Create html scaffold if missing

lib/DOMParser.js

@@ -3,7 +3,7 @@ const htmlparser = require("htmlparser2");
 const DOMImplementation = require('./DOMImplementation');
 const HTMLElement = require('./HTMLElement');
 
-const domTreeToW3C = (document, { type, name, attribs, children = [], data }) => {
+const objTreeToW3C = (document, { type, name, attribs, children = [], data }) => {
   const nodeTypeMapping = {
     tag: () => document.createElement(name),
     text: () => document.createTextNode(data),
@@ -19,7 +19,7 @@ const domTreeToW3C = (document, { type, name, attribs, children = [], data }) =
   const node = nodeTypeMapping[type](arguments);
 
   for (let child of children) {
-    const el = domTreeToW3C(document, child);
+    const el = objTreeToW3C(document, child);
     node.appendChild(el);
   }
 
@@ -42,20 +42,61 @@ class DOMParser extends XMLDOMParser {
     if (/\/x?html?$/.test(mimeType)) {
       const impl = new DOMImplementation();
       const document = impl.createHTMLDocument();
+
+      // We're going to replace initial scaffold
       while (document.lastChild) {
         document.removeChild(document.lastChild);
       }
+
+      // Actually parse html string
       let tree;
+
       const handler = new htmlparser.DomHandler(function (error, dom) {
         if (error) {
           throw error;
         }
         tree = dom;
       });
       const parser = new htmlparser.Parser(handler);
+
       parser.write(source);
       parser.end();
-      tree.forEach(el => document.appendChild(domTreeToW3C(document, el)));
+
+      // Wrap tree into proper scaffold if missing
+      let root = tree.find(node => node.name === 'html');
+
+      if (!root) {
+        root = {
+          type: 'tag',
+          name: 'html',
+          attribs: {},
+          children: tree
+        };
+      }
+
+      tree = [ root ];
+
+      const body = root.children.find(node => node.name === 'body');
+
+      if (!body) {
+        root.children = [{
+          type: 'tag',
+          name: 'body',
+          attribs: {},
+          children: root.children
+        }];
+      }
+
+      // Transform to w3c-compliant object
+      const fragment = document.createDocumentFragment();
+
+      tree.forEach(node => {
+        const w3cNode = objTreeToW3C(document, node);
+
+        fragment.appendChild(w3cNode);
+      });
+      document.appendChild(fragment);
+
       return document;
     }
   }