在 AngularJS 单元测试中模拟 $modal

Question

我正在为一个控制器编写一个单元测试，该控制器启动 $modal 并使用返回的承诺来执行一些逻辑。我可以测试触发 $modal 的父控制器，但我一生都无法弄清楚如何模拟一个成功的承诺。

我尝试了很多方法，包括使用$q 和$scope.$apply() 来强制解决promise。但是，我得到的最接近的是将类似于 this SO 帖子中最后一个答案的内容放在一起；

我见过几次用“旧”$dialog 模态询问这个问题。 我找不到太多关于如何使用“新”$dialog 模态来做到这一点。

一些指针将不胜感激。

为了说明问题，我使用了example provided in the UI Bootstrap docs，并进行了一些小的修改。

控制器（主要和模式）

'use strict';

angular.module('angularUiModalApp')
    .controller('MainCtrl', function($scope, $modal, $log) {
        $scope.items = ['item1', 'item2', 'item3'];

        $scope.open = function() {

            $scope.modalInstance = $modal.open({
                templateUrl: 'myModalContent.html',
                controller: 'ModalInstanceCtrl',
                resolve: {
                    items: function() {
                        return $scope.items;
                    }
                }
            });

            $scope.modalInstance.result.then(function(selectedItem) {
                $scope.selected = selectedItem;
            }, function() {
                $log.info('Modal dismissed at: ' + new Date());
            });
        };
    })
    .controller('ModalInstanceCtrl', function($scope, $modalInstance, items) {
        $scope.items = items;
        $scope.selected = {
            item: $scope.items[0]
        };

        $scope.ok = function() {
            $modalInstance.close($scope.selected.item);
        };

        $scope.cancel = function() {
            $modalInstance.dismiss('cancel');
        };
    });

视图 (main.html)

<div ng-controller="MainCtrl">
    <script type="text/ng-template" id="myModalContent.html">
        <div class="modal-header">
            <h3>I is a modal!</h3>
        </div>
        <div class="modal-body">
            <ul>
                <li ng-repeat="item in items">
                    <a ng-click="selected.item = item">{{ item }}</a>
                </li>
            </ul>
            Selected: <b>{{ selected.item }}</b>
        </div>
        <div class="modal-footer">
            <button class="btn btn-primary" ng-click="ok()">OK</button>
            <button class="btn btn-warning" ng-click="cancel()">Cancel</button>
        </div>
    </script>

    <button class="btn btn-default" ng-click="open()">Open me!</button>
    <div ng-show="selected">Selection from a modal: {{ selected }}</div>
</div>

测试

'use strict';

describe('Controller: MainCtrl', function() {

    // load the controller's module
    beforeEach(module('angularUiModalApp'));

    var MainCtrl,
        scope;

    var fakeModal = {
        open: function() {
            return {
                result: {
                    then: function(callback) {
                        callback("item1");
                    }
                }
            };
        }
    };

    beforeEach(inject(function($modal) {
        spyOn($modal, 'open').andReturn(fakeModal);
    }));


    // Initialize the controller and a mock scope
    beforeEach(inject(function($controller, $rootScope, _$modal_) {
        scope = $rootScope.$new();
        MainCtrl = $controller('MainCtrl', {
            $scope: scope,
            $modal: _$modal_
        });
    }));

    it('should show success when modal login returns success response', function() {
        expect(scope.items).toEqual(['item1', 'item2', 'item3']);

        // Mock out the modal closing, resolving with a selected item, say 1
        scope.open(); // Open the modal
        scope.modalInstance.close('item1');
        expect(scope.selected).toEqual('item1'); 
        // No dice (scope.selected) is not defined according to Jasmine.
    });
});

Answer 1

当你在 beforeEach 中窥探 $modal.open 函数时，

spyOn($modal, 'open').andReturn(fakeModal);

or 

spyOn($modal, 'open').and.returnValue(fakeModal); //For Jasmine 2.0+

您需要返回 $modal.open 通常返回的模拟，而不是 $modal 的模拟，它不包括您在 fakeModal 模拟中布置的 open 函数。假模态必须有一个 result 对象，该对象包含一个 then 函数来存储回调（在单击 OK 或 Cancel 按钮时调用）。它还需要一个close 函数（模拟一个确定按钮单击模态）和一个dismiss 函数（模拟一个取消按钮单击模态）。 close 和 dismiss 函数在调用时会调用必要的回调函数。

