How do I create unit test with context based on integration component?
I have identified problem as the Extension is trying to resolve implementation and returning error message:
"Object reference not set to an instance of an object."
My class:
public sealed class GetListOfServiceIdsToProcess
{
public InOutArgument<IArguments> Arguments { get; set; }
protected override void Execute(CodeActivityContext context)
{
// I am recieving my error exception here
context.GetExtension<lib.Extension.MyExtenstion>();
var targetIds= (List<int>)Settings.Get("targetIds");
var wfa = this.Arguments.Get(context);
wfa.ListTargetIds = targetIds;
Arguments.Set(context, wfa);
}
}
My Test so far:
I have problem with implementation of the test as far i could get it:
/// <summary>
///A test for Execute
///</summary>
[TestMethod()]
public void ExecuteTest()
{
// create Isettings mock to return collection of service ids
var expected = new List<int>() { 30, 20 };
var wfaInput = new TestWorkFlow();
var serviceIdList = new GetListOfServiceIdsToProcess();
var wfParam = new Dictionary<string, object>();
wfParam.Add("WorkFlowArguments", wfaInput);
var results = WorkflowInvoker.Invoke(serviceIdList, wfParam);
var wfaResult = (IWorkFlowArguments)results["WorkFlowArguments"];
Assert.AreEqual(expected, wfaResult.ListOfServiceIdsToProcess);
}
Instead of using the static WorkflowInvoker.Invoke() new up a WorkflowInvoker instance and add a mock, or whatever is needed for your test, lib.Extension.MyExtenstion to the Extensions collection.
[TestMethod]
public void ExecuteTest()
{
// ...
var invoker = new WorkflowInvoker(activityToTest);
// This way your extension will be available during execution
invoker.Extensions.Add(new MyExtension());
var results = invoker.Invoke(inputArgs);
// ....
}
I have run through multiple options and the problem what I have is MS Workflow.
I have extracted all logic away from workflow code activity into separate class and this class has been put under tests.
This is the best I could do for this. As I have base classes, that are injected, but I could not easily implement what I needed.
Thank you all for help anyway.
Related
I am working on an ASP.Net Core MVC Web application.
My Solution contains 2 projects:
One for the application and
A second project, dedicated to unit tests (XUnit).
I have added a reference to the application project in the Tests project.
What I want to do now is to write a class in the XUnit Tests project which will communicate with the database through entity framework.
What I was doing in my application project was to access to my DbContext class through constructor dependency injection.
But I cannot do this in my tests project, because I have no Startup.cs file. In this file I can declare which services will be available.
So what can I do to get a reference to an instance of my DbContext in the test class?
You can implement your own service provider to resolve DbContext.
public class DbFixture
{
public DbFixture()
{
var serviceCollection = new ServiceCollection();
serviceCollection
.AddDbContext<SomeContext>(options => options.UseSqlServer("connection string"),
ServiceLifetime.Transient);
ServiceProvider = serviceCollection.BuildServiceProvider();
}
public ServiceProvider ServiceProvider { get; private set; }
}
public class UnitTest1 : IClassFixture<DbFixture>
{
private ServiceProvider _serviceProvider;
public UnitTest1(DbFixture fixture)
{
_serviceProvider = fixture.ServiceProvider;
}
[Fact]
public void Test1()
{
using (var context = _serviceProvider.GetService<SomeContext>())
{
}
}
}
But bear in your mind using EF inside a unit test is not a good idea and it's better to mock DbContext.
The Anatomy of Good Unit Testing
You can use Xunit.DependencyInjection
For unit tests you need to mock your context.
There is a great nuget package for mocking that is called Moq.
