public async Task Given_AddressServiceSuccess_When_GetAddressCityGroups_Then_ReturnSuccessWithData() { _addressService.GetAddressCityGroups().Returns(Task.FromResult( new List <AddressCityGroup>() )); var result = await _sut.GetAddressCityGroups() as ObjectResult; Assert.True(result.StatusCode == 200); Assert.IsInstanceOf <List <AddressCityGroup> >(result.Value); }