is the difference between __dirname/__filename in CommonJS and their equivalents in ES Modules?

In CommonJS, __dirname and __filename are automatically available in every module, providing the absolute path to the current file's directory and the file itself. ES Modules don't have these globals at all (since ESM was designed to be more portable, including for non-file-based module sources); the equivalent in ESM is derived from import.meta.url, typically converted to a filesystem path using the node:url module's fileURLToPath() function.

// CommonJS
console.log(__dirname);  // /path/to/current/directory
console.log(__filename); // /path/to/current/directory/file.js

// ES Modules equivalent
import { fileURLToPath } from 'node:url';
import { dirname } from 'node:path';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);