Unit test the update method with laravel 8 and fakers

Alright so I'm pretty new to both unit testing, Fakers and laravel. I'm trying to unit test my resource controller, but I'm stuck at the update function.

Here's my controller:

     public function store(Request $request)
        {
            DB::beginTransaction();
            try {
                $newOrder = new Order;
                $newOrder->fill($request->all());
                $newOrder->user_id = $request->user()->id; 
                
                  if (!$request->doAssigned) {
                    $newOrder->status = ($request->doValidate) ? 'pending' : 'draft';
                }
                $newOrder->save();
                DB::commit();
                 return $newOrder; 
            } catch (\Exception $e) {
                DB::rollback();
                abort(400, $e);
            }
        }
 public function update(Request $request, $id)
    {
        DB::beginTransaction();
        try {
            $oOrder = Order::with(['contact', 'contact.company'])->find($id);
            $bChangeStatus = $oOrder->status !== $request->status;
            $oOrder->fill($request->all());
            $oOrder->save();

            // update the status
            if ($bChangeStatus && $request->status === 'canceled') {
                Transport_order::where('order_id', $id)
                    ->whereNotIn('status', ['billed', 'delivered'])
                    ->update(['status' => 'canceled']);
            }
            // ....... the same if conditions for other status
            
            if ($request->merchandise) {
                foreach ($request->merchandise as $oNewMerchandise) {
                    $oMerchandise = Merchandise::find($oNewMerchandise->id);
                    $oMerchandise->fill($oNewMerchandise);
                    $oMerchandise->save();
                }
            }
            $oOrder->equipments()->sync($request->equipment_ids);
            DB::commit();
            return $oOrder;
        } catch (\Exception $e) {
            DB::rollback();
            abort(400, $e);
        }
    }

I have already made a test of the store method but I'm stuck with the update methode I can't handle it .

public function testStore_draft()
{
    Sanctum::actingAs($this->user, ['*']);
    $orderStore = array (
                  
        'external_ref' => '44' ,
        'contact_id'=> '19',
        'comment' => 'oioio',
        'user_id'=> '3',
        'doAssigned' => false,
        'doValidate' => false, 
      );
    $response = $this->json('POST', 'api/order',$orderStore,  $this->headers) 
    ->assertStatus(201)
         ->assertJsonFragment( ['status'=>'draft']); 

} 

Any help is welcome ! Thank you very much !