Unit testing not using correct mocking class - unit-testing

Question

I am using Rhino.Mocks and Structure map to help unit test my code. I have several tests that pass when they are ran by themselves, but when ran as a group fail to pass. The setup code for these unit tests is:
[TestInitialize()]
public void Setup()
{
ObjectFactory.Initialize(x =>
{
x.For(IManager)().Use(Handler)();
});
}
In my tests, I stub out this interface and call the method.
[TestMethod]
public void AreMultiple_Test()
{
var mackIManager = MockRepository.GenerateMock<IManager>();
mackIManager.Stub(u => u.GetTwoUserName(Arg<int>.Is.Anything)).Return(null);
ObjectFactory.Inject(typeof(IManager), mackIManager);
StepAdditionalActionBase actionBase = new StepAdditionalActionBase();
bool areMultiple = actionBase.AreMultiple(new WorkOrder { Id = "123" });
Assert.IsFalse(areMultiple);
}
Test Method 2
[TestMethod]
public void AreMultiple_Test()
{
var mackIManager = MockRepository.GenerateMock<IManager>();
mackIManager.Stub(u => u.GetTwoUserName(Arg<int>.Is.Anything)).Return("123");
ObjectFactory.Inject(typeof(IManager), mackIManager);
StepAdditionalActionBase actionBase = new StepAdditionalActionBase();
bool areMultiple = actionBase.AreMultiple(new WorkOrder { Id = "123" });
Assert.IsTrue(areMultiple);
}
This is unit testing the following code.
public bool AreMultiple(WorkOrder workOrder)
{
string secondUser = _handler.GetTwoUserName(_workflowManager.GetNumberForProject(workOrder.Id));
if (String.IsNullOrEmpty(secondUser ))
{
return false;
}
return true;
}
When I run them by themselves, they work fine. When I run them together, the first passes and the second fails. When I debug the second one, I find that that the return value in the Stubbed method is still coming back as null. How do I get this to use the new Stubbed method.
UPDATE.
I am using StructureMap as my container. From what I have been able to find, the following code is what is used to dispose of the container I got it from this link. When I added this, the test still fail when ran together, but pass when ran individually.
[TestCleanup()]
public void TestCLeanup()
{
ObjectFactory.Container.Dispose();
}

Answer 1

The tests work one by one but fails if run all together. The problem should be in the common part which is being shared across the tests making them dependent from each other. In this particular case that is static ObjectFactory which is nothing else but a Service Locator (anti-pattern).
In the tests, you mock the IManager interface and register it in the ObjectFactory:
ObjectFactory.Inject(typeof(IManager), mackIManager);
Then the SUT uses the ObjectFactory service locator to resolve and use the mocked interface (_handler field):
string secondUser = _handler.GetTwoUserName(...)
I suspect the first test registers the _handler and never clean it up properly, so that the same instance appears in the second test. You should reset the ObjectFactory between tests following the Register Resolve Release pattern.
Another (preferable) option is to refactor your SUT to receive the IManager handler dependency explicitly via constructor. That would simplify both SUT and tests moving the ObjectFactory configuration to the Composition Root.