I'm trying to figure out the best way to build my unit tests for an MVC app. I created a simple model and interface, which is used by the controller constructors so that the testing framework (Nsubstitute) can pass a mocked version of the repository. This test passes, as expected.
My problem is now I want to take this a step further and test the file I/O operations in the "real" instantiation of IHomeRepository. This implementation should read a value from a file in the App_Data directory.
I've tried building a test without passing a mocked version of IHomeRepsotory in, however HttpContext.Current is null when I run my test.
Do I need to mock HttpContext? Am I even going about this in the right way?
//The model
public class VersionModel
{
public String BuildNumber { get; set; }
}
//Interface defining the repository
public interface IHomeRepository
{
VersionModel Version { get; }
}
//define the controller so the unit testing framework can pass in a mocked reposiotry. The default constructor creates a real repository
public class HomeController : Controller
{
public IHomeRepository HomeRepository;
public HomeController()
{
HomeRepository = new HomeRepoRepository();
}
public HomeController(IHomeRepository homeRepository)
{
HomeRepository = homeRepository;
}
.
.
.
}
class HomeRepoRepository : IHomeRepository
{
private VersionModel _version;
VersionModel IHomeRepository.Version
{
get
{
if (_version == null)
{
var absoluteFileLocation = HttpContext.Current.Server.MapPath("~/App_Data/repo.txt");
if (absoluteFileLocation != null)
{
_version = new VersionModel() //read the values from file (not shown here)
{
BuildNumber = "value from file",
};
}
else
{
throw new Exception("path is null");
}
}
return _version;
}
}
}
[Fact]
public void Version()
{
// Arrange
var repo = Substitute.For<IHomeRepository>(); //using Nsubstitute, but could be any mock framework
repo.Version.Returns(new VersionModel
{
BuildNumber = "1.2.3.4",
});
HomeController controller = new HomeController(repo); //pass in the mocked repository
// Act
ViewResult result = controller.Version() as ViewResult;
var m = (VersionModel)result.Model;
// Assert
Assert.True(!string.IsNullOrEmpty(m.Changeset));
}
I believe you want test the real instantiation of IHomeRepository, which connects to a real database. In that case you need an App.config file, which specify the connection string. This is not a Unit test and it would an Integration Test. With HttpContext being null, you still can fake the HttpContext, retrieve real data from the database. See also here.
Related
I can make it work, but I want to know what the best practice is and why. I have a Controller, a Model, and a Repository and now I want to Unit Test the Controller. I am just writing a simple test to ensure that the correct view is being returned.
This is my method in the controller:
public ActionResult Selections(SelectionsViewModel model)
{
for (int i = 0; i < model.Sends.Count; i++)
{
Send send = new Send(new SendService(new Database().GetConnectionString()))
{
SendID = model.Sends[i].SendID,
Title = model.Sends[i].Title,
Subject = model.Sends[i].Subject,
SentDate = model.Sends[i].SentDate,
TimesViewed = model.Sends[i].TimesViewed,
Include = model.Sends[i].Include,
Exclude = model.Sends[i].Exclude
};
send.UpdateIncludeExclude();
}
return View(model);
}
Here is my GetConnectionString() method in the Database class that is being sent via my SendService constructor.
public string GetConnectionString()
{
return System.Configuration.ConfigurationManager.ConnectionStrings["DEVConnectionString"].ToString();
}
And lastly, my unit test:
[Test]
public void TestAssignmentSelections()
{
var obj = new AssignmentController();
var actResult = obj.Selections() as ViewResult;
NUnit.Framework.Assert.That(actResult.ViewName, Is.EqualTo("Selections"));
}
Now, my unit test fails, and I get why. My unit test project has no access to the web.config of the project I am testing where my connection string resides.
I've done some research, and apparently just adding a web.config to my unit test project and putting the connection string in there as well will make it work.. but that seems like a hack.
What's the best way to go about this? Is there another way to write my code to accommodate for this?
You want to make your controller unit testable ? Don't do this.
new SendService(
With this code,you are hardcoding your concrete service implementation & your data access code implementation. In your unit test, you should not be really accessing the data from your database. Instead you should be providing a mock data access implementation.
Here comes interfaces, you need to create an interface for your SendService.
public interface ISendService
{
void SomeMethod();
}
now your SendService will be a concrete implementation of this interface
public class SendService : ISendService
{
public void SomeMethod()
{
// Do something
}
}
Now update your controller to have a constructor where we will inject an implementation of ISendService.
public class YourController : Controller
{
private ISendService sendService;
public YourController(ISendService sendService)
{
this.sendService = sendService;
}
public ActionResult YourActionMethod()
{
// use this.sendService.SomeMethod();
}
}
And you may use some dependency injection frameworks to tell the MVC framework which implementation of the interface to use when the code runs. If you are using MVC6,It has an inbuilt dependency injection provider you can use. So go to your Startup class and in your ConfigureServices method, you can map an interface to a concrete implementation.
