TypeError：undefined不是构造函数 [英] TypeError: undefined is not a constructor

问题描述

我是Angular的新手，我正试图将其中的大部分内容弄清楚。我正在使用我从Yeoman Generator生成的Angular 1.5.8编写一些测试。

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.

具体来说，我试图弄清楚如何操作$ httpBackend结果（我不确定这是否重要）...

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

在我的app.js文件中，我有以下代码：

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 = "";
}])

大约一半的线（我添加评论的地方）失败了。具体来说， endsWith 函数失败（toLower很好），出现此错误：

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

这是我的测试代码（从不同的例子中修改了一些垃圾 - 只是试图让它工作）：

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);

    });
});

我不怀疑我在这里做错了什么，我只是不太明白这是什么。这个错误到底意味着什么？为什么它不喜欢我对的调用endsWith ？

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?

谢谢

推荐答案

undefined不是构造函数

undefined is not a constructor

是当您尝试调用未定义的函数时PhantomJS显示的错误消息。这取决于PhantomJS支持的ECMAScript版本。正如您所说，它在Chrome中运行良好，因为此浏览器支持您在测试中使用的功能。
为了解决您的问题并且仍然可以使用PhantomJS，您可以用自己的PhantomJS功能替换未知的PhantomJS功能。

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 your own.

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