RhinoMocks return value when a method has not been called

Question

I want to do the following...

Until a method has been called a certain property must always return value x After a method has been called a certain property must always return value y

I am familiar with the WhenCalled method in RhinoMocks, which allows me to set that return value after the method has been called, but I cannot think of a way to set the return value before the call. So far I have the following code...

counter.Expect(n => n.IncreaseCounter())
   .WhenCalled(i => counter.Expect(n => n.GetCounter)
   .Return(Y).Repeat.Any());

Is this possible?

score 4 · Accepted Answer · edited May 23 '17 at 10:26

There are 2 solutions to do the trick:

With usage WhenCalled():

var counter = MockRepository.GenerateStub<ICounter>();

int cnt = 1;

counter
    .Stub(c => c.GetCounter)
    .Return(0)
    .WhenCalled(invocation => { invocation.ReturnValue = cnt; });

counter
    .Stub(c => c.IncreaseCounter())
    .WhenCalled(invocation => { ++cnt; });

With usage Do() handler

var counter = MockRepository.GenerateStub<ICounter>();

int cnt = 1;

counter
    .Stub(c => c.GetCounter)
    .Do((Func<int>)(() => cnt));

counter
    .Stub(c => c.IncreaseCounter())
    .Do((Action)(() => ++cnt));

The idea is the same in both cases: Initially GetCounter returns 1. Each IncreaseConter() call increases value which is returned by GetCounter.

PS
If you are not going to do assertions against counter then it is probably suitable to setup it with Stub() rather than with Expect(). See e.g. this question for details.

Thanks Alex, this helped and was jsut what I was looking for... with a slight modification — Mark Pearl, Jan 14 '13 at 14:23

score 1 · Answer 2 · answered Dec 31 '12 at 14:20

1

Just setup new return value for property in a callback of mocked method:

Mock<IFoo> fooMock = new Mock<IFoo>();
fooMock.Setup(foo => foo.Property).Returns(1);
fooMock.Setup(foo => foo.Method())
       .Callback(() => fooMock.Setup(x => x.Property).Returns(42));

Mocked property will return 1 until mocked method will be called. Then its return value will be set to 42. All further calls to mocked property will return 42.

answered Dec 31 '12 at 14:20

Sergey Berezovskiy

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Oops, my bad :) Will fix soon – Sergey Berezovskiy Dec 31 '12 at 15:59

score 0 · Answer 3 · answered Jan 14 '13 at 14:29

Based on Alexander's solution... the following was what I was looking for...

var counter = MockRepository.GenerateStub<ICounter>();

int x = 1;
int y = 2;
int cnt = x;

counter
    .Stub(c => c.GetCounter)
    .Return(0)
    .WhenCalled(invocation =>
    {
        invocation.ReturnValue = cnt;
        cnt = y;
    });

RhinoMocks return value when a method has not been called

3 Answers3