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 |
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17 | class AuthenticatorService implements ServiceInterface |
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18 | { |
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19 | |||
20 | /** @var AbstractController */ |
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21 | protected $controller; |
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22 | |||
23 | /** @var DbService */ |
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24 | protected $orm; |
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25 | |||
26 | /** @var Config */ |
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27 | protected $config; |
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28 | |||
29 | /** @var string */ |
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30 | protected $redirectAfterAuth; |
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31 | |||
32 | /** |
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33 | * Authenticator constructor. |
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34 | * @param AbstractController $controller |
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35 | * @param Config $config |
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36 | */ |
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37 | public function __construct(AbstractController $controller, Config $config) |
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42 | |||
43 | /** |
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44 | * @param Entity $user |
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45 | * @param bool $shouldBeActive |
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46 | * @return bool |
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47 | * @codeCoverageIgnore |
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48 | */ |
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49 | public function loginUser(Entity $user, $shouldBeActive) |
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87 | |||
88 | /** |
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89 | * @return bool |
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90 | */ |
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91 | View Code Duplication | public function redirectToAccessDeniedPage() |
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99 | |||
100 | /** |
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101 | * @return bool |
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102 | */ |
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103 | View Code Duplication | public function redirectToAuthentication() |
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111 | |||
112 | /** |
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113 | * @param array $roles |
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114 | * @return bool |
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115 | */ |
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116 | public function isPermitted(array $roles) |
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135 | |||
136 | /** |
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137 | * @param Entity $user |
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138 | * @codeCoverageIgnore |
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139 | */ |
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140 | public function saveUserInSession(Entity $user) |
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144 | |||
145 | /** |
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146 | * @param string $entity |
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147 | * @return Entity |
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148 | * @codeCoverageIgnore |
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149 | */ |
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150 | public function getUserFromSession(string $entity = '') |
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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: