build.js

#!/usr/bin/env node
/*
 * Zero-dependency build: turns the ESM source into ESM + UMD bundles and
 * copies the stylesheet. No bundler required — the library has no imports.
 */
import { readFileSync, writeFileSync, mkdirSync, copyFileSync } from 'node:fs';
import { fileURLToPath } from 'node:url';
import { dirname, join } from 'node:path';

const root = dirname(fileURLToPath(import.meta.url));
const src = join(root, 'src');
const dist = join(root, 'dist');
mkdirSync(dist, { recursive: true });

const esm = readFileSync(join(src, 'supersplit.js'), 'utf8');

// ---- ESM build (source is already ESM) ----
writeFileSync(join(dist, 'supersplit.esm.js'), esm);

// ---- UMD build: strip ESM export syntax, wrap as UMD returning SuperSplit ----
const body = esm
  .replace(/^export\s+class\s+/m, 'class ')
  .replace(/^export\s*\{[^}]*\};\s*$/m, '')
  .replace(/^export\s+default\s+SuperSplit;\s*$/m, '');

const umd = `(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global = typeof globalThis !== 'undefined' ? globalThis : global || self, global.SuperSplit = factory());
})(this, function () {
'use strict';
${body}
return SuperSplit;
});
`;
writeFileSync(join(dist, 'supersplit.umd.js'), umd);
// same UMD content, but a .cjs extension so Node's require() always treats it
// as CommonJS regardless of the package's "type": "module".
writeFileSync(join(dist, 'supersplit.cjs'), umd);

// ---- styles ----
copyFileSync(join(src, 'supersplit.css'), join(dist, 'supersplit.css'));

console.log('✓ built dist/supersplit.esm.js, dist/supersplit.umd.js, dist/supersplit.cjs, dist/supersplit.css');