fix(location): allow empty string param: Ng1LocationServices.url('')

Closes #3563

Author: christopherthielen

src/locationServices.ts

@@ -2,7 +2,7 @@
  * @internalapi
  * @module ng1
  */ /** */
-import { LocationConfig, LocationServices, UIRouter, ParamType } from "@uirouter/core";
+import { LocationConfig, LocationServices, UIRouter, ParamType, isDefined } from "@uirouter/core";
 import { val, createProxyFunctions, removeFrom, isObject } from "@uirouter/core";
 import { ILocationService, ILocationProvider } from "angular";
 
@@ -46,7 +46,7 @@ export class Ng1LocationServices implements LocationConfig, LocationServices {
   }
 
   url(newUrl?: string, replace = false, state?) {
-    if (newUrl) this.$location.url(newUrl);
+    if (isDefined(newUrl)) this.$location.url(newUrl);
     if (replace) this.$location.replace();
     if (state) this.$location.state(state);
     return this.$location.url();

test/urlRouterSpec.ts

@@ -208,6 +208,37 @@ describe("UrlRouter", function () {
         expect(router.locationService.url).toHaveBeenCalledWith("/hello/", undefined);
       }));
 
+      it('can push an empty url', inject(function($urlRouter, $location) {
+        spyOn(router.locationService, "url");
+        $urlRouter.push($umf.compile('/{id}', { params: { id: { squash: true, value: null } } }));
+        expect(router.locationService.url).toHaveBeenCalledWith("", undefined);
+      }));
+
+      // Angular 1.2 doesn't seem to support $location.url("")
+      if (angular.version.minor >= 3) {
+        // Test for https://github.com/angular-ui/ui-router/issues/3563
+        it('updates url after an empty url is pushed', inject(function($urlRouter, $location) {
+          $lp.html5Mode(false);
+          spyOn(router.locationService, "url").and.callThrough();
+          $urlRouter.push($umf.compile('/foobar'));
+          expect(router.locationService.url).toHaveBeenCalledWith("/foobar", undefined);
+          $urlRouter.push($umf.compile('/{id}', { params: { id: { squash: true, value: null } } }));
+          expect(router.locationService.url).toHaveBeenCalledWith("", undefined);
+          expect(router.locationService.url()).toBe('/');
+        }));
+
+        // Test #2 for https://github.com/angular-ui/ui-router/issues/3563
+        it('updates html5mode url after an empty url is pushed', inject(function($urlRouter, $location) {
+          $lp.html5Mode(true);
+          spyOn(router.locationService, "url").and.callThrough();
+          $urlRouter.push($umf.compile('/foobar'));
+          expect(router.locationService.url).toHaveBeenCalledWith("/foobar", undefined);
+          $urlRouter.push($umf.compile('/{id}', { params: { id: { squash: true, value: null } } }));
+          expect(router.locationService.url).toHaveBeenCalledWith("", undefined);
+          expect(router.locationService.url()).toBe('/');
+        }));
+      }
+
       it('can push location changes that include a #fragment', inject(function($urlRouter, $location) {
         // html5mode disabled
         $lp.html5Mode(false);