Injecting dependent services when unit testing AngularJS services - javascript

I'm testing service A, but service A depends on service B (i.e. service B is injected into service A).
I've seen this question but my case is a bit different because in my opinion it makes more sense to mock service B instead of injecting an actual instance of service B. I'd mock it with a jasmine spy.
Here's a sample test:
describe("Sample Test Suite", function() {
beforeEach(function() {
module('moduleThatContainsServiceA');
inject([
'serviceA', function(service) {
this.service = service;
}
]);
});
it('can create an instance of the service', function() {
expect(this.service).toBeDefined();
});
});
The error I get is:
Error: Unknown provider: serviceBProvider
How could I do something like this?

Actually in AngularJS Dependency Injection uses the 'last wins' rule. So you can define your service in your test just after including your module and dependencies, and then when service A that you're testing will request service B using DI, AngularJS will give mocked version of service B.
This is often is done by defining new module like MyAppMocks, putting mocked services/values there and then just adding this module as dependency.
Kind of (schematically):
beforeEach(function() {
angular.module('MyAppMocks',[]).service('B', ...));
angular.module('Test',['MyApp','MyAppMocks']);
...

I was doing this in CoffeeScript and found an extra gotcha. (Also, I found the code on this page to be confusingly terse.) Here's a complete working example:
describe 'serviceA', ->
mockServiceB = {}
beforeEach module 'myApp' # (or just 'myApp.services')
beforeEach ->
angular.mock.module ($provide) ->
$provide.value 'serviceB', mockServiceB
null
serviceA = null
beforeEach inject ($injector) ->
serviceA = $injector.get 'serviceA'
it 'should work', ->
expect( true ).toBe( true )
#serviceA.doStuff()
Without explicitly returning null after $provide.value, I kept getting Error: Argument 'fn' is not a function, got Object. I found the answer in this Google Groups thread.

The Valentyn solution worked for me, but there is another alternative.
beforeEach(function () {
angular.mock.module("moduleThatContainsServiceA", function ($provide) {
$provide.value('B', ...);
});
});
Then when AngularJS service A request the Service B by Dependency Injection, your mock of Service B will be provided instead of the Service B from moduleThatContainsServiceA.
This way you don't need to create an additional angular module just to mock a Service.

I find the simplest method is just to inject service B and mock it. e.g. Service car depends on service Engine. Now we need to mock Engine when testing Car:
describe('Testing a car', function() {
var testEngine;
beforeEach(module('plunker'));
beforeEach(inject(function(engine){
testEngine = engine;
}));
it('should drive slow with a slow engine', inject(function(car) {
spyOn(testEngine, 'speed').andReturn('slow');
expect(car.drive()).toEqual('Driving: slow');
}));
});
Reference: https://github.com/angular/angular.js/issues/1635

This is what worked for me. The key is defining a real module to be mocked. Calling angular.mock.module makes the real module mockable and allows things to be connected.
beforeEach( ->
#weather_service_url = '/weather_service_url'
#weather_provider_url = '/weather_provider_url'
#weather_provider_image = "test.jpeg"
#http_ret = 'http_works'
module = angular.module('mockModule',[])
module.value('weather_service_url', #weather_service_url)
module.value('weather_provider_url', #weather_provider_url)
module.value('weather_provider_image', #weather_provider_image)
module.service('weather_bug_service', services.WeatherBugService)
angular.mock.module('mockModule')
inject( ($httpBackend,weather_bug_service) =>
#$httpBackend = $httpBackend
#$httpBackend.when('GET', #weather_service_url).respond(#http_ret)
#subject = weather_bug_service
)
)

Related

Unit testing angular service with dependencies

I have the following Jasmine unit test:
describe('myService', function () {
var myService, $q;
// Instantiate the app
beforeEach(module('myApp'));
beforeEach(inject(function (_myService_, fileSystemService, $q) {
myService = _myService_;
spyOn(fileSystemService, 'listFiles').and.callFake(function () {
var deferred = $q.defer();
deferred.resolve('mockresult');
return deferred.promise;
});
}));
it('checks the number of outbound files', inject(function ($rootScope) {
var result;
myService.sendOutboundFiles2().then(function (res) {
result = res;
});
$rootScope.$digest();
expect(result).toBe('mockresult');
}));
});
Which tests this very simple service function:
sendOutboundFiles2() {
return fileSystemService.listFiles('Cached/Outbound').then(function(outfiles) {
return outfiles;
})
}
However when the test runs, it fails with a spurious Error: Unexpected request: GET blah\blah\blah.html No more request expected at $httpBackend error but i have no idea why as neither this test nor the service dependencies do anything with $httpBackend.
MORE INFO
If i comment out my existing controller tests, I get this error:
If i add my controller tests back in, I get this error:
So depending on which tests i add or remove, the HTML file in the GET error changes. But all the controller tests run fine. WTF?!?!?!!??!?!!?
The problem is caused by Ionic's keen prefetching of all templates into a cache. No idea why this doesn't occur when testing a controller though. The problem only appears when i was testing a service. Any way, I found this thread: Karma test breaks after using ui-router and the relevant fix is to add this snippets before injecting any dependencies:
beforeEach(module(function($provide) {
$provide.value('$ionicTemplateCache', function(){} );
}));
This stubs out the $ionicTemplateCache and prevents it from trying to preload all ui-router templates into the Ionic cache.

