public async Task CreateTruck_ChassisAlreadyExists_ReturnsConflict()
{
// create model
var model = new Model();
model.Description = Guid.NewGuid().ToString();
IActionResult actionResult1 = await _modelController.PostModel(model);
var modelCreatedResult = actionResult1 as CreatedAtActionResult;
Assert.IsNotNull(modelCreatedResult);
Assert.AreEqual(201, modelCreatedResult.StatusCode);
model.ModelId = Convert.ToInt32(modelCreatedResult.RouteValues["id"]);
// create truck
var truck = new Truck();
truck.Chassis = Guid.NewGuid().ToString();
truck.Year = Convert.ToInt16(new Random().Next(1900, 2019));
truck.Model = model;
IActionResult actionResult2 = await _truckController.PostTruck(truck);
var truckCreatedResult = actionResult2 as CreatedAtActionResult;
Assert.IsNotNull(truckCreatedResult);
Assert.AreEqual(201, truckCreatedResult.StatusCode);
// try create another with same chassis
IActionResult actionResult3 = await _truckController.PostTruck(truck);
var conflictResult = actionResult3 as ConflictResult;
Assert.IsNotNull(conflictResult);
Assert.AreEqual(409, conflictResult.StatusCode);
Assert.Pass();
}