public async void FileExtension_Create_null()
        {
            Mock <IDocumentRepository> documentRepository = new Mock <IDocumentRepository>();

            documentRepository.Setup(x => x.Get(It.IsAny <Guid>())).Returns(Task.FromResult(new Document()));

            var validator = new ApiDocumentRequestModelValidator(documentRepository.Object);
            await validator.ValidateCreateAsync(new ApiDocumentRequestModel());

            validator.ShouldHaveValidationErrorFor(x => x.FileExtension, null as string);
        }
        public async void FileExtension_Update_length()
        {
            Mock <IDocumentRepository> documentRepository = new Mock <IDocumentRepository>();

            documentRepository.Setup(x => x.Get(It.IsAny <Guid>())).Returns(Task.FromResult(new Document()));

            var validator = new ApiDocumentRequestModelValidator(documentRepository.Object);
            await validator.ValidateUpdateAsync(default(Guid), new ApiDocumentRequestModel());

            validator.ShouldHaveValidationErrorFor(x => x.FileExtension, new string('A', 9));
        }
        public async void Title_Create_length()
        {
            Mock <IDocumentRepository> documentRepository = new Mock <IDocumentRepository>();

            documentRepository.Setup(x => x.Get(It.IsAny <Guid>())).Returns(Task.FromResult(new Document()));

            var validator = new ApiDocumentRequestModelValidator(documentRepository.Object);
            await validator.ValidateCreateAsync(new ApiDocumentRequestModel());

            validator.ShouldHaveValidationErrorFor(x => x.Title, new string('A', 51));
        }