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddTransient<ISendService, SendService>();
}
}
If you are in a previous version of MVC, You may consider DI frameworks like Unity,Ninject etc. You can do the same approach for your Data access later / Service layers. ie: Create an interface for data access and inject that to your SendService.
public Interface IDataAccess
{
string GetName(int id);
}
and an implementation which uses your specific data access code/ORM
public class EFDataAccess : IDataAccess
{
public string GetName(int id)
{
// return a string from db using EF
}
}
So now your Service class will be
public class SendService : ISendService
{
private IDataAccess dataAccess;
public SendService(IDataAccess dataAccess)
{
this.dataAccess=dataAccess;
}
// to do : Implement methods of your ISendService interface.
// you may use this.dataAccess in those methods as needed.
}
In your unit tests, you can create a mock implementation of your interfaces which returns static data instead of accessing the database.
For example, If you are using Moq mocking framework, you can do this.
var m = new Mock<IDataAccess>();
var m.Setup(s=>s.GetName(It.IsAny<int>())).Returns("Test");
var s = new SendService(m);
var result= s.SomeMethod();
I'm just learning how dependency injection and mocking work, but I'd like some feedback on how I'm setting up a couple of tests. I can get them to pass, but I'm not sure this is all I need.
This is an MVC application that makes Web API calls to return data. For this example I'm running queries in the Web APIs that populate dropdowns.
Please give me any and all suggestions about what I'm doing right or wrong here or anything I should be doing differently.
Setup file for Dependency Injection - Unity.WebAPI (NuGet Package)
UnityConfig.cs
public static class UnityConfig
{
public static void RegisterComponents()
{
var container = new UnityContainer();
// register all your components with the container here
// it is NOT necessary to register your controllers
// e.g. container.RegisterType<ITestService, TestService>();
container.RegisterType<IDropDownDataRepository, DropDownDataRepository>();
GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
}
}
CONTROLLER
public class DropDownDataController : ApiController
{
private IDropDownDataRepository _dropDownDataRepository;
//Dependency Injection (I'm using Unity.WebAPI)
public DropDownDataController(IDropDownDataRepository dropDownDataRepository)
{
_dropDownDataRepository = dropDownDataRepository;
}
[HttpGet]
public HttpResponseMessage DateList()
{
try
{
return _dropDownDataRepository.DateList();
}
catch
{
throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.NotFound));
}
}
}
REPOSITORY
public class DropDownDataRepository : IDropDownDataRepository
{
//Is this fine in here, or should it be injected somehow too?
private MyDatabaseEntities db = new MyDatabaseEntities();
public HttpResponseMessage DateList()
{
var sourceQuery = (from p in db.MyProcedure()
select p).ToList();
string result = JsonConvert.SerializeObject(sourceQuery);
var response = new HttpResponseMessage();
response.Content = new StringContent(result, System.Text.Encoding.Unicode, "application/json");
return response;
}
}
INTERFACE
public interface IDropDownDataRepository
{
HttpResponseMessage DateList();
}
UNIT TESTS
/// <summary>
/// Tests the DateList method is run
/// I pieced this kind of test together from examples online
/// I'm assuming this is good for a simple test
/// </summary>
[TestMethod]
public void DateListTest1()
{
//Arrange
var mockRepository = new Mock<IDropDownDataRepository>();
mockRepository.Setup(x => x.DateList());
var controller = new DropDownDataController(mockRepository.Object);
//Act
controller.DateList();
//Assert
mockRepository.VerifyAll();
}
/// <summary>
/// Tests the DateList method returns correct status code.
/// This will run with success, but I'm not sure if that's just
/// because I'm telling it to return what I'm expecting.
/// I welcome suggestions for improvement.
/// </summary>
[TestMethod]
public void DateListTest2()
{
//Arrange
var mockRepository = new Mock<IDropDownDataRepository>();
mockRepository
.Setup(x => x.DateList())
//This will only succeed if I have the Returns property here,
//but isn't that just bypassing the actual "test" of whether or
//not this works?
.Returns(new HttpResponseMessage(HttpStatusCode.OK));
DropDownDataController controller = new DropDownDataController(mockRepository.Object);
controller.Request = new HttpRequestMessage();
controller.Configuration = new HttpConfiguration();
//Act
var response = controller.DateList();
//Assert
Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
}
UPDATE 1
One of my main questions here is what the .Returns property actually does. In my second unit test, I'm telling it to return OK, then check if it returns OK. I can't see how that's actually testing anything.
