I am quite new to TDD and am going with NUnit and Moq. I have got a method where I expect an exception, so I wanted to play a little with the frameworks features.

My test code looks as follows:

    [Test]
    [ExpectedException(ExpectedException = typeof(MockException), ExpectedMessage = "Actual differs from expected")]
    public void Write_MessageLogWithCategoryInfoFail()
    {
        string message = "Info Test Message";

        Write_MessageLogWithCategory(message, "Info");

        _LogTest.Verify(writeMessage =>
            writeMessage.Info("This should fail"),
            "Actual differs from expected"
        );
    }

But I always receive the errormessage that the error message that the actual exception message differs from the expected message. What am I doing wrong?