Mocked Interface returning NULL - c#

I've read similar questions but could not manage to solve my own. I'm using xUnit and I'm running into an issue when one of my methods calls, it's returning null but in fact that I have mocked it.
Interface
public interface IApplicantService
{
Task<Applicant> AddAsync(Applicant applicant);
// other methods
}
Test Case
public class ApplicationControllerTests
{
private readonly Mock<IApplicantService> _mockApplicantService;
private readonly ApplicantController _applicantController;
private readonly IMapper _mockMapper;
public ApplicationControllerTests()
{
_mockApplicantService = new Mock<IApplicantService>();
var mapperConfig = new MapperConfiguration(cfg =>
{
cfg.AddProfile(new ResourceToModelProfile());
cfg.AddProfile(new ModelToResourceProfile());
});
_mockMapper = mapperConfig.CreateMapper();
_applicantController = new ApplicantController(_mockApplicantService.Object, _mockMapper);
}
[Fact]
public async void CreateAsync_WhenApplicantNotExist_ShouldReturn_CreatedAtActionResult_With_Resource()
{
var applicantDto = new ApplicantCreateDto
{
PersonId = 1,
VacancyId = 1
};
_mockApplicantService.Setup(e => e.AddAsync(It.IsAny<Applicant>()))
.Returns(Task.FromResult(new Applicant { Id = 1, PersonId = 1, VacancyId = 1}));
var result = await _applicantController.CreateAsync(applicantDto);
var createdAtActionResult = result as CreatedAtActionResult;
var model = createdAtActionResult.Value as ApplicantResponseDto;
var actual = model.PersonId;
Assert.NotNull(model);
Assert.Equal(1, actual);
Assert.NotNull(createdAtActionResult);
}
}
Controller
[HttpPost]
[Route("CreateAsync")]
[ProducesResponseType(StatusCodes.Status201Created)]
[ProducesResponseType(StatusCodes.Status409Conflict)]
[ProducesResponseType(StatusCodes.Status500InternalServerError)]
public async Task<IActionResult> CreateAsync([FromBody] ApplicantCreateDto applicantCreateDto)
{
try
{
var applicant = _mapper.Map<ApplicantCreateDto, Applicant>(applicantCreateDto);
var result = await _applicantService.AddAsync(applicant);
// here, result is null, but it was mocked to return an Applicant object
var resource = _mapper.Map<Applicant, ApplicantResponseDto>(result);
return CreatedAtAction(nameof(GetAsync), new { id = result.Id }, resource);
}
catch (ResourceExistException ex)
{
return Conflict(ex.Message);
}
catch(Exception ex)
{
// log exception
return StatusCode(500);
}
}
The mocked method is returning null and I'm getting System.NullReferenceException

This is how your fixed unit test could look like:
[Fact]
public async Task CreateAsync_WhenApplicantNotExist_ShouldReturn_CreatedAtActionResult_With_Resource()
{
//Arrange
var applicantDto = new ApplicantCreateDto { PersonId = 1, VacancyId = 1 };
var applicant = new Applicant { Id = 1, PersonId = 1, VacancyId = 1 };
_mockApplicantService
.Setup(svc => svc.AddAsync(It.IsAny<Applicant>()))
.ReturnsAsync(applicant);
//Act
var result = await _applicantController.CreateAsync(applicantDto);
//Assert
var createdAtActionResult = Assert.IsAssignableFrom<CreatedAtActionResult>(result);
var model = Assert.IsAssignableFrom<ApplicationResponseDto>(createdAtActionResult.Value);
Assert.Equal(1, model.PersonId);
}
I've replaced async void to async Task that way your await will be evaluated properly
I've changed the Returns(Task.FromResult(...)) to ReturnsAsync(...) because this is the recommended way to specify return value in case of async methods
I've also added some comments to separate the different phases of your unit test from each other (Arrange-Act-Assert)
I've changed your assertion logic to use IsAssingableFrom to verify the type itself rather than doing null checks

Related

How to write unit test case for SaveChangesAsync()

I am writing unit test case for my Entity Framework Core SaveAsync method.
try
{
// Here add business logic to insert record in to new database
var dbObj = new TableName()
{
Code = 1,
Description = "test"
};
_ = _dbContext.TableName.AddAsync(dbObj);
_ = _dbContext.SaveChangesAsync(context.CancellationToken);
}
catch (Exception ex)
{
_logger.LogCritical($"{GetType().Name}:{nameof(Consume)} {ex}");
}
await Task.CompletedTask;
I have written unit test case by mocking:
Mock<MyDbContext> dbContext = new();
var data = return new List<TableName>()
{
new TableName
{
Id = 1,
Description = "test"
}
};
dbContext.Setup(r => r.TableName).ReturnsDbSet(data);
dbContext.Setup(r => r.SaveChangesAsync(It.IsAny<CancellationToken>())).ReturnsAsync(1);
// Check that each method was only called once.
//dbContext.Verify(x => x.TableName.Add(It.IsAny<TableName>()), Times.Once());
dbContext.Verify(x => x.SaveChangesAsync(It.IsAny<CancellationToken>()), Times.Once());
Below is what I get as a result
Moq.MockException : Expected invocation on the mock once, but was 0 times
While debugging the test case, I am getting the below.
Firstly,add await into try catch block.otherwise it would not catch excption
try
{
// Here add business logic to insert record in to new database
var dbObj = new TableName()
{
Code = 1,
Description = "test"
};
_ = await _dbContext.TableName.AddAsync(dbObj);
_ = await _dbContext.SaveChangesAsync(context.CancellationToken);
}
//remove this line
await Task.CompletedTask;
The document related with Asynchronous programming
And you could check the document related with testing non query scenarios
I tried as below:
Assuming a controller:
public async Task<IActionResult> Create([Bind("Id,Name")] SomeEntity someEntity)
{
if (ModelState.IsValid)
{
try
{
await _context.AddAsync(someEntity);
await _context.SaveChangesAsync();
}
catch (Exception e)
{
}
return RedirectToAction(nameof(Index));
}
return View(someEntity);
}
Test:
public class UnitTest1
{
[Fact]
public async Task Test1()
{
var mockset = new Mock<DbSet<SomeEntity>>();
var mockdbcontext = new Mock<WebApplication8Context>(new DbContextOptions<WebApplication8Context>() );
mockdbcontext.Setup(x=>x.SomeEntity).Returns(mockset.Object);
var a = mockdbcontext.Object;
var controller = new SomeEntitiesController(mockdbcontext.Object);
await controller.Create(new SomeEntity() { Name = "someName" });
mockdbcontext.Verify(x => x.SaveChangesAsync(default(CancellationToken)), Times.Once);
}
}
Result:

How can I write unit Tests in .NET for web api

My controller for the delete method :
[HttpDelete("{toDoListId}")]
public async Task<ActionResult> DeleteToDoList(int toDoListId)
{
var toDoListEntity = await _toDoListRepository.GetSpecificTodoAsync(toDoListId);
if (toDoListEntity == null)
{
return NotFound();
}
_toDoListRepository.DeleteToDoList(toDoListEntity);
await _toDoListRepository.SaveChangesAsync();
return NoContent();
}
My repository :
public async Task<ToDoList?> GetSpecificTodoAsync(int taskId)
{
return await _context.ToDoLists.Where(c => c.Id == taskId).FirstOrDefaultAsync();
}
public void DeleteToDoList(ToDoList toDoListDto)
{
_context.ToDoLists.Remove(toDoListDto);
}
My testcase for checking if the item got deleted and if it returns no content after being deleted. But both of my test cases are failing. Any help on how to write test cases for the delete part, I would be really grateful. I am also trying to test other methods but I am unfortunately stuck here. Please kindly help me
public class UnitTest1
{
private readonly Mock<IToDoListRepository> repositoryStub = new ();
private readonly Mock<IMapper> mapper = new Mock<IMapper>();
private readonly Random Rand = new();
private ToDoList GenerateRandomItem()
{
return new()
{
Id = Rand.Next(),
Description= Guid.NewGuid().ToString(),
Title = Guid.NewGuid().ToString(),
StartDate = DateTime.Now,
EndDate = DateTime.Now,
Done = false
};
}
[Fact]
public void Delete_removesEntry()
{
//arrange
var existingItem = GenerateRandomItem();
var controller = new ToDoController(repositoryStub.Object, mapper.Object);
var itemID = existingItem.Id;
//act
controller.DeleteToDoList(itemID);
//assert
Assert.Null(repositoryStub.Object.GetSpecificTodoAsync(itemID));
}
[Fact]
public async Task DeleteItemAsync_WithExistingItem_ReturnNoContent()
{
//Arrange
var existingItem = GenerateRandomItem();
repositoryStub.Setup(repo => repo.GetSpecificTodoAsync(existingItem.Id)).ReturnsAsync((existingItem));
var itemID = existingItem.Id;
var controller = new ToDoController(repositoryStub.Object, mapper.Object);
//Act
var result = await controller.DeleteToDoList(itemID);
//assert
result.Should().BeOfType<NoContentResult>();
}
Both test cases are failing because the mock has not been setup to behave as expected for each test case.
There is also a potential race condition in the shown tests since they are sharing the same mock instance. This will cause issues when setting up the mock as one test case could potentially override the setup of another case.
Update the tests so that they are isolated from each other.
In the first test, the expected behavior can be verified by checking the mock to see if the expected member was invoked.
[Fact]
public async Task DeleteToDoList_Should_RemoveEntry() {
//arrange
ToDoList existingItem = GenerateRandomItem();
var itemID = existingItem.Id;
Mock<IToDoListRepository> repositoryStub = new ();
//Setup expected behavior of mock
repositoryStub
.Setup(_ => _.GetSpecificTodoAsync(itemID))
.ReturnsAsync(existingItem);
var controller = new ToDoController(repositoryStub.Object, mapper.Object);
//act
await controller.DeleteToDoList(itemID);
//assert
repositoryStub.Verify(_ => _.DeleteToDoList(existingItem));
}
In the other test, the mock needs be setup to make sure the subject executes to completion.
[Fact]
public async Task DeleteToDoList_WithExistingItem_Should_ReturnNoContent() {
//Arrange
ToDoList existingItem = GenerateRandomItem();
var itemID = existingItem.Id;
Mock<IToDoListRepository> repositoryStub = new ();
//Setup expected behavior of mock
repositoryStub
.Setup(_ => _.GetSpecificTodoAsync(itemID))
.ReturnsAsync(existingItem);
repositoryStub.Setup(_ => _.SaveChangesAsync()).ReturnsAsynt(true);
var controller = new ToDoController(repositoryStub.Object, mapper.Object);
//Act
ActionResult result = await controller.DeleteToDoList(itemID);
//assert
result.Should().BeOfType<NoContentResult>();
}

Xunit in asp.net core

I'm new at asp.net and moq and xunit test, I want to create a test case for my asp.net project. I have the service file that is CRUD action,
I have been written for Create Method it's Ok but at Get, GetAll, Delete, Put method I don't know what should I setup
public void Test1()
{
var tutorRequest = new Mock<ITutorRequestService>();
//What should i set up for Get and GetAll
tutorRequest.Setup(r => r.Get(It.IsAny<int>(), It.IsAny<string?>()))
.ReturnsAsync(() => new Entity());
var logger = new Mock<ILogger<TutorRequestsController>>();
var controller = new TutorRequestsController(tutorRequest.Object, logger.Object);
var rs = controller.Get(1, "");
Assert.NotNull(rs);
}
My service class
public async Task<TutorRequest> Create(TutorRequestModel tutor)
{
var entity = _mapper.Map<TutorRequest>(tutor);
CheckDataNotNull("entity", entity);
entity = await _repository.Add(entity);
return _mapper.Map<TutorRequest>(entity);
}
public async Task<TutorRequest> Delete(int tutorId)
{
var entity = await _repository.Delete(tutorId);
return _mapper.Map<TutorRequest>(entity);
}
public async Task<Entity> Get(int id, string? fields)
{
var entity = await _repository.Get(id);
CheckDataNotNull("tutor request", entity);
var shaped = _dataShaper.ShapeData(entity, fields);
CheckDataNotNull("shaped", shaped);
return _mapper.Map<Entity>(shaped);
}
public PageList<Entity> GetAll(TutorRequestParams param)
{
var listAll = _repository.GetAll();
CheckDataNotNull("shaped", listAll);
Search(ref listAll, param);
var sortedStudent = _sortHelper.ApplySort(listAll, param.OrderBy);
var shapedOwners = _dataShaper.ShapeData(sortedStudent, param.Fields);
return PageList<Entity>.ToPageList(shapedOwners, param.PageNume, param.PageSize);
}
public async Task<TutorRequest> Update(TutorRequestModel tutor)
{
var entity = _mapper.Map<TutorRequest>(tutor);
entity = await _repository.Update(entity);
return _mapper.Map<TutorRequest>(entity);
}
If you're expecting the GetAll method to return something, you need to set up the call for the mocked service.
mockRepo.Setup(r => r.GetAll(It.IsAny<TutorRequestParams>())).Returns(
new PagedList<ExpandoObject>
{
// result you're expecting
}
);
I have write a test case for Get method that similar to your example, you can check it out
public void Test_Get_Method()
{
var questService = new Mock<IQuestService>();
questService.Setup(x => x.Get(It.IsAny<Guid>()))
.ReturnsAsync(new QuestResponseModel()
{
Id = Guid.Empty,
Title = "Test",
Description = "TestDescription",
Price = 100,
Status = "Pending",
AvailableTime = DateTime.Now,
EstimatedTime = "120",
QuestTypeId = 1
});
var mapperMock = new Mock<IMapper>();
var controller = new QuestController(questService.Object);
var result = controller.Get(Guid.Empty);
Assert.Equal("TestDescription", result.Result.Data.Description);
}

How do you unit test HTTP Response/Requests in c# controller?

I am trying to unit test a c# controller method. I have looked up many questions and nothing quite gives me instructions on how to unit test the API controller. The code that is correct is below for the method. How do you unit test for the brackets.
I have figured out how to test the method "Reverse Payment", but I am using moq and xunit to test the actual c# method. This is my current unit test:
public class PaymentsControllerTests : BackOfficeIntegrationTestBase
{
private readonly CurrentDateProvider _currentDateProvider;
[BackOfficeRolesAuthorize(BackOfficeUserRole.Admin, BackOfficeUserRole.CSR, BackOfficeUserRole.DealerSupportRep,
BackOfficeUserRole.CSRManager)]
[Fact]
public async Task AdminReversalPermissions()
{
IFixture fixture = new Fixture().Customize(new AutoMoqCustomization());
var mediator = fixture.Freeze<Mock<IMediator>>();
var currentDateProvider = fixture.Freeze<CurrentDateProvider>();
var mockRepo = new Mock<IMediator>();
var controller = new PaymentsController(mockRepo.Object);
// Setup Dependencies
//DataContext dataContext = SetUpDatabase(fixture);
ReversePaymentSetup(fixture, mediator);
var result = await controller.ReversePayment(LeaseInfo.ApplicationId, 100);
var viewResult = result as NoContentResult;
Assert.NotNull(viewResult);
}
private void ReversePaymentSetup(IFixture fixture, Mock<IMediator> mediator)
{
PaymentData data = new PaymentData();
//Mock the mediator
var paymentPlan = new Data.Model.PaymentPlan()
{
LeaseId = 1,
LeaseTerm = LeaseTerm.Year,
DefermentDays = 5,
FirstPaymentDate = DateTime.ParseExact("01/01/2019", "d", CultureInfo.InvariantCulture),
StoreState = "VA"
};
var responseData = new BuildPaymentPlanResponse();
responseData.Data = new BuildPaymentPlanResponse.InitializePaymentPlanResponseData()
{
PaymentPlan = paymentPlan
};
PaymentStatusChangeManualRequest request = fixture.Build<PaymentStatusChangeManualRequest>()
.With(x => x.PaymentPlanId, LeaseInfo.ApplicationId)
.With(x => x.PaymentId, 100)
.With(x => x.Status, PaymentStatus.Reversed)
.Create();
Assert.Equal(PaymentStatus.Reversed, request.Status);
Assert.Equal(100, request.PaymentId);
Assert.NotNull(LeaseInfo.ApplicationId);
}
}
}
[ProducesResponseType(typeof(ErrorResponse), (int)HttpStatusCode.NotFound)]
[HttpPut("{paymentId}/ReversePayment")]
[BackOfficeRolesAuthorize(BackOfficeUserRole.Admin, BackOfficeUserRole.CSR, BackOfficeUserRole.DealerSupportRep,
BackOfficeUserRole.CSRManager)]
public async Task<IActionResult> ReversePayment(int paymentPlanId, int paymentId)
{
await _mediator.Send(new PaymentStatusChangeManualRequest
{
PaymentPlanId = paymentPlanId,
PaymentId = paymentId,
Status = PaymentStatus.Reversed
});
return NoContent();
}

How to test async Task<IActionResult> returning IEnumerable<model> using moq in xunit?

I want to test GetMoviesAsync of my Controller. I don't know where I am doing wrong in my Moq setup. I am getting 0 item from GetMoviesAsync.
What am I doing wrong?
// Api-Controller:
public interface ICommand
{
Task<IEnumerable<Movie>> GetMoviesAsync();
}
public class SampleController : ControllerBase
{
private readonly ICommand movieCommand;
public SampleController(ICommand command)
{
movieCommand = command;
}
[HttpGet]
public async Task<IActionResult> GetMoviesAsync()
{
var movies = await movieCommand.GetMoviesAsync();
return Ok(movies);
}
}
// Unit-Test:
public class SampleControllerTest
{
private IEnumerable<Movie> MovieList()
{
IList<Movie> movies = new List<Movie>()
{
new Movie()
{
ID =1,
Title = "Test",
ReleaseDate = DateTime.Now,
RunningTimeInMinutes = 100
}
};
return movies;
}
private SampleController GetSampleController()
{
var command = new Mock<ICommand>();
return new SampleController(command.Object);
}
[Fact]
public async Task GetMovies_Test()
{
// Arrange
var controller = GetSampleController();
var commadMock = new Mock<ICommand>();
// How to setup moq here?
commadMock.Setup(s => s.GetMoviesAsync()).Returns(Task.FromResult<IEnumerable<Movie>>(MovieList())).Verifiable();
// Act
var response = await controller.GetMoviesAsync() as OkObjectResult;
// Problem is here,
var li=response.Value as IEnumerable<Movie>;
}
}
What am I doing wrong?
Two completely different mocks are being used.
One is used to create the controller
private SampleController GetSampleController()
{
var command = new Mock<ICommand>();
return new SampleController(command.Object);
}
and another is being created and setup in the test.
var controller = GetSampleController();
var commadMock = new Mock<ICommand>();
// How to setup moq here?
commadMock.Setup(s => s.GetMoviesAsync()).Returns(Task.FromResult<IEnumerable<Movie>>(MovieList())).Verifiable();
To solve this, use the same mock to get the desired behavior
[Fact]
public async Task GetMovies_Test() {
// Arrange
var commadMock = new Mock<ICommand>();
var controller = new SampleController(commadMock.Object); //<---
commadMock
.Setup(_ => _.GetMoviesAsync())
.ReturnsAsync(MovieList())
.Verifiable();
// Act
var response = await controller.GetMoviesAsync() as OkObjectResult;
//Assert
var list = response.Value as IEnumerable<Movie>;
//...
}
Note the use of ReturnsAsync to setup the returned Task
It seems that you are not using the correct mock on the Controller. The one that you are using does not have any setup on top of the method GetMoviesAsync
For me helped almost the solution offered by Nkosi but with little difference
[Fact]
public async Task GetMovies_Test() {
// Arrange
var commadMock = new Mock<ICommand>();
var controller = new SampleController(commadMock.Object); //<---
commadMock
.Setup(_ => _.GetMoviesAsync())
.ReturnsAsync(MovieList());
// Act
var response = await controller.GetMoviesAsync();
//Assert
var returnValue = Assert.IsType<ViewResult>(response);
var model = returnValue.Model as IEnumerable<Movie>;
//...
}

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