public async Task GetAll_SupplierDTOList_ShouldReturnSupplierDTOList() { // Arrange int supplierCount = 5; var mockRepo = new Mock <ISupplierRepository>(); var suppliers = _supplierFixture.GetValidSupplierListModel(supplierCount); mockRepo.Setup(repo => repo.GetAll()).ReturnsAsync(suppliers); // Act SupplierService service = new SupplierService(mockRepo.Object, AutoMapperSingleton.Mapper); var result = await service.GetAll(); // Assert result.Should().HaveCount(supplierCount) .And.ContainItemsAssignableTo <SupplierDTO>(); }