TypeError: undefined is not a constructor

Question

I'm very new to Angular and I'm trying to figure much of this out still. I'm writing some tests using Angular 1.5.8 which I generated from the Yeoman Generator.

Specifically, I'm trying to figure out how to manipulate $httpBackend results (I'm not sure if that's important or not)...

In my app.js file I have the following code:

.run(['$rootScope', '$location', 'breadcrumbService', function ($rootScope, $location, breadcrumbService) {     $rootScope.$on('$viewContentLoaded', function () {         jQuery('html, body').animate({scrollTop: 0}, 200);     });      $rootScope.isEditMode = false;     $rootScope.$on('$stateChangeSuccess', function () {         // ------------ this next line is failing -----------         $rootScope.isEditMode = $location.path().toLowerCase().endsWith('/edit') || $location.path().toLowerCase().endsWith('/new');     });      $rootScope.parseJson = function (value) {         return angular.fromJson(value);     };      $rootScope.bc = breadcrumbService;      $rootScope.title = ""; }]) 

The line about halfway down (where I added the comment) is failing. Specifically, the endsWith function is failing (toLower is fine), with this error:

PhantomJS 2.1.1 (Windows 8 0.0.0) Service: breadcrumbService should return breadcrumb label in json format FAILED         TypeError: undefined is not a constructor (evaluating '$location.path().toLowerCase().endsWith('/edit')') in app/scripts/app.js (line 44)         app/scripts/app.js:44:72         $broadcast@bower_components/angular/angular.js:18005:33         bower_components/angular-ui-router/release/angular-ui-router.js:3353:32         processQueue@bower_components/angular/angular.js:16383:30         bower_components/angular/angular.js:16399:39         $eval@bower_components/angular/angular.js:17682:28         $digest@bower_components/angular/angular.js:17495:36         $apply@bower_components/angular/angular.js:17790:31         done@bower_components/angular/angular.js:11831:53         handleResponse@bower_components/angular-mocks/angular-mocks.js:1368:17         flush@bower_components/angular-mocks/angular-mocks.js:1808:26         test/spec/services/breadcrumbservice.js:33:27         invoke@bower_components/angular/angular.js:4718:24         workFn@bower_components/angular-mocks/angular-mocks.js:3085:26 

Here is my test code (some junk modified from different examples - just trying to get it to work):

'use strict';  describe('Service: breadcrumbService', function () {      // load the service's module     beforeEach(module('myModule'));      var $httpBackend, $rootScope, createController, authRequestHandler;     beforeEach(inject(function($injector) {          $httpBackend = $injector.get('$httpBackend');         console.log('Is null? '+ ($httpBackend == null));         $httpBackend.whenGET(/views\/.*/).respond(200, [{}, {}, {}]);          authRequestHandler = $httpBackend.when('GET', '/api/v1/SiteStagings')             .respond({userId: 'userX'}, {'A-Token': 'xxx'});          // Get hold of a scope (i.e. the root scope)         $rootScope = $injector.get('$rootScope');         $httpBackend.flush();     }));      // instantiate service     var breadcrumbService;     beforeEach(inject(function (_breadcrumbService_) {         breadcrumbService = _breadcrumbService_;     }));      it('svc should exist', function () {         expect(!!breadcrumbService).toBe(true);     });      it('should return breadcrumb label in json format', function () {         var result = breadcrumbService.getFromCache('site', 'SiteGroupStagings', 46, 'SiteGroupDesc');         console.log(result);         expect(!!result).toBe(true);      }); }); 

I don't doubt that I'm doing something wrong here, I just can't quite understand what it is. What does this error really mean and why does it not like my call to endsWith?

Thanks

Answer 1

undefined is not a constructor

is an error message PhantomJS displays when you tried to call a function that is not defined. It depends on the version of ECMAScript which your PhantomJS supports. So as you said it works fine in Chrome, because this browser supports the function you are using in test. In order to fix your problem and still be able to use PhantomJS you can replace the "unknown to PhantomJS" function with some alternative function.

Answer 2

I was getting TypeError: undefined is not a constructor error using the includes() method. The includes() and endsWith() methods are new in ECMAScript 2015, and are not supported in Internet Explorer, and evidently not by PhantomJS.

There is a chance your end user may be using Internet Explorer. In which case, you may want to use the fully supported indexOf() method instead of includes() or endsWith()

For example, in my case, everything worked great in chrome, but my tests were failing on the line:

if (item.name.includes('contents')) 

I changed to using the indexOf() method instead:

if (item.name.indexOf('contents') !== -1) 

And then I was no longer getting the error

TypeError: undefined is not a constructor