Javascript AngularJS Mocking$http返回错误

我在用Jasmine测试AngularJs中的HTTP帖子时遇到了一些问题

我有一个控制器，看起来是这样的：-

appControllers.controller("TaskAddController", function ($scope, $http) {
    $scope.task = {};
    $scope.messages = {};

    $scope.actions = {
        save : function() {
            $http.post("/ajax/tasks/save", $scope.task)
            .then(function() {
                $scope.messages.success = true;
                $scope.task = {};
            });
        }
    };
});

describe("TaskAddController", function() {
    var createController, scope, $httpBackend;

    beforeEach(function () {
        module('appControllers');

        scope = {};

        inject(function ($injector) {
            $httpBackend = $injector.get("$httpBackend");
        });

        inject(function ($controller) {
            createController = function () {
                return $controller("TaskAddController", { $scope: scope });
            };
        });
    });

    afterEach(function () {
        $httpBackend.verifyNoOutstandingExpectation();
        $httpBackend.verifyNoOutstandingRequest();
    });

    it("when actions.save is called then should call service", function () {
        var task = {
            title: "Title",
            description: "Description"
        };

        $httpBackend.expectPOST("/ajax/tasks/save", task);
        createController();
        scope.task = task;
        scope.actions.save();
        $httpBackend.flush();
    });
});

我正在这样测试它：-

appControllers.controller("TaskAddController", function ($scope, $http) {
    $scope.task = {};
    $scope.messages = {};

    $scope.actions = {
        save : function() {
            $http.post("/ajax/tasks/save", $scope.task)
            .then(function() {
                $scope.messages.success = true;
                $scope.task = {};
            });
        }
    };
});

describe("TaskAddController", function() {
    var createController, scope, $httpBackend;

    beforeEach(function () {
        module('appControllers');

        scope = {};

        inject(function ($injector) {
            $httpBackend = $injector.get("$httpBackend");
        });

        inject(function ($controller) {
            createController = function () {
                return $controller("TaskAddController", { $scope: scope });
            };
        });
    });

    afterEach(function () {
        $httpBackend.verifyNoOutstandingExpectation();
        $httpBackend.verifyNoOutstandingRequest();
    });

    it("when actions.save is called then should call service", function () {
        var task = {
            title: "Title",
            description: "Description"
        };

        $httpBackend.expectPOST("/ajax/tasks/save", task);
        createController();
        scope.task = task;
        scope.actions.save();
        $httpBackend.flush();
    });
});

这导致我得到以下错误

错误：没有待处理的刷新请求

我做错了什么

谢谢。
您使用的是什么版本的AngularJS

当我运行代码时，我得到：
错误：没有定义响应

当我添加响应时，测试通过：

$httpBackend.expectPOST("/ajax/tasks/save", task).respond({});

非常感谢。我真不敢相信我错过了。我在深夜尝试做事，真是罪有应得！