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Rhino Mocks - Set a property if a method is called

Answer 1

A:

There might be some conditions under which you would need to do this, but generally I would expect that you would simply instrument your mock/stub so that it returns the proper values in response to your code. The only exceptions to this that I can think of are partial mocks where you are testing one part of a class and want to mock the other parts.

Setting a mock on a property is pretty easy.

callMonitor.Expect( x => x.HangUp() );
callMonitor.Expect( x => x.InACall ).Return( false );

If callMonitor is a stub, then you can set the property directly.

callMonitor.Stub( x => x.HangUp() );
callMonitor.InACall = false;

tvanfosson 2009-08-28 21:15:40

Answer 2

+1 A:

Yes, you can use the Callback method:

 callMonitor.Expect(x => x.HangUp()).Callback(() => callMonitor.InCall = false);

Mark Seemann 2009-08-28 21:16:53

Exactly what I would have written (had I come across this question 6 minutes ago ;)

Richard Szalay 2009-08-28 21:24:19

Horrible abuse of the callback mechanism. It's hard to tell, since there's not a lot of info in the post, but I think the OP is not being focused enough in the tests. Read Ayende's cautions on using callbacks at http://ayende.com/Wiki/(S(zwkmge45vdgkgvznp13mgc55))/Rhino+Mocks+Callbacks.ashx

tvanfosson 2009-08-28 21:45:01

FWIW -- the callback is supposed to be used to evaluate whether or not the expectation was met, not to do arbitrary computation.

tvanfosson 2009-08-28 21:48:42

Answer 3

A:

I'm no RhinoMocks expert, but I believe this should work.

SetupResult.For(callMonitor.InACall).Return(false);

Stephan 2009-08-28 21:17:15

I believe that that was not what he asked about. He asked if there is a way to give the HangUp method an impromptu implementation that sets the InCall property to false when the HangUp method is called. What you have there will cause the InACall method to return false no matter if the HangUp method was called or not.

Mark Seemann 2009-08-28 21:20:54

Answer 4

+4 A:

You can use the "WhenCalled" method to run your own code when a stub is called; pretty sure it should work with Mocks, too. According to the documentation, WhenCalled is a replacement/upgrade for Callback.

callMonitor.Expect(x => x.HangUp())
.WhenCalled(invocation => callMonitor.InCall = false);

Some info at the end of this post: http://grahamnash.blogspot.com/2008/10/rhino-mocks-35.html

Mark Simpson 2009-08-28 21:26:35

Still an abuse, even though the method name has changed. WhenCalled, like Callback, is intended to be used in advanced expectation evaluation, not to do arbitrary computation.

tvanfosson 2009-08-28 22:00:48

What would you recommend instead? A hand rolled test double?

Mark Simpson 2009-08-28 22:30:18

Actually, I'd like to see the test. It seems to me if the test is focused enough, there may not be a need for it.

tvanfosson 2009-08-28 22:49:38

To see the test see this question: http://stackoverflow.com/questions/1349324/unit-testing-with-computer-owned-states If there is a "Right way" then I would like to know it.

Vaccano 2009-08-31 15:00:18

tvanfosson: I've used it in a few cases to set local variables in tests, though generally not for setting properties on a mock/stub as in this case. It's not caused me any problems as of yet, but I'd like to understand why this is considered an abuse? Is there some form of canonical documentation for Rhino Mocks that says "thou shalt not abuse WhenCalled"? (serious question! I find the Rhino Mocks documentation to be a bit fast and loose + scattered all over the place). Cheers.

Mark Simpson 2009-08-31 17:02:08

I agree with Mark. If this is bad then I would like to know why. For my test to work I need to simulate the device hanging up a call. This requires something to happen when the HangUp() method is called. If there is a better way to do this then I want to know it so I can do this right.

Vaccano 2009-09-02 06:37:22

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