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

[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.

public class TestClass : IDisposable
{
    public void Dispose()
    {
    }
}

[TestClass]
public class Fixture
{
    public interface ITest { }

    [TestMethod]
    public async Task Test()
    {
        ITest mock = Mock.Create<ITest>();
        using TestClass test = new();
    }
}

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);
}

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.

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

[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);
}

using Azure.Messaging.ServiceBus;

public class Class2
{
	private static ServiceBusSender messageToTopicSender;
	private static string topicName;

	public static void SetRequestTopicClient(string serviceBusConnectionString, string topName)
	{
		topicName = topName;

		ServiceBusClient serviceBusClient = new ServiceBusClient(serviceBusConnectionString);
		messageToTopicSender = serviceBusClient.CreateSender(topicName);
	}
}

and the following tests

[TestClass]
public class Class1Test
{
	[TestInitialize]
	public void SetUp()
	{
		Mock.Arrange(() => Class2.SetRequestTopicClient("", "")).DoNothing();
	}

	[TestMethod]
	public void TestA()
	{
		Class2.SetRequestTopicClient("", "");
	}
}

[TestClass]
public class Class2Test
{
	static ServiceBusClient serviceBusClient = Mock.Create<ServiceBusClient>();
	ServiceBusSender messageToTopicSender = Mock.Create<ServiceBusSender>();

	[TestInitialize]
	public void SetUp()
	{
		Mock.Arrange(() => new ServiceBusClient("conStr")).Returns(serviceBusClient);
		Mock.Arrange(() => serviceBusClient.CreateSender("myTopic")).Returns(messageToTopicSender);
	}

	[TestMethod]
	public void TestB()
	{
		Class2.SetRequestTopicClient("conStr", "myTopic");
	}
}

Executing the tests in order TestA -> TestB results in failed TestB, but changing the order or runining them standalone succeeds.The outcome of the tests should not be dependent of the execution order.

public class DbContext1 : DbContext
{
    public DbContext1(string connectionString)
    {
    }
}

public class Program
{
    private static readonly SemaphoreSlim _lock = new SemaphoreSlim(1, 1);

    public async Task Run()
    {
        await _lock.WaitAsync();
        try
        {
            await InsertDbRow();
        }
        finally
        {
            _lock.Release();
        }
    }

    private static async Task InsertDbRow()
    {
        await RetryWrapperAsync(async () =>
        {
            using DbContext1 dbContext = new DbContext1("con str");
            await dbContext.SaveChangesAsync();
        });
    }

    public static async Task RetryWrapperAsync(Func<Task> operation)
    {
        for (int i = 0; i < 3; i++)
        {
            try
            {
                await operation();
                break;
            }
            catch (Exception)
            {
                await Task.Delay(100);
            }
        };
    }
}

[TestClass]
public class ProgramTest
{
    private readonly DbContext1 mockContext1 = Mock.Create<DbContext1>();

    [TestInitialize]
    public void SetUp()
    {
        Mock.Arrange(() => new DbContext1("con str")).Returns(mockContext1);
    }

    [TestMethod]
    public async Task TestMethod()
    {
        // Arrange
        Program program = new Program();

        // Act
        await program.Run(); // <-- at this point the test hangs
    }
}

            Mock.Arrange(() => foo.CalcData(Arg.AnyInt, Arg.AnyInt), new IBehavior[]
            {
                new LogInvocation(),
                new ReturnBaseOrDefaultValue(),
            });