public void BorrowBookAction_BookBALIsCalled() { // Arrange var bookBALMoq = new Mock <IBookService>(); bookBALMoq.Setup(x => x.BorrowBook(It.IsAny <int>(), fakeUser.Id)).Returns(() => true); BooksController bookController = CreateControllerWithFakeUser(bookBALMoq.Object); // Act var result = bookController.BorrowBook(1) as RedirectToRouteResult; // Assert bookBALMoq.Verify(x => x.BorrowBook(It.IsAny <int>(), fakeUser.Id), Times.Once); Assert.IsTrue(result != null); }