Angular karma test: TypeError readonly property

Question

I'm trying to mock out this 'usermanager' provider in my controller test and I always end up getting this error

TypeError: Attempted to assign to readonly property.
at workFn (c:{...}/bower_components/angular-mocks/angular-mocks.js:2105)

Here is my controller:

angular.module('sasApp')
.controller('RegisterCtrl', function ($scope, usermanager) {

  // variables
  $scope.captcha = {};

  // Get captcha from server
  usermanager.getCaptcha().then(function (captcha) {
    $scope.captcha = captcha;
  }, function (reason) {
    console.log('Failed: ' + reason);
  });
});

And here is my test:

describe('Controller: RegisterCtrl', function () {
  // load the controller's module
  beforeEach(module('sasApp'));

  var RegisterCtrl,
      scope,
      mockUsermanager;

  mockUsermanager = {
    getCaptcha: function () {
      return {
        test: 1
      };
    }
  };

  // Initialize the controller and a mock scope
  beforeEach(inject(function ($controller, $rootScope) {
    scope = $rootScope.$new();
    RegisterCtrl = $controller('RegisterCtrl', {
      $scope: scope,
      usermanager: mockUsermanager
    });
  }));

  describe('Initialization', function () {

    it('should have \'captcha\' object defined', function () {
      expect(scope.captcha).toBeDefined();
    });
  });
});

The thing is, I didn't get this error until I tried setting up the mocking of the 'usermanager' provider. If I remove the line 'usermanager: mockUsermanager' in the beforeEach statement, then it all runs well.

Can you spot what is wrong ? Thanks in advance!

Answer 1

It might not be the best answer but I've made a Plnkr that does not reproduce the issue here: http://plnkr.co/GgUeKnsvxEHmD3Wcyocx?p=preview

A quick note: usermanager.getCaptcha() has to return a promise otherwise the next part of test would blow up when it tries calling .then . So I've just put in a bogus one in.

Let me know if you spot any differences (I don't know what angular version you're on for example). And I can see about updating