public void TestMicrowaveOven_ArchiveMessageMethod() { Mock <IWriter> writer = new Mock <IWriter>(); Mock <IRepository> repo = new Mock <IRepository>(); IClient microwave = new MicrowaveOven(writer.Object, repo.Object); microwave.ArchiveMessageInServer(Msg); repo.Verify(x => x.ArchiveMessage(It.Is <string>(s => s == Msg)), Times.Once, "The given message was not stored in the repository"); }