public async Task GetByIdAsyncWhenNoEnterpriseFoundReturnsEnterpriseNotFoundResponse() { // Arrange var mockEnterpriseRepository = GetDefaultIEnterpriseRepositoryInstance(); var mockUnitOfWork = GetDefaultIUnitOfWorkInstance(); var enterpriseId = 1; mockEnterpriseRepository.Setup(r => r.FindById(enterpriseId)) .Returns(Task.FromResult <Enterprise>(null)); var service = new EnterpriseService(mockEnterpriseRepository.Object, mockUnitOfWork.Object); // Act EnterpriseResponse result = await service.GetByIdAsync(enterpriseId); var message = result.Message; // Assert message.Should().Be("Enterprise not found"); }