Moq - how to initialize testing object once for multiple tests - c#

I am trying to structure my unit test in such a way that if I change the constructor of the object being tested I don't have to change a lot of tests. Here is a simplified example of my set up right now:
[TestMethod]
public void Test1()
{
_mockedObject1.Setup(etc);
_mockedObject2.Setup(etc);
var service = new TestedService(_mockedObject1.Object, _mockedObject2.Object, ...,
_mockedObject7.Object);
//Act and Assert
}
Now I've got 20 unit tests that are arranged this same way. If I have to change the constructor of TestedService I have to go into all 20 tests and change the line that creates service. Can I pull this line of code out into TestInitialize or something so that I would only have to change it one time? My first thought is that I can't because then service would get created before my .Setups. Is there another way to handle this?

Yes, you can pull the creation of your service before setting up the dependencies. The SetUp will still be bound to the mocked objects. You could try something like:
private TestedService service;
[SetUp]
public void SetUp()
{
this.service = new TestedService(_mockedObject1.Object, _mockedObject2.Object, ...,
_mockedObject7.Object);
}
[TestMethod]
public void Test1()
{
_mockedObject1.Setup(etc);
_mockedObject2.Setup(etc);
//Act and Assert
this.service.Whatever(...);
}

Take a look at Automoqing since you are already using Moq it would do what you want or even better. Simply it is Dependency Injection container that injects mocks.

You can initialize these objects in the function with a [ClassInitialize()] attribute. This is supposed to run before any tests within that class run.

Related

NUnit TestFixtures do not work with RestSharp

I'm trying to use NUnit TestAttributes to create and delete a RestSharp RestClient
https://github.com/nunit/docs/wiki/TestFixture-Attribute
using NUnit.Framework;
using RestSharp;
namespace Sanitized.Sanitized.Steps
{
[TestFixture]
public class SetupAndTeardown
{
public RestClient restClient;
[SetUp]
public void Init()
{
restClient = new RestClient();
}
[TearDown]
public void Cleanup()
{
restClient = null;
}
}
}
But, I get the error Object reference not set to an instance of an object. when trying to use this in another class i.e. with my automated steps.
I don't understand this, as I thought code that's in the [SetUp] [Teardown] attributes are called at the beginning and end of the test respectively.
You created a TestFixture, which is a class that contains tests. If the fixture had any tests, then NUnit would run them and would also run the setup before each test and the teardown after each test. Since you have no tests, that isn't happening. NUnit recognizes the fixture but finds nothing to run there.
You say that you have a problem when you "use" this fixture in another class. Test fixtures are not intended to be "used" by other code. Rather, they are run by NUnit.
For a better answer about how to do what you are trying to do, we first need to know what you are trying to do. When do you want the "setup" and "teardown" to run? How often should they run? Depending on those things, I can update this answer.
Replying further to your comment... If your tests are in another class, then that class is your test fixture. Is there a reason you don't want it to be the fixture?

Any way to use Moq to imitate properties of a real-world constructor automatically?