Karma + PhantomJS TypeError: undefined is not an object (evaluating scope.jackpot)

I am still very new to unit testing, and to be honest, there isn't anything that I could even think of testing, but I cannot build my app unless I have at least 1 test case, so I attempted to make the most simple test case I could, on the smallest block of code in the controller, and it doesn't seem to be working.
I believe it's an error in my test case, and not in my controller's code itself, because when I view my app in the browser with grunt serve the console shows no errors.
This is the error it gives me:
PhantomJS 2.1.1 (Linux 0.0.0) Controller: MainCtrl should attach a list of jackpot to the scope FAILED
/home/elli0t/Documents/Yeoman Projects/monopoly/app/bower_components/angular/angular.js:3746:53
forEach#[native code]
forEach#/home/elli0t/Documents/Yeoman Projects/monopoly/app/bower_components/angular/angular.js:323:18
loadModules#/home/elli0t/Documents/Yeoman Projects/monopoly/app/bower_components/angular/angular.js:3711:12
createInjector#/home/elli0t/Documents/Yeoman Projects/monopoly/app/bower_components/angular/angular.js:3651:22
workFn#/home/elli0t/Documents/Yeoman Projects/monopoly/app/bower_components/angular-mocks/angular-mocks.js:2138:60
TypeError: undefined is not an object (evaluating 'scope.jackpot') in /home/elli0t/Documents/Yeoman Projects/monopoly/test/spec/controllers/main.js (line 20)
/home/elli0t/Documents/Yeoman Projects/monopoly/test/spec/controllers/main.js:20:17
PhantomJS 2.1.1 (Linux 0.0.0): Executed 1 of 1 (1 FAILED) ERROR (0.04 secs / 0.007 secs)
This is my test case:
it('should attach a list of jackpot to the scope', function () {
expect(scope.jackpot.length).toBe(2);
});
And this is the block of code I'm attempting to run the test on:
var countInJackpot = localStorageService.get('jackpot');
$scope.jackpot = countInJackpot || [
{
letter: '$',
prize: '$1,000,000 Cash',
numbers: ['$611A','$612B','$613C','$614D','$615E','$616F','$617G','$618F'],
count: [0,0,0,0,0,0,0,0]
},
{
letter: '?',
prize: '$500,000 Vacation Home',
numbers: ['?619A','?620B','?621C','?622D','?632E','?624F','?625G','?626H'],
count: [0,0,0,0,0,0,0,0]
}
];
For the time being, I really just want to write 1 simple test case, so it will let me build the app. I'm currently studying unit testing, but I still don't feel ready to write more complex test cases on my own. I will save that for later.
I have included the entire contents of the files in a gist for reference, if needed, and I can include the contents of the karma.conf.js if necessary.
My gist
Within your test case, scope should be $scope?
OR
You probably haven't setup your testing environment to load in your controller.
Here is an example of mine on testing a controller... Angular makes the setup a little iffy to learn, But once you understand the flow. It's pretty great :)
I'm going to try and add as many comments to explain each piece as I can... but let me know if your need clarification. You might be using jasmine, but keep in mind, this is mocha, im using the angular mock library loaded in via the karma.conf.
describe('myController', function() {
var $scope,
createController;
// Runs before each test. Re-extantiating the controller we want to test.
beforeEach(inject(function($injector) {
// Get hold of a scope (i.e. the root scope)
$scope = $injector.get('$rootScope');
// The $controller service is used to create instances of controllers
var $controller = $injector.get('$controller');
createController = function() {
// Creates the controller instance of our controller.
// We are injecting $scope so we will have access to it
// after the controllers code runs
return $controller('myCtrl', {
'$scope': $scope
});
};
}));
describe('#myFunction', function() {
it('jackpot should contain two objects', function() {
expect($scope.jackpot.length).to.equal(2);
});
});
});
Hope that helped. Here's some of the resources I used to learn :) Good Luck!
https://quickleft.com/blog/angularjs-unit-testing-for-real-though/
http://jaketrent.com/post/run-single-mocha-test/
I would expect you'd want to test both cases of the localStorageService having and not having data. To do so, create a spy for localStorageService (see Spies) and write your tests like this...
'use strict';
describe('Controller: MainCtrl', function () {
var scope, localStorageService, localData;
beforeEach(function() {
localData = {};
module('monopolyApp');
localStorageService = jasmine.createSpyObj('localStorageService', ['get', 'set']);
localStorageService.get.and.callFake(function(key) {
return localData[key];
});
inject(function($rootScope) {
scope = $rootScope.$new();
});
});
it('assigns jackpots from local storage if present', inject(function($controller) {
localData.jackpot = 'whatever, does not matter';
$controller('MainCtrl', {
$scope: scope,
localStorageService: localStorageService
});
expect(localStorageService.get).toHaveBeenCalledWith('jackpot');
expect(scope.jackpot).toBe(localData.jackpot);
}));
it('assigns jackpots from default array if none present in local storage', inject(function($controller) {
$controller('MainCtrl', {
$scope: scope,
localStorageService: localStorageService
});
expect(localStorageService.get).toHaveBeenCalledWith('jackpot');
expect(scope.jackpot.length).toEqual(2);
// maybe include some other checks like
expect(scope.jackpot[0].letter).toEqual('$');
expect(scope.jackpot[1].letter).toEqual('?');
}));
});

