WIP: add explicit check for outside changes to location inside $browser.url() getter

Related to angular#6976

Author: jeffbcross

src/ng/browser.js

@@ -29,7 +29,8 @@ function Browser(window, document, $log, $sniffer) {
       history = window.history,
       setTimeout = window.setTimeout,
       clearTimeout = window.clearTimeout,
-      pendingDeferIds = {};
+      pendingDeferIds = {},
+      urlChangedOutsideAngular = false;
 
   self.isMock = false;
 
@@ -146,6 +147,7 @@ function Browser(window, document, $log, $sniffer) {
    * @param {boolean=} replace Should new url replace current history record ?
    */
   self.url = function(url, replace) {
+    var currentHref;
     // Android Browser BFCache causes location, history reference to become stale.
     if (location !== window.location) location = window.location;
     if (history !== window.history) history = window.history;
@@ -175,10 +177,41 @@ function Browser(window, document, $log, $sniffer) {
       // - newLocation is a workaround for an IE7-9 issue with location.replace and location.href
       //   methods not updating location.href synchronously.
       // - the replacement is a workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=407172
-      return newLocation || location.href.replace(/%27/g,"'");
+      if (newLocation) {
+        return newLocation;
+      }
+      if (lastBrowserUrl !== (currentHref = location.href.replace(/%27/g,"'"))) {
+        urlChangedOutsideAngular = true;
+      }
+      return currentHref;
     }
   };
 
+  /**
+   * @name $browser#urlChangedOutsideAngular
+   *
+   * @description
+   * GETTER:
+   * Without any argument, this method just returns current value of urlChangedOutsideAngular.
+   *
+   * SETTER:
+   * With at least one argument, this method sets urlChangedOutsideAngular to new value.
+   *
+   * NOTE: this api is intended for use only by the $location service inside of $locationWatch.
+   *
+   * @param {boolean} val New value to set as urlChangedOutsideAngular,
+   *                  typically used to reset value to false.
+   */
+  self.urlChangedOutsideAngular = function(val) {
+    if (isDefined(val)) {
+      urlChangedOutsideAngular = val;
+      return self;
+    }
+    else {
+      return urlChangedOutsideAngular;
+    }
+  }
+
   var urlChangeListeners = [],
       urlChangeInit = false;
 

src/ng/location.js

@@ -738,7 +738,21 @@ function $LocationProvider(){
       if (!changeCounter || oldUrl != $location.absUrl()) {
         changeCounter++;
         $rootScope.$evalAsync(function() {
-          if ($rootScope.$broadcast('$locationChangeStart', $location.absUrl(), oldUrl).
+          /**
+           * $browser should detect if url was changed outside of Angular, in which
+           * case $location should automatically update to the new url.
+           *
+           * NOTE: Detecting outside changes to location happens automatically in $browser via
+           *       window events (or polling if events aren't supported), but those methods are
+           *       async. For this reason, $browser.url() will perform a comparison with each call
+           *       to the method as a getter.
+           * NOTE: Method does not exist on mock $browser
+           */
+          if ($browser.urlChangedOutsideAngular && $browser.urlChangedOutsideAngular()) {
+            $location.$$parse(oldUrl);
+            $browser.urlChangedOutsideAngular(false);
+          }
+          else if ($rootScope.$broadcast('$locationChangeStart', $location.absUrl(), oldUrl).
               defaultPrevented) {
             $location.$$parse(oldUrl);
           } else {

test/ng/locationSpec.js

@@ -769,30 +769,25 @@ describe('$location', function() {
     });
 
 
-    iit('should not cause infinite digest when replacing outside of Angular', function() {
+    it('should update location when location changed outside of Angular', function() {
       module(function($windowProvider, $locationProvider, $browserProvider) {
-        // $locationProvider.html5Mode(true);
-
-        $browserProvider.$get = function($document, $window) {
-          var sniffer = {history: true, hashchange: true}
-          var logs = {log:[], warn:[], info:[], error:[]};
-          var fakeLog = {log: function() { logs.log.push(slice.call(arguments)); },
-                     warn: function() { logs.warn.push(slice.call(arguments)); },
-                     info: function() { logs.info.push(slice.call(arguments)); },
-                     error: function() { logs.error.push(slice.call(arguments)); }};
-
-
-          var b = new Browser($window, $document, fakeLog, sniffer);
+        $locationProvider.html5Mode(true);
+        $browserProvider.$get = function($document, $window, $log, $sniffer) {
+          var b = new Browser($window, $document, $log, $sniffer);
           b.pollFns = [];
           return b;
         }
       });
 
-      inject(function($rootScope, $location){
-        window.history.replaceState(null, '', '/hello');
-        expect(function() {
-          $rootScope.$digest();
-        }).not.toThrow();
+      inject(function($rootScope, $browser, $location, $sniffer){
+        if ($sniffer.history) {
+          window.history.replaceState(null, '', '/hello');
+          // Verify that infinite digest reported in #6976 no longer occurs
+          expect(function() {
+            $rootScope.$digest();
+          }).not.toThrow();
+          expect($location.path()).toBe('/hello');
+        }
       });
     });