public void DeleteDiplomaReturnsDiploma() { //Arrange long doctorId = 1; long diplomaId = doctorId + 1; diplomaRepository.Setup(d => d.Get(It.IsAny <object[]>())).ReturnsAsync((object[] key) => { return(new Diploma { Id = (long)key[0], DoctorId = doctorId }); }); diplomaRepository.Setup(d => d.Delete(It.IsAny <object[]>())).ReturnsAsync((object[] key) => { return(new Diploma { Id = (long)key[0] }); }); //Act var result = (controller.DeleteDiploma(doctorId, diplomaId).Result as OkObjectResult).Value; //Assert Assert.IsInstanceOfType(result, typeof(Diploma)); Assert.AreEqual(diplomaId, (result as Diploma)?.Id); }