isolateScope() returns undefined when using templateUrl - angularjs

Question

I have a directive that I want to unittest, but I'm running into the issue that I can't access my isolated scope. Here's the directive:
<my-directive></my-directive>
And the code behind it:
angular.module('demoApp.directives').directive('myDirective', function($log) {
return {
restrict: 'E',
templateUrl: 'views/directives/my-directive.html',
scope: {},
link: function($scope, iElement, iAttrs) {
$scope.save = function() {
$log.log('Save data');
};
}
};
});
And here's my unittest:
describe('Directive: myDirective', function() {
var $compile, $scope, $log;
beforeEach(function() {
// Load template using a Karma preprocessor (http://tylerhenkel.com/how-to-test-directives-that-use-templateurl/)
module('views/directives/my-directive.html');
module('demoApp.directives');
inject(function(_$compile_, _$rootScope_, _$log_) {
$compile = _$compile_;
$scope = _$rootScope_.$new();
$log = _$log_;
spyOn($log, 'log');
});
});
it('should work', function() {
var el = $compile('<my-directive></my-directive>')($scope);
console.log('Isolated scope:', el.isolateScope());
el.isolateScope().save();
expect($log.log).toHaveBeenCalled();
});
});
But when I print out the isolated scope, it results in undefined. What really confuses me though, if instead of the templateUrl I simply use template in my directive, then everything works: isolateScope() has a completely scope object as its return value and everything is great. Yet, somehow, when using templateUrl it breaks. Is this a bug in ng-mocks or in the Karma preprocessor?
Thanks in advance.

Answer 1

I had the same problem. It seems that when calling $compile(element)($scope) in conjunction with using a templateUrl, the digest cycle isn't automatically started. So, you need to set it off manually:
it('should work', function() {
var el = $compile('<my-directive></my-directive>')($scope);
$scope.$digest(); // Ensure changes are propagated
console.log('Isolated scope:', el.isolateScope());
el.isolateScope().save();
expect($log.log).toHaveBeenCalled();
});
I'm not sure why the $compile function doesn't do this for you, but it must be some idiosyncracy with the way that templateUrl works, as you don't need to make the call to $scope.$digest() if you use an inline template.

Answer 2

With Angularjs 1.3, if you disable debugInfoEnabled in the app config:
$compileProvider.debugInfoEnabled(false);
isolateScope() returns undefined also!

Answer 3

I had to mock and flush the $httpBackend before isolateScope() became defined. Note that $scope.$digest() made no difference.
Directive:
app.directive('deliverableList', function () {
return {
templateUrl: 'app/directives/deliverable-list-directive.tpl.html',
controller: 'deliverableListDirectiveController',
restrict = 'E',
scope = {
deliverables: '=',
label: '#'
}
}
})
test:
it('should be defined', inject(function ($rootScope, $compile, $httpBackend) {
var scope = $rootScope.$new();
$httpBackend.expectGET('app/directives/deliverable-list-directive.tpl.html').respond();
var $element = $compile('<deliverable-list label="test" deliverables="[{id: 123}]"></deliverable-list>')(scope);
$httpBackend.flush();
$httpBackend.verifyNoOutstandingExpectation();
$httpBackend.verifyNoOutstandingRequest();
expect($element).toBeDefined();
expect($element.controller).toBeDefined();
scope = $element.isolateScope();
expect(scope).toBeDefined();
expect(scope.label).toEqual('test');
expect(scope.deliverables instanceof Array).toEqual(true);
expect(scope.deliverables.length).toEqual(1);
expect(scope.deliverables[0]).toEqual({id: 123});
}));
I'm using Angular 1.3.

Answer 4

You could configure karma-ng-html2js-preprocessor plugin. It will convert the HTML templates into a javascript string and put it into Angular's $templateCache service.
After set a moduleName in the configuration you can declare the module in your tests and then all your production templates will available without need to mock them with $httpBackend everywhere.
beforeEach(module('partials'));
You can find how to setup the plugin here: http://untangled.io/how-to-unit-test-a-directive-with-templateurl/

Answer 5

In my case, I kept running into this in cases where I was trying to isolate a scope on a directive with no isolate scope property.
function testDirective() {
return {
restrict:'EA',
template:'<span>{{ message }}</span>'
scope:{} // <-- Removing this made an obvious difference
};
}
function testWithoutIsolateScopeDirective() {
return {
restrict:'EA',
template:'<span>{{ message }}</span>'
};
}
describe('tests pass', function(){
var compiledElement, isolatedScope, $scope;
beforeEach(module('test'));
beforeEach(inject(function ($compile, $rootScope){
$scope = $rootScope.$new();
compiledElement = $compile(angular.element('<div test-directive></div>'))($scope);
isolatedScope = compiledElement.isolateScope();
}));
it('element should compile', function () {
expect(compiledElement).toBeDefined();
});
it('scope should isolate', function () {
expect(isolatedScope).toBeDefined();
});
});
describe('last test fails', function(){
var compiledElement, isolatedScope, $scope;
beforeEach(module('test'));
beforeEach(inject(function ($compile, $rootScope){
$scope = $rootScope.$new();
compiledElement = $compile(angular.element('<div test-without-isolate-scope-directive></div>'))($scope);
isolatedScope = compiledElement.isolateScope();
}));
it('element should compile', function () {
expect(compiledElement).toBeDefined();
});
it('scope should isolate', function () {
expect(isolatedScope).toBeDefined();
});
});