public void GetDistrictsReturnsListOfDistricts() { //Arrange var moq = new Mock <IRegionsRepository>(); moq.Setup(m => m.GetDistricts(It.IsAny <int>())).Returns(Task.FromResult(new List <District>() as IEnumerable <District>)); RegionsController controller = new RegionsController(moq.Object); //Act var result = controller.GetDistricts(3).Result; //Arrange Assert.IsInstanceOfType(result, typeof(IEnumerable <District>)); }