How does the createSpy work in Angular + Jasmine? - angularjs

I made a simple demo of a factory and I am trying to test this using jasmine. I am able to run the test but I am using the spyOn method. I would rather use jasmine.createSpy or jasmine.createSpyObj to do the same test. Could someone help me to refactor my code so that uses these methods instead in my example?
http://plnkr.co/edit/zdfYdtWbnQz22nEbl6V8?p=preview
describe('value check',function(){
var $scope,
ctrl,
fac;
beforeEach(function(){
module('app');
});
beforeEach(inject(function($rootScope,$controller,appfactory) {
$scope = $rootScope.$new();
ctrl = $controller('cntrl', {$scope: $scope});
fac=appfactory;
spyOn(fac, 'setValue');
fac.setValue('test abc');
}));
it('test true value',function(){
expect(true).toBeTruthy()
})
it('check message value',function(){
expect($scope.message).toEqual(fac.getValue())
})
it("tracks that the spy was called", function() {
expect(fac.setValue).toHaveBeenCalled();
});
it("tracks all the arguments of its calls", function() {
expect(fac.setValue).toHaveBeenCalledWith('test abc');
});
})
update
angular.module('app',[]).factory('appfactory',function(){
var data;
var obj={};
obj.getValue=getValue;
obj.setValue=setValue;
return obj;
function getValue(){
return data;
}
function setValue(datavalue){
data=datavalue;
}
}).controller('cntrl',function($scope,appfactory){
appfactory.setValue('test abc');
$scope.message=appfactory.getValue()
})

I have changed your plunkr:
spy = jasmine.createSpy('spy');
fac.setValue = spy;
Edit
In Jasmine, mocks are referred to as spies. There are two ways to
create a spy in Jasmine: spyOn() can only be used when the method
already exists on the object, whereas jasmine.createSpy() will return
a brand new function.
Found the information here. The link has a lot more information about creating spies.

As said in the comments, you have absolutely no need for spies to test such a service. If you had to write the documentation for your service: you would say:
setValue() allows storing a value. This value can then be retrieved by calling getValue().
And that's what you should test:
describe('appfactory service',function(){
var appfactory;
beforeEach(module('app'));
beforeEach(inject(function(_appfactory_) {
appfactory = _appfactory_;
}));
it('should store a value and give it back',function() {
var value = 'foo';
appfactory.setValue(value);
expect(appfactory.getValue()).toBe(value);
});
});
Also, your service is not a factory. A factory is an object that is used to create things. Your service doesn't create anything. It is registered in the angular module using a factory function. But the service itself is not a factory.

Related

How to unit test / mock a $timeout call?

