fix(viewService): Allow root ui-view to be wrapped in ng-if

Fixed an off-by-one error in viewService which caused the root ui-view to not be deregistered properly.
Closes #3004

Author: christopherthielen

src/view/view.ts

@@ -185,7 +185,7 @@ export class ViewService {
 
     return () => {
       let idx = uiViews.indexOf(uiView);
-      if (idx <= 0) {
+      if (idx === -1) {
         trace.traceViewServiceUIViewEvent("Tried removing non-registered uiView", uiView);
         return;
       }

test/core/viewServiceSpec.ts

@@ -0,0 +1,60 @@
+/// <reference path='../../node_modules/@types/jasmine/index.d.ts' />
+
+import {UIRouter} from "../../src/router";
+import {tree2Array} from "../testUtils.ts";
+import {StateRegistry} from "../../src/state/stateRegistry";
+import {ViewService} from "../../src/view/view";
+import {ActiveUIView} from "../../src/view/interface";
+
+let router: UIRouter = null;
+let registry: StateRegistry = null;
+let $view: ViewService = null;
+let statetree = {
+  A: {
+    B: {
+      C: {
+        D: {
+
+        }
+      }
+    }
+  }
+};
+
+let count = 0;
+const makeUIView = (): ActiveUIView => ({
+  $type: 'test',
+  id: count++,
+  name: '$default',
+  fqn: '$default',
+  config: null,
+  creationContext: null,
+  configUpdated: function() {}
+});
+
+describe("View Service", () => {
+  beforeEach(() => {
+    router = new UIRouter();
+    registry = router.stateRegistry;
+    $view = router.viewService;
+    tree2Array(statetree, true).forEach(state => registry.register(state));
+    registry.stateQueue.autoFlush(router.stateService);
+  });
+
+  describe('registerUIView', () => {
+    it("should track a ui-view", () => {
+      expect($view.available().length).toBe(0);
+      $view.registerUIView(makeUIView());
+      expect($view.available().length).toBe(1);
+    });
+
+    it("should return a deregistration function", () => {
+      expect($view.available().length).toBe(0);
+      let deregistrationFn = $view.registerUIView(makeUIView());
+      expect(typeof deregistrationFn).toBe('function');
+      expect($view.available().length).toBe(1);
+      deregistrationFn();
+      expect($view.available().length).toBe(0);
+    });
+  });
+});

test/ng1/viewSpec.ts

@@ -1,7 +1,7 @@
-/// <reference path='../../typings/angularjs/angular.d.ts' />
-/// <reference path='../../typings/angularjs/angular-mocks.d.ts' />
-/// <reference path='../../typings/jasmine/jasmine.d.ts' />
-
+/// <reference path='../../node_modules/@types/angular/index.d.ts' />
+/// <reference path='../../node_modules/@types/angular-mocks/index.d.ts' />
+/// <reference path='../../node_modules/@types/jasmine/index.d.ts' />
+import * as angular from "angular";
 var module = angular.mock.module;
 
 import {inherit, extend, tail} from "../../src/common/common";
@@ -52,7 +52,7 @@ describe('view', function() {
   }));
 
   describe('controller handling', function() {
-    let state, path, ctrlExpression;
+    let state, path: PathNode[], ctrlExpression;
     beforeEach(() => {
       ctrlExpression = null;
       state = register({