unit testing directive with link using controller - angularjs

Question

I'm trying to unit test my directive that set form validity depending on a controller variable.
My directive code :
angular.module('myModule',[])
.directive('myDirective', function() {
return {
restrict: 'A',
link: function(scope, element, attr, ctrl) {
scope.$watch("mailExist", function(){
if(scope.mailExist) {
ctrl.$setValidity('existingMailValidator', false);
} else {
ctrl.$setValidity('existingMailValidator', true);
}
});
}
};
});
When trying to unit test this directive, I'm trying to isolate the controller ctrl with this code:
describe('directive module unit test implementation', function() {
var $scope,
ctrl,
form;
beforeEach(module('myModule'));
beforeEach(inject(function($compile, $rootScope) {
$scope = $rootScope;
var element =angular.element(
'<form name="testform">' +
'<input name="testinput" user-mail-check>' +
'</form>'
);
var ctrl = element.controller('userMailCheck');
$compile(element)($scope);
$scope.$digest();
form = $scope.testform;
}));
describe('userMailCheck directive test', function() {
it('should test initial state', function() {
expect(form.testinput.$valid).toBe(true);
});
});
});
Running this test, I still obtain:
Cannot read property '$setValidity' of undefined
that's mean I haven't really inject a controller.
What is wrong in my test?

Answer 1

Finally in found the solution:
first in code I have add :
require: 'ngModel',
and then modified the unit test as follow:
describe('directive module unit test implementation', function() {
var scope,
ngModel,
form;
beforeEach(module('myModule'));
beforeEach(inject(function($compile, $rootScope) {
scope = $rootScope.$new();
var element =angular.element(
'<form name="testform">' +
'<input name="testinput" ng-model="model" user-mail-check>' +
'</form>'
);
var input = $compile(element)(scope);
ngModel = input.controller('ngModel');
scope.$digest();
form = scope.testform;
}));
describe('userMailCheck directive test', function() {
it('should test initial state', function() {
expect(form.testinput.$valid).toBe(true);
});
});
});
and everything works fined.