public void TestDirectoryCreation() { var operationsFactoryMock = new Mock <IOperationsFactory>(); var directoryServiceMock = new Mock <IDirectoryService>(); var fullDirectoryPath = Path.Combine(SelectedDirectoryName, DirectoryName); directoryServiceMock .Setup(m => m.CreateDirectory(fullDirectoryPath)) .Verifiable(); var fileOpeningServiceMock = new Mock <IFileOpeningService>(); var fileServiceMock = new Mock <IFileService>(); var pathServiceMock = new Mock <IPathService>(); pathServiceMock .Setup(m => m.Combine(SelectedDirectoryName, DirectoryName)) .Returns(fullDirectoryPath); IOperationsService operationsService = new OperationsService( operationsFactoryMock.Object, directoryServiceMock.Object, fileOpeningServiceMock.Object, fileServiceMock.Object, pathServiceMock.Object); operationsService.CreateDirectory(SelectedDirectoryName, DirectoryName); directoryServiceMock.Verify(m => m.CreateDirectory(fullDirectoryPath), Times.Once()); }