fix(ng_repeat): fix ng_repeat not moving views for elements that have not moved

Closes dart-archive#1154

Author: vicb

lib/directive/ng_repeat.dart

@@ -87,8 +87,7 @@ class NgRepeat {
   Function _generateId = (key, value, index) => value;
   Watch _watch;
 
-  NgRepeat(this._viewPort, this._boundViewFactory, this._scope,
-           this._parser, this.formatters);
+  NgRepeat(this._viewPort, this._boundViewFactory, this._scope, this._parser, this.formatters);
 
   set expression(value) {
     assert(value != null);
@@ -154,6 +153,9 @@ class NgRepeat {
     final changeFunctions = new List<Function>(length);
     final removedIndexes = <int>[];
     final int domLength = _rows == null ? 0 : _rows.length;
+    // DOM indexes of the former rows not yet handled in the
+    // They are stored in reverse order to simplify the code in removeFn which is called with
+    // indexes in ascending order
     final leftInDom = new List.generate(domLength, (i) => domLength - 1 - i);
     var domIndex;
 
@@ -220,9 +222,14 @@ class NgRepeat {
       var changeFn = changeFunctions[targetIndex];
       if (changeFn == null) {
         rows[targetIndex] = _rows[targetIndex];
-        domIndex--;
         // The element has not moved but `$last` and `$middle` might still need
         // to be updated
+        var childContext =  _updateContext(rows[targetIndex].scope.context, targetIndex, length);
+        if (domIndex < 0 || leftInDom[domIndex] != targetIndex) {
+          _viewPort.move(rows[targetIndex].view, moveAfter: previousView);
+          leftInDom.remove(targetIndex);
+        }
+        domIndex--;
         _updateContext(rows[targetIndex].scope.context, targetIndex, length);
       } else {
         changeFn(targetIndex, previousView);

test/directive/ng_repeat_spec.dart

@@ -420,6 +420,14 @@ main() {
         lis = element.querySelectorAll('li');
       });
 
+      it(r'should correctly update rows orders - gh1154', () {
+        scope.context['items'] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+        scope.apply();
+        expect(element).toHaveText('0123456789');
+        scope.context['items'] = [1, 2, 6, 7, 4, 3, 5, 8, 9, 0];
+        scope.apply();
+        expect(element).toHaveText('0123456789');
+      });
 
       it(r'should preserve the order of elements', () {
         scope.context['items'] = [a, c, d];