How do I mock the timeout call, here?
$scope.submitRequest = function () {
var formData = getData();
$scope.form = JSON.parse(formData);
$timeout(function () {
$('#submitForm').click();
}, 2000);
};
I want to see timeout has been called with the correct function.
I would like an example of the spyon function mocking $timeout.
spyOn(someObject,'$timeout')
First of all, DOM manipulation should only be performed in directives.
Also, it's better to use angular.element(...), than $(...).
Finally, to do this, you can expose your element's click handler to the scope, spy on it, and check if that handler has been called:
$timeout.flush(2000);
$timeout.verifyNoPendingTasks();
expect(scope.myClickHandler).toHaveBeenCalled();
EDIT:
since that's a form and there is no ng-click handler, you can use ng-submit handler, or add a name to your form and do:
$timeout.flush(2000);
$timeout.verifyNoPendingTasks();
expect(scope.formName.$submitted).toBeTruthy();
$timeout can be spied or mocked as shown in this answer:
beforeEach(module('app', ($provide) => {
$provide.decorator('$timeout', ($delegate) => {
var timeoutSpy = jasmine.createSpy().and.returnValue($delegate);
// methods aren't copied automatically to spy
return angular.extend(timeoutSpy, $delegate);
});
}));
There's not much to test here, since $timeout is called with anonymous function. For testability reasons it makes sense to expose it as scope/controller method:
$scope.submitFormHandler = function () {
$('#submitForm').click();
};
...
$timeout($scope.submitFormHandler, 2000);
Then spied $timeout can be tested:
$timeout.and.stub(); // in case we want to test submitFormHandler separately
scope.submitRequest();
expect($timeout).toHaveBeenCalledWith(scope.submitFormHandler, 2000);
And the logic inside $scope.submitFormHandler can be tested in different test.
Another problem here is that jQuery doesn't work well with unit tests and requires to be tested against real DOM (this is one of many reasons why jQuery should be avoided in AngularJS applications when possible). It's possible to spy/mock jQuery API like shown in this answer.
$(...) call can be spied with:
var init = jQuery.prototype.init.bind(jQuery.prototype);
spyOn(jQuery.prototype, 'init').and.callFake(init);
And can be mocked with:
var clickSpy = jasmine.createSpy('click');
spyOn(jQuery.prototype, 'init').and.returnValue({ click: clickSpy });
Notice that it's expected that mocked function will return jQuery object for chaining with click method.
When $(...) is mocked, the test doesn't require #submitForm fixture to be created in DOM, this is the preferred way for isolated unit test.
Create mock for $timeout provider:
var f = () => {}
var myTimeoutProviderMock = () => f;
Use it:
beforeEach(angular.mock.module('myModule', ($provide) => {
$provide.factory('$timeout', myTimeoutProviderMock);
}))
Now you can test:
spyOn(f);
expect(f).toHaveBeenCalled();
P.S. you'd better test result of function in timeout.
Assuming that piece of code is within the controller or being created in the test by $controller, then $timeout can be passed in the construction parameter. So you could just do something like:
var timeoutStub = sinon.stub();
var myController = $controller('controllerName', timeoutStub);
$scope.submitRequest();
expect(timeoutStub).to.have.been.called;
Unit Tesitng $timeout with flush delay
You have to flush the queue of the $timeout service by calling $timeout.flush()
describe('controller: myController', function(){
describe('showAlert', function(){
beforeEach(function(){
// Arrange
vm.alertVisible = false;
// Act
vm.showAlert('test alert message');
});
it('should show the alert', function(){
// Assert
assert.isTrue(vm.alertVisible);
});
it('should hide the alert after 5 seconds', function(){
// Act - flush $timeout queue to fire off deferred function
$timeout.flush();
// Assert
assert.isFalse(vm.alertVisible);
});
})
});
Please checkout this link http://jasonwatmore.com/post/2015/03/06/angularjs-unit-testing-code-that-uses-timeout
I totally agree with Frane Poljak's answer. You should surely follow his way. Second way to do it is by mocking $timeout service like below:
describe('MainController', function() {
var $scope, $timeout;
beforeEach(module('app'));
beforeEach(inject(function($rootScope, $controller, $injector) {
$scope = $rootScope.$new();
$timeout = jasmine.createSpy('$timeout');
$controller('MainController', {
$scope: $scope,
$timeout: $timeout
});
}));
it('should submit request', function() {
$scope.submitRequest();
expect($timeout).toHaveBeenCalled();
});
Here is the plunker having both approaches: http://plnkr.co/edit/s5ls11

