fix(viewService): No error on clearHistory for empty history

Author: mlynch

js/angular/service/viewService.js

@@ -550,21 +550,23 @@ function($rootScope, $state, $location, $window, $injector, $animate, $ionicNavV
       histories = $rootScope.$viewHistory.histories,
       currentView = $rootScope.$viewHistory.currentView;
 
-      for(var historyId in histories) {
+      if(histories) {
+        for(var historyId in histories) {
 
-        if(histories[historyId].stack) {
-          histories[historyId].stack = [];
-          histories[historyId].cursor = -1;
-        }
+          if(histories[historyId].stack) {
+            histories[historyId].stack = [];
+            histories[historyId].cursor = -1;
+          }
 
-        if(currentView.historyId === historyId) {
-          currentView.backViewId = null;
-          currentView.forwardViewId = null;
-          histories[historyId].stack.push(currentView);
-        } else if(histories[historyId].destroy) {
-          histories[historyId].destroy();
-        }
+          if(currentView && currentView.historyId === historyId) {
+            currentView.backViewId = null;
+            currentView.forwardViewId = null;
+            histories[historyId].stack.push(currentView);
+          } else if(histories[historyId].destroy) {
+            histories[historyId].destroy();
+          }
 
+        }
       }
 
       for(var viewId in $rootScope.$viewHistory.views) {
@@ -573,7 +575,9 @@ function($rootScope, $state, $location, $window, $injector, $animate, $ionicNavV
         }
       }
 
-      this.setNavViews(currentView.viewId);
+      if(currentView) {
+        this.setNavViews(currentView.viewId);
+      }
     }
 
   };

test/unit/angular/service/viewService.unit.js

@@ -697,6 +697,10 @@ describe('Ionic View Service', function() {
     });
   }));
 
+  it('should not error when clearing empty history', function() {
+    expect(viewService.clearHistory.bind(null)).not.toThrow();
+  });
+
   it('should create a viewService view', inject(function($location) {
     var newView = viewService.createView();
     expect(newView).toEqual(null);