public void GetAllData_Test() { Mock <IAnimalRepository> repoMock = new Mock <IAnimalRepository>(); Animal firstAnimal = new Animal { Id = 1, Name = "Bobita", Description = "Cat" }; Animal secondAnimal = new Animal { Id = 2, Name = "Rex", Description = "Dog" }; List <Animal> personList = new List <Animal> { firstAnimal, secondAnimal }; repoMock.Setup(x => x.GetAll()).Returns(personList); AnimalController animalController = new AnimalController(repoMock.Object); List <Animal> result = animalController.GetAll().ToList(); Assert.AreEqual(2, result.Count); }