public async void NextChainId_Create_Invalid_Reference() { Mock <IClaspRepository> claspRepository = new Mock <IClaspRepository>(); claspRepository.Setup(x => x.GetChain(It.IsAny <int>())).Returns(Task.FromResult <Chain>(null)); var validator = new ApiClaspRequestModelValidator(claspRepository.Object); await validator.ValidateCreateAsync(new ApiClaspRequestModel()); validator.ShouldHaveValidationErrorFor(x => x.NextChainId, 1); }