Mark Monster

Mocking with Rhino Mocks: Expecting a method not to be called

This morning I thought about trying out some Mocking with Rhino Mocks. First of all I was having some little trouble of testing method’s that returned void. Oren Eini suggested somewhere to make use of method chaining, so I changed it to use method chaining.

So what’s next? Expecting a method not to be called. For example the situation on line 12: I expect the WriteLog method with parameter EventLogEntryType.SuccesAudit not to be called. I think the test I wrote should work.

 1 [Test]
 2 public void TestInterpretationForAuditFailureNotWorking()
 3 {
 4   MockRepository mocks = new MockRepository();
 5   ILogWriter eventLogMock = (ILogWriter) mocks.DynamicMock(
 6                                       typeof (ILogWriter));
 7   ILog log = new Log(null, eventLogMock, "MOCK", true, false);
 8 
 9   Expect.Call(eventLogMock.WriteLog(
10               EventLogEntryType.FailureAudit, "MOCK", null, null, 0)
11     ).Return(true);
12   Expect.Call(eventLogMock.WriteLog(
13               EventLogEntryType.SuccessAudit, "MOCK", null, null, 0)
14     ).Return(true).Repeat.Never();
15   mocks.ReplayAll();
16 
17   log.Audit(Audit.Failure, null, null);
18   mocks.VerifyAll();
19 }

The test actually doesn’t work. I get an InvalidOperationException when I call VerifyAll.

System.InvalidOperationException: Can set only a single return value or
exception to throw or delegate to throw on the same method call.at Rhino.Mocks.Expectations.AbstractExpectation.ActionOnMethodNotSpesified()
at Rhino.Mocks.Expectations.AbstractExpectation.set_ExceptionToThrow(Exception value)
at Rhino.Mocks.Impl.MethodOptions.Never()

Does anyone know how this can be solved? What am I doing wrong? The only thing I want is: Expect a method not to be called.

Update: 1 August 2007

After some e-mail contact with Oren he came with the following solution:

12   Expect.Call(eventLogMock.WriteLog(
13               EventLogEntryType.SuccessAudit, "MOCK", null, null, 0)
14     ).Return(true).Repeat.Never();

The solution mentions not to use Return, because you don’t expect anything in return. You expect the method not to be called.

4 Responses to “Mocking with Rhino Mocks: Expecting a method not to be called”

1. Ayende Rahien Says:
   July 30th, 2007 at 21:57

   Does “new Log(null, eventLogMock, “MOCK“, true, false);” this calls to eventLogMock

2. Mark Monster Says:
   July 31st, 2007 at 07:39

   No I do not call eventLogMock in the constructor.

   The “log.Audit(Audit.Failure, null, null);” on line 17 does the call to the eventLogMock.

   The “log.Audit(Audit.Succes, null, null);” that does not exist should not call the eventLogMock because of a value in a config key. I want to evaluate if the interpretation of my config was right.

3. Mark Monster Says:
   August 1st, 2007 at 15:24

   Small update with the solution from Oren alias Ayende.

4. jbierman Says:
   January 14th, 2010 at 22:42

   Awesome little tip! Thank you!

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