I've got a controller with a lot of constructor injection:
public MoviesController(ISession session, IClientContext clientContext, PManager pManager, ISegmentationService segmentationService, IGeoLocator geoLocator, IBus bus)
{
_session = session;
_clientContext = clientContext;
_pManager = pManager;
_segmentationService = segmentationService;
_geoLocator = geoLocator;
_bus = bus;
}
From my understanding (just read about Mocking), I've got a lot of Mock object properties to manually set if I wish to make a comprehensive test suite based on this controller.
For one method I'm only using one service (I'd even like to automate that with little effort if possible):
public object Show(Guid id)
{
var movie = _session.Get<movie>(id);
return movie;
}
But in another there are many services being used - is there any way to set those Moq objects up quickly? I could really use some examples as I'm new to testing. It's an asp.net mvc project with webapi 1 bundled in (testing the webapi controller here)
As has been said in the comments, if you have common setup code, you can put it in a Setup method that is called automatically from your testing framework before each test. It's decorated with a Setup attribute if you're using Nunit TestInitialize if you're using MStest. If you're using XUnit then it's a bit different.
So, your class might look like this:
public class SomeTests {
Mock<ISession> _sessionMock;
Mock<IClientContext> _clientContextMock;
[Setup]
public void Setup() {
_sessionMock = new Mock<ISession>();
_clientContextMock = new Mock <IClientContext();
}
MovieController CreateSut() {
return new MovieController(_sessionMock.Object, _clientContextMock.Object, ...);
}
[Test]
public void TestSomething() {
_sessionMock.Setup(x=>...);
//...
var sut = CreateSut();
//...
}
}
If you're trying to get away from completely creating the mocks manually, then you might want to look at something like AutoFixture with AutoMoq. Which will automatically supply mock instances when creating objects that accept interfaces. AutoFixture can be quite useful, but there is a learning curve to using it effectively so you might want to look at a tutorial / quickstart.
You could also configure an IOC container to supply mock instances for your test project, although I've never gone down that route myself.
For your example, you only need to mock the session, and can leave all the other dependencies null, since their behaviour should be irrelevant to the behaviour you are testing:
Mock<ISession> mockSession = new Mock<ISesssion>();
MoviesController controller = new MoviesController(mockSession.Object, null,null,null,null,null);
There is no need for you to set up any mocks other than the ones you need for this particular test

Unit Testing Quartz.net Execute()

First off, I am new to Quartz.net and Moq.
I am trying to unit test Quartz.net Execute method using Moq. The Execute() is defined in the IJob interface. The Execute method needs an IJobExecutionContext to be passed to it.
I have created a new job class named RunItinerary that inherits from the IJob interface. Below is an example of what I have.
public class RunItinerary : IJob
{
public RunItinerary()
{
}
public RunItinerary(IBFDatabase db) : base(db)
{
}
public override void Execute(IJobExecutionContext context)
{
// magic happens
}
}
Below is an example of my unit test. I have been unsuccessful in all my attempts to run a simple unit test. Here is an example of a test I tried.
var mockIJobExecutionContext = new Mock<IJobExecutionContext>();
var runItinerary = new RunItinerary();
runItinerary.Execute(mockIJobExecutionContext.Object);
mockIJobExecutionContext.VerifyAll();
Below is the error: (the x's are to mask internal names)
Test method xx.xxxxxx.xxxxxxxx.xxxJobs.UnitTest.RunItineraryTest.Execute_Success threw exception:
xx.common.Data.Exceptions.DatabaseConfigurationSectionNotFoundException: JobDatabase
at xx.common.Data.Abstract.xxDatabase..ctor(String configSectionName) in xxDatabase.cs: line 39
at xx.windows.Scheduler.Data.JobDatabase..ctor(String configSectionName) in JobDatabase.cs: line 24
at xx.windows.Scheduler.Data.JobDatabase..ctor() in JobDatabase.cs: line 20
at xx.windows.Scheduler.Jobs.BaseJob..ctor() in BaseJob.cs: line 45
at xx.windows.Scheduler.xxxJobs.RunItinerary..ctor() in RunItinerary.cs: line 31
at xx.windows.Scheduler.xxxJobs.UnitTest.RunItineraryTest.Execute_Success() in RunItineraryTest.cs:
line 177
I believe something that I am missing is in the mockIJobExecutionContext.Setup(x => x.???????), I just cannot figure out what it is that I need to do with the .Setup()
I have reviewed similar posted questions about unit testing this Execute() but there has not been a clear answer with sample code.
If someone can provide an answer can you please provide a sample unit test for this?
It seems that the RunItinerary (the class you are testing) has a 'default' behaviour when it comes to its dependency on IBFDatabase, which seems to be to new up an instance of a concrete class JobDatabase. Because this is a unit test, the JobDatabase is failing presumably because of missing configuration (e.g. connection strings etc)
xx.windows.Scheduler.Data.JobDatabase..ctor() in JobDatabase.cs: line 20
Fortunately, it would appear that you have an alternate RunItinerary constructor allowing you to provide the IBFDatabase dependency:
var mockJobExecutionContext = new Mock<IJobExecutionContext>();
var mockBFDatabase = new Mock<IBFDatabase>();
// You may need to do the minimal required Setups on `mockBFDatabase` here
var runItinerary = new RunItinerary(mockBFDatabase.Object); // i.e. use the other ctor
runItinerary.Execute(mockIJobExecutionContext.Object);
mockJobExecutionContext.Verify(x => x.SomeMethod(someParam), Times.Once);
mockBFDatabase.Verify(x => x.FetchSomeData(theIdIAmExpecting), Times.Once);
Although it is quite commonplace when retrofitting unit tests (and dependency injection) into legacy code to have 'fallbacks' which couple classes to their dependencies if no injected dependency is provided, I would recommend that you try remove these ASAP to eliminate the coupling to concrete dependencies and replace this with an IoC container managed strategy - this way you can be 100% sure that the code you are unit testing is indeed the real production code.

