added tween.destroy() method + unit tests

src/Tween.js

@@ -78,7 +78,9 @@
         this.reset();
     };
 
+    // start/diff object = attrs.nodeId.tweenId.attr
     Kinetic.Tween.attrs = {};
+    // tweenId = tweens.nodeId.attr
     Kinetic.Tween.tweens = {};
 
     Kinetic.Tween.prototype = {
@@ -238,7 +240,18 @@
          * @memberof Kinetic.Tween.prototype
          */
         destroy: function() {
+            var nodeId = this.node._id,
+                thisId = this._id,
+                attrs = Kinetic.Tween.tweens[nodeId],
+                key;
 
+            this.pause();
+
+            for (key in attrs) {
+                delete Kinetic.Tween.tweens[nodeId][key];
+            }
+
+            delete Kinetic.Tween.attrs[nodeId][thisId];
         }
     };
 

tests/js/unit/tweenTests.js

@@ -61,5 +61,48 @@ Test.Modules.TWEEN = {
         test(Kinetic.Tween.attrs[circle._id][tween._id].x !== undefined, 'x should not be undefined');
         test(Kinetic.Tween.attrs[circle._id][tween._id].y !== undefined, 'y should not be undefined');
 
+    },
+    'tween node': function(containerId) {
+        var stage = new Kinetic.Stage({
+            container: containerId,
+            width: 578,
+            height: 200
+        });
+
+        var layer = new Kinetic.Layer();
+
+        var circle = new Kinetic.Circle({
+            x: 100,
+            y: stage.getHeight() / 2,
+            radius: 70,
+            fill: 'green',
+            stroke: 'blue',
+            strokeWidth: 4
+        });
+
+        layer.add(circle);
+        stage.add(layer);
+
+
+        var tween = new Kinetic.Tween({
+            node: circle,
+            duration: 0.2,
+            x: 200,
+            y: 100
+        }).play();
+
+        // start/diff object = attrs.nodeId.tweenId.attr
+        // tweenId = tweens.nodeId.attr
+
+        test(tween._id !== undefined, 'tween.play should return an instance of the tween');
+        test(Kinetic.Tween.tweens[circle._id].x === tween._id, 'circle should be in the tweens hash');
+        test(Kinetic.Tween.attrs[circle._id][tween._id] !== undefined, 'tween should be in the attrs hash');
+
+        tween.destroy();
+
+        test(Kinetic.Tween.tweens[circle._id].x === undefined, 'circle should not be in the tweens hash');
+        test(Kinetic.Tween.attrs[circle._id][tween._id] === undefined, 'tween should not be in the attrs hash');
+
+
     }
 };