public async Task UpdateTruck_ChassisAlreadyExists_ReturnsConflict()
{
// create model
var model = new Model();
model.Description = Guid.NewGuid().ToString();
IActionResult actionResult = await _modelController.PostModel(model);
var modelCreatedResult = actionResult as CreatedAtActionResult;
Assert.IsNotNull(modelCreatedResult);
Assert.AreEqual(201, modelCreatedResult.StatusCode);
model.ModelId = Convert.ToInt32(modelCreatedResult.RouteValues["id"]);
// create truck 1
var truck1 = new Truck();
truck1.Chassis = Guid.NewGuid().ToString();
truck1.Year = Convert.ToInt16(new Random().Next(1900, 2019));
truck1.Model = model;
actionResult = await _truckController.PostTruck(truck1);
var createdResult = actionResult as CreatedAtActionResult;
Assert.IsNotNull(createdResult);
Assert.AreEqual(201, createdResult.StatusCode);
// create truck 2
var truck2 = new Truck();
truck2.Chassis = Guid.NewGuid().ToString();
truck2.Year = Convert.ToInt16(new Random().Next(1900, 2019));
truck2.Model = model;
actionResult = await _truckController.PostTruck(truck2);
createdResult = actionResult as CreatedAtActionResult;
Assert.IsNotNull(createdResult);
Assert.AreEqual(201, createdResult.StatusCode);
// try to update truck 2 with truck1.chassis
truck2.Chassis = truck1.Chassis;
actionResult = await _truckController.PutTruck(truck2.TruckId, truck2);
var conflictResult = actionResult as ConflictResult;
Assert.IsNotNull(conflictResult);
Assert.AreEqual(409, conflictResult.StatusCode);
Assert.Pass();
}