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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| 23 | class RemovedGlobalVariablesSniff extends AbstractRemovedFeatureSniff  | 
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| 24 | { | 
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| 25 | |||
| 26 | /**  | 
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| 27 | * A list of removed global variables with their alternative, if any.  | 
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| 28 | *  | 
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| 29 | * The array lists : version number with false (deprecated) and true (removed).  | 
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| 30 | * If's sufficient to list the first version where the variable was deprecated/removed.  | 
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| 31 | *  | 
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| 32 | * @var array(string|null)  | 
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| 33 | */  | 
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| 34 | protected $removedGlobalVariables = array(  | 
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| 35 | 'HTTP_POST_VARS' => array(  | 
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| 36 | '5.3' => false,  | 
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| 37 | '5.4' => true,  | 
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| 38 | 'alternative' => '$_POST',  | 
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| 39 | ),  | 
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| 40 | 'HTTP_GET_VARS' => array(  | 
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| 41 | '5.3' => false,  | 
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| 42 | '5.4' => true,  | 
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| 43 | 'alternative' => '$_GET',  | 
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| 44 | ),  | 
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| 45 | 'HTTP_ENV_VARS' => array(  | 
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| 46 | '5.3' => false,  | 
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| 47 | '5.4' => true,  | 
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| 48 | 'alternative' => '$_ENV',  | 
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| 49 | ),  | 
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| 50 | 'HTTP_SERVER_VARS' => array(  | 
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| 51 | '5.3' => false,  | 
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| 52 | '5.4' => true,  | 
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| 53 | 'alternative' => '$_SERVER',  | 
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| 54 | ),  | 
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| 55 | 'HTTP_COOKIE_VARS' => array(  | 
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| 56 | '5.3' => false,  | 
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| 57 | '5.4' => true,  | 
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| 58 | 'alternative' => '$_COOKIE',  | 
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| 59 | ),  | 
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| 60 | 'HTTP_SESSION_VARS' => array(  | 
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| 61 | '5.3' => false,  | 
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| 62 | '5.4' => true,  | 
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| 63 | 'alternative' => '$_SESSION',  | 
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| 64 | ),  | 
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| 65 | 'HTTP_POST_FILES' => array(  | 
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| 66 | '5.3' => false,  | 
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| 67 | '5.4' => true,  | 
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| 68 | 'alternative' => '$_FILES',  | 
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| 69 | ),  | 
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| 70 | |||
| 71 | 'HTTP_RAW_POST_DATA' => array(  | 
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| 72 | '5.6' => false,  | 
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| 73 | '7.0' => true,  | 
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| 74 | 'alternative' => 'php://input',  | 
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| 75 | ),  | 
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| 76 | |||
| 77 | 'php_errormsg' => array(  | 
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| 78 | '7.2' => false,  | 
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| 79 | 'alternative' => 'error_get_last()',  | 
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| 80 | ),  | 
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| 81 | );  | 
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| 82 | |||
| 83 | |||
| 84 | /**  | 
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| 85 | * Returns an array of tokens this test wants to listen for.  | 
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| 86 | *  | 
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| 87 | * @return array  | 
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| 88 | */  | 
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| 89 | public function register()  | 
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| 94 | |||
| 95 | |||
| 96 | /**  | 
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| 97 | * Processes this test, when one of its tokens is encountered.  | 
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| 98 | *  | 
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| 99 | * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned.  | 
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| 100 | * @param int $stackPtr The position of the current token in the  | 
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| 101 | * stack passed in $tokens.  | 
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| 102 | *  | 
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| 103 | * @return void  | 
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| 104 | */  | 
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| 105 | public function process(\PHP_CodeSniffer_File $phpcsFile, $stackPtr)  | 
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| 145 | |||
| 146 | |||
| 147 | /**  | 
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| 148 | * Get the relevant sub-array for a specific item from a multi-dimensional array.  | 
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| 149 | *  | 
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| 150 | * @param array $itemInfo Base information about the item.  | 
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| 151 | *  | 
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| 152 | * @return array Version and other information about the item.  | 
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| 153 | */  | 
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| 154 | public function getItemArray(array $itemInfo)  | 
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| 158 | |||
| 159 | |||
| 160 | /**  | 
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| 161 | * Get the error message template for this sniff.  | 
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| 162 | *  | 
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| 163 | * @return string  | 
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| 164 | */  | 
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| 165 | protected function getErrorMsgTemplate()  | 
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| 169 | |||
| 170 | |||
| 171 | /**  | 
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| 172 | * Filter the error message before it's passed to PHPCS.  | 
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| 173 | *  | 
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| 174 | * @param string $error The error message which was created.  | 
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| 175 | * @param array $itemInfo Base information about the item this error message applied to.  | 
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| 176 | * @param array $errorInfo Detail information about an item this error message applied to.  | 
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| 177 | *  | 
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| 178 | * @return string  | 
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| 179 | */  | 
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| 180 | protected function filterErrorMsg($error, array $itemInfo, array $errorInfo)  | 
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| 187 | |||
| 188 | /**  | 
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| 189 | * Run some additional checks for the `$php_errormsg` variable.  | 
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| 190 | *  | 
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| 191 | * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned.  | 
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| 192 | * @param int $stackPtr The position of the current token in the  | 
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| