angularjs - Angular error, in npm build [$injector:nomod] Module 'testApp' is not available -

studying , practicing npm build, im trying compile script using npm run build , got error

[$injector:nomod] module 'testapp' not available! either misspelled module name or forgot load it. if registering module ensure specify dependencies second argument.

any advice.

app.js  import angular 'angular'; import 'angular-ui-router'; import './services/router.js';  angular.module('testapp', [   'ui-router' ]);  -----------------------------  roter.js  'use strict'; angular   .module('testapp')   .config([     '$urlrouterprovider',     '$stateprovider',     '$locationprovider',   function($urlrouterprovider, $stateprovider, $locationprovider) {     $locationprovider.html5mode(false).hashprefix('');     $urlrouterprovider.otherwise('/');      $stateprovider       .state('home', {         url: '/',         templateurl: 'components/views/homepage.html',         controller: 'productcontroller'       })        .state('about', {         url: '/about',         templateurl: 'components/views/about.html'       })        .state('product', {         url: '/product/:id/:name',         templateurl: 'components/views/product.html',         controller: 'productviewcontroller'       }) }]); 

change

from

angular.module('testapp', [   'ui-router' ]); 

to

angular.module('testapp', [   'ui.router' ]);