fix(uiSref): nagivate to state when url is ""

fix($state.href): generate href for state with url: ""
test(uiSref): add tests for html5Mode

Made resolve values ignore any keys that we're actively trying to resolve, when they also exist in some parent state.
Made ui-sref ignore a single preventDefault that comes from the <a> directive when there is no href (and the ui-sref is on an <a>)

Closes #1363

src/state.js

@@ -1116,7 +1116,7 @@ function $StateProvider(   $urlRouterProvider,   $urlMatcherFactory) {
 
       var nav = (state && options.lossy) ? state.navigable : state;
 
-      if (!nav || !nav.url) {
+      if (!nav || nav.url === undefined || nav.url === null) {
         return null;
       }
       return $urlRouter.href(nav.url, filterByKeys(objectKeys(state.params), params || {}), {

src/stateDirectives.js

@@ -86,6 +86,7 @@ function $StateRefDirective($state, $timeout) {
     link: function(scope, element, attrs, uiSrefActive) {
       var ref = parseStateRef(attrs.uiSref, $state.current.name);
       var params = null, url = null, base = stateContext(element) || $state.$current;
+      var newHref = null, isAnchor = element.prop("tagName") === "A";
       var isForm = element[0].nodeName === "FORM";
       var attr = isForm ? "action" : "href", nav = true;
 
@@ -102,7 +103,7 @@ function $StateRefDirective($state, $timeout) {
         if (newVal) params = newVal;
         if (!nav) return;
 
-        var newHref = $state.href(ref.state, params, options);
+        newHref = $state.href(ref.state, params, options);
 
         var activeDirective = uiSrefActive[1] || uiSrefActive[0];
         if (activeDirective) {
@@ -134,8 +135,11 @@ function $StateRefDirective($state, $timeout) {
           });
           e.preventDefault();
 
+          // if the state has no URL, ignore one preventDefault from the <a> directive.
+          var ignorePreventDefaultCount = isAnchor && !newHref ? 1: 0;
           e.preventDefault = function() {
-            $timeout.cancel(transition);
+            if (ignorePreventDefaultCount-- <= 0)
+              $timeout.cancel(transition);
           };
         }
       });

test/stateDirectivesSpec.js

@@ -1,10 +1,11 @@
 describe('uiStateRef', function() {
 
-  var el, template, scope, document;
+  var timeoutFlush, el, el2, template, scope, document, _locationProvider;
 
   beforeEach(module('ui.router'));
 
-  beforeEach(module(function($stateProvider) {
+  beforeEach(module(function($stateProvider, $locationProvider) {
+    _locationProvider = $locationProvider;
     $stateProvider.state('top', {
       url: ''
     }).state('contacts', {
@@ -74,29 +75,30 @@ describe('uiStateRef', function() {
     }));
   });
 
-  describe('links', function() {
-    var timeoutFlush, el2;
 
-    beforeEach(inject(function($rootScope, $compile, $timeout) {
-      el = angular.element('<a ui-sref="contacts.item.detail({ id: contact.id })">Details</a>');
-      el2 = angular.element('<a ui-sref="top">Top</a>');
-      scope = $rootScope;
-      scope.contact = { id: 5 };
-      scope.$apply();
+  function buildDOM($rootScope, $compile, $timeout) {
+    el = angular.element('<a ui-sref="contacts.item.detail({ id: contact.id })">Details</a>');
+    el2 = angular.element('<a ui-sref="top">Top</a>');
+    scope = $rootScope;
+    scope.contact = { id: 5 };
+    scope.$apply();
 
-      $compile(el)(scope);
-      $compile(el2)(scope);
-      scope.$digest();
+    $compile(el)(scope);
+    $compile(el2)(scope);
+    scope.$digest();
 
-      timeoutFlush = function() {
-        try {
-          $timeout.flush();
-        } catch (e) {
-          // Angular 1.0.8 throws 'No deferred tasks to be flushed' if there is nothing in queue.
-          // Behave as Angular >=1.1.5 and do nothing in such case.
-        }
+    timeoutFlush = function () {
+      try {
+        $timeout.flush();
+      } catch (e) {
+        // Angular 1.0.8 throws 'No deferred tasks to be flushed' if there is nothing in queue.
+        // Behave as Angular >=1.1.5 and do nothing in such case.
       }
-    }));
+    }
+  };
+
+  describe('links', function() {
+    beforeEach(inject(buildDOM));
 
     it('should generate the correct href', function() {
       expect(el.attr('href')).toBe('#/contacts/5');
@@ -217,7 +219,7 @@ describe('uiStateRef', function() {
       expect($state.current.name).toEqual('top');
       expect($stateParams).toEqualData({});
     }));
-    
+
     it('should allow passing params to current state', inject(function($compile, $rootScope, $state) {
       $state.current.name = 'contacts.item.detail';
 
@@ -243,6 +245,38 @@ describe('uiStateRef', function() {
     }));
   });
 
+  describe('links in html5 mode', function() {
+    beforeEach(function() {
+      _locationProvider.html5Mode(true);
+    });
+
+    beforeEach(inject(buildDOM));
+
+    it('should generate the correct href', function() {
+      expect(el.attr('href')).toBe('/contacts/5');
+      expect(el2.attr('href')).toBe('');
+    });
+
+    it('should update the href when parameters change', function() {
+      expect(el.attr('href')).toBe('/contacts/5');
+      scope.contact.id = 6;
+      scope.$apply();
+      expect(el.attr('href')).toBe('/contacts/6');
+    });
+
+    it('should transition states when the url is empty', inject(function($state, $stateParams, $q) {
+      // Odd, in html5Mode, the initial state isn't matching on empty url, but does match if top.url is "/".
+//      expect($state.$current.name).toEqual('top');
+
+      triggerClick(el2);
+      timeoutFlush();
+      $q.flush();
+
+      expect($state.current.name).toEqual('top');
+      expect($stateParams).toEqualData({});
+    }));
+  });
+
   describe('forms', function() {
     var el, scope;