将fakeModal更改为以下，单元测试将通过：

var fakeModal = {
    result: {
        then: function(confirmCallback, cancelCallback) {
            //Store the callbacks for later when the user clicks on the OK or Cancel button of the dialog
            this.confirmCallBack = confirmCallback;
            this.cancelCallback = cancelCallback;
        }
    },
    close: function( item ) {
        //The user clicked OK on the modal dialog, call the stored confirm callback with the selected item
        this.result.confirmCallBack( item );
    },
    dismiss: function( type ) {
        //The user clicked cancel on the modal dialog, call the stored cancel callback
        this.result.cancelCallback( type );
    }
};

此外，您可以通过在取消处理程序中添加要测试的属性来测试取消对话框案例，在本例中为$scope.canceled：

$scope.modalInstance.result.then(function (selectedItem) {
    $scope.selected = selectedItem;
}, function () {
    $scope.canceled = true; //Mark the modal as canceled
    $log.info('Modal dismissed at: ' + new Date());
});

一旦设置了取消标志，单元测试将如下所示：

it("should cancel the dialog when dismiss is called, and $scope.canceled should be true", function () {
    expect( scope.canceled ).toBeUndefined();

    scope.open(); // Open the modal
    scope.modalInstance.dismiss( "cancel" ); //Call dismiss (simulating clicking the cancel button on the modal)
    expect( scope.canceled ).toBe( true );
});

Answer 2

为了补充 Brant 的答案，这里有一个稍微改进的模拟，可以让您处理其他一些场景。

var fakeModal = {
    result: {
        then: function (confirmCallback, cancelCallback) {
            this.confirmCallBack = confirmCallback;
            this.cancelCallback = cancelCallback;
            return this;
        },
        catch: function (cancelCallback) {
            this.cancelCallback = cancelCallback;
            return this;
        },
        finally: function (finallyCallback) {
            this.finallyCallback = finallyCallback;
            return this;
        }
    },
    close: function (item) {
        this.result.confirmCallBack(item);
    },
    dismiss: function (item) {
        this.result.cancelCallback(item);
    },
    finally: function () {
        this.result.finallyCallback();
    }
};

这将允许模拟处理...

您将模式与 .then()、.catch() 和 .finally() 处理程序样式一起使用，而不是将 2 个函数 (successCallback, errorCallback) 传递给 .then()，例如：

modalInstance
    .result
    .then(function () {
        // close hander
    })
    .catch(function () {
        // dismiss handler
    })
    .finally(function () {
        // finally handler
    });

Answer 3

由于modals 使用承诺，您绝对应该将$q 用于此类事情。

代码变成：

function FakeModal(){
    this.resultDeferred = $q.defer();
    this.result = this.resultDeferred.promise;
}
FakeModal.prototype.open = function(options){ return this;  };
FakeModal.prototype.close = function (item) {
    this.resultDeferred.resolve(item);
    $rootScope.$apply(); // Propagate promise resolution to 'then' functions using $apply().
};
FakeModal.prototype.dismiss = function (item) {
    this.resultDeferred.reject(item);
    $rootScope.$apply(); // Propagate promise resolution to 'then' functions using $apply().
};

// ....

// Initialize the controller and a mock scope
beforeEach(inject(function ($controller, $rootScope) {
    scope = $rootScope.$new();
    fakeModal = new FakeModal();
    MainCtrl = $controller('MainCtrl', {
        $scope: scope,
        $modal: fakeModal
   });
}));

// ....

it("should cancel the dialog when dismiss is called, and  $scope.canceled should be true", function () {
    expect( scope.canceled ).toBeUndefined();

    fakeModal.dismiss( "cancel" ); //Call dismiss (simulating clicking the cancel button on the modal)
    expect( scope.canceled ).toBe( true );
});

Answer 4

Brant 的回答显然很棒，但这种变化让我觉得更好：

  fakeModal =
    opened:
      then: (openedCallback) ->
        openedCallback()
    result:
      finally: (callback) ->
        finallyCallback = callback

然后在测试区：

  finallyCallback()

  expect (thing finally callback does)
    .toEqual (what you would expect)