public async void GetAddressesByClientIdAsync_Returns_All_Addresses_for_One_Client(int client_id) { //gets all BillableActivities for one employee var _addressesForClient = _addresses.Where(ad => ad.Client_Id == client_id); IEnumerable <AddressDTO> expectedDtos = _mapper.Map <IEnumerable <AddressDTO> >(_addressesForClient); //Setup repository _mockRepository.Setup(repo => repo.GetByAsync(co => co.Client_Id == client_id)) .ReturnsAsync(_addressesForClient); //instantiate System Under Test var controller = new AddressesController(_mockRepository.Object, _mapper, _logger);; //call SUT method var actionResult = await controller.GetAddressesByClientIdAsync(client_id); //Assert results Assert.NotNull(actionResult); //Assert object in actionresult var result = Assert.IsType <OkObjectResult>(actionResult.Result); var actualAddresses = (IEnumerable <AddressDTO>)(result.Value); IEnumerable <AddressDTO> actualDtos = _mapper.Map <IEnumerable <AddressDTO> >(actualAddresses); //use FluentAssertions to compare Collections of Reference types actualDtos.Should().BeEquivalentTo(expectedDtos, options => options.ComparingByMembers <AddressDTO>()); }