public void SubscribeTest() { //Arrange: var testApp = new ApplicationUT(fileSystemVisitor); var appMock = new Moq.Mock <Application>(fileSystemVisitor) { CallBase = true }; appMock .Protected() .Setup <bool>("Subscribe") .Returns(true); //Act: var result = testApp.SubscribeTest(); appMock.Object.Start(); //Assert: Assert.IsTrue(result); appMock.Protected().Verify("Subscribe", Times.Once()); }