Merge pull request #159 from staltz/master

Fix patch() so that the root is patched instead of recreated

snabbdom.js

@@ -39,7 +39,9 @@ function init(modules, api) {
   }
 
   function emptyNodeAt(elm) {
-    return VNode(api.tagName(elm).toLowerCase(), {}, [], undefined, elm);
+    var id = elm.id ? '#' + elm.id : '';
+    var c = elm.className ? '.' + elm.className.split(' ').join('.') : '';
+    return VNode(api.tagName(elm).toLowerCase() + id + c, {}, [], undefined, elm);
   }
 
   function createRmCb(childElm, listeners) {

test/core.js

@@ -136,6 +136,17 @@ describe('snabbdom', function() {
         done();
       }
     });
+    it('is a patch of the root element', function () {
+      var elmWithIdAndClass = document.createElement('div');
+      elmWithIdAndClass.id = 'id';
+      elmWithIdAndClass.className = 'class';
+      var vnode1 = h('div#id.class', [h('span', 'Hi')]);
+      elm = patch(elmWithIdAndClass, vnode1).elm;
+      assert.strictEqual(elm, elmWithIdAndClass);
+      assert.equal(elm.tagName, 'DIV');
+      assert.equal(elm.id, 'id');
+      assert.equal(elm.className, 'class');
+    });
   });
   describe('pathing an element', function() {
     it('changes the elements classes', function() {