Identifier 'root' has already been declared error

[thdoan]

In some cases we need to dynamically write out the script tag for grid-gallery.js (e.g., when used in modals). In this case, if the container is destroyed and recreated, it will throw an "Uncaught SyntaxError: Identifier 'root' has already been declared" error because the constant root is still in memory.

Steps to reproduce:

1. Go to https://codepen.io/thdoan/pen/yLjjLPw
2. Launch the modal
3. Close the modal (click on empty space below)
4. Launch the modal
5. Observe the JS error in the console

Fix: wrap everything in an IIFE to preserve variable scope.

(() => {
  const root = document.querySelector("body, html");
  ...
})();