fix(previous): Previous state now tracked using $transition$ promise

 - This allows previous state to properly manage transition cancelled and redirected

 Closes #120

files.js

@@ -22,6 +22,7 @@ modules.sticky.src = ['src/stickyProvider.js'].concat(modules.sticky.src);
 modules.core.src.push('src/util.js');
 modules.future.test.push('src/fsfactories/ngload.js');
 modules.future.test.push('src/fsfactories/iframe.js');
+modules.previous.test.push('build/modular/ct-ui-router-extras.transition.js');
 
 // Build the monolithic module 'all' which sucks in all the others
 modules.all = {

src/previous.js

@@ -1,25 +1,15 @@
-angular.module('ct.ui.router.extras.previous', [ 'ct.ui.router.extras.core' ]).service("$previousState",
+angular.module('ct.ui.router.extras.previous', [ 'ct.ui.router.extras.core', 'ct.ui.router.extras.transition' ]).service("$previousState",
   [ '$rootScope', '$state',
     function ($rootScope, $state) {
-      var previous = null;
-      var memos = {};
+      var previous = null, lastPrevious = null, memos = {};
 
-      var lastPrevious = null;
-
-      $rootScope.$on("$stateChangeStart", function (evt, toState, toStateParams, fromState, fromStateParams) {
-        // State change is starting.  Keep track of the CURRENT previous state in case we have to restore it
+      $rootScope.$on("$transitionStart", function(evt, $transition$) {
         lastPrevious = previous;
-        previous = { state: fromState, params: fromStateParams };
-      });
-
-      $rootScope.$on("$stateChangeError", function () {
-        // State change did not occur due to an error.  Restore the previous previous state.
-        previous = lastPrevious;
-        lastPrevious = null;
-      });
+        previous = $transition$.from;
 
-      $rootScope.$on("$stateChangeSuccess", function () {
-        lastPrevious = null;
+        $transition$.promise.then(commit).catch(revert);
+        function commit() { lastPrevious = null; }
+        function revert() { previous = lastPrevious; }
       });
 
       var $previousState = {

test/previousSpec.js

@@ -61,6 +61,18 @@ describe("$previousState", function () {
       $q.flush();
       expect($state.current.name === "tabs.tabs2");
     });
+
+    // Test for #120
+    it("should go to previous state after another transition is cancelled", inject(function($rootScope) {
+      testGo("top", { entered: 'top' });
+      testGo("top.people.managerlist", { entered: ['top.people', 'top.people.managerlist'] });
+
+      var transitionNum = 0;
+      $rootScope.$on("$stateChangeStart", function(evt) { if (transitionNum++ === 0) { evt.preventDefault(); } });
+
+      testGo("top.inv.storelist", undefined, { redirect: 'top.people.managerlist'}); // Cancelled, so we're still at original state
+      expect($previousState.get().state.name).toBe("top");
+    }));
   });
 
   describe('.memo()', function () {