Unit Test with Ninject Instantiate

I'm trying to test my service using ninject and an unit test project with visual studio 2012. My inject works ok on my controllers, but when I try to do the same in the unit test class I get an Exception.
System.NullReferenceException: Object reference not set to an instance of an object.
namespace Trex.UnitTests
{
[TestClass]
public class GiftServiceTests
{
private IGiftService _giftService;
public void GiftServiceTest(IGiftService giftService)
{
_giftService = giftService;
}
[TestMethod]
public void AddGift()
{
var list = _gift.FindAll(); <--- this line throw an exception
}
}
}
I think there is something wrong with the injection but I dont get it.
It looks to me like a typo of _giftService. In addition, attribute [TestInitialize] needs to be used in your constructor.
Try the following code by placing the correct service name _giftService - that your code is injecting instead:
var list = __giftService.FindAll();
Edit: Unit testing should be done without Ninject. Just create an instance of the object under test and inject a mock for every dependency manually.
Here is a sample with [TestInitialize]:
The unit test must have a default constructor:
[TestClass]
public class TestControllersHomeController
{
private HomeController _sut;
[TestInitialize]
public void MyTestInitialize()
{
var kernel = NinjectWebCommon.CreatePublicKernel();
_sut = kernel.Resolve<HomeController>();
}
[TestMethod]
public void TestIndex()
{
var result = _sut.Index();
Assert.IsNotNull(result);
}
}
The only way dependency injection is able to call your constructor and fill it with a parameter that has a value is if the dependency injection kernel is the one that instantiates your class.
In your case, MSTest is instantiating your test class, so Ninject does not have a chance to call your constructor.
To be honest, you are going about this the wrong way. You will battle MSTest if you pursue this further to try to get Ninject (or any other DI framework) to instantiate your test classes.
I would recommend you use 'new' to instantiate the class under test (_giftService = new GiftService();). If that class has dependencies in its constructor, use a mocking framework to pass in mocked version of those dependencies. This way you isolate your unit tests to only the functionality of the class under test.
_gift is null. Your variable is _giftService. You also should use the [TestInitialize] attribute for your constructor.
Extra tip:
You shouldn't create any dependencies in your unit test. So the giftService which you want to use should be a mock or a stub.

Best approach for breaking dependencies in C#?

