How to capture $compile or $digest error? (AngularJS directive with templateUrl) - angularjs-directive

Question

I'm writing a unit test of an AngularJS 1.x directive.
If I use "template" it works.
If I use "templateUrl" it does not work (the directive element remains the same original HTML instead of being "compiled").
This is how I create the directive element to test in Jasmine:
function createDirectiveElement() {
scope = $rootScope.$new();
var elementHtml = '<my-directive>my directive</my-directive>';
var element = $compile(elementHtml)(scope);
scope.$digest();
if (element[0].tagName == "my-directive".toUpperCase()) throw Error("Directive is not compiled");
return element;
};
(this does not actually work, see Update for real code)
I'm using this workaround to use the $httpBackend from ngMockE2E (instead of the one in ngMock). In the browser developer "network" tab I don't see any request to the template file. It seems to work because I solved the error "Object # has no method 'passThrough'".
I know that the call to the template is done asynchronously using the $httpBackend (this means $compile exit before the template is really applied).
My question is:
obviously $compile is not doing what I expect. How can I trap this error?
If I use a wrong address in the templateUrl I don't receive any error.
How can I found the problem happened when I called $compile(directive) or scope.$digest() ?
Thanks,
Alex
[Solution]
As suggested by #Corvusoft I inject $exceptionHandler and I check for errors after every test.
In the end this is the only code I have added:
afterEach(inject(function ($exceptionHandler) {
if ($exceptionHandler.errors.length > 0)
throw $exceptionHandler.errors;
}));
Now I can clearly see the errors occurred in the Jasmine test result (instead of search for them in the console), example:
Error: Unexpected request: GET /api/category/list
No more request expected,Error: Unexpected request: GET /api/category/list
No more request expected thrown
And, most important, my tests does not pass in case there are some errors.
[Update to show real example case]
Actually the real code to make templateUrl work use asynchronous beforeEach ("done") and a timeout to wait the end of compile/digest.
My directive use some prividers/services and the template contains other directives which in turn use their templateUrl and make calls to some APIs in the link function().
This is the current (working) test code:
// workaround to have .passThrough() in $httpBackend
beforeEach(angular.mock.http.init); // set $httpBackend to use the ngMockE2E to have the .passThrough()
afterEach(angular.mock.http.reset); // restore the $httpBackend to use ngMock
beforeEach(inject(function (_$compile_, _$rootScope_, _$http_, $httpBackend, $templateCache, $injector) {
$compile = _$compile_;
$rootScope = _$rootScope_;
$http = _$http_;
$httpBackend.whenGET(/\/Scripts of my app\/Angular\/*/).passThrough();
$httpBackend.whenGET(/\/api\/*/).passThrough(); // comment out this to see the errors in Jasmine
}));
afterEach(inject(function ($exceptionHandler) {
if ($exceptionHandler.errors.length > 0)
throw $exceptionHandler.errors;
}));
beforeEach(function(done) {
createDirectiveElementAsync(function (_element_) {
element = _element_;
scope = element.isolateScope();
done();
});
});
function createDirectiveElementAsync(callback) {
var scope = $rootScope.$new();
var elementHtml = '<my-directive>directive</my-directive>';
var element = $compile(elementHtml)(scope);
scope.$digest();
// I haven't found an "event" to know when the compile/digest end
setTimeout(function () {
if (element.tagName == "my-directive".toUpperCase()) throw Error("Directive is not compiled");
callback(element);
}, 0.05*1000); // HACK: change it accordingly to your system/code
};
it("is compiled", function () {
expect(element).toBeDefined();
expect(element.tagName).not.toEqual("my-directive".toUpperCase());
});
I hope this example helps someone else.

Answer 1

$exceptionHandler
Any uncaught exception in AngularJS expressions is delegated to this
service. The default implementation simply delegates to $log.error
which logs it into the browser console.
In unit tests, if angular-mocks.js is loaded, this service is overridden by mock $exceptionHandler which aids in testing.
angular.
module('exceptionOverwrite', []).
factory('$exceptionHandler', ['$log', 'logErrorsToBackend', function($log, logErrorsToBackend) {
return function myExceptionHandler(exception, cause) {
logErrorsToBackend(exception, cause);
$log.warn(exception, cause);
};
}]);