Override $exceptionHandler behaviour in service unit test - angularjs

Question

I have a service which throws an error, and I'd like to unit test that, but somehow I cannot get it overwritten, which I did manage to do for controllers:
describe('some test', function () {
var myService, exceptionHandler;
beforeEach(angular.mock.module('myModule', function($exceptionHandlerProvider) {
$exceptionHandlerProvider.mode("log");
}));
beforeEach(inject(function ($injector, $exceptionHandler) {
exceptionHandler = $exceptionHandler;
myService = $injector.get('myService');
}));
it('should throw an error', function () {
theService.somefunction('create an error');
expect(exceptionHandler.errors.length).toBe(1);
expect(exceptionHandler.errors[0].message).toBe('some text');
});
});
});
in somefunction I just do this:
throw new Error('some text')
The problem is that the error is just logged to the console in Karma, so it seems to be rethrown rather then logged.
How can I fix this?

Answer 1

It's advised to use sinon when stubbing an object (will show both ways though):
describe('some test', function () {
var myService, exceptionHandler = {};
exceptionHandler.fn = function(exception, cause) {
throw exception;
};
beforeEach(module('myModule', function($provide) {
$provide.factory('$exceptionHandler', function(){
return function(exception, cause){
return exceptionHandler.fn(exception, cause);
};
});
}));
beforeEach(inject(function ($injector) {
myService = $injector.get('myService');
}));
it('should throw an error', function () {
var old = exceptionHandler.fn, caught = false, message = '';
exceptionHandler.fn = function(exception, cause) {
caught = true;
message = exception.message;
};
myService.somefunction('create an error');
expect(caught).toBe(true);
expect(message).toBe('message');
exceptionHandler.fn = old; //restore
// using sinon.js
sinon.stub(exceptionHandler, 'fn', function(exception){ });
myService.somefunction('create an error');
expect(exceptionHandler.fn.called).toBe(true);
expect(exceptionHandler.fn.getCall(0).args[0]).toMatch(/message/);
exceptionHandler.fn.restore();
});
});
sinon makes it easier to stub stuff, and check the call count and restore functionality after you're done