feat(ChangeDetector): change View to construct a WatchGroup hierarchy

modules/change_detection/src/watch_group.js

@@ -94,6 +94,7 @@ export class WatchGroup {
     this.prev = null;
   }
 
+  /// addRecord must be called before addChild
   addRecord(record:Record) {
     if (isPresent(this.tailRecord)) {
       this.tailRecord.next = record;
@@ -156,14 +157,12 @@ export class WatchGroup {
   addChild(child:WatchGroup) {
     if (isBlank(this.childTail)) {
       this.childHead = this.childTail = child;
-      this._attachRecordsFromWatchGroup(child);
-
     } else {
       this.childTail.next = child;
       child.prev = this.childTail;
       this.childTail = child;
-      this._attachRecordsFromWatchGroup(child);
     }
+    this._attachRecordsFromWatchGroup(child);
   }
 
   _attachRecordsFromWatchGroup(child:WatchGroup) {
@@ -199,14 +198,6 @@ export class WatchGroup {
       record.updateContext(context);
     }
   }
-
-  get _tailRecordIncludingChildren():Record {
-    var lastGroup = this;
-    while (lastGroup.childTail !== null) {
-      lastGroup = lastGroup.childTail;
-    }
-    return lastGroup.tailRecord;
-  }
 }
 
 export class WatchGroupDispatcher {

modules/change_detection/test/watch_group_spec.js

@@ -137,6 +137,22 @@ export function main() {
         expect(parent.childHead).toBe(firstChild);
         expect(parent.childTail).toBe(secondChild);
       });
+
+      // todo: vsavkin: enable after refactoring addChild
+      xit("should update head and tail of the parent when disabling the only record" +
+        "of the child", () => {
+        var parent = new WatchGroup(null, null);
+
+        var child = new WatchGroup(null, null);
+        var record = createRecord(child);
+        child.addRecord(record);
+        parent.addChild(child);
+
+        child.disableRecord(record);
+
+        expect(parent.headRecord).toBeNull();
+        expect(parent.tailRecord).toBeNull();
+      });
     });
 
     describe("enabling/disabling records", () => {

modules/core/src/compiler/view.js

@@ -65,6 +65,7 @@ export class View {
 
   addChild(childView: View) {
     ListWrapper.push(this.childViews, childView);
+    this.watchGroup.addChild(childView.watchGroup);
   }
 }
 

modules/core/test/compiler/integration_spec.js

@@ -74,10 +74,6 @@ export function main() {
 
           cd.detectChanges();
 
-          // TODO(rado): this should be removed once watchgroups addChild is implemented.
-          var childWatchGroup = view.childViews[0].watchGroup;
-          new ChangeDetector(childWatchGroup).detectChanges();
-
           expect(view.nodes[0].shadowRoot.childNodes[0].nodeValue).toEqual('hello');
           done();
         });