Jasmine Js - SpyOn Fakecall during the controller initialization

I have seen a set of duplicates for this question but was unable to solve the issue.
I have a controller and during the controller initialization, fetchtemplate() is getting called first and then my mock fetchtemplate() is getting called.
How do I stop the actual(controller) fetchtemplate() getting called during the controller initialization? My intention is to mock the function fetchtemplate() in my spec.Please have a look at my spec -
describe("...",function(){
beforeEach(inject(function($controller,...) {
scope = $rootScope.$new();
this.init = function() {
$controller('ChangeControlCreateController', {
$scope: scope
});
}
}));
describe('Function', function() {
it("-- check for trueness",function(){
this.init() ; //Initialization of the controller
spyOn(scope,'fetchtemplate').and.callFake(function() {
return 101;
});
var fakeResponse = scope.fetchtemplate();
expect(scope.fetchtemplate).toHaveBeenCalled();
expect(fakeResponse).toEqual(101);
});
});
});
I have tried placing the spyOn before the this.init() which gave error as the fetchtemplate() doesn't exist at that time to spyOn.
My controller code structure looks like -
angular.module('...', [...])
.controller('ChangeControlCreateController', ["$scope"...,
function ChangeControlCreateController($scope,...) {
$scope.fetchtemplate = function() {
console.log("controller's function");
...
};
$scope.fetchtemplate();
});
The result what I am getting is - First the console item "controller's function" and then the spec is executing with mock function. I want the mock function to execute without the controller's function to execute
So if I understand correctly you are doing some call to a function that is doing something you want to prevent for test purposes. Probably an http call or some thing of the sort ?
Whatever it is doing the proper way to handle something like that is usually to put that method inside a service instead and then to spy on that service method. Here is an example of test if the service is TemplateService :
describe("...",function(){
var $controller, scope, TemplateService, YourController;
beforeEach(inject(function(_$controller_, _TemplateService_, ...) {
scope = $rootScope.$new();
$controller = _$controller_;
TemplateService = _TemplateService_;
}
it("-- check for trueness",function(){
spyOn(TemplateService,'fetchTemplate').and.returnValue('101');
YourController = $controller('YourController');
expect(...);
});
});
I hope that's helpful

Spy on scope function that executes when an angular controller is initialized

I want to test that the following function is in fact called upon the initialization of this controller using jasmine. It seems like using a spy is the way to go, It just isn't working as I'd expect when I put the expectation for it to have been called in an 'it' block. I'm wondering if there is a special way to check if something was called when it wasn't called within a scope function, but just in the controller itself.
App.controller('aCtrl', [ '$scope', function($scope){
$scope.loadResponses = function(){
//do something
}
$scope.loadResponses();
}]);
//spec file
describe('test spec', function(){
beforeEach(
//rootscope assigned to scope, scope injected into controller, controller instantiation.. the expected stuff
spyOn(scope, 'loadResponses');
);
it('should ensure that scope.loadResponses was called upon instantiation of the controller', function(){
expect(scope.loadResponses).toHaveBeenCalled();
});
});
You need to initialise the controller yourself with the scope you've created. The problem is, that you need to restructure your code. You can't spy on a non-existing function, but you need to spyOn before the function gets called.
$scope.loadResponses = function(){
//do something
}
// <-- You would need your spy attached here
$scope.loadResponses();
Since you cannot do that, you need to make the $scope.loadResponses() call elsewhere.
The code that would successfully spy on a scoped function is this:
var scope;
beforeEach(inject(function($controller, $rootScope) {
scope = $rootScope.$new();
$controller('aCtrl', {$scope: scope});
scope.$digest();
}));
it("should have been called", function() {
spyOn(scope, "loadResponses");
scope.doTheStuffThatMakedLoadResponsesCalled();
expect(scope.loadResponses).toHaveBeenCalled();
});
Setting the spy before controller instantiation (in the beforeEach) is the way to test controller functions that execute upon instantiation.
EDIT: There is more to it. As a comment points out, the function doesn't exist at the time of ctrl instantiation. To spy on that call you need to assign an arbitrary function to the variable (in this case you assign scope.getResponses to an empty function) in your setup block AFTER you have scope, but BEFORE you instantiate the controller. Then you need to write the spy (again in your setup block and BEFORE ctrl instantiation), and finally you can instantiate the controller and expect a call to have been made to that function. Sorry for the crappy answer initially
The only way I have found to test this type of scenarios is moving the method to be tested to a separate dependency, then inject it in the controller, and provide a fake in the tests instead.
Here is a very basic working example:
angular.module('test', [])
.factory('loadResponses', function() {
return function() {
//do something
}
})
.controller('aCtrl', ['$scope', 'loadResponses', function($scope, loadResponses) {
$scope.loadResponses = loadResponses;
$scope.loadResponses();
}]);
describe('test spec', function(){
var scope;
var loadResponsesInvoked = false;
var fakeLoadResponses = function () {
loadResponsesInvoked = true;
}
beforeEach(function () {
module('test', function($provide) {
$provide.value('loadResponses', fakeLoadResponses)
});
inject(function($controller, $rootScope) {
scope = $rootScope.$new();
$controller('aCtrl', { $scope: scope });
});
});
it('should ensure that scope.loadResponses was called upon instantiation of the controller', function () {
expect(loadResponsesInvoked).toBeTruthy();
});
});
For real world code you will probably need extra work (for example, you may not always want to fake the loadResponses method), but you get the idea.
Also, here is a nice article that explains how to create fake dependencies that actually use Jasmine spies: Mocking Dependencies in AngularJS Tests
EDIT: Here is an alternative way, that uses $provide.delegate and does not replace the original method:
describe('test spec', function(){
var scope, loadResponses;
var loadResponsesInvoked = false;
beforeEach(function () {
var loadResponsesDecorator = function ($delegate) {
loadResponsesInvoked = true;
return $delegate;
}
module('test', function($provide) {
$provide.decorator('loadResponses', loadResponsesDecorator);
});
inject(function($controller, $rootScope) {
scope = $rootScope.$new();
$controller('aCtrl', { $scope: scope });
});
});
it('should ensure that scope.loadResponses was called upon instantiation of the controller', function () {
expect(loadResponsesInvoked).toBeTruthy();
});
});
I didn't quite understand any of the answers above.
the method I often use - don't test it, instead test the output it makes..
you have not specified what loadResponses actually does.. but lets say it puts something on scope - so test existence of that..
BTW - I myself asked a similar question but on an isolated scope
angular - how to test directive with isolatedScope load?
if you still want to spy - on an unisolated scope, you could definitely use a technique..
for example, change your code to be
if ( !$scope.loadResponses ){
$scope.loadResponses = function(){}
}
$scope.loadResponses();
This way you will be able to define the spy before initializing the controller.
Another way, is like PSL suggested in the comments - move loadResponses to a service, spy on that and check it has been called.
However, as mentioned, this won't work on an isolated scope.. and so the method of testing the output of it is the only one I really recommend as it answers both scenarios.

