How to create unit-testing for array function in AngularJS with Jasmine

The xf variable is not acessible from the outside of the controller's scope (i.e. not accessible in the unit test files).

You must've done the following thing:

angular
  .module('myModule')
  .controller(function ($scope) {
    var xf = [];
    // etc.
  });

You could attach the xf variable to the MyController instance once Angular instantiates it:

angular
  .module('myModule')
  .controller(function ($scope) {
    this.xf = [];
    // etc.
  });

But that's not really a clean way of doing it. A better way (in my opinion) would be to create a factory:

angular
  .module('myModule')
  .factory('xfService', function () {
    var xf = [];

    function validateUsername(text) {
      // etc.
    }

    function get() {
      return xf;
    }

    return {
      get: get,
      validateUsername: validateUsername
    };
  });

Now, you can inject the factory in your controller to use xf:

angular
  .module('myModule')
  .controller(function ($scope, xfService) {
    // somewhere
    var isValid = xfService.validateEmail($scope.email, '256');
    // to get the values in the array
    var values = xfService.get();
  });

Finally, for the unit tests, it becomes really easy to test the validateEmail method.

describe('Unit tests - xfService', function () {
  var xfService;
  beforeEach(angular.module('myModule'));
  beforeEach(angular.inject(function (_xfService_) {
      xfService = _xfService_;
    });
  });

  describe('xfService.validateUsername', function () {
    it('should return a boolean value', function () {
      // for example
      expect(typeof xfService.validateUsername('test')).toBe('boolean');
    });
    // add more unit tests to check that the method works as expected
  });
});

You'll need to add the angular-mocks file to the Karma config.

Thanks to Paul Podlech and Claies for the hints in the comments/answers.

I'm not sure to completely understand your question. But there are a few thinks i think you are doing wrong:

• If xf it's a global variable you should mock it, since you are testing the controller, not the global variable.

• If you want to check the real function of your global variable, go to the karma.conf.js file and add the js file path to the files option:

  files: [ ..., 'fx-script.js', ... ],

• callThrough should be used before the actual function is invoked:

  it ('checkEmail', function(){ var ctrl = $controller('MyCtrl', { $scope: $scope }); spyOn(window, ctrl.xf.validateUsername).and.callThrough(); ctrl.xf.validateUsername(); });

I recommend you to separately test your controller, service, or global scripts, and add mocks whenever you need to inject a dependency or global variable, so if you can tell for sure which module/script is failing any time.

you should move functionality in xf into separate service/factory. Then inject it in controller. That makes it pretty easy to mock it while testing.

Try this in the controller

var xf = this.xf = [];

and this in your test

it ('checkEmail', function(){
 var xf = $controller('MyCtrl', { $scope: $scope }).xf;
 spyOn(xf, 'validateUsername').and.callThrough();
 xf.validateUsername();
});

But you should realize that this exposes your xf object on the Controller as mentioned in the comment of Claies.