public async Task AccountExist_Get_WhenAccountExist() { //arrange var IdTo = 3; var loggerMock = new Mock <ILogger <OperationController> >(); var accountMock = new Mock <IAsyncRepository <BankAccount> >(); var mediatorMock = new Mock <IMediator>(); mediatorMock.Setup(x => x.Send(It.IsAny <CheckAccountExistQuery>(), It.IsAny <CancellationToken>())) .ReturnsAsync(true) .Verifiable(); var controller = new OperationController(mediatorMock.Object, accountMock.Object, loggerMock.Object); //act var result = await controller.AccountExist(IdTo); //assert var viewResult = Assert.IsType <JsonResult>(result); Assert.True((bool)viewResult.Value); }