text: "use strict";
  
  Object.defineProperty(exports, "__esModule", {
    value: true
  });
  exports.default = normalizeAttributeValues;
  const caseInsensitiveAttributes = {
    autocomplete: ['form'],
    charset: ['meta', 'script'],
    contenteditable: null,
    crossorigin: ['audio', 'img', 'link', 'script', 'video'],
    dir: null,
    draggable: null,
    dropzone: null,
    formmethod: ['button', 'input'],
    inputmode: ['input', 'textarea'],
    kind: ['track'],
    method: ['form'],
    preload: ['audio', 'video'],
    referrerpolicy: ['a', 'area', 'iframe', 'img', 'link'],
    sandbox: ['iframe'],
    spellcheck: null,
    scope: ['th'],
    shape: ['area'],
    sizes: ['link'],
    step: ['input'],
    translate: null,
    type: ['a', 'link', 'button', 'embed', 'object', 'script', 'source', 'style', 'input', 'menu', 'menuitem'],
    wrap: ['textarea']
  };
  
  function normalizeAttributeValues(tree) {
    tree.walk(node => {
      if (!node.attrs) {
        return node;
      }
  
      Object.entries(node.attrs).forEach(([attrName, attrValue]) => {
        const attrNameLower = attrName.toLowerCase();
  
        if (Object.hasOwnProperty.call(caseInsensitiveAttributes, attrNameLower) && (caseInsensitiveAttributes[attrNameLower] === null || caseInsensitiveAttributes[attrNameLower].includes(node.tag))) {
          node.attrs[attrName] = attrValue.toLowerCase ? attrValue.toLowerCase() : attrValue;
        }
      });
      return node;
    });
    return tree;
  }