Very simple RhinoMocks test failing - Whats wrong here?

Question

I'm trying to work out why some of my test cases (using RhinoMocks 3.6 Build 20) aren't working, and I've narrowed the issue down to the following minimal unit test:

public interface ITest
{
    string Something { get; }
}

[Test]
public void TestStub()
{
    var mockery = new MockRepository();
    var testItem = mockery.Stub<ITest>();
    testItem.Stub(x => x.Something).Return("Hello");
    Assert.AreEqual("Hello", testItem.Something);
}

This fails with the message:

Expected: "Hello" But was: null

Any ideas what I'm doing wrong here? I've found a few examples on SO and the Rhino Wiki on how to stub read-only properties, and as far as I can tell, this should work fine.

Cheers in advance.

EDIT: Based on sll's advice below, I tried replacing

testItem.Stub(x => x.Something).Return("Hello");

with

testItem.Expect(x => x.Something).Return("Hello");

and the test still fails in the same manner.

Edit 2: I've got this working by adding the line

mockery.ReplayAll();

before the Assert - but I thought this was no longer required (from the wiki: "Mocks/stubs returned from MockRepository.GenerateMock() and MockRepository.GenerateStub() are returned in replay mode, and do not require explicit move to replay mode.")

sll · Answer 1 · 2012-04-03T10:20:53.317

1

Try out generating Mock instead:

var testItem = MockRepository.GenerateMock<ITest>();     
testItem.Expect(x => x.Something).Return("Hello");     
Assert.AreEqual("Hello", testItem.Something);

Als make sure you shared entire test method, perhaps you ignored some lines of code? Try out usign Repeat.Any() perhaps proeprty accessed before you are doing expectation.

testItem.Expect(x => x.Something).Return("Hello").Repeat.Any();

On example page Stub() used for methods, and suggested using Mock's Expect() for properties:

Using Expect() to set up properties

The Expect() extention method can be used to set up expectations and return values for properties.

edited Apr 03 '12 at 10:20

answered Apr 03 '12 at 10:01

sll

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I'm aware that generating a mock works, but all the documentation I've seen suggests that the case above should work (eg http://stackoverflow.com/questions/2090191/stubbing-a-read-only-property-with-rhino-mocks and http://stackoverflow.com/questions/1087619/how-to-setup-return-value-for-a-readonly-property-using-rhinomocks-in-vb-net). I'm not setting the expectation on the stub (that would be a call to Expect), I'm (trying to) stub the property. – AlexC Apr 03 '12 at 10:03
Ary you using RhinoMocks 3.5? – sll Apr 03 '12 at 10:05
Documentation is not clear but from examples we can see that `Stub's Stub()` used for methods and `Mock's Expect()` for proeprties, perhaps this is how we should do as well – sll Apr 03 '12 at 10:10
Still fails - original question updated. EDIT: Oh I see you mean use Mock for the item. I dont think that's the solution - a lot of googling suggests that stubs CAN be used for read only properties. – AlexC Apr 03 '12 at 10:13
have you created a mock before setting `Expect()`? also perhaps you give us a part of real test? Try out adding `Return(..).Repeat.Any()` – sll Apr 03 '12 at 10:19
Nope - nothing else was done in this test case. I've got this working by adding the line mockery.ReplayAll() before the Assert - but I thought this was no longer required (from the wiki: Mocks/stubs returned from MockRepository.GenerateMock() and MockRepository.GenerateStub() are returned in replay mode, and do not require explicit move to replay mode.) – AlexC Apr 03 '12 at 10:25

score 1 · Accepted Answer · answered Apr 03 '12 at 10:33

Got it:

From the RhinoMocks 3.6 Blog Post comments:

09/03/2009 05:34 PM by Kurt Harriger

FYI,

I had a few dozen tests fail after upgrading to v 3.6 from code like this:

var mocks = new MockRepository();

var something = mocks.Stub

something.Stub(x=>x.DoSomething() ).Return(true);

something.DoSomething();

The root cause of the problem appears that mock.Stub/Mock/etc no longer returns the mock in replay mode. To fix replaced mock.Stub with MockRepository.GenerateStub.

Ayende Rahien 09/03/2009 06:50 PM by Ayende Rahien

Kurt,

That is actually expected, that should have never worked

So, by changing the test to:

    [Test]
    public void TestStub()
    {
        var testItem = MockRepository.GenerateStub<ITest>();
        testItem.Stub(x => x.Something).Return("Hello");
        Assert.AreEqual("Hello", testItem.Something);
    }

this now works.

Cheers

score -1 · Answer 3 · answered Apr 03 '12 at 10:03

-1

You are just setting the value so you would expect to do this like this:

public interface ITest
{
    string Something { get; }
}

[Test]
public void TestStub()
{
    var mockery = new MockRepository();
    var testItem = mockery.Stub<ITest>();
    testItem.Something = "Hello";
    Assert.AreEqual("Hello", testItem.Something);
}

No need to Stub with Func.

answered Apr 03 '12 at 10:03

Davin Tryon

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This wont compile - "Something" is read-only, so the "testItem.Something = "Hello";" line will cause a compile time error. – AlexC Apr 03 '12 at 10:06

Very simple RhinoMocks test failing - Whats wrong here?

3 Answers3