Mock of Rebus message context needs transaction - autofac

Question

I have this code to mock a Rebus MessageContext
IBus fakeBus;
IMessageContext messageContext;
[TestInitialize]
public void TestInitialize()
{
fakeBus = new FakeBus();
var mock = new Mock<IMessageContext>();
mock.Setup(m => m.ReturnAddress).Returns("queuename");
mock.Setup(h => h.Headers).Returns(new Dictionary<string, object>());
mock.Setup(m => m.Items).Returns(new Dictionary<string, object>());
mock.Setup(m => m.RebusTransportMessageId).Returns(Guid.NewGuid().ToString());
messageContext = mock.Object;
var fakeContext = FakeMessageContext.Establish(messageContext); // error here
}
But the last line return the stack trace below. What am I missing here?
Sidenote: I am still on Rebus 0.84.
Result StackTrace:
at Rebus.MessageContext.Establish(IMessageContext messageContext, Boolean overwrite)
at Rebus.Testing.FakeMessageContext.Establish(IMessageContext messageContext)
at MyApp.Messaging.Tests.Handlers.RegisterPaymentCallbackTests.TestInitialize() in C:\CUT.Tests\Handlers\RegisterPaymentCallbackTests.cs:line 57
Result Message: Initialization method MyApp.Tests.Handlers.RegisterPaymentCallbackTests.TestInitialize threw exception. System.InvalidOperationException: Could not find a transaction context. There should always be a transaction context - though it might be a NoTransaction transaction context..

Answer 1

I haven't really used the fake message context myself, as I've usually found it easier to either use SagaFixture or do my unit testing of slightly larger units.
When I look at the old Rebus code I can see that all the tests that exercise FakeMessageContext establish a transaction context first, like so:
using (TransactionContext.None())
using (FakeMessageContext.Establish(fakeContext))
{
// do stuff
}
so that must be the way to do it :)