public async Task DeleteDeck_Returns_204_When_Deck_Exists()
        {
            //Arrange
            var mockRepository = new Mock <IFlashcardDataRepository>();

            mockRepository.Setup(x => x.DeleteDeckById(11)).Returns((int id) => Task.FromResult <bool>(true));

            DecksController decksController = new DecksController(mockRepository.Object, iMapper);

            //Act
            var result = await decksController.DeleteDeckById(11);

            //Assert
            var noContentResult = Assert.IsType <NoContentResult>(result);
        }
        public async Task DeleteDeck_Returns_NotFound_When_Deck_NotExist()
        {
            //Arrange
            var mockRepository = new Mock <IFlashcardDataRepository>();

            mockRepository.Setup(x => x.DeleteDeckById(10)).Returns((int id) => Task.FromResult <bool>(false));

            DecksController decksController = new DecksController(mockRepository.Object, iMapper);

            //Act
            var result = await decksController.DeleteDeckById(10);

            //Assert
            var notFoundObjectResult = Assert.IsType <NotFoundObjectResult>(result);
            var errorResponse        = Assert.IsType <ErrorResponse>(notFoundObjectResult.Value);

            Assert.Equal("Deck with Id 10 not found", errorResponse.Errors[0]);
        }