| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  | namespace CultureKings\Afterpay\Service\InStore; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  | use CultureKings\Afterpay\Model; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  | use CultureKings\Afterpay\Traits; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  | use GuzzleHttp\Client; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  | use GuzzleHttp\HandlerStack; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  | use JMS\Serializer\SerializerInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  |  * Class AbstractService | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  |  * @package CultureKings\Afterpay\Service\InStore | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  | abstract class AbstractService | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |     use Traits\ClientTrait; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  |     use Traits\AuthorizationTrait; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  |     use Traits\SerializerTrait; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  |      * Device constructor. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |      * @param Model\InStore\Authorization $auth | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |      * @param Client                      $client | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |      * @param SerializerInterface         $serializer | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |     public function __construct(Model\InStore\Authorization $auth, Client $client, SerializerInterface $serializer) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |         $this->setAuthorization($auth); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 |  |  |         $this->setClient($client); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |         $this->setSerializer($serializer); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 |  |  |      * @param object|array      $model | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |      * @param HandlerStack|null $stack | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 |  |  |      * @return array | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 39 |  |  |      */ | 
            
                                                        
            
                                    
            
            
                | 40 |  |  |     protected function generateParams($model, HandlerStack $stack = null) | 
            
                                                        
            
                                    
            
            
                | 41 |  |  |     { | 
            
                                                        
            
                                    
            
            
                | 42 |  |  |         $params = [ | 
            
                                                        
            
                                    
            
            
                | 43 |  |  |             'headers' => [ | 
            
                                                        
            
                                    
            
            
                | 44 |  |  |                 'Accept' => 'application/json', | 
            
                                                        
            
                                    
            
            
                | 45 |  |  |                 'Content-Type' => 'application/json', | 
            
                                                        
            
                                    
            
            
                | 46 |  |  |                 'Authorization' => sprintf('Bearer %s', $this->getAuthorization()->getDeviceToken()), | 
                            
                    |  |  |  | 
                                                                                        
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                | 47 |  |  |                 'Operator' => $this->getAuthorization()->getOperator(), | 
                            
                    |  |  |  | 
                                                                                        
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                | 48 |  |  |                 'User-Agent' => $this->getAuthorization()->getUserAgent(), | 
            
                                                        
            
                                    
            
            
                | 49 |  |  |             ], | 
            
                                                        
            
                                    
            
            
                | 50 |  |  |             'body' => $this->getSerializer()->serialize( | 
            
                                                        
            
                                    
            
            
                | 51 |  |  |                 $model, | 
            
                                                        
            
                                    
            
            
                | 52 |  |  |                 'json' | 
            
                                                        
            
                                    
            
            
                | 53 |  |  |             ), | 
            
                                                        
            
                                    
            
            
                | 54 |  |  |             'timeout' => Model\InStore\Authorization::REQUEST_TIMEOUT_SECONDS, | 
            
                                                        
            
                                    
            
            
                | 55 |  |  |         ]; | 
            
                                                        
            
                                    
            
            
                | 56 |  |  |         if ($stack !== null) { | 
            
                                                        
            
                                    
            
            
                | 57 |  |  |             $params['handler'] = $stack; | 
            
                                                        
            
                                    
            
            
                | 58 |  |  |         } | 
            
                                                        
            
                                    
            
            
                | 59 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 60 |  |  |         return $params; | 
            
                                                        
            
                                    
            
            
                | 61 |  |  |     } | 
            
                                                        
            
                                    
            
            
                | 62 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 63 |  |  |  | 
            
                        
Let’s take a look at an example:
In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break.
Available Fixes
Change the type-hint for the parameter:
Add an additional type-check:
Add the method to the interface: