javascript - 如何使用 Jasmine 对链式方法进行单元测试

Question

我在对以下方法进行单元测试时遇到问题:

 $scope.changeLocation = function (url) {
        $location.path(url).search({ ref: "outline" });
    };

我编写了以下单元测试，但目前因出现此错误而失败(类型错误:无法读取未定义的属性“搜索”):

var $locationMock = { path: function () { }, search: function () { } };

it('changeLocation should update location correctly', function () {
        $controllerConstructor('CourseOutlineCtrl', { $scope: $scope, $location: $locationMock });

        var url = "/url/";
        spyOn($locationMock, "path");
        spyOn($locationMock, "search");

        $scope.changeLocation(url);

        expect($locationMock.search).toHaveBeenCalledWith({ ref: "outline" });
        expect($locationMock.path).toHaveBeenCalledWith(url);
    });

如果我将函数更改为以下内容，则测试通过:

$scope.changeLocation = function (url) {
        $location.path(url);
        $location.search({ ref: "outline" });
    };

当我使用方法链时，如何对这个方法进行单元测试？我需要以不同的方式设置我的 $locationMock 吗？对于我的生活，我无法弄清楚这一点。

Answer 1

那是因为您的 mock 不返回能够链接的位置对象。使用 Jasmine 2.0，您可以将 mock 更改为:

var $locationMock = { path: function () { return $locationMock; }, 
                      search: function () { return $locationMock; } };

和

spyOn($locationMock, "path").and.callThrough();
spyOn($locationMock, "search").and.callThrough(); //if you are chaining from search

或添加:

spyOn($locationMock, "path").and.returnValue($locationMock);
spyOn($locationMock, "search").and.returnValue($locationMock); //if you are chaining from search

或者只是创建一个 spy 对象(更少的代码):

var $locationMock = jasmine.createSpyObj('locationMock', ['path', 'search']);

和

$locationMock.path.and.returnValue($locationMock);
$locationMock.search.and.returnValue($locationMock); //if you are chaining from search