public void GetAll() { // Arrange _mock.Setup(s => s.GetAll()).Returns(_trainings); // Act var result = _trainingController.GetAll(); var trainingsResult = result as OkNegotiatedContentResult <List <Training> >; // Assert Assert.IsInstanceOfType(result, typeof(OkNegotiatedContentResult <List <Training> >)); Assert.AreEqual(_trainings.Count, trainingsResult.Content.Count()); }