moved var declaration upper

lib/single-file/util/doc-helper.js

@@ -131,8 +131,8 @@ this.docHelper = this.docHelper || (() => {
 	function getShadowRootsData(element, data = { indexElement: 0, shadowRootsData: [] }) {
 		element.querySelectorAll("*").forEach(element => {
 			if (element.shadowRoot) {
-				element.setAttribute(SHADOW_ROOT_ATTRIBUTE_NAME, data.indexElement);
 				const indexEntry = data.indexElement;
+				element.setAttribute(SHADOW_ROOT_ATTRIBUTE_NAME, indexEntry);
 				data.indexElement++;
 				getShadowRootsData(element.shadowRoot, data);
 				data.shadowRootsData[indexEntry] = { content: element.shadowRoot.innerHTML };