将html转换为字符串尾随的新行

function htmlToStringWithNewLine(html) {
  const parser = new DOMParser();
  const doc = parser.parseFromString(html, "text/html");
  
  function traverse(node) {
    let str = "";
    
    if (node.nodeType === Node.TEXT_NODE) {
      str += node.textContent;
    } else if (node.nodeType === Node.ELEMENT_NODE) {
      str += `<${node.tagName.toLowerCase()}`;
      
      for (let i = 0; i < node.attributes.length; i++) {
        const attr = node.attributes[i];
        str += ` ${attr.name}="${attr.value}"`;
      }
      
      str += ">\n";
      
      for (let i = 0; i < node.childNodes.length; i++) {
        str += traverse(node.childNodes[i]);
      }
      
      str += `</${node.tagName.toLowerCase()}>\n`;
    }
    
    return str;
  }
  
  return traverse(doc.body);
}

const html = "<div><h1>Title</h1><p>Paragraph</p></div>";
const result = htmlToStringWithNewLine(html);
console.log(result);