We are looking at adding unit tests to our C# code base. I am finding it easy to add unit tests to simple classes, but classes that interact with other dependencies are more difficult. I have been looking at mocking frameworks, but was wondering about the best approach to write classes in the first place to break external dependencies, like file system, database and messaging system dependencies.
To give an example, a routine listens on a socket for a message in a certain format - say MessageA. This is decoded, some calculations are done, this is re-encoded into a different binary format and the resulting message then sent, MessageB.
My current testing approach is as follows. I extract an interface for all socket interactions, and create a mock interface. I set the interface in a singleton. Then run the class against hard coded inputs. The class under test will use the interface in the singleton to send/receive.
I do a similar thing to test database interactions.
This does not seem like the most flexible approach, how would you go about improving this to make it easier to test? If a mocking framework is the answer, how would I design the classes?
Example code :
[SetUp]
public void init()
{
// set message interface in singleton as mock interface
CommAdapter.Instance.MessageAdapter = new MockMessage();
// build reference message from hard coded test variables
initialiseMessageA();
// set input from mock message socket
((MockMessage) CommAdapter.Instance.MessageAdapter).MessageIn = m_messageA;
}
[Test]
public void test_listenMessage_validOutput()
{
// initialise test class
MessageSocket tS = new MessageSocket();
// read from socket
tS.listenMessage();
// extract mock interface from singleton
MockMessage mm = ((MockMessage) CommAdapter.Instance.MessageAdapter);
// assert sent message is in correct / correstpoinding format
Assert.AreEqual(1000001, mm.SentMessageB.TestField);
}
Instead of using Singletons to set your component implementations, use a Dependency Injection, and a DI library like Ninject. This is exactly the type of scenario they were designed for.
Not pushing you to Ninject specifically, but they have a good tutorial :) The concepts will transfer to other frameworks (like Unity).
https://github.com/ninject/ninject/wiki
With DI alone, the code will look something like this:
class Samurai {
private IWeapon _weapon;
public Samurai(IWeapon weapon) {
_weapon = weapon;
}
public void Attack(string target) {
_weapon.Hit(target);
}
}
class Shuriken : IWeapon {
public void Hit(string target) {
Console.WriteLine("Pierced {0}'s armor", target);
}
}
class Program {
public static void Main() {
Samurai warrior1 = new Samurai(new Shuriken());
Samurai warrior2 = new Samurai(new Sword());
warrior1.Attack("the evildoers");
warrior2.Attack("the evildoers");
}
}
This looks clean now, but wait until your dependencies have dependencies, or further :) You can use a DI library to solve that, though.
With a library to handle the wiring up for you, it will look something like:
class Program {
public static void Main() {
using(IKernel kernel = new StandardKernel(new WeaponsModule()))
{
var samurai = kernel.Get<Samurai>();
warrior1.Attack("the evildoers");
}
}
}
// Todo: Duplicate class definitions from above...
public class WarriorModule : NinjectModule {
public override void Load() {
Bind<IWeapon>().To<Sword>();
Bind<Samurai>().ToSelf().InSingletonScope();
}
}
With either of these approaches, plus a mock object framework like Moq, your unit tests look something like this:
[Test]
public void HitShouldBeCalledByAttack()
{
// Arrange all our data for testing
const string target = "the evildoers";
var mock = new Mock<IWeapon>();
mock.Setup(w => w.Hit(target))
.AtMostOnce();
IWeapon mockWeapon = mock.Object;
var warrior1 = new Samurai(mockWeapon);
// Act on our code under test
warrior1.Attack(target);
// Assert Hit was called
mock.Verify(w => w.Hit(target));
}
You'll notice you can just pass mock instances straight into the code under test, and you don't have to mess around with setting singletons. This will help you avoid problems like needing to set up the state multiple times, or in between calls. It means no hidden dependencies.
You'll also notice I didn't use the DI container in the tests. If your code is well factored, it will only be testing a single class (and as often as possible, only a single method), and you will only need to mock out the direct dependencies of that class.
In addition to a DI container (I'm using MS Unity 2.0 currently but there are many to choose from) you will need a good mocking framework, my preference is MOQ. A common pattern/process for breaking concrete dependencies is:
define the dependency via an interface; you may luck out and already have an interface, like IDbConnection or you may need to use Proxy to wrap a concrete type and define your own interface.
resolve the concrete implementation via your DI container
inject your mock implementations into your DI container at test setup time (inject real impls. at system startup)

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