Function unwrapTemplate

packages/engine/src/utils/htmlTemplate.ts:21–42

(html: string)

 * of inputs that contain multiple sibling templates or other top-level content.
 */
export function unwrapTemplate(html: string): string {
  const lowered = html.toLowerCase();
  if (!lowered.includes("<template") || !lowered.includes("</template>")) {
    return html;
  }

  const { body } = parseHTMLContent(html);
  if (!body) return html;

  let container: Element = body;
  const bodyWrapper = getSingleMeaningfulChild(container);
  if (bodyWrapper?.tagName === "BODY") {
    container = bodyWrapper;
  }

  const template = getSingleMeaningfulChild(container);
  if (template?.tagName !== "TEMPLATE") {
    return html;
  }

  return template.innerHTML ?? html;
}