Mock.Arrange throws NullReferenceException

[Viktor zhivkov]

I have a problem with this code:

public interface IProcessDataPersister
{
List<TaskWarning> GetTaskWarnings(Guid taskId);
}

//in a method
var localPersister = Mock.Create<IProcessDataPersister>();
Mock.Arrange(() => localPersister.GetTaskWarnings(new Guid("{00000000-0000-0000-0001-000000000003}")))
.Returns(new List<TaskWarning>() { new TaskWarning(new Guid("{00000000-0000-0000-0001-000000000003}")) { EscalationLevel = 0 } })
.MustBeCalled();

Mock.Arrange(...) throws the following exception:
System.NullReferenceException occurred
  Message=Object reference not set to an instance of an object.
  Source=Telerik.JustMock
  StackTrace:
       at .™.(Type valueType, Object value) in c:\B\Basilisk\Basilisk CI Build\Sources\CodeBase\Telerik.JustMock\Utility.cs:line 334
  InnerException: 

If I change the Arrange method to use Arg.IsAny<Guid>() instead of the explicit value there is no exception and everything works fine.
I am using the latest internal JustMock Free Edition build 2011.1.620.0.
Also test it on the official build and the results were the same.
Hope that will help you solve the problem.

[Ricky]

Hi Viktor,

Thanks again for sending issue. Yes you are right about it and therefore I filed a bug regarding it and hopefully it will be fixed in the coming Q2 release.


Should you find  any more exceptions, please feel free to write us back.

Kind Regards,
Ricky
the Telerik team

[Viktor zhivkov]

I am looking forward the fix.
Meantime if anyone else struggles with the same issue here is my own workaround:

var localPersister = Mock.Create<IProcessDataPersister>();
Mock.Arrange(() => localPersister.GetTaskWarnings(Arg.IsAny<Guid>()))
.Returns((Guid id) =>
{
string strId = id.ToString();

switch (strId)
{
    case "00000000-0000-0000-0001-000000000001":
        return new List<TaskWarning>() { new TaskWarning(id) { EscalationLevel = 1 } };
    case "00000000-0000-0000-0001-000000000002":
        return new List<TaskWarning>() {
            new TaskWarning(id) { EscalationLevel = 1 },
            new TaskWarning(id) { EscalationLevel = 2 } };
    default:
        return new List<TaskWarning>();
}
});