public async Task AddCity_When_adding_city_Then_Save_of_UnitOfWork_called() { var cityRepository = A.Fake <IRepository <CityEntity> >(); var uow = A.Fake <IUnitOfWork>(); A.CallTo(() => uow.Repository <CityEntity>()).Returns(cityRepository); var weatherService = new WeatherService(uow); await weatherService.AddCityAsync(new CityEntity { Id = 1, Name = "name" }); A.CallTo(() => uow.Save()).MustHaveHappened(Repeated.Exactly.Once); }