public void Handle_InnerIsCalled() { IRequestHandler <Request, string> inner = Substitute.For <IRequestHandler <Request, string> >(); var logger = Substitute.For <ILogger>(); var handler = new LoggingHandler <Request, string>(inner, logger); handler.Handle(new Request()); logger.Received().Information(Arg.Is <string>(s => s.Contains("Logging:"))); inner.Received().Handle(Arg.Any <Request>()); }