public void DeleteReturnsDoctorSpecialty() { //Arrange long id = 1; specialtyRepository.Setup(s => s.Exists(It.IsAny <long>(), It.IsAny <int>())).ReturnsAsync( new DoctorSpecialty { Id = id }); specialtyRepository.Setup(s => s.Delete(It.IsAny <object[]>())).ReturnsAsync( (object[] key) => { return(new DoctorSpecialty { Id = (long)key[0] }); }); //Act var result = (controller.DeleteSpecialty(1, 2).Result as OkObjectResult).Value; //Assert Assert.IsInstanceOfType(result, typeof(DoctorSpecialty)); Assert.AreEqual(id, (result as DoctorSpecialty)?.Id); }