fix(ngAnimate): allow removing classes that are added by a running animation

This allows follow-up animations to remove a class that is currently
being added.

Fixes angular#13339
Fixes angular#13380
Closes angular#13414

Author: Narretz

src/ngAnimate/animateQueue.js

@@ -5,13 +5,36 @@ var NG_ANIMATE_PIN_DATA = '$ngAnimatePin';
 var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
   var PRE_DIGEST_STATE = 1;
   var RUNNING_STATE = 2;
+  var ONE_SPACE = ' ';
 
   var rules = this.rules = {
     skip: [],
     cancel: [],
     join: []
   };
 
+  function makeTruthyCssClassMap(classString) {
+    if (!classString) {
+      return null;
+    }
+
+    var keys = classString.split(ONE_SPACE);
+    var map = Object.create(null);
+
+    forEach(keys, function(key) {
+      map[key] = true;
+    });
+    return map;
+  }
+
+  function hasMatchingClasses(classString, classMap) {
+    if (classString && classMap) {
+      return classString.split(ONE_SPACE).some(function(className) {
+        return classMap[className];
+      });
+    }
+  }
+
   function isAllowed(ruleType, element, currentAnimation, previousAnimation) {
     return rules[ruleType].some(function(fn) {
       return fn(element, currentAnimation, previousAnimation);
@@ -59,11 +82,24 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
   });
 
   rules.cancel.push(function(element, newAnimation, currentAnimation) {
-    var nO = newAnimation.options;
-    var cO = currentAnimation.options;
 
-    // if the exact same CSS class is added/removed then it's safe to cancel it
-    return (nO.addClass && nO.addClass === cO.removeClass) || (nO.removeClass && nO.removeClass === cO.addClass);
+
+    var nA = newAnimation.options.addClass;
+    var nR = newAnimation.options.removeClass;
+    var cA = currentAnimation.options.addClass;
+    var cR = currentAnimation.options.removeClass;
+
+    // early detection to save the global CPU shortage :)
+    if ((!isDefined(nA) && !isDefined(nR)) || (!isDefined(cA) && !isDefined(cR))) {
+      return false;
+    }
+
+    var cancelSomething = false;
+
+    cA = makeTruthyCssClassMap(cA);
+    cR = makeTruthyCssClassMap(cR);
+
+    return (hasMatchingClasses(nA, cR)) || (hasMatchingClasses(nR, cA));
   });
 
   this.$get = ['$$rAF', '$rootScope', '$rootElement', '$document', '$$HashMap',

test/ngAnimate/integrationSpec.js

@@ -387,6 +387,45 @@ describe('ngAnimate integration tests', function() {
 
       dealoc(element);
     }));
+
+
+    it("should remove a class when the same class is currently being added by a joined class-based animation",
+      inject(function($animate, $animateCss, $rootScope, $document, $rootElement, $$rAF) {
+
+      ss.addRule('.hide', 'opacity: 0');
+      ss.addRule('.hide-add, .hide-remove', 'transition: 1s linear all');
+
+      jqLite($document[0].body).append($rootElement);
+      element = jqLite('<div></div>');
+      $rootElement.append(element);
+
+      // These animations will be joined together
+      $animate.addClass(element, 'red');
+      $animate.addClass(element, 'hide');
+      $rootScope.$digest();
+
+      expect(element).toHaveClass('red-add');
+      expect(element).toHaveClass('hide-add');
+
+      // When a digest has passed, but no $rAF has been issued yet, .hide hasn't been added to
+      // the element yet
+      $animate.removeClass(element, 'hide');
+      $rootScope.$digest();
+      $$rAF.flush();
+
+      expect(element).not.toHaveClass('hide-add hide-add-active');
+      expect(element).toHaveClass('hide-remove hide-remove-active');
+
+      //End the animation process
+      browserTrigger(element, 'transitionend',
+        { timeStamp: Date.now() + 1000, elapsedTime: 2 });
+      $animate.flush();
+
+      expect(element).not.toHaveClass('hide-add-active red-add-active');
+      expect(element).toHaveClass('red');
+      expect(element).not.toHaveClass('hide');
+    }));
+
   });
 
   describe('JS animations', function() {