One of my main questions here is what the .Returns property actually
does. In my second unit test, I'm telling it to return OK, then check
if it returns OK. I can't see how that's actually testing anything.
The code:
mockRepository
.Setup(x => x.DateList())
//This will only succeed if I have the Returns property here,
//but isn't that just bypassing the actual "test" of whether or
//not this works?
.Returns(new HttpResponseMessage(HttpStatusCode.OK));
Says that when the mockRepository recieves a call to DateList() then it should return a new HttpResponseMessage(HttpStatusCode.OK).
So inside
[HttpGet]
public HttpResponseMessage DateList()
when the unit test reaches the line
return _dropDownDataRepository.DateList();
The mocked object fires and returns new HttpResponseMessage(HttpStatusCode.OK)
A better name for this test would be instead of DateListTest2 something like DateList_Returns_Status_Code_From_Repository as that is what you're arranging in the test.
To be honest controller.DateList() doesn't have much logic so that's about the only golden path test you could have.
I'm starting with unit testing in the asp.net mvc 4 framework.
I got a repository with basic crud methods and a save method. When I create a unit test I create a test repository and test if e.g. a item to the collection is added. That all goes smoothly but I cannot test if the save method is hit.
I tried to add a boolean property to the test repository which will be set to true if .save() is hit. But then I need to change the interface, and also the database repository. Which is in my opinion neither practical nor best practice.
What is the best method to test this? Thank you in advance for your answer.
My code:
the fake repository:
public class TestUserRepository : IUserManagementRepository
{
/// <summary>
/// entries used used for testing
/// </summary>
private List<User> _entities;
/// <summary>
/// constructor
/// </summary>
public TestUserRepository()
{
_entities = new List<User>();
_entities.Add(new User
{
Id = 1,
InsertDate = DateTime.Now,
LastUpdate = DateTime.Now,
Username = "TestUserName",
Password = "TestPassword"
});
}
...
public void Create(User task)
{
_entities.Add(task);
}
public void Save()
{
//do nothing
}
}
the controller to test:
[HttpPost]
public ActionResult Create(User user)
{
if (ModelState.IsValid)
{
_repository.Create(user);
_repository.Save();
return RedirectToAction("Index");
}
else
{
return View(user);
}
}
and the test
[TestMethod()]
public void CreateTest()
{
IUserManagementRepository repository = new TestUserRepository();
UserController controller = new UserController(repository);
User user = new User { Username = "UnitTestUserName", InsertDate = DateTime.Now, LastUpdate = DateTime.Now, Password = "Password" };
ActionResult actionResult = controller.Create(user);
User returnedUser = repository.FindBy(u => u.Username == "UnitTestUserName").First<User>();
Assert.IsNotNull(actionResult);
Assert.AreEqual(user, returnedUser);
}
You must be careful not to write a bunch of unit tests that just test your test repository.
Consider the following scenario:
You have a service method, that is supposed to add an item to your repository.
Your unit test calls this method, and you should verify that the appropriate "AddX" method was called on the repository.
This is a valid unit test scenario, to test it you can use your test repository. Since it is your test object, you have full control over it. You can expose properties such as "AddXMethodCallCount" or something similar.
Over time you will find yourself writing a lot of test code that is pretty much boilerplate. The alternative, which I strongly recommend, is to use a mocking framework:
https://stackoverflow.com/questions/37359/what-c-sharp-mocking-framework-to-use
It takes some getting used to, but once you get it, it will speed up your unit testing significantly.
If you don't want to use mocking yet, but want to still achieve your goal of verifying whether or not Save() is called, I would suggest just adding a publicly exposed SaveMethodCallCount property:
public class TestUserRepository : IUserManagementRepository
{
...
public SaveMethodCallCount {get; set;}
...
public void Save()
{
SaveMethodCallCount++;
}
}
This works, because in your unit test you can actually say:
TestUserRepository repository = new TestUserRepository();
The UserController does not care, as long as the passed in parameter implements the IUserManagementRepository interface. The controller interacts with the repository object through the interface, but the unit test does not have to, and the TestUserRepository, being a test class, is allowed to have much more functionality, that does not have to be exposed through the interface.
