fix($interval): do not invoke $apply when invokeApply is false

This CL allows $q Deferred objects to avoid invoking $rootScope.$digest, by optionally adding
asynchronously invoked functions to a different queue which is processed outside of $digest.

Closes angular#7103

Author: caitp

src/ng/interval.js

@@ -138,6 +138,7 @@ function $IntervalProvider() {
           iteration = 0,
           skipApply = (isDefined(invokeApply) && !invokeApply);
 
+      deferred.$$skipApply = skipApply;
       count = isDefined(count) ? count : 0;
 
       promise.then(null, null, fn);

src/ng/q.js

@@ -171,8 +171,8 @@
 function $QProvider() {
 
   this.$get = ['$rootScope', '$exceptionHandler', function($rootScope, $exceptionHandler) {
-    return qFactory(function(callback) {
-      $rootScope.$evalAsync(callback);
+    return qFactory(function(callback, skipApply) {
+      $rootScope.$evalAsync(callback, skipApply);
     }, $exceptionHandler);
   }];
 }
@@ -208,7 +208,7 @@ function qFactory(nextTick, exceptionHandler) {
         if (pending) {
           var callbacks = pending;
           pending = undefined;
-          value = ref(val);
+          value = ref(val, deferred.$$skipApply);
 
           if (callbacks.length) {
             nextTick(function() {
@@ -217,7 +217,7 @@ function qFactory(nextTick, exceptionHandler) {
                 callback = callbacks[i];
                 value.then(callback[0], callback[1], callback[2]);
               }
-            });
+            }, deferred.$$skipApply);
           }
         }
       },
@@ -239,7 +239,7 @@ function qFactory(nextTick, exceptionHandler) {
                 callback = callbacks[i];
                 callback[2](progress);
               }
-            });
+            }, deferred.$$skipApply);
           }
         }
       },
@@ -331,14 +331,14 @@ function qFactory(nextTick, exceptionHandler) {
   };
 
 
-  var ref = function(value) {
+  var ref = function(value, skipApply) {
     if (value && isFunction(value.then)) return value;
     return {
       then: function(callback) {
         var result = defer();
         nextTick(function() {
           result.resolve(callback(value));
-        });
+        }, skipApply);
         return result.promise;
       }
     };

src/ng/rootScope.js

@@ -904,18 +904,35 @@ function $RootScopeProvider(){
        *    - `function(scope)`: execute the function with the current `scope` parameter.
        *
        */
-      $evalAsync: function(expr) {
+      $evalAsync: function(expr, skipApply) {
         // if we are outside of an $digest loop and this is the first time we are scheduling async
         // task also schedule async auto-flush
-        if (!$rootScope.$$phase && !$rootScope.$$asyncQueue.length) {
-          $browser.defer(function() {
-            if ($rootScope.$$asyncQueue.length) {
-              $rootScope.$digest();
-            }
-          });
+        if (!skipApply) {
+          if (!$rootScope.$$phase && !$rootScope.$$asyncQueue.length) {
+            $browser.defer(function() {
+              if ($rootScope.$$asyncQueue.length) {
+                $rootScope.$digest();
+              }
+            });
+          }
+          this.$$asyncQueue.push({scope: this, expression: expr});
+        } else {
+          var asyncQueue = ($rootScope.$$liteAsyncQueue || ($rootScope.$$liteAsyncQueue = []));
+          var asyncTask;
+          if (!asyncQueue.length) {
+            $browser.defer(function() {
+              while (asyncQueue.length) {
+                try {
+                  asyncTask = asyncQueue.shift();
+                  asyncTask.scope.$eval(asyncTask.expression);
+                } catch (e) {
+                  $exceptionHandler(e);
+                }
+              }
+            });
+          }
+          asyncQueue.push({scope: this, expression: expr});
         }
-
-        this.$$asyncQueue.push({scope: this, expression: expr});
       },
 
       $$postDigest : function(fn) {

test/ng/intervalSpec.js

@@ -98,6 +98,21 @@ describe('$interval', function() {
   }));
 
 
+  it('should NOT call $rootScope.$digest if invokeApply is set to false',
+      inject(function($interval, $rootScope, $window, $browser) {
+    var digestSpy = spyOn($rootScope, '$digest').andCallThrough();
+    var resolveSpy = jasmine.createSpy('resolve');
+    var notifySpy = jasmine.createSpy('notify');
+    $interval(noop, 1000, 1, false).then(resolveSpy, null, notifySpy);
+
+    $window.flush(4000);
+    $browser.defer.flush();
+    expect(digestSpy).not.toHaveBeenCalled();
+    expect(resolveSpy).toHaveBeenCalledOnce();
+    expect(notifySpy).toHaveBeenCalledOnce();
+  }));
+
+
   it('should allow you to specify the delay time', inject(function($interval, $window) {
     var counter = 0;
     $interval(function() { counter++; }, 123);