fix(karma): adding checks to prevent null pointers in clean-up phase

Author: Dan Bucholtz

Diff for: js/angular/controller/refresherController.js

@@ -306,13 +306,17 @@ IonicModule
     };
 
     function destroy() {
-      ionic.off(touchStartEvent, handleTouchstart, scrollChild);
-      ionic.off(touchMoveEvent, handleTouchmove, scrollChild);
-      ionic.off(touchEndEvent, handleTouchend, scrollChild);
-      ionic.off('mousedown', handleMousedown, scrollChild);
-      ionic.off('mousemove', handleTouchmove, scrollChild);
-      ionic.off('mouseup', handleTouchend, scrollChild);
-      ionic.off('scroll', handleScroll, scrollParent);
+      if ( scrollChild ){
+        ionic.off(touchStartEvent, handleTouchstart, scrollChild);
+        ionic.off(touchMoveEvent, handleTouchmove, scrollChild);
+        ionic.off(touchEndEvent, handleTouchend, scrollChild);
+        ionic.off('mousedown', handleMousedown, scrollChild);
+        ionic.off('mousemove', handleTouchmove, scrollChild);
+        ionic.off('mouseup', handleTouchend, scrollChild);
+      }
+      if ( scrollParent ){
+        ionic.off('scroll', handleScroll, scrollParent);
+      }
       scrollParent = null;
       scrollChild = null;
     }

Diff for: js/angular/controller/scrollController.js

@@ -84,8 +84,10 @@ function($scope,
     deregisterInstance();
     scrollView && scrollView.__cleanup && scrollView.__cleanup();
     angular.element($window).off('resize', resize);
-    $element.off('scroll', scrollFunc);
-    scrollView = self.scrollView = scrollViewOptions = self._scrollViewOptions = scrollViewOptions.el = self._scrollViewOptions.el = $element = self.$element = element = null;
+    if ( $element ){
+      $element.off('scroll', scrollFunc);
+      scrollView = self.scrollView = scrollViewOptions = self._scrollViewOptions = scrollViewOptions.el = self._scrollViewOptions.el = $element = self.$element = element = null;
+    }
   });
 
   $timeout(function() {