fix(ngAnimate): ensure that animate promises resolve when the document is hidden

Prior to this fix any promise/callback chained on a call to the $animate
methods would only flush if and when the browser page is visible. This
fix ensures that a timeout will be used instead when the document
is hidden.

Author: matsko

src/ng/animateRunner.js

@@ -28,8 +28,8 @@ var $$AnimateAsyncRunFactoryProvider = function() {
 };
 
 var $$AnimateRunnerFactoryProvider = function() {
-  this.$get = ['$q', '$sniffer', '$$animateAsyncRun',
-       function($q,   $sniffer,   $$animateAsyncRun) {
+  this.$get = ['$q', '$sniffer', '$$animateAsyncRun', '$document', '$timeout',
+       function($q,   $sniffer,   $$animateAsyncRun,   $document,   $timeout) {
 
     var INITIAL_STATE = 0;
     var DONE_PENDING_STATE = 1;
@@ -74,8 +74,19 @@ var $$AnimateRunnerFactoryProvider = function() {
     function AnimateRunner(host) {
       this.setHost(host);
 
+      var rafTick = $$animateAsyncRun();
+      var timeoutTick = function(fn) {
+        $timeout(fn, 0, false);
+      };
+
       this._doneCallbacks = [];
-      this._runInAnimationFrame = $$animateAsyncRun();
+      this._tick = function(fn) {
+        if ($document[0].hidden) {
+          timeoutTick(fn);
+        } else {
+          rafTick(fn);
+        }
+      };
       this._state = 0;
     }
 
@@ -148,7 +159,7 @@ var $$AnimateRunnerFactoryProvider = function() {
         var self = this;
         if (self._state === INITIAL_STATE) {
           self._state = DONE_PENDING_STATE;
-          self._runInAnimationFrame(function() {
+          self._tick(function() {
             self._resolve(response);
           });
         }

test/ng/animateRunnerSpec.js

@@ -162,6 +162,43 @@ describe("$$AnimateRunner", function() {
     expect(animationFailed).toBe(true);
   }));
 
+  it("should use timeouts to trigger async operations when the document is hidden", function() {
+    var doc;
+
+    module(function($provide) {
+      doc = jqLite({
+        body: document.body,
+        hidden: true
+      });
+      $provide.value('$document', doc);
+    });
+
+    inject(function($$AnimateRunner, $rootScope, $$rAF, $timeout) {
+      var spy = jasmine.createSpy();
+      var runner = new $$AnimateRunner();
+      runner.done(spy);
+      runner.complete(true);
+      expect(spy).not.toHaveBeenCalled();
+      $$rAF.flush();
+      expect(spy).not.toHaveBeenCalled();
+      $timeout.flush();
+      expect(spy).toHaveBeenCalled();
+
+      doc[0].hidden = false;
+
+      spy = jasmine.createSpy();
+      runner = new $$AnimateRunner();
+      runner.done(spy);
+      runner.complete(true);
+      expect(spy).not.toHaveBeenCalled();
+      $$rAF.flush();
+      expect(spy).toHaveBeenCalled();
+      expect(function() {
+        $timeout.flush();
+      }).toThrow();
+    });
+  });
+
   they("should expose the `finally` promise function to handle the final state when $prop",
     { 'rejected': 'cancel', 'resolved': 'end' }, function(method) {
     inject(function($$AnimateRunner, $rootScope) {