appendHtml, when sanitizing, should create document fragment in the right context

tests/html/element_add_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file
 
 library ElementAddTest;
 import 'package:unittest/unittest.dart';
 import 'package:unittest/html_config.dart';
 import 'util.dart';
 import 'dart:html';
 
@@ skipping 44 matching lines @@
       expect(el.children[0], equals(span));
       expect(el.children[1], isDivElement);
     });
 
     test('documentFragment', () {
       var fragment = new DocumentFragment();
       fragment.appendHtml('<span>something</span>');
       expect(fragment.children.length, equals(1));
       expect(fragment.children[0], isSpanElement);
     });
+
+    test('html interpreted in correct context', () {
+      // appendHtml, in order to sanitize, needs to create a document fragment,
+      // but it needs to be created in the right context. If we try to append
+      // table components then the document fragment needs the table context
+      // or it will fail to create them.
+      var el = new TableElement();
+      el.appendHtml('<tr><td>foo</td></tr>');
+      expect(el.children.length, 1);
+      var section = el.children.first;
+      expect(section is TableSectionElement, isTrue);
+      var row = section.children.first;
+      expect(row is TableRowElement, isTrue);
+      var item = row.children.first;
+      expect(item is TableCellElement, isTrue);
+      expect(item.innerHtml, 'foo');
+    });
+
+    test("use body context for elements that are don't support it", () {
+      // Some elements can't be used as context for createContextualFragment,
+      // often because it doesn't make any sense. So adding children to a
+      // <br> has no real effect on the page, but we can do it. But the
+      // document fragment will have to be created in the body context. Verify
+      // that this doesn't throw and that the children show up.
+      var el = new BRElement();
+      el.appendHtml("<p>Stuff</p>");
+      expect(el.children.length, 1);
+      expect(el.children[0].outerHtml, "<p>Stuff</p>");
+    });
   });
 
   group('appendText', () {
     test('htmlelement', () {
       var el = new DivElement();
       el.appendText('foo');
       // No children were created.
       expect(el.children.length, equals(0));
       // One text node was added.
       expect(el.nodes.length, equals(1));
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       var child = new DivElement();
       parent.children.add(child);
 
       parent.insertAdjacentText('beforeend', 'test');
 
       expect(parent.nodes.length, 2);
       expect(parent.nodes[1], isText);
     });
   });
 }