Unit testing ControllerAs with forms in AngularJS

Question

I have the following situation with Angular:

Controller

function Controller () {
    // form used in template
    this.form ...
}

Template that has a form and uses this controller

Template

<div ng-controller="Controller as ctrl">
    <form name="ctrl.form">
    ...
</div>

I have to say I'm in general confused why Angular doesn't have a better way of adding the form to the controller other than automatically adding either this.form or $scope.form, depending on how you use controllers, but that's I guess another question.

The real issue I have right now is that I'm not sure how I should test this. If I just instantiate the controller in the test, then my form is undefined

$controller('Controller as ctrl')

I did find a way, by just compiling the template

$scope = $rootScope.$new();
$compile(template)($scope);

But because ng-controller in the template starts a new scope, I can't access the controller directly with $scope.ctrl, instead I'd have to do something like $scope.$$childHead.login

... and I feel it's getting too complicated. edit: not to mention that $$ indicates a 'private' property.

score 2 · Answer 1 · answered Jun 18 '15 at 06:47

I've solved it myself, but I'm leaving it here unaccepted because I don't think the solution is very nice. If anyone knows a better way, please post.

The problem with compiling templates is that it's also not possible to insert mock services in the controller, at least I didn't figure it out. You get a controller instance on $scope, like $scope.ctrl, but that's it.

The second attempt was to locate just the form in the template, compile and add it to a controller that was instantiated separately. This worked, but not really, because the $scope for the form and controller were different and so any update to a field didn't reflect on the controller state.

The way it works in the end is to instantiate the controller with a $scope

ctrl = $controller('Controller as ctrl', {
        someDependency: mockDependency,
        $scope: $scope
    });

and then to compile the partial template (just the form) with the same $scope

var formTpl = angular.element(template).find('form');
form = $compile(formTpl)($scope);

This way, the controller ends up in $scope.ctrl, but because the form is already named name="ctrl.form" it gets inserted into $scope.ctrl.form and it's visible inside a controller.

Jonas Masalskis · Answer 2 · 2017-03-14T19:17:29.240

When using controllerAs, you can access your form in tests like so:

// 1. Create a new scope
var $scope = $rootScope.$new();

// 2. Run the controller
var Controller = $controller("Controller as ctrl", { $scope: $scope });

// 3. Compile the template against our scope
// This will add property $scope.ctrl.form (assuming that form has name="ctrl.form")
$compile(angular.element(templateHtml))($scope);

// 4. Controller.form should now also be defined
expect(Controller.form).toBeDefined();

Meanwhile mocking can be achieved by using angular's $provide:

beforeEach(angular.mock.module(function ($provide) {
    function ApiServiceMock() {
        this.getName() = function () {
            return "Fake Name";
        };
    }

    // Provide our mocked service instead of 'ApiService' 
    // when our controller's code requests to inject it
    $provide.value("ApiService", ApiServiceMock);
}));

Full example (using both - mocking & form compilation with controllerAs):

Main app code:

angular.module("my.module", [])

    .service("ApiService", function () {
        this.getName = function () {
            return "Real Name";
        };
    })

    .controller("Controller", function (ApiService) {
        var ctrl = this;
        ctrl.someProperty = ApiService.getName();
    });

HTML:

<div ng-controller="Controller as ctrl">
    <form name="ctrl.form">
        <input type="email" name="email" />
    </form>
</div>

Test:

describe("Controller", function () {
    var $scope,
        Controller;

    beforeEach(angular.mock.module("my.module"));

    beforeEach(angular.mock.module(function ($provide) {
        function ApiServiceMock() {
            this.getName() = function () {
                return "Fake Name";
            };
        }

        $provide.value("ApiService", ApiServiceMock);
    }));

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

        Controller = $controller("Controller as ctrl", { $scope: $scope });

        // FIXME: Use your own method of retrieving template's HTML instead 'getTemplateContents' placeholder
        var html = getTemplateContents("./my.template.html"),
            formTpl = angular.element(html).find('form');

        $compile(formTpl)($scope);
    }));

    it('should contain someProperty', function () {
        expect(Controller.someProperty).toBeDefined();
    });

    it('form should contain an email field', function () {
        expect(Controller.form.email).toBeDefined();
    });
});

Unit testing ControllerAs with forms in AngularJS

2 Answers2