public void AcceptBookingRecordsEventWithCorrectBookingId() { // Arrange const int BOOKING_ID = 123; var eventTrackingManager = new Mock<IEventTrackingManager>(); eventTrackingManager.Setup(b => b.CreateBookingEvent(It.Is<int>(i => i == BOOKING_ID), It.Is<BookingEventType>(i => i == BookingEventType.Accepted), It.IsAny<string>())); var bookingManager = new BookingManager { EventTrackingManager = eventTrackingManager.Object }; // Act bookingManager.AcceptBooking(BOOKING_ID); // Assert eventTrackingManager.VerifyAll(); }