So your test could look something like:
[TestMethod()]
public void CreateTest()
{
TestUserRepository repository = new TestUserRepository();
UserController controller = new UserController(repository);
User user = new User { Username = "UnitTestUserName", InsertDate = DateTime.Now, LastUpdate = DateTime.Now, Password = "Password" };
ActionResult actionResult = controller.Create(user);
User returnedUser = repository.FindBy(u => u.Username == "UnitTestUserName").First<User>();
Assert.IsNotNull(actionResult);
Assert.AreEqual(user, returnedUser);
Assert.AreEqual(1, repository.SaveMethodCallCount);
}
To make my example complete, let me show you what this would look like if you used a mocking framework, like Moq. You can see some more examples here. The example test method uses Moq and Arrange/Act/Assert, and tests only one thing - that Save() is called when Create() is called.
[TestMethod()]
public void Test_SaveCalledWhenCreateCalled()
{
// Arrange
// First, instead of creating an instance of your test class, you create a mock repository.
// In fact, you don't need to write any code, the mocking framework handles it.
var mockRepository = new Mock<IUserManagementRepository>();
// and pass the mock repository (which implements the IUserManagementRepository) to your controller
UserController controller = new UserController(mockRepository);
// Act
ActionResult actionResult = controller.Create(user);
// Assert
// see how easy it is to do with a mocking framework:
mockRepository.Verify(rep => rep.Save(), Times.AtLeastOnce());
}
I'm trying to unit test a custom action result. I recently watched Jimmy Bogard's excellent MvcConf video ("put your controllers on a diet") http://www.viddler.com/explore/mvcconf/videos/1/ and have started to try and implement some custom action results. I've managed that without a problem, the ActionResult works fine at runtime but I'm having trouble trying to unit test them.
Unfortunately in the code download there are no unit tests for Jimmy's custom action methods... which make me wonder.
I realise that action methods just return instances of the ActionResult types and its the MVC framework that actually calls the ExecuteResult method, which of course is not available when running the unit test. So my unit test is now just creating an instance of my custom ActionResult and I then call ExecuteResult.
Unfortunatley in the ExecuteResult method of my custom ActionResult it is also calling the ExecuteResult method of a ViewResult that I passed it. At that point it blows up. How should I be mocking/stubbing these things to get my unit test working?
public class SendToAFriendActionResult : ActionResult
{
public const string INVALID_CAPTCHA = "You don't appear to have filled out the two words from the security image correctly to prove you're a human. Please try again.";
public const string INVALID_MODEL_STATE = "You don't appear to have filled out all the details correctly. Please try again.";
public const string CONTACT_FAIL = "Unfortunately we experiend a problem sending the link. Please try again later.";
public const string SEND_TO_A_FRIEND_FAIL_KEY = "ContactFail";
private RedirectResult _success;
private ViewResult _failure;
private readonly SendToAFriendModel _model;
private readonly bool _captchaValid;
private readonly MessageBuilderServiceBase _mbs;
public RedirectResult Success
{
get { return _success; }
set { _success = value; }
}
public ViewResult Failure
{
get { return _failure; }
set { _failure = value; }
}
public SendToAFriendActionResult(RedirectResult success, ViewResult failure, SendToAFriendModel model, bool captchaValid, MessageBuilderServiceBase mbs)
{
_success = success;
_failure = failure;
_model = model;
_captchaValid = captchaValid;
_mbs = mbs;
}
public override void ExecuteResult(ControllerContext context)
{
if (!_captchaValid)
{
Failure.TempData[SEND_TO_A_FRIEND_FAIL_KEY] = INVALID_CAPTCHA;
// On reaching this point I receive the error
// Object reference not set to an instance of an object
// as the MVC framework calls FindView
Failure.ExecuteResult(context);
return;
}
if (!context.Controller.ViewData.ModelState.IsValid)
{
Failure.TempData[SEND_TO_A_FRIEND_FAIL_KEY] = INVALID_MODEL_STATE;
Failure.ExecuteResult(context);
return;
}
_mbs.RecipientEmailAddress = _model.EmailRecipient;
_mbs.SendersName = _model.SendersName;
_mbs.Url = _model.URL;
var result = _mbs.sendMessage();
if (!result)
{
Failure.TempData[SEND_TO_A_FRIEND_FAIL_KEY] = CONTACT_FAIL;
Failure.ExecuteResult(context);
return;
}
Success.ExecuteResult(context);
}
}
Here's the start of my unit test ...
IMessageService _emailMessageSerivce;
IGalleryRepository _repository;
var stfModel = new SendToAFriendModel
{
SendersName = "Someone",
URL = "http://someurl.com",
EmailRecipient = "a-friend#somewherelse.com"
};
var failure = new ViewResult() {ViewName ="SendToFriend"};
const bool captchaValid = false;
var fakeControlllerContext = MockRepository.GenerateStub<ControllerContext>(null);
var stf = new SendToAFriendActionResult(null, failure, stfModel, captchaValid, null);
stf.ExecuteResult(fakeControlllerContext);
I've put comments in the SUT to show were the problem occurs.
