public void AddWeekDay_Success_Test() { // Arrange WeekDayDTO dto = SampleWeekDayDTO(1); // create mock for repository var mock = new Mock <IWeekDayRepository>(); mock.Setup(s => s.AddWeekDay(Moq.It.IsAny <R_WeekDay>())).Returns(1); // service WeekDayService weekDayService = new WeekDayService(); WeekDayService.Repository = mock.Object; // Act int id = weekDayService.AddWeekDay(dto); // Assert Assert.AreEqual(1, id); Assert.AreEqual(1, dto.WeekDayId); }