public async Task GetPaymentDetailsCallsThroughToMediator() { Guid paymentId = Guid.NewGuid(); var mediator = new Mock <IMediator>(); var sut = new PaymentsController(mediator.Object); await sut.GetPaymentDetails(paymentId); mediator.Verify(x => x.Send(It.Is <GetPaymentRequest>(y => y.PaymentId == paymentId), It.IsAny <CancellationToken>()), Times.Once); }