Adding tests for Element & Node lists insert method.

tests/html/node_test.dart

 // Copyright (c) 2011, 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 NodeTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_individual_config.dart';
 import 'dart:html';
 import 'dart:svg' as svg;
 
@@ skipping 209 matching lines @@
 
       b.nodes.addAll(a.children);
       expect(a.children.length, 0);
       expect(b.children.length, childrenLength);
 
       a.nodes.addAll(b.nodes);
       expect(b.nodes.length, 0);
       expect(a.nodes.length, nodesLength);
     });
 
+    test('insert', () {
+      var node = new DivElement();
+      node.nodes.insert(0, new BRElement());
+      expect(node.nodes[0], isBRElement);
+      node.nodes.insert(0, new HRElement());
+      expect(node.nodes[0], isHRElement);
+      node.nodes.insert(1, new ImageElement());
+      expect(node.nodes[1], isImageElement);
+      node.nodes.insert(node.nodes.length, new InputElement());
+      expect(node.nodes.last, isInputElement);
+    });
+
     test('clear', () {
       var node = makeNodeWithChildren();
       node.nodes.clear();
       expect(node.nodes, []);
     });
 
     test('removeLast', () {
       var node = makeNodeWithChildren();
       expect(node.nodes.removeLast(), isComment);
       expect(node.nodes.length, 2);
@@ skipping 24 matching lines @@
     });
 
     test('getRange', () {
       var range = makeNodeList().getRange(1, 2);
       expect(range, isNodeList);
       expect(range[0], isBRElement);
       expect(range[1], isComment);
     });
   });
 }