To replicate the problem using the provided project, follow these steps:

1. Open the solution in Rider.
2. Set breakpoints at the beginning of the test.
3. Start debugging the test.
4. Step into the constructor of the Car class and inspect the contents of the array. Note that if this step is skipped, the issue will not be reproducible.
5. Step out of the constructor.
6. Continue execution until just before calling the virtual function for the Number property.
7. Step into the function.

**EXPECTED** The value of Name should be visible.

**ACTUAL** A debugger error occurs.

The issue can appear in both Visual Studio (showing "Internal error in the C# compiler") and Rider (showing "Read out of bounds"). 

Good morning,

Could you please give me a help in order to use JustMock to moch the HttpContext of my API controller?

I have inclosed you my code extracted from my software with the minimal code I could.

In this one, DealControllerReadByIdShouldReturnDtos works fine but unfortunately I tried for hour to make my DealControllerReadAllShouldReturnDtos test works.

Could you please help me?

In advance I thank you

Davy MANGOLD - Humrig

My setup includes my local dev environment and so called "grid node" server used by NCrunch.

Yesterday I've updated JustMock to version 2025.2.520.440.
After that update I received an error mentioning my License file not to include Telerik Just Mock.
So I've updated my License file by the way mentioned in the Release Notes.

After that my NCrunch Build crashed with an TypeInitializationException "The type initializer for 'Telerik.JustMock.Core.Licensing.LicenseManager'. String was not recognized as a valid DateTime."

I've updated my License file again today and the Exception Message has changed to "String '5/20/2025' was not recognized as a valid DateTime."

I than set my local DateDime format from dd.MM.yyyy to yyyy-MM-dd and the problem is gone.
So it seems like the current version has a problem with our German / European format.

With version 2025.1.211.365 everything worked fine.

So would you please so kind to have a look onto that?
Thank you

We're using this DevOps task in our pipeline, however since yesterday we get the following warning:

##[warning]Task 'Telerik JustMock VSTest v.2' version 2 (JustMockVSTest@2) is dependent on a Node version (6) that is end-of-life. Contact the extension owner for an updated version of the task. Task maintainers should review Node upgrade guidance: https://aka.ms/node-runner-guidance

We're running it using a build agent hosted at the Azure DevOps cloud.

This article mentions a package that can be used to very easily mock Entity Framework types (mainly DbContext). However, this package only works for Entity Framework 6, and not Entity Framework Core, which my project uses. I would love to see this package updated to greatly simplify unit testing for my project.

I'm specifically looking to mock the following types: IDbContextFactory, my subclass of DbContext, and DbSet. All of this is currently possible of course with the standard JustMock interface but it's a hassle.

Having the simple class

public class MyClass
{
    public event Func<EventArgs, Task>? MyEventAsync;
}

and the test that tries to rise the declared event

[TestMethod]
public void TestMethod1()
{
    var mockClass = Mock.Create<MyClass>(Behavior.Strict);
    mockClass.MyEventAsync += (args) => Task.CompletedTask;

    Mock.Raise(() => mockClass.MyEventAsync += null, EventArgs.Empty);
}

Execution triggers the following error:

Telerik.JustMock.Core.MockException : Event signature System.Threading.Tasks.Task OnMyEventAsync(System.EventArgs) is incompatible with argument types (Castle.Proxies.ExternalMockMixinProxy, System.EventArgs)

which is kind of unexpected since the supplied arguments are matching to the event's signature.

Collection mock (result from ReturnCollection clause) does not support async queries due to the unimplemented IAsyncQueryProvider interface. The issue could be easily reproduced with the following simple test:

[Fact]
public void ShouldReturnEntity()
{
    var db = Mock.Create<MyModel.MyModel>();
    Mock.Arrange(() => db.SomeEntities).ReturnsCollection(someEntities);

    var entity = db.SomeEntities.SingleAsync(x => x.Id == 1);

    Assert.NotNull(entity);
}

The outcome is the the following exception:

System.InvalidOperationException
The provider for the source 'IQueryable' doesn't implement 'IAsyncQueryProvider'. Only providers that implement 'IAsyncQueryProvider' can be used for Entity Framework asynchronous operations.

With R3 2023 (2023.3.1011.155) JustMock introduces a new functionality that might lead to a huge performance drop and event to unexpected failures. Currently, the issue could be suppressed by setting up an environment variable JUSTMOCK_NEWOBJ_INTERCEPTION_ON_OVERWRITE_ENABLED to 0 (the default value is 1), but a more reliable and independent solution should be found.

The issue is about interoperability between JustMock and AutoFixture. The unit test run can be 90% faster if all the fixtures are created before the JustMock arrangements.

