public void Test1() { var process = new Process(); //without MOQ , test case fail SubProcess mailObject = new SubProcess(); var response = process.AddProcess(mailObject); Assert.AreEqual(response, true); //with MOQ , test success //Mock<SubProcess> mailObject = new Mock<SubProcess>(); //mailObject.Setup(x => x.AnotherProcess()).Returns(1); //var response = process.AddProcess(mailObject.Object); //Assert.AreEqual(response, true); }