Some help to get you started:
public ClassName : IDisposable
{
private SomeClassRepository _repository;
private Mock<DbSet<SomeClass>> _mockSomeClass;
public ClassName()
{
_mockSomeClass = new Mock<DbSet<SomeClass>>();
var mockContext = new Mock<IApplicationDbContext>();
mockContext.SetupGet(c => c.SomeClass).Returns(_mockSomeClass.Object);
_repository = new SomeClassRepository(mockContext.Object);
}
public void Dispose()
{
// Anything you need to dispose
}
[Fact]
public void SomeClassTest()
{
var someClass = new SomeClass() { // Initilize object };
_mockSomeClass.SetSource(new[] { someClass });
var result = _repository.GetSomethingFromRepo( ... );
// Assert the result
}
}
For integration tests you do the same thing but the setup is:
_context = new ApplicationDbContext();
Make sure that your TestClass inherits from IDisposable (TestClass : IDisposable) so that you can dispose the context after each test.
https://xunit.github.io/docs/shared-context
You can to use package Microsoft.EntityFrameworkCore.InMemory
var _dbContextOptions = new DbContextOptionsBuilder<DbContext>().UseInMemoryDatabase(Guid.NewGuid().ToString()).Options;
And then
var context = new DbContext(_dbContextOptions);
I been trying to figure out how i can unit test service and so far have got nowhere.
I am using xUnit and NSubstitute (as advised by friends), below is the simple test that i want to run (which fails currently).
public class UnitTest1
{
private readonly RallyService _rallyService;
public UnitTest1(RallyService rallyService)
{
_rallyService= rallyService;
}
[Fact]
public void Test1()
{
var result = _rallyService.GetAllRallies();
Assert.Equal(2, result.Count());
}
}
My rally service class makes a simple call to the db to get all Rally entites and returns those:
public class RallyService : IRallyService
{
private readonly RallyDbContext _context;
public RallyService(RallyDbContext context)
{
_context = context;
}
public IEnumerable<Rally> GetAllRallies()
{
return _context.Rallies;
}
}
Any guidance would be appreciated.
Since you use .NET Core, I assume you also use Entity Framework Core. While it was possible to mock most of the operations in the previous EF version, however the EF Core suggests to use in-memory database for unit testing. I.e. you don't need to mock RallyDbContext, hence NSubstitute is not needed for this particular test. You would need NSubstitute to mock the service when testing a controller or application using the service.
Below is your Test1 written using in-memory database.
public class UnitTest1
{
private readonly DbContextOptions<RallyDbContext> _options;
public UnitTest1()
{
// Use GUID for in-memory DB names to prevent any possible name conflicts
_options = new DbContextOptionsBuilder<RallyDbContext>()
.UseInMemoryDatabase(Guid.NewGuid().ToString())
.Options;
}
[Fact]
public async Task Test1()
{
using (var context = new RallyDbContext(_options))
{
//Given 2 records in database
await context.AddRangeAsync(new Rally { Name = "rally1" }, new Rally { Name = "rally2" });
await context.SaveChangesAsync();
}
using (var context = new RallyDbContext(_options))
{
//When retrieve all rally records from the database
var service = new RallyService(context);
var rallies = service.GetAllRallies();
//Then records count should be 2
Assert.Equal(2, rallies.Count());
}
}
}
A working test application with this unit test is in my GitHub for your reference. I used SQL Express in the actual app.
I don't think it is standard to have a unit test constructor with a parameter. The unit test runner will new up this class, and unless you are using something that will auto-inject that parameter I think the test will fail to run.
Here is a standard fixture layout:
public class SampleFixture {
[Fact]
public void SampleShouldWork() {
// Arrange stuff we need for the test. This may involved configuring
// some dependencies, and also creating the subject we are testing.
var realOrSubstitutedDependency = new FakeDependency();
realOrSubstitutedDependency.WorkingItemCount = 42;
var subject = new Subject(realOrSubstitutedDependency);
// Act: perform the operation we are testing
var result = subject.DoWork();
// Assert: check the subject's operation worked as expected
Assert.Equal(42, result);
}
[Fact]
public void AnotherTest() { /* ... */ }
}
If you need a common setup between tests, you can use a parameterless constructor and do common initialisation there.
In terms of the specific class you are trying to test, you need to make sure your RallyDbContext is in a known state to repeatably and reliably test. You may want to look up answers specific to testing Entity Framework for more information.
I am attempting to Unit Test a method that uses Automapper ProjectTo and I'm not sure how to register the mappings in MVC Core. I am using the built in unit testing.
The following is my unit test.
[TestClass]
public class BusinessGenderServiceTest
{
[ClassInitialize]
public static void Init(TestContext context)
{
}
[TestMethod]
public void GetTest()
{
var options = new DbContextOptionsBuilder<GotNextDbContext>()
.UseInMemoryDatabase(databaseName: "GetTest")
.Options;
using (var context = new GotNextDbContext(options))
{
context.GenderLanguage.Add(new GenderLanguage { Id = 1, Name = "Male", Language = 1 });
context.GenderLanguage.Add(new GenderLanguage { Id = 2, Name = "Female", Language = 1 });
context.GenderLanguage.Add(new GenderLanguage { Id = 3, Name = "Hombre", Language = 2 });
context.GenderLanguage.Add(new GenderLanguage { Id = 4, Name = "Hombre", Language = 2 });
context.SaveChanges();
}
using (var context = new GotNextDbContext(options))
{
var service = new GenderService(context);
var result = service.Get(1);
Assert.AreEqual(2, result.Count());
}
}
}
I am getting the following error when I run the test:
Message: Test method GotNext.Test.BusinessGenderServiceTest.GetTest threw exception:
System.InvalidOperationException: Mapper not initialized. Call Initialize with appropriate configuration. If you are trying to use mapper instances through a container or otherwise, make sure you do not have any calls to the static Mapper.Map methods, and if you're using ProjectTo or UseAsDataSource extension methods, make sure you pass in the appropriate IConfigurationProvider instance.
I was able to solve this problem by configuring and initializing automapper in the Init method of each test class.
For example
[ClassInitialize]
public static void Init(TestContext testContext)
{
var mappings = new MapperConfigurationExpression();
mappings.AddProfile<LocationProfile>();
mappings.AddProfile<CompanyProfile>();
Mapper.Initialize(mappings);
}
You can configure AutoMapper in class like this:
public static class AutoMapperConfig
{
public static IMapper Initialize()
{
return new MapperConfiguration((cfg =>
{
cfg.CreateMap<User, UserDto>();
})).CreateMapper();
}
}
And next use it in startup.cs ConfigureService method
services.AddSingleton(AutoMapperConfig.Initialize());
Create a class or classes that configure AutoMapper and instantiate (and call methods, if applicable) in the Startup class.
I got this same error ("System.InvalidOperationException: Mapper not initialized. Call Initialize with appropriate configuration. ...") when I inadvertently / mindlessly switched between AutoMapper's Instance API (which I did have configured) and AutoMapper's Static API (which I did NOT have configured).
Looking closely at the line of code flagged in the error message, I realized I used upper-case 'M' Mapper.Map() instead of my instance member lower-case 'm' mapper.Map().
I am working on a unit test of an instance method. The method happens to be an ASP.NET MVC 4 controller action, but I don't think that really matters much. We just found a bug in this method, and I'd like to use TDD to fix the bug and make sure it doesn't come back.
The method under test calls a service which returns an object. It then calls an internal method passing a string property of this object. The bug is that under some circumstances, the service returns null, causing the method under test to throw a NullReferenceException.
The controller uses dependency injection, so I have been able to mock the service client to have it return a null object. The problem is that I want to change the method under test so that when the service returns null, the internal method should be called with a default string value.
The only way I could think to do this is to use a mock for the class under test. I want to be able to assert, or Verify that this internal method has been called with the correct default value. When I try this, I get a MockException stating that the invocation was not performed on the mock. Yet I was able to debug the code and see the internal method being called, with the correct parameters.
What's the right way to prove that the method under test calls another method passing a particular parameter value?
I think there's a code smell here. The first question I'll ask myself in such a situation is, is the "internal" method really internal/ private to the controller under test. Is it the controller's responsibility to do the "internal" task? Should the controller change when the internal method's implementation changes? May be not.
In that case, I would pull out a new targeted class, which has a public method which does the stuff which was until now internal to the controller.
With this refactoring in place, I would use the callback mechanism of MOQ and assert the argument value.
So eventually, you will end up mocking two dependancies:
1. The external service
2. The new targeted class which has the controller's internal implementation
Now your controller is completely isolated and can be unit tested independently. Also, the "internal" implementation becomes unit testable and should have its own set of unit tests too.
So your code and test would look something like this:
public class ControllerUnderTest
{
private IExternalService Service { get; set; }
private NewFocusedClass NewFocusedClass { get; set; }
const string DefaultValue = "DefaultValue";
public ControllerUnderTest(IExternalService service, NewFocusedClass newFocusedClass)
{
Service = service;
NewFocusedClass = newFocusedClass;
}
public void MethodUnderTest()
{
var returnedValue = Service.ExternalMethod();
string valueToBePassed;
if (returnedValue == null)
{
valueToBePassed = DefaultValue;
}
else
{
valueToBePassed = returnedValue.StringProperty;
}
NewFocusedClass.FocusedBehvaior(valueToBePassed);
}
}
public interface IExternalService
{
ReturnClass ExternalMethod();
}
public class NewFocusedClass
{
public virtual void FocusedBehvaior(string param)
{
}
}
public class ReturnClass
{
public string StringProperty { get; set; }
}
[TestClass]
public class ControllerTests
{
[TestMethod]
public void TestMethod()
{
//Given
var mockService = new Mock<IExternalService>();
mockService.Setup(s => s.ExternalMethod()).Returns((ReturnClass)null);
var mockFocusedClass = new Mock<NewFocusedClass>();
var actualParam = string.Empty;
mockFocusedClass.Setup(x => x.FocusedBehvaior(It.IsAny<string>())).Callback<string>(param => actualParam = param);
//when
var controller = new ControllerUnderTest(mockService.Object, mockFocusedClass.Object);
controller.MethodUnderTest();
//then
Assert.AreEqual("DefaultValue", actualParam);
}
}
Edit: Based on the suggestion in the comments to use "verify" instead of callback.
Easier way to verify the parameter value is by using strict MOQ behavior and a verify call on the mock after system under test is executed.
Modified test could look like below:
[TestMethod]
public void TestMethod()
{
//Given
var mockService = new Mock<IExternalService>();
mockService.Setup(s => s.ExternalMethod()).Returns((ReturnClass)null);
var mockFocusedClass = new Mock<NewFocusedClass>(MockBehavior.Strict);
mockFocusedClass.Setup(x => x.FocusedBehvaior(It.Is<string>(s => s == "DefaultValue")));
//When
var controller = new ControllerUnderTest(mockService.Object, mockFocusedClass.Object);
controller.MethodUnderTest();
//Then
mockFocusedClass.Verify();
}
"The only way I could think to do this is to use a mock for the class under test."
I think you should not mock class under test. Mock only external dependencies your class under test has. What you could do is to create a testable-class. It would be a class which derives from your CUT and here you can catch the calls to the another method and verify it's parameter later. HTH
Testable class in the example is named MyTestableController
Another method is named InternalMethod.
Short example:
[TestClass]
public class Tests
{
[TestMethod]
public void MethodUnderTest_WhenServiceReturnsNull_CallsInternalMethodWithDefault()
{
// Arrange
Mock<IService> serviceStub = new Mock<IService>();
serviceStub.Setup(s => s.ServiceCall()).Returns((ReturnedFromService)null);
MyTestableController testedController = new MyTestableController(serviceStub.Object)
{
FakeInternalMethod = true
};
// Act
testedController.MethodUnderTest();
// Assert
Assert.AreEqual(testedController.SomeDefaultValue, testedController.FakeInternalMethodWasCalledWithThisParameter);
}
private class MyTestableController
: MyController
{
public bool FakeInternalMethod { get; set; }
public string FakeInternalMethodWasCalledWithThisParameter { get; set; }
public MyTestableController(IService service)
: base(service)
{ }
internal override void InternalMethod(string someProperty)
{
if (FakeInternalMethod)
FakeInternalMethodWasCalledWithThisParameter = someProperty;
else
base.InternalMethod(someProperty);
}
}
}
The CUT could look something like this:
public class MyController : Controller
{
private readonly IService _service;
public MyController(IService service)
{
_service = service;
}
public virtual string SomeDefaultValue { get { return "SomeDefaultValue"; }}
public EmptyResult MethodUnderTest()
{
// We just found a bug in this method ...
// The method under test calls a service which returns an object.
ReturnedFromService fromService = _service.ServiceCall();
// It then calls an internal method passing a string property of this object
string someStringProperty = fromService == null
? SomeDefaultValue
: fromService.SomeProperty;
InternalMethod(someStringProperty);
return new EmptyResult();
}
internal virtual void InternalMethod(string someProperty)
{
throw new NotImplementedException();
}
}
I'm new to Unit Testing and I'm using Rhino Mock in ASP.NET MVC
I have created a main test class with this code :
[TestFixture]
public class PersistenceTest
{
[Test]
protected T SaveAndLoadEntity<T>(T entity) where T : BaseEntity
{
var mockDataSource = MockRepository.GenerateMock<IRepository<T>>();
mockDataSource.Add(entity);
var fromDb = mockDataSource.FindBy(entity.Id);
return fromDb;
}
}
and create a customer test class like this :
[TestFixture]
public class CustomerTests : PersistenceTest
{
[Test]
public void Can_Save_And_Load_Customer()
{
var customer = new Customer()
{
Id = 12,
Name = "Reza",
Family = "Pazooki",
Company = "Rozaneh",
Email = "ipazooki#gmail.com",
Mobile = "09352463668",
Fax = "021-44869059",
Tel = "021-44869059",
WebSite = "www.rozanehmedia.com"
};
var fromDb = SaveAndLoadEntity(customer);
fromDb.ShouldNotBeNull();
}
}
but when run the code, it says that return value from Database is NULL!!!
I don't know what is wrong with my code but I save and retrieve data from mock repository and it seems every thing is ok.
tnx form any help in forward :)
Mocks are used to record invocations on objects for further verification or to provide values when called (later behavior requires setup).
In your SaveAndLoadEntity method you make calls to mock (Add and FindBy). Since mock is a fake object with no real behavior, those calls do nothing (they don't save nor extract any entities to/from database).
If you want to test persistence layer you should be doing tests against real database instance (or optionally, in-memory one).
// [Test] attribute is not needed
protected T SaveAndLoadEntity<T>(T entity) where T : BaseEntity
{
var dataSource = new DataSource("connection string");
dataSource.Add(entity);
var fromDb = dataSource.FindBy(entity.Id);
return fromDb;
}
At the moment you are making calls to not-setup mock which doesn't achieve anything.
Thank you jimmy_keen.
I change my code according to your advice like this and it worked great :)
[TestFixture]
public class PersistenceTest
{
protected ISession Session;
protected ITransaction Transaction;
[SetUp]
public void SetUp()
{
var helper = new NHibernateHelper("...connectionString....");
Session = helper.SessionFactory.OpenSession();
Transaction = Session.BeginTransaction();
}
protected T SaveAndLoadEntity<T>(T entity) where T : BaseEntity
{
Session.Save(entity);
Transaction.Commit();
var fromDb = Session.Get<T>(entity.Id);
return fromDb;
}
}