How can I test data set in a service callback when testing a controller in AngularJS?

Lets say I have a service which queries some data and sets it in the controller, a little similar to:
(Method on controller)
DogService.query(function(data)){
if(data.isSuccess){
$scope.IloveDogs = true;
$scope.dogLovers += 1;
}
})
It is highly simplified, but how would I in my controller test that when calling a mocked dogService, that it sets the correct data?
If for simplicity we say that the function isn't asynchronous and deals with promises, I would create and inject a mock to the controller. The mock could look like:
var DogService = {
query: function(){
return true;
}
}
This unfortunately doesn't run the code where the $scope.IloveDogs is set to true, and the dogLovers is incremented by one.
Any ideas, since I would rather not have to duplicate the code in my controller from the service to the mocked service?
This is how I would normally mock a service in a unit test.
(You didn't mention which testing framework you use, so I am going to assume Jasmine as it's the most popular one at the moment).
I just create a dumb object to act as my mock and then just Jasmine's built-in spy functionality to dictate what it returns. Note that this is syntax for Jasmine 2.0.
I use $q to create a promise, and make sure I am able to reference it from my tests so I can resolve it.
describe('Spec', function() {
var scope;
var catServiceMock;
var deferredCatCall;
beforeEach(module('myModule'));
beforeEach(inject(function($controller, $rootScope, $q) {
scope = $rootScope;
//Create a mock and spy on it to return a promise
deferredCatCall = $q.defer();
catServiceMock = {
query: function() {}
};
spyOn(catServiceMock, 'query').and.returnValue(deferredCatCall.promise);
//Inject the mock into the controller
$controller('MyCtrl', {
$scope: scope,
catService: catServiceMock
});
}));
it('proves that cats are better than dogs', function() {
//resolve the promise that was returned by the mock
deferredCatCall.resolve({
isSuccess: true
});
//Need to trigger a $digest loop so angular process the resolved promise
scope.$digest();
//Check that the controller callback did something
expect(scope.iLoveCats).toBeTruthy();
});
});
For a service that does not use promises, I would possibly do something like this:
describe('Spec', function() {
var scope;
var catServiceMock;
beforeEach(module('myModule'));
beforeEach(inject(function($controller, $rootScope, $q) {
scope = $rootScope;
//Create a mock and spy on it to return a value
catServiceMock = {
query: function() {}
};
spyOn(catServiceMock, 'query').and.returnValue({
isSuccess: true
});
//Inject the mock into the controller
$controller('MyCtrl', {
$scope: scope,
catService: catServiceMock
});
}));
it('proves that cats are better than dogs', function() {
//Check that the controller callback did something
expect(scope.iLoveCats).toBeTruthy();
});
});
The main problem with this approach is that you're forced to dictate what the service will return before you instantiate the controller. This means that if you want to test how the controller behaves to different data received from the service you're going to have to have multiple beforeEach blocks nested in different describe blocks and while it looks at a glance like it's less boilerplate in the test you will end up with a lot more.
This is one of the reasons why I prefer my services to return promises even if they are not asynchronous.

