public void Should_Add_ErrorMessageWithException() { // Given var fixture = new AppVeyorFixture(); fixture.IsRunningOnAppVeyor(); var appVeyor = fixture.CreateAppVeyorService(); const string message = "Hello world"; var exception = new CakeException("This is an exception", new ArgumentException()); // When appVeyor.AddErrorMessage(message, exception); // Then fixture.ProcessRunner.Received(1).Start( Arg.Is <FilePath>(p => p.FullPath == "appveyor"), Arg.Is <ProcessSettings>(p => p.Arguments.Render() == string.Format("AddMessage \"{0}\" -Category \"Error\" -Details \"{1}\"", message, exception.ToString()))); }