Here is a sample code that figures out the issue:

[Fact]
public void Slow
{ 
    var fixture = new Fixture():

    var items1 = fixture.Create<List<Item>>();
    Nock.Arrange(() => ItemsRepository.GetItems1()).Returns(items1);

    var items2 = fixture.Create<List<Item>>();
    Nock.Arrange(() => ItemsRepository.GetItems2()).Returns(items2);

    var items3 = fixture.Create<List<Item>>();
    Nock.Arrange(() => ItemsRepository.GetItems3()).Returns(items3);

    var items4 = fixture.Create<List<Item>>();
    Nock.Arrange(() => ItemsRepository.GetItems4()).Returns(items4);
}

[Fact]
public void Fast()
{
    var fixture = new Fixture():

    var items1 = fixture.Create<List<Item>>();
    var items2 = fixture.Create<List<Item>>();
    var items3 = fixture.Create<List<Item>>();
    var items4 = fixture.Create<List<Item>>();

    Nock.Arrange(() => ItemsRepository.GetItems1()).Returns(items1);
    Nock.Arrange(() => ItemsRepository.GetItems2()).Returns(items2);
    Nock.Arrange(() => ItemsRepository.GetItems3()).Returns(items3);
    Nock.Arrange(() => ItemsRepository.GetItems4()).Returns(items4);
}

The test duration should not be dependent on the exact implementation.

There are no ReturnsAsync methods for mocking container async methods.

There should be a set of methods to mock async methods of a container similar to regular object mocking.

As a user I should be able to write code like:

container.Arrange<IContainer>(r => r.SomeAsyncMethod("data")).ReturnsAsync("returnValue");

Provide support for .NET MAUI projects. 

Let me explain in details the current situation:

I have Unit Test project using JustMock and running into a problem. It seems like JustMock is using the wrong version number to locate the SDK. let me explain:

The project is set to: <TargetFramework>net7.0</TargetFramework>

But it also has <UseMaui>true</UseMaui> enabled

I am getting the following error:

"Framework: 'Microsoft.Maui.Core', version '7.0.92' (x64)
.NET location: C:\Program Files\dotnet
No frameworks were found.

That 7.0.92 version is only for the MAUI workload version, not the SDK versions. It seems JustMock uses a workload version as a SDK version. 

Hi.

i saw this: https://www.telerik.com/forums/how-can-i-mock-multiple-instances-of-a-struct

but still dont understand why JustMock works that way in the first place. why does it union struct mocks by value?

the above solution is only possible when i mock a struct i can change (and then add the id to it) but what about struct's from the framework that i cannot control? Is there a way to tell JustMock not to union mock structs?

Thanks,

Yosi

Dear Telerik team,
It is nice to have a way to generate mocks.

But it is annoying to have lots of those messages for references in XML comments. I had to turn the feature off. Which might be the case for other customers too.

Maybe you want to have a look into it.

I am unable to mock interfaces that contain a method with an `in` parameter. When running the following code snippet, the result is an exception:

Message: 
  Test method Example.UnitTests.UnitTest.TestMethod threw exception:
  Telerik.JustMock.Core.MockException: Abstract type 'Example.UnitTests.InParamExample' is not accessible for inheritance.

Stack Trace: 
  MocksRepository.Create(Type type, MockCreationSettings settings)
  <>c__38`1.<Create>b__38_0()
  ProfilerInterceptor.GuardInternal[T](Func`1 guardedAction)
  UnitTest.TestMethod() line 23

namespace Example.UnitTests
{
    using Microsoft.VisualStudio.TestTools.UnitTesting;
    using Telerik.JustMock;

    public interface ParamExample
    {
        void Foo(int param);
    }

    public interface InParamExample
    {
        void Foo(in int param);
    }

    [TestClass]
    public class UnitTest
    {
        [TestMethod]
        public void TestMethod()
        {
            var mockedParamExample = Mock.Create<ParamExample>();
            var mockedInParamExample = Mock.Create<InParamExample>();
        }
    }
}

JustMock interprets anonymous types as tuples. The sample below demonstrates the issue:

public interface IAnsweringService
{
    (int code, string desc) GetAnswer(string question);
}


[TestMethod]
public void AnswerToTheUniverseQuestionTest()
{
    var apiMock = Mock.Create<IAnsweringService>();

    var expectedAnswer = new { code = 42, desc = "Answer to the Ultimate Question of Life" };

    Mock.Arrange(() => apiMock.GetAnswer(Arg.AnyString)).Returns(expectedAnswer);

    var actualAnswer = apiMock.GetAnswer("What is a universe question answer?");

    Assert.AreEqual(expectedAnswer.code, actualAnswer.code);
    Assert.AreEqual(expectedAnswer.desc, actualAnswer.desc);
}

Telerik.JustMock.Core.MockException: The chained return value type '<>f__AnonymousType1`2[System.Int32,System.String]' is not compatible with the arranged method's return type 'System.ValueTuple`2[System.Int32,System.String]'