Angularjs and Jasmine: Testing a controller with a service making ajax call

I am very new to testing javascript. My application is using angularjs. I am using jasmine as a testing framework.
Here is the controller I am testing:
angular.module('logonController', ["ngval", "accountFactory"])
.controller("logonController", function logOnController(accountFactory, $scope, $window) {
$scope.hasServerError = false;
$scope.Logon = function () {
accountFactory.Logon($scope.data.LogOnModel)
.then(function (data) {
$window.location.href = "/";
},
function (data) {
$scope.hasServerError = true;
});
}
})
where accountFactory.Logon is making a Post request to the server.
What I want to test is when calling accountFactory.Logon:
On success - window.location.href is called
On error $scope.hasServerError is set to true
So far I have managed to do this:
"use strict";
describe("Logon Controller", function () {
var $scope, $location, $rootScope, $httpBackend, $controller, $window, createController;
beforeEach(function () {
module("logonController");
});
beforeEach(inject(function ($injector) {
$rootScope = $injector.get("$rootScope");
$scope = $rootScope.$new();
$location = $injector.get("$location");
$httpBackend = $injector.get("$httpBackend");
$controller = $injector.get("$controller");
$window = $injector.get("$window");
}));
beforeEach(function () {
createController = function () {
return $controller("logonController", {
"$scope": $scope,
});
};
$scope.data = {
LogOnModel: { username: "user", password: "pass" }
};
$window = { location: { href: jasmine.createSpy() } };
});
it("should redirect on successfull login", function () {
var controller = createController();
$httpBackend.whenPOST("/Account/Logon").respond(function (method, url, data, headers) {
return [200, {}, {}];
});
$scope.Logon();
$httpBackend.flush();
expect($window.location.href).toHaveBeenCalled();
});
});
My idea is to create a spy on $window.location.href and only check if it is called. But I am getting
Expected spy unknown to have been called.
As I said I am very new to testing javascript, so any help will be appreciated.
Sten Muchow's Answer is wrong in several aspects:
you can't specify a compound property name ("location.href") as 2nd parameter to spyOn. You have to give a real property name.
And even if you would do the spyOn correctly, andCallThrough() would still raise an exception, as $window.location.href is not a function which could be called through.
But he is still right in saying that you should not intermingle your controller test with the service test.
To answer the question:
The reason, that your expectation is not met (that even the spy still exists*) is, that you're doing the $window.location.href assignment inside a promise's then() function. That means, it will be executed asynchronously, namely AFTER your expect() call. To go around this, you would need to make your test work asynchronously (for how to do this I would like to advise you to the Jasmine documentation: http://jasmine.github.io/2.0/introduction.html).
* In accountFactory.Logon, by doing $window.location.href = (i.e. assignment) you will effectively overwrite your spy.
Even better solution:
Instead of manipulating $window.location.href, you should use $location.url().
$location is an Angular core service. You will benefit from the integration within the Angular application lifecycle (i.e. watchers will be automatically processed when the url changes) + it is seamlessly integrated with existing HTML5 APIs like History API: https://docs.angularjs.org/guide/$location
Then, you can spy on $location.url() as you would have spied on $window.location.href (if it had been a function).
You need to create a spy:
spyOn($window, 'location.href').andCallThrough();
But on a bigger note though, you shouldnt be testing the functionality of your service in the controller test.

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