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