public async Task GetAllCitiesForCountry_ShouldBeDoneSuccessfully() { // Arrange var cities = new List <City>() { new City() { Id = 1 } }; var citiesToReturn = new List <CityToReturnDto>() { new CityToReturnDto() { Id = 1, } }; _unitOfWorkMock.Setup(x => x.Cities.GetAllCitiesForCountry(It.IsAny <int>())) .ReturnsAsync(cities); _mapperMock.Setup(x => x.Map <ICollection <CityToReturnDto> >(cities)) .Returns(citiesToReturn); // Act var result = await _sut.GetAllCitiesForCountry(It.IsAny <int>()); // Assert Assert.Equal(cities.FirstOrDefault().Id, result.FirstOrDefault().Id); }