public void DetailsController_SubRegionDetails_IsNotNull() { // Arrange var regionInfo = new RegionDetails() { Name = "TestSubRegion" }; _mediator.Setup(s => s.GetSubRegionDetails("TestSubRegion")).ReturnsAsync(regionInfo); var controller = new DetailsController(_mediator.Object); // Act var result = controller.SubRegionDetails("TestSubRegion").Result; // Assert result.Should().NotBeNull(); }