fix($rootScope) ensure $watchCollection correctly handles arrayLike objects

Author: Gonzalo Ruiz de Villa

src/ng/rootScope.js

@@ -376,7 +376,7 @@ function $RootScopeProvider(){
               oldValue = newValue;
               changeDetected++;
             }
-          } else if (isArray(newValue)) {
+          } else if (isArrayLike(newValue)) {
             if (oldValue !== internalArray) {
               // we are transitioning from something which was not an array into array.
               oldValue = internalArray;

test/ng/rootScopeSpec.js

@@ -463,6 +463,23 @@ describe('Scope', function() {
           $rootScope.$digest();
           expect(log).toEqual([ '[{},[]]' ]);
         });
+
+        it('should watch array-like objects like arrays', function () {
+          var arrayLikelog = [];
+          $rootScope.$watchCollection('arrayLikeObject', function logger(obj) {
+            forEach(obj, function (element){
+              arrayLikelog.push(element.name);
+            })
+          });
+          document.body.innerHTML = "<p>" +
+                                      "<a name='x'>a</a>" +
+                                      "<a name='y'>b</a>" +
+                                    "</p>";
+
+          $rootScope.arrayLikeObject =  document.getElementsByTagName('a')
+          $rootScope.$digest();
+          expect(arrayLikelog).toEqual(['x', 'y']);
+        });
       });