public void AddingCities() { var list = new List <City>(); var mockRepo = new Mock <IDeletableEntityRepository <City> >(); mockRepo.Setup(x => x.AllAsNoTracking()).Returns(list.AsQueryable()); mockRepo.Setup(x => x.AddAsync(It.IsAny <City>())); var service = new CitiesService(mockRepo.Object); var city = new City { Id = 1, Name = "Sofia", }; list.Add(city); var expected = new List <KeyValuePair <string, string> >() { new KeyValuePair <string, string>("1", "Sofia"), }; Assert.Equal(expected, service.GetAllAsKeyValuePairs()); }