public async Task CanValidateModelFields_UpdateVehicle_RequiredFielsAreMissing() { SaveVehicleResource vehicleResource = new SaveVehicleResource { Contact = null }; _controller.ModelState.AddModelError("Contact", "The Contact Name field is required."); IActionResult actual = await _controller.UpdateVehicleAsync(123, vehicleResource); _vehiclesRepository.Verify(db => db.GetWithDependenciesAsync(It.IsAny <int>()), Times.Never); _vehiclesRepository.Verify(db => db.IsModelExists(It.IsAny <int>()), Times.Never); _vehiclesRepository.Verify(db => db.IsFeatureExists(It.IsAny <int>()), Times.Never); Assert.IsInstanceOf <BadRequestObjectResult>(actual); }