| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  |  * ePayService driver for the Omnipay PHP payment processing library. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  |  * @link      https://github.com/hiqdev/omnipay-epayservice | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  |  * @package   omnipay-epayservice | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  |  * @license   MIT | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  |  * @copyright Copyright (c) 2015-2017, HiQDev (http://hiqdev.com/) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  | namespace Omnipay\ePayService\Message; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  | use Omnipay\Common\Exception\InvalidResponseException; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  | use Omnipay\Common\Message\AbstractResponse; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  | use Omnipay\Common\Message\RequestInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  |  * ePayService Complete Purchase Response. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  | class CompletePurchaseResponse extends AbstractResponse | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 | 3 |  |     public function __construct(RequestInterface $request, $data) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 | 3 |  |         $this->request = $request; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 | 3 |  |         $this->data    = $data; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 | 3 |  |         if ($this->getHash() !== $this->calculateHash()) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 | 1 |  |             throw new InvalidResponseException('Invalid hash'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 | 2 |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 | 3 |  |     public function getHash() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 | 3 |  |         return strtolower($this->data['check_key']); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 | 3 |  |     public function calculateHash() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 39 | 3 |  |         return md5($this->data['EPS_AMOUNT'] . $this->data['EPS_GUID'] . $this->request->getSecret()); | 
                            
                    |  |  |  | 
                                                                                        
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                | 40 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 | 1 |  |     public function isSuccessful() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 | 1 |  |         return $this->data['EPS_RESULT'] === 'done'; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 | 1 |  |     public function getTransactionId() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 | 1 |  |         return $this->data['EPS_TRID']; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 51 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 52 | 1 |  |     public function getTransactionReference() | 
            
                                                                        
                            
            
                                    
            
            
                | 53 |  |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 54 | 1 |  |         return $this->data['EPS_ACCNUM']; | 
            
                                                                        
                            
            
                                    
            
            
                | 55 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 | 1 |  |     public function getAmount() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 58 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 | 1 |  |         return $this->data['EPS_AMOUNT']; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |     public function getTestMode() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |         return (bool) $this->data['testMode']; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 | 1 |  |     public function getCurrency() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 | 1 |  |         return $this->data['EPS_CURRENCY']; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 71 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 72 |  |  |  | 
            
                        
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: