I want to test that a method adds a record to a DBSet under a certain condition:
public static void AddTriggeredInternalTransactions(IDataContext dc, ExternalTransaction transaction)
{
if (transaction [meets condition A])
dc.InternalTransactions.CreateInverseTransaction(transaction);
// do other stuff under other conditions
}
private static void CreateInverseTransaction(this IDbSet<InternalTransaction> transactions, ExternalTransaction from)
{
var internalTransaction = transactions.Create();
from.CopyToInternalTransaction(internalTransaction);
transactions.Add(internalTransaction);
}
Now, I already have tests for CopyToInternalTransaction(). I just need to call AddTriggeredInternalTransactions() and verify that [condition A] results in the new record being added).
I started with http://msdn.microsoft.com/en-us/data/dn314429.aspx, then used other Google and StackOverflow searches. Before tackling my "real" test, I'm trying to do a simple test just to verify whether a record has been added to a dataset, but I'm stuck on this. Can anyone point out my flaw(s)?
var internals = new Mock<DbSet<InternalTransaction>>();
var theData = new List<InternalTransaction>().AsQueryable();
internals.As<IQueryable<InternalTransaction>>().Setup(m => m.Provider).Returns(theData.Provider);
internals.As<IQueryable<InternalTransaction>>().Setup(m => m.Expression).Returns(theData.Expression);
internals.As<IQueryable<InternalTransaction>>().Setup(m => m.ElementType).Returns(theData.ElementType);
internals.As<IQueryable<InternalTransaction>>().Setup(m => m.GetEnumerator()).Returns(theData.GetEnumerator());
var mockDC = new Mock<IDataContext>();
mockDC.Setup(q => q.InternalTransactions).Returns(internals.Object);
mockDC.Setup(q => q.InternalTransactions.Create()).Returns(new InternalTransaction());
mockDC.Setup(q => q.InternalTransactions.Add(It.IsAny<InternalTransaction>()));
var it = mockDC.Object.InternalTransactions.Create();
it.Id = "123";
mockDC.Object.InternalTransactions.Add(it);
internals.Verify(e => e.Add(It.Is<InternalTransaction>(d => d.Id == "123")), Times.Once());
//or: Assert.Equal(1, mockDC.Object.InternalTransactions.Count());
This test fails with: Expected invocation on the mock once, but was 0 times: e => e.Add(It.Is(d => d.Id == "123")) No setups configured. No invocations performed.
The Assert statement, if used instead, fails with a NotImplementedException: "The member IQueryable.Provider has not been implemented on type DbSet~1Proxy_1 which inherits from DbSet1. Test doubles for DbSet1 must provide implementations of methods and properties that are used."
After comments by Adam and Stuart plus further experimentation, I was able to reduce my test case to the following working test case:
var internals = new Mock<DbSet<InternalTransaction>>();
var mockDC = new Mock<IDataContext>();
mockDC.Setup(q => q.InternalTransactions).Returns(internals.Object);
internals.Setup(q => q.Create()).Returns(new InternalTransaction());
var transaction = new ExternalTransaction { [set criteria for Condition A] };
SomeBusinessObject.AddTriggeredInternalTransactions(mockDC.Object, transaction);
// verify the Add method was executed exactly once
internals.Verify(e => e.Add(It.IsAny<InternalTransaction>()), Times.Once());
Related
I am writing a C# .NET 5 application that will act as a backend for an Angular frontend, providing CRUD APIs. The purpose of the app is managing a flight school.
I am writing the API methods that will return the list of pilots and the single pilot, that is https://myapp/api/pilots and https://myapp/api/pilots/{id}.
I have three methods here:
GetPilots() for the complete list
GetPilot(long idPilot) for the detail
an auxiliary method GetFlightTime(long idPilot) to return the total flight time of each pilot doing the sum of the flight durations.
My problem: the detail method works because I first call the auxiliary function and then I use the result in the returned viewmodel. But GetPilots() doesn't work and returns the error System.InvalidOperationException: The client projection contains a reference to a constant expression of 'QTBWeb.Models.PilotsRepository' through the instance method 'GetFlightTime'. This could potentially cause a memory leak; consider making the method static so that it does not capture constant in the instance.
Is this because I am calling the GetFlightTime method inside the LINQ expression? I don't understand the make the method static suggestion. How can I reformat the code to make it work?
Thanks!
public IEnumerable<PilotViewModel> GetPilots() // THIS METHOD RETURNS ERROR
{
return _context.Pilots
.Select(pilot => new PilotViewModel
{
Id = pilot.Id,
Name = pilot.Name,
FlightMinutes = GetFlightTime(pilot.Id) // THE PROBLEM IS HERE
})
.ToList();
}
public PilotViewModel GetPilot(long idPilot) // THIS METHOD WORKS
{
var _flightMinutes = GetFlightTime(idPilot);
return _context.Pilots
.Select(pilot => new PilotViewModel
{
Id = pilot.Id,
Name = pilot.Name,
FlightMinutes = _flightMinutes
})
.Where(pilot => pilot.Id == idPilot)
.FirstOrDefault();
}
public int GetFlightTime(long idPilot)
{
return _context.Flights
.Where(flight => flight.pilot == idPilot)
.Select(flight => flight.Duration).Sum();
}
A good way to solve this would be to make sure that your Pilot class has a collection of Flights, serving as the other side of the one-to-many map you have as Flight.Pilot.
You can then use this collection to calculate the sum, without having to query the database for every looped instance of Pilot.
Your code would look something like this:
public IEnumerable<PilotViewModel> GetPilots()
{
return _context.Pilots
.Include(pilot => pilot.Flights) // Include Flights to join data
.Select(pilot => new PilotViewModel
{
Id = pilot.Id,
Name = pilot.Name,
FlightMinutes = pilot.Flights.Sum(flight => flight.Duration)
});
}
public PilotViewModel GetPilot(long idPilot)
{
return _context.Pilots
.Include(pilot => pilot.Flights) // Include Flights to join data
.Where(pilot => pilot.Id == idPilot) // Notice how we filter first
.Select(pilot => new PilotViewModel
{
Id = pilot.Id,
Name = pilot.Name,
FlightMinutes = pilot.Flights.Sum(flight => flight.Duration)
})
.FirstOrDefault();
}
I'm trying to mock AnyAsync method in my repository with below codes but repository always returns false.
The signature of AnyAsync is:
Task<bool> AnyAsync<TEntity>(Expression<Func<TEntiry, bool>> predicate)
I tried the following setups:
1:
mockCustomerRepository.Setup(r => r.AnyAsync(c => c.Email == "some#one.com"))
.ReturnsAsync(true);
2:
Expression<Func<CustomerEntity, bool>> predicate = expr =>
expr.CustomerPerson.Email == "some#one.com";
mockCustomerRepository.Setup(r => r.AnyAsync(It.Is<Expression<Func<CustomerEntity, bool>>>
(criteria => criteria == predicate))).ReturnsAsync(true);
3:
mockCustomerRepository.Setup(r => r.AnyAsync(It.IsAny<Expression<Func<CustomerEntity, bool>>>()))
.ReturnsAsync(true);
My test:
public class Test
{
Mock<ICustomerRepository> mockCustomerRepository;
public Test()
{
mockCustomerRepository = new Mock<ICustomerRepository>();
}
[Fact]
public async Task CustomerTest()
{
var customer = ObjectFactory.CreateCustomer(email: "some#one.com");
var sut = new CustomerService(mockCustomerRepository.Object);
var result = await sut.ValidateCustomerAsync(customer);
.
.
.
}
}
My CustomerService.ValidateCustomerAsync method:
public async Task<OperationResult> ValidateCustomerAsync(CustomerEntity customer)
{
var errors = new List<ValidationResult>();
if (await _repository.AnyAsync(c => c.Email == customer.Email))
errors.Add(new ValidationResult("blah blah")));
I've also read this but it doesn't work too.
The following snippet shows the correct way to mock your AnyAsync method:
[TestMethod]
public async Task TestMethod1()
{
var fakeCustomerRepo = new Mock<ICustomerRepository>();
var foo = false;
fakeCustomerRepo.Setup(repository => repository.AnyAsync(It.IsAny<Expression<Func<CustomerEntity, bool>>>()))
.Callback<Expression<Func<CustomerEntity, bool>>>(
expression =>
{
var func = expression.Compile();
foo = func(new CustomerEntity() {Email = "foo#gmail.com"});
})
.Returns(() => Task.FromResult(foo));
var customer = new CustomerEntity() {Email = "foo#gmail.com"};
var result = await fakeCustomerRepo.Object.AnyAsync<CustomerEntity>(c => c.Email == customer.Email);
Assert.IsTrue(result);
customer = new CustomerEntity() { Email = "boo#gmail.com" };
result = await fakeCustomerRepo.Object.AnyAsync<CustomerEntity>(c => c.Email == customer.Email);
Assert.IsFalse(result);
}
using the above setup you can verify your predicate which is part of your unit behavior.
I think you're running into the difficulties of matching predicates. Funcs or expressions of Funcs use reference-equality, so just using == to compare the two instances isn't going to work. (As a general rule, if you can't get predicate1.Equals(predicate2) to return true, Moq's argument matchers aren't going to match.)
This is a little unorthodox, but I refer you to my answer to a similar question for FakeItEasy matchers, which in turn points you at a number of techniques for validating predicates.
All I can see that should cause this problem are two options:
1. The repository method does not come from an interface that you should mock to return the desired value, as it is not marked with virtual.
2. The types (TEntity) you use in method do not match when you are using the moq.
AnyAsync<TEntity>(Expression<Func<TEntity, bool>>
as you can setup for let's say MemberEntity and call the ValidateCustomerAsync with a CustomerEntity.
Maybe I am wrong but, but as far as I have read for methods that return only a Task, .Returns(Task.FromResult(default(object))) can and should be used.
So in your case it would be mocksCustomerRepository.Setup(r => r.AnyAsync(c => c.Email == "some#one.com")).Returns(Task.FromResult(true));
I'm trying to mock DbContext and DbSet. This works for my previous unit tests, but problem occurs while my code was calling ToList method on DbSet second time.
First dbSet.ToList() returns mocked results.
Second one returns 0 elements;
var queryableData = new List<string>{ "a", "b", "c" }.AsQueryable();
var mockDbSet = new Mock<DbSet<string>>();
var q = mockDbSet.As<IQueryable<string>>();
q.Setup(m => m.Provider).Returns(queryableData.Provider);
q.Setup(m => m.Expression).Returns(queryableData.Expression);
q.Setup(m => m.ElementType).Returns(queryableData.ElementType);
q.Setup(m => m.GetEnumerator()).Returns(queryableData.GetEnumerator());
DbSet<string> dbset = mockDbSet.Object;
IQueryable<string> query = dbset;
//RESULTS: abc
var a1 = dbset.ToList();
foreach (var a in a1)
Console.Write(a);
//NO RESULTS
var a2 = dbset.ToList();
foreach (var a in a2)
Console.Write(a);
You return the very same enumerator instance upon each call to GetEnumerator. When it enumerates once, it is done, EF doesn't call its Reset method, rather it asks for a new enumerator.
But you return the one that just has yielded all elements and yields no more.
Instead, return a function that returns the enumerator, that will return a new enumerator each time you ask for it.
q.Setup(m => m.GetEnumerator()).Returns( () => queryableData.GetEnumerator() );
I just wanted to added to Wiktor Zychla's answer my little part. If someone is looking for Async version of this mock (coming from this tutorial: http://msdn.microsoft.com/en-us/data/dn314429.aspx#async) then this is my modification to TestDbAsyncEnumerator<T> class:
internal class TestDbAsyncEnumerator<T> : IDbAsyncEnumerator<T>
{
private readonly IEnumerator<T> _inner;
public TestDbAsyncEnumerator(IEnumerator<T> inner)
{
_inner = inner;
}
public TestDbAsyncEnumerator(Func<IEnumerator<T>> valueFunction)
{
_inner = valueFunction();
}
public void Dispose()
{
_inner.Dispose();
}
public Task<bool> MoveNextAsync(CancellationToken cancellationToken)
{
return Task.FromResult(_inner.MoveNext());
}
public T Current
{
get { return _inner.Current; }
}
object IDbAsyncEnumerator.Current
{
get { return Current; }
}
}
Then like Wiktor suggested you have to setup it with delegate so in case of async it would be like that:
mockSet.As<IDbAsyncEnumerable<Blog>>()
.Setup(m => m.GetAsyncEnumerator())
.Returns(new TestDbAsyncEnumerator<Blog>(() => data.GetEnumerator()));
If someone wants source for that then here you go: https://github.com/kelostrada/EntityFrameworkWithMock.Test
I can't comment on Wiktor's post as I haven't got enough reputation, but i would like to add a little extra to Wiktor's answer.
The code
mockSet.Setup((m => m.GetEnumerator()).Returns(() => data.GetEnumerator())
Will fail if you give it a zero argument lambda like in the example(At least the version I am using).
Passing an argument that is never used will allow it to meet the signature requirement however.
mockSet.Setup((m => m.GetEnumerator()).Returns(x => data.GetEnumerator())
Will compile however, and works as expected.
And this also applies to Kelu's answer as well (Although he has added the lambda in the wrong place.
mockSet.As<IDbAsyncEnumerable<Blog>>()
.Setup(m => m.GetAsyncEnumerator())
.Returns(x => new TestDbAsyncEnumerator<Blog>(data.GetEnumerator()));
Not trying to nitpick answers here, i'm just adding because i made these mistakes myself :)
If you put a "Where" clause before the .ToList() call, the data should remain present.
var a1 = dbset.Where(m => m != null).ToList();
var a2 = dbset.Where(m => m != null).ToList();
For one of my assignments I've had to make a method that will return the next item from a database using IRepository as a base. I'm using a TDD design cycle, and so far, this is what I have:
[TestMethod]
public void ShouldReturnNextExportRequest()
{
var requests = new List<ExportRequest>();
for (var i = 0; i < 100; i++)
{
var exportRequest = new Mock<ExportRequest>();
exportRequest.SetupGet(req => req.Id).Returns(i);
requests.Add(exportRequest.Object);
}
// Over-writing variables is bad
requests = requests.OrderBy(er => er.Id).ToList();
/**
* Mock the IRepository so that the Min() call returns the export request with the minimum Id
*/
var repo = new Mock<IRepository<ExportRequest>>();
repo.Setup(rep => rep.Min(It.IsAny<Expression<Func<ExportRequest, int>>>()))
.Returns<Expression<Func<ExportRequest, int>>>(expr => requests.Min(e => e.Id));
repo.Setup(rep => rep.Get(It.IsAny<int>())).Returns<int>(requests.ElementAt);
repo.Setup(rep => rep.Delete(It.IsAny<ExportRequest>()))
.Callback<ExportRequest>(req => Assert.IsTrue(requests.Remove(req), "Couldn't remove {0} from list", req.Id));
var exportRequestRepository = new ExportRequestRepository(repo.Object);
exportRequestRepository.GetNextRequest();
exportRequestRepository.GetNextRequest();
var third = exportRequestRepository.GetNextRequest();
var top = requests.First();
Assert.AreEqual(top.Id, third.Id, "Top element in list has id of {0}, but return from repository is {1}", top.Id, third.Id);
}
The GetNextRequest() method simply does this:
public ExportRequest GetNextRequest()
{
var top = _exportRequestRepository.Min(er => er.Id);
var element = _exportRequestRepository.Get(top);
_exportRequestRepository.Delete(element);
return element;
}
It all works perfectly fine, however the second element - with an id of 1 - is never removed from the list. I've worked this out to be down to the IEnumerable.Min implementation on List, as when it never seems to return an element with Id of 1 (determined by looking at the List in debug mode).
Am I missing something obvious?
NOTE:
I'm using a mocked IRepository from SharpRepository. Not that it makes a difference, as a Moq-ed interface has no inherent actions, but it's worth noting.
EDIT: test output.
Test Name: ShouldReturnNextExportRequest
Test FullName: ExportService.Tests.ExportRequestRepositorySpecification.ShouldReturnNextExportRequest
Test Source: c:\Users\dan.pantry\Desktop\RUMM\ExportService.Tests\ExportRequestRepositorySpecification.cs : line 17
Test Outcome: Failed
Test Duration: 0:00:00.211873
Result Message: Assert.AreEqual failed. Expected:<1>. Actual:<3>. Top element in list has id of 1, but return from repository is 3
Result StackTrace: at ExportService.Tests.ExportRequestRepositorySpecification.ShouldReturnNextExportRequest() in c:\Users\dan.pantry\Desktop\RUMM\ExportService.Tests\ExportRequestRepositorySpecification.cs:line 49
EDIT2: So I put a Callback on Get() like so:
repo.Setup(rep => rep.Get(It.IsAny<int>())).Returns<int>(requests.ElementAt)
.Callback<int>(req => Console.WriteLine("Retrieved {0}", req));
And now my output looks a bit like this:
Retrieved 0
Retrieved 1
Retrieved 1
EDIT3: Here is the origin of _exportRequestRepository in GetNextRequest() - In the test it's the mocked Repository and is injected into the constructor
public ExportRequestRepository(IRepository<ExportRequest> exportRequestRepository)
{
_exportRequestRepository = exportRequestRepository;
}
Issue solved.
The problem was that I was using ElementAt when I should have been using Find, and that I was calling First() before GetNextRequest() (get next request "pops" the elements from the underlying repository - will probably change that, though).
var repo = new Mock<IRepository<ExportRequest>>();
repo.Setup(rep => rep.Min(It.IsAny<Expression<Func<ExportRequest, int>>>()))
.Returns<Expression<Func<ExportRequest, int>>>(expr => requests.Min(e => e.Id));
repo.Setup(rep => rep.Get(It.IsAny<int>())).Returns<int>(i => requests.Find(er => er.Id == i));
repo.Setup(rep => rep.Delete(It.IsAny<ExportRequest>()))
.Callback<ExportRequest>(req => Assert.IsTrue(requests.Remove(req), "Couldn't remove {0} from list", req.Id));
var exportRequestRepository = new ExportRequestRepository(repo.Object);
Assert.AreEqual(0, exportRequestRepository.GetNextRequest().Id);
Assert.AreEqual(1, exportRequestRepository.GetNextRequest().Id);
var top = requests.First();
var third = exportRequestRepository.GetNextRequest();
Assert.AreEqual(top.Id, third.Id, "Top element in list has id of {0}, but return from repository is {1}", top.Id, third.Id);
Solved code is as above. As you can see, Get now uses requests.Find() rather than requests.ElementAt
I have the following sample test code
public Stage Test(Stage Stage)
{
var StartStage = StageRepository.Single(x => x.Order == 1);
var EndStage = StageRepository.Single(x => x.Order == 5);
var ErrorStage = StageRepository.Single(x => x.Name == "Error");
if (Stage == StartStage)
{
return EndStage;
}
else
{
return ErrorStage;
}
}
And I am trying to test it using the following unit test
[TestMethod]
public void XXXTest()
{
//// Arrange
var AutoMocker = new RhinoAutoMocker<StageService>(MockMode.AAA);
MockRepository mockRepository = new MockRepository();
var MockStageRepository = AutoMocker.Get<IRepository<Stage>>();
Stage StartStage = mockRepository.Stub<Stage>();
StartStage.Order = 1;
Stage EndStage = mockRepository.Stub<Stage>();
EndStage.Order = 5;
Stage ErrorStage = mockRepository.Stub<Stage>();
ErrorStage.Name = "Error";
System.Linq.Expressions.Expression<Func<Entities.Stage, bool>> StartParam = x => x.Order == 1;
MockStageRepository
.Stub(x => x.Single(Arg<System.Linq.Expressions.Expression<Func<Entities.Stage, bool>>>.Is.Equal(StartParam)))
.Return(StartStage);
System.Linq.Expressions.Expression<Func<Entities.Stage, bool>> EndParam = x => x.Order == 1;
MockStageRepository
.Stub(x => x.Single(Arg<System.Linq.Expressions.Expression<Func<Entities.Stage, bool>>>.Is.Equal(EndParam)))
.Return(EndStage);
System.Linq.Expressions.Expression<Func<Entities.Stage, bool>> ErrorParam = x => x.Order == 1;
MockStageRepository
.Stub(x => x.Single(Arg<System.Linq.Expressions.Expression<Func<Entities.Stage, bool>>>.Is.Equal(ErrorParam)))
.Return(ErrorStage);
StageService StageService = AutoMocker.ClassUnderTest;
//Act
var ReturnStage = StageService.Test(StartStage);
//Assert
Assert.AreEqual(ReturnStage, EndStage);
}
However this is not working as it is not returning anything when I call StageRepository.Single(). If I change the stub code to ignore the argument then it does return something but it will be the same object returned for each call to Single() which I don't want.
Is it possible to configure RhinoMocks in such a way as to return different objects from a stub depending on the lambda that is passed into it?
I think the root of your problem is that equality on the Expression<Func<T,U>> type is performed by reference rather than value. That means your telling Rhino Mocks to look for instances of expressions created in the test rather than the ones created in the code your testing.
Two possible approaches come to mind:
One would be to provide a way to pass the lambda expressions in to the Stage class from the test, so that when the argument checks happen they are working against the same instances.
Maybe something like:
internal void SetStartStage(Expression<Func<Entities.Stage,bool>> predicate)
{
...
}
The inverse of this would also work, i.e. provide the Expression objects as fields/properties that can be accessed by you're test, and then use those when setting up your mock:
internal Expression<Func<Entities.State,bool>> StartStagePredicate
{
get{ return x => x.Order == 1; }
}
Another option would be to use the Matches method on Args to see if the argument checks the Stage object state correctly. This would require creating some Stage objects in your test that would match the criteria:
var startStageTester = new Stage { Order = 1 };
MockStageRepository
.Stub(x => x.Single(Arg<System.Linq.Expressions.Expression<Func<Entities.Stage, bool>>>.Matches(y => y.Compile()(startStageTester)))
.Return(StartStage);
The call to Compile() is a little jarring, but since you're dealing with an Expression and not a straight-up lambda, you've got to compile it in order to evaluate it.
Now, if a Stage is something that is hard to create, then you may need to create a Mock/Stub of one (or use you're StartStage) and have it return 1 from the Order property (in the case of the StartStage anyway).
There are probably some others I'm not thinking of at the moment as well.
IF the linq condition is not important, I would propose to match it as any, something like this
repository.Stub(x => x.Find(Arg<System.Linq.Expressions.Expression<Func<Entity, bool>>>.Is.Anything)).Return(entitiesList.AsQueryable());
Hope this help.
Thanks for that. That worked a treat. The one thing that I was missing was the Compile method on an ExpressionTree. There is a small bug in your sample code (you use x twice). For completeness here is the working code.
MockStageRepository2
.Stub(x => x.Single(Arg<System.Linq.Expressions.Expression<Func<Entities.Stage, bool>>>.Matches(y => y.Compile()(StartStage2))))
.Return(StartStage2);