public async void CreateFeedbackCase_ShouldCallGateway() { // Arrange _mockGateway .Setup(_ => _.CreateCase(It.IsAny <Case>())) .ReturnsAsync(new HttpResponse <string> { StatusCode = HttpStatusCode.OK, ResponseContent = "123456" }); var model = new FeedbackDetails { CouncilDepartment = "test", Feedback = "test" }; // Act await _service.CreateFeedbackCase(model); // Assert _mockGateway.Verify(_ => _.CreateCase(It.IsAny <Case>()), Times.Once); }