I know I should be stubbing/mocking somehow but I just can't seem to resolve this.
From ASP.NET MVC 2 In Action (coauthored by Jimmy Bogard):
By taking that hard-to-test code out
of an action and putting it into the
Execute method of an action result,
you ensure that the actions become
significantly easier to unit-test.
That’s because when you unit-test an
action, you assert the type of action
result that the action returns and the
state of the action result. The
Execute method of the action result
isn’t executed as part of the unit
test.
Unit tests are designed to isolate behavior and concerns. You're mixing concerns by calling ExecuteResult from within your custom Action. Instead, I would have the SendToAFriendActionResult return the actual ActionResult (Failure or Success):
public ActionResult GetAction(..)
{
ActionResult result;
//logic here to determine which ActionResult to return
return result;
}
In your Controller:
public ViewResult SendToAFriend()
{
return SendToAFriendActionResult(null, failure, stfModel, captchaValid, null)
.GetAction();
}
This method will allow the MVC framework to do its job and isolates those concerns outside your custom ActionResult. Your test should assert that the correct type of Action, failure or success, is returned based on the parameters you set going in.
I'm currently testing the controller in my mvc app and I'm creating a fake repository for testing. However I seem to be writing more code and spending more time for the fakes than I do on the actual repositories. Is this right?
The code I have is as follows:
Controller
public partial class SomeController : Controller
{
IRepository repository;
public SomeController(IRepository rep)
{
repository = rep;
}
public virtaul ActionResult Index()
{
// Some logic
var model = repository.GetSomething();
return View(model);
}
}
IRepository
public interface IRepository
{
Something GetSomething();
}
Fake Repository
public class FakeRepository : IRepository
{
private List<Something> somethingList;
public FakeRepository(List<Something> somethings)
{
somthingList = somthings;
}
public Something GetSomething()
{
return somethingList;
}
}
Fake Data
class FakeSomethingData
{
public static List<Something> CreateSomethingData()
{
var somethings = new List<Something>();
for (int i = 0; i < 100; i++)
{
somethings.Add(new Something
{
value1 = String.Format("value{0}", i),
value2 = String.Format("value{0}", i),
value3 = String.Format("value{0}", i)
});
}
return somethings;
}
}
Actual Test
[TestClass]
public class SomethingControllerTest
{
SomethingController CreateSomethingController()
{
var testData = FakeSomethingData.CreateSomethingData();
var repository = new FakeSomethingRepository(testData);
SomethingController controller = new SomethingController(repository);
return controller;
}
[TestMethod]
public void SomeTest()
{
// Arrange
var controller = CreateSomethingController();
// Act
// Some test here
// Arrange
}
}
All this seems to be a lot of extra code, especially as I have more than one repository. Is there a more efficient way of doing this? Maybe using mocks?
Thanks
You can mock the repository.
(I use Moq, Mock a database repository using Moq)
As CD proposed, use a mocking framework. I too use Moq, and with Moq your test code could be refactored to something like this:
// Arrange
var repoMock = new Mock<IRepository>();
repoMock.Setup(r => r.GetSomething()).Returns(TestData.SomeThings);
var controller = new SomethingController(repoMock.Object);
// Act
controller.DoStuff();
// Assert
...
I usually find it convenient to put all my test data in a separate TestData class with static properties for everything - that way I know that I test with the same data in each test. This is what you need in TestData for this example:
public static List<Something> SomeThings
{
get
{
var somethings = new List<Something>();
for (int i = 0; i < 100; i++)
{
somethings.Add(new Something
{
value1 = String.Format("value{0}", i),
value2 = String.Format("value{0}", i),
value3 = String.Format("value{0}", i)
});
}
return somethings;
}
}
The better way is using Dev Magic Fake, so you can Mock the database and can be permanent too, you can also Mock the UI
Just add a reference to DevMagicFake.dll
And you can code the following:
[HttpPost]
public ActionResult Create(VendorForm vendorForm)
{
var repoistory = new FakeRepository<VendorForm>();
repoistory.Save(vendorForm);
return View("Page", repoistory.GetAll());
}
This will save the VendorForm permanent in the memory, and you can retrieve it anytime
You can also generate data for this object or any other object in your model, for more information about Dev Magic Fake see the following Link on CodePlex:
http://devmagicfake.codeplex.com
Thanks
M.Radwan