(function () {
  'use strict';

  const root = window.PixelIslandModules ||= {};
  const pending = new Map();

  function loadScript(src) {
    if (pending.has(src)) return pending.get(src);
    const promise = new Promise((resolve, reject) => {
      const script = document.createElement('script');
      script.src = src;
      script.defer = true;
      script.onload = () => resolve(script);
      script.onerror = () => reject(new Error(`Could not load ${src}`));
      document.head.appendChild(script);
    });
    pending.set(src, promise);
    return promise;
  }

  root.ModuleLoader = { loadScript };
})();