Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php |
||
| 17 | class AuthenticatorService implements ServiceInterface |
||
| 18 | { |
||
| 19 | |||
| 20 | /** @var AbstractController */ |
||
| 21 | protected $controller; |
||
| 22 | |||
| 23 | /** @var DbService */ |
||
| 24 | protected $orm; |
||
| 25 | |||
| 26 | /** @var Config */ |
||
| 27 | protected $config; |
||
| 28 | |||
| 29 | /** @var string */ |
||
| 30 | protected $redirectAfterAuth; |
||
| 31 | |||
| 32 | /** |
||
| 33 | * Authenticator constructor. |
||
| 34 | * @param AbstractController $controller |
||
| 35 | * @param Config $config |
||
| 36 | */ |
||
| 37 | public function __construct(AbstractController $controller, Config $config) |
||
| 42 | |||
| 43 | /** |
||
| 44 | * @param Entity $user |
||
| 45 | * @param bool $shouldBeActive |
||
| 46 | * @return bool |
||
| 47 | * @codeCoverageIgnore |
||
| 48 | */ |
||
| 49 | public function loginUser(Entity $user, $shouldBeActive) |
||
| 87 | |||
| 88 | /** |
||
| 89 | * @return bool |
||
| 90 | */ |
||
| 91 | View Code Duplication | public function redirectToAccessDeniedPage() |
|
| 99 | |||
| 100 | /** |
||
| 101 | * @return bool |
||
| 102 | */ |
||
| 103 | View Code Duplication | public function redirectToAuthentication() |
|
| 111 | |||
| 112 | /** |
||
| 113 | * @param array $roles |
||
| 114 | * @return bool |
||
| 115 | */ |
||
| 116 | public function isPermitted(array $roles) |
||
| 135 | |||
| 136 | /** |
||
| 137 | * @param Entity $user |
||
| 138 | * @codeCoverageIgnore |
||
| 139 | */ |
||
| 140 | public function saveUserInSession(Entity $user) |
||
| 144 | |||
| 145 | /** |
||
| 146 | * @param string $entity |
||
| 147 | * @return Entity |
||
| 148 | * @codeCoverageIgnore |
||
| 149 | */ |
||
| 150 | public function getUserFromSession(string $entity = '') |
||
| 167 | |||
| 168 | } |
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: