public void Import_Success_And_AddUser() { // ARRANGE var result = new Result { cell = "", dob = new Dob { age = 25, date = DateTime.Now }, email = "", gender = "", location = new Location { city = "", coordinates = new Coordinates { latitude = "", longitude = "" }, country = "", postcode = "", state = "", street = new Street { name = "", number = 1 }, timezone = new Timezone { description = "", offset = "" } }, login = new Login { md5 = "", password = "", salt = "", sha1 = "", sha256 = "", username = "", uuid = "" }, name = new Name { first = "", last = "", title = "" }, nat = "", phone = "", picture = new Picture { large = "", medium = "", thumbnail = "" }, registered = new Registered { age = 25, date = DateTime.Now } }; var objResult = new RootObject { results = new System.Collections.Generic.List <Result>() }; objResult.results.Add(result); var mockRepository = Substitute.For <IRandomRepository>(); var mockUserRepository = Substitute.For <IUserRepository>(); var mockNotifications = Substitute.For <INotifier>(); mockRepository.GetUsersRandom(100).Returns(objResult); // ACT IAddUser useCase = new AddUser(mockRepository, mockUserRepository, mockNotifications); // ASSERT Assert.NotNull(useCase.AddUsers(1)); }