Testing Angular Factory with prototypes in Jasmine

I'm trying to test a angular factory constructed as the following:
angular.module('app')
.factory('PaymentCalculatorFactory', [
function() {
return {
function1: function1,
function2: function2,
// more functions
};
function function1() {
// implementation
}
function function2(){
// implementation
}
}]);
I'm using angular mocks and Jasmine with a tried and true pattern that I've used elsewhere but for some reason I'm getting the DI error
Unknown provider: PaymentCalculatorFactoryProvider <- PaymentCalculatorFactory
Here is the start of my jasmine tests
describe("Payment Calculator Factory", function() {
var factory;
beforeEach(module('app'));
beforeEach(inject(function(PaymentCalculatorFactory) {
factory = PaymentCalculatorFactory;
}));
// more describes and its and such
As far as I can tell all the files are in the correct location for testing. Any suggestions?
It was the ordering in the Grunt config... I had to put the file that contained the "app" module before the file that contained the PaymentCalculatorFactory. Thanks to #MicahWilliamson for pointing me towards the config.

Spyon provider during config phase in angular.js application

I am writing unit tests for an Angular.js application (with karma and jasmine), and I want to test a certain behavior in the CONFIG phase of a module. I would like to confirm that a certain function of a PROVIDER is being called. I thought I could do this with a spy on the provider's method, but gaining access to the provider before the "expect" has proven rather tricky.
Here is some example code:
Module Code (being tested)
var myApp = angular.module('myApp', ['restangular']);
myApp.config(['RestangularProvider', function (RestangularProvider) {
RestangularProvider.setBaseUrl('http://someurl:someport/');
}]);
I've tried various solutions to get a reference to the RestangularProvider and apply a spy to it, and all failed. The closest I was able to get was the code below:
Unit Test Code
describe("Test if setBaseUrl was called", function () {
var RestangularProvider;
beforeEach(module('myApp', function(_RestangularProvider_) {
RestangularProvider = _RestangularProvider_;
spyOn(RestangularProvider, "setBaseUrl").and.callThrough();
}));
it("should call setBaseUrl.", function() {
expect(RestangularProvider.setBaseUrl).toHaveBeenCalled();
});
});
I do actually get the reference to the RestangularProvider, but the "config" function of the module gets called before that, so I think the spy doesn't get set-up.
I did find a post where the author solved a similar situation with a "work around" by testing the configured "service" instead of testing the actual call to the provider's method. In the example above, I would test the Restangular.configuration.baseUrl in my expect instead of testing the actual call to the provider's setBaseUrl method, but this seemed like it would not be adequate in certain situations.
I am rather new to Angular.js so this may simply be a case of being totally clueless as to the whole "testing config phase", so if that's the case, please feel free to set me straight :]
Any suggestions, critiques or pointers?
I finally solved the problem by separating out the module, whose provider I wanted to spy on, into a diferent "beforeEach" block. The altered code is below, but I still would appreciate any comments as to the whole idea of whether or not this is actually an "adequate test".
describe("Test if setBaseUrl was called", function () {
var RestangularProvider;
//Setup the spy.
beforeEach(function () {
module("restangular", function(_RestangularProvider_) {
RestangularProvider = _RestangularProvider_;
spyOn(_RestangularProvider_, 'setBaseUrl').and.callThrough();
});
});
beforeEach(module('myApp'));
it("should call setBaseUrl.", function() {
expect(RestangularProvider.setBaseUrl).toHaveBeenCalled();
});
});
As described by OP above, you do need to get the provider before calling the module you want to test.
However, there's no need to separate it in two beforeEach blocks. You also must call inject() function (even if you have nothing to inject) at the end of the beforeEach block.
describe('Test if setBaseUrl was called', function () {
var RestangularProvider;
//Setup the spy.
beforeEach(function () {
module('restangular', function(_RestangularProvider_) {
RestangularProvider = _RestangularProvider_;
spyOn(_RestangularProvider_, 'setBaseUrl').and.callThrough();
});
module('myApp');
inject();
});
it('should call setBaseUrl.', function() {
expect(RestangularProvider.setBaseUrl).toHaveBeenCalled();
});
});
Source: http://java.dzone.com/articles/unit-testing-config-and-run

Unit test when loading things at app run with AngularJS

I need my app to run some configuration at runtime vi an HTTP endpoint.
I wrote a simple service to do that:
module.factory('config', function ($http, analytics) {
return {
load: function () {
$http.get('/config').then(function (response) {
analytics.setAccount(response.googleAnalyticsAccount);
});
}
}
});
Next, I call this module in a run block of my app module:
angular.module('app').***.run(function(config) {
config.load();
});
All is working well when the app is running but in my unit tests, I get this error: "Error: Unexpected request: GET /config"
I know what it means but I don't know how to mock it when it happens from a run block.
Thanks for your help
EDIT to add spec
Calling this before each
beforeEach(angular.mock.module('app'));
Tried this to mock $httpBackend:
beforeEach(inject(function($httpBackend) {
$httpBackend.expectGET('/config').respond(200, {'googleAnalyticsAccount':});
angular.mock.module('app')
$httpBackend.flush();
}));
But got:
TypeError: Cannot read property 'stack' of null
at workFn (/Users/arnaud/workspace/unishared-dredit/test/lib/angular/angular-mocks.js:1756:55)
TypeError: Cannot read property 'stack' of null
at workFn (/Users/arnaud/workspace/unishared-dredit/test/lib/angular/angular-mocks.js:1756:55)
TypeError: Cannot read property 'stack' of null
at workFn (/Users/arnaud/workspace/unishared-dredit/test/lib/angular/angular-mocks.js:1756:55)
EDIT since update to AngularJS 1.0.6
Since I've updated to AngularJS 1.0.6, advised by Igor from the Angular team, the issue is gone but now I've now got this one, which sounds more "normal" but I still can't figure out how to make it works.
Error: Injector already created, can not register a module!
I struggled with this error for a little while, but managed to come up with an sensible solution.
What I wanted to achieve is to successfully stub the Service and force a response, on controllers it was possible to use $httpBackend with a request stub or exception before initiating the controller.
In app.run() when you load the module it initialises the object and it's connected Services etc.
I managed to stub the Service using the following example.
describe('Testing App Run', function () {
beforeEach(module('plunker', function ($provide) {
return $provide.decorator('config', function () {
return {
load: function () {
return {};
}
};
});
}));
var $rootScope;
beforeEach(inject(function (_$rootScope_) {
return $rootScope = _$rootScope_;
}));
it("defines a value I previously could not test", function () {
return expect($rootScope.value).toEqual('testing');
});
});
I hope this helps your app.run() testing in the future.
I don't know if you are still looking for an answer to this question. But here is some information that might help.
$injector is a singleton for an application and not for a module. However, angular.injector will actually try to create a new injector for each module (I suppose you have a
beforeEach(module("app"));
at the beginning.
I had the same problem while using Angular, RequireJS, Karma and Jasmine and I figured out two ways to solve it. I created a provider for the injector function as a separate dependency in my tests. For example MyInjectorProvider which provides a singleton instance of $injector.
The other way was to move the following statements:
beforeEach(module("app"));
beforeEach(inject(function($injector){
...
})
inside the test suite description. So here is how it looked before:
define(['services/SignupFormValidator'], function(validator){
var validator;
beforeEach(module("app"));
beforeEach(inject(function($injector){
validator = $injector.get("SignupFormValidator");
})
describe("Signup Validation Tests", function(){
it("...", function(){...});
});
});
After applying the fix it looks like this:
define(['services/SignupFormValidator'], function(validator){
var validator;
describe("Signup Validation Tests", function(){
beforeEach(module("app"));
beforeEach(inject(function($injector){
validator = $injector.get("SignupFormValidator");
});
it("...", function(){...});
});
});
Both the solutions worked in my case.
You should mock every HTTP request with ngMock.$httpBackend. Also, here is a guide.
Update
You don't need the angular.mock.module thing, just need to inject your app module. Something like this:
var httpBackend;
beforeEach(module('app'));
beforeEach(inject(function($httpBackend) {
httpBackend = $httpBackend;
$httpBackend.expectGET('/config').respond(200, {'googleAnalyticsAccount': 'something'});
}));
In your tests, when you need the mocked http to answer, you will call httpBackend.flush(). This is why we have a reference to it, so you don't need to inject it in every single test you have.
Note you will need to load angular-mock.js in order to it work.

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