在测试我的 AngularJS 控制器时，如何在 $http.get 承诺中模拟结果? [英] How do I mock the result in a $http.get promise when testing my AngularJS controller?

问题描述

经过大量阅读，从 AngularJS 控制器调用 Web 服务的推荐方法似乎是使用工厂并从中返回一个承诺.

After much reading, it seems that the recommended way to call a web service from an AngularJS controller is to use a factory and return a promise from that.

这里我有一个调用示例 API 的简单工厂.

Here I have a simple factory which calls a sample API.

myApp.factory('MyFactory', ['$http',function($http) {
var people = {
        requestPeople: function(x) {
            var url = 'js/test.json';
            return $http.get(url);
        }
    };
return people;
}]);

这就是我在控制器中的调用方式

And this is how I call it in the controller

myApp.controller('MyCtrl1', ['$scope', 'MyFactory', function ($scope, MyFactory) {
        MyFactory.requestPeople(22).then(function(result) {
             $scope.peopleList = result;
        });
}]);

虽然它工作正常，但我希望能够模拟调用 then 时传入的 result.这可能吗?

While it works fine, I would like to be able to mock the result that is passed in when then is called. Is this possible?

到目前为止，我的尝试没有产生任何结果.这是我的尝试:

My attempt so far has produced nothing. This is my attempt:

//Fake service
var mockService = {
    requestPeople: function () {
        return {
            then: function () {
                return {"one":"three"};
            }
        }

    }
};


//Some setup
beforeEach(module('myApp.controllers'));
var ctrl, scope;

beforeEach(inject(function ($rootScope, $controller) {
    scope = $rootScope.$new();

    ctrl = $controller('MyCtrl1', { $scope: scope, MyFactory: mockService });
}));

//Test
it('Event Types Empty should default to false', inject(function () {
    expect(scope.peopleList.one).toBe('three');
}));

我在 karma runner 中运行时遇到的错误是

The error that I get when running this in karma runner, is

TypeError: 'undefined' 不是一个对象(评估 'scope.peopleList.one')

TypeError: 'undefined' is not an object (evaluating 'scope.peopleList.one')

如何让这个测试与我的模拟数据一起工作?

How can I get this test working with my mocked data?

推荐答案

我不认为 $httpBackend 是你在这里所追求的，你希望整个工厂都被嘲笑而不依赖于 $http?

I don't think $httpBackend is what you're after here, you want the whole factory to be mocked without it having a dependency on $http?

看看$q，特别是Testing下的代码示例标题.您的问题可能会通过如下所示的代码得到解决:

Take a look at $q, in particular the code sample under the Testing header. Your issue might be resolved with code that looks like this:

'use strict';

describe('mocking the factory response', function () {

    beforeEach(module('myApp.controllers'));

    var scope, fakeFactory, controller, q, deferred;

    //Prepare the fake factory
    beforeEach(function () {
        fakeFactory = {
            requestPeople: function () {
                deferred = q.defer();
                // Place the fake return object here
                deferred.resolve({ "one": "three" });
                return deferred.promise;
            }
        };
        spyOn(fakeFactory, 'requestPeople').andCallThrough();
    });

    //Inject fake factory into controller
    beforeEach(inject(function ($rootScope, $controller, $q) {
        scope = $rootScope.$new();
        q = $q;
        controller = $controller('MyCtrl1', { $scope: scope, MyFactory: fakeFactory });
    }));

    it('The peopleList object is not defined yet', function () {
        // Before $apply is called the promise hasn't resolved
        expect(scope.peopleList).not.toBeDefined();
    });

    it('Applying the scope causes it to be defined', function () {
        // This propagates the changes to the models
        // This happens itself when you're on a web page, but not in a unit test framework
        scope.$apply();
        expect(scope.peopleList).toBeDefined();
    });

    it('Ensure that the method was invoked', function () {
        scope.$apply();
        expect(fakeFactory.requestPeople).toHaveBeenCalled();
    });

    it('Check the value returned', function () {
        scope.$apply();
        expect(scope.peopleList).toBe({ "one": "three" });
    });
});

我已经围绕 $apply 的功能添加了一些测试，直到我开始玩这个我才知道！

I've added some tests around what $apply does, I didn't know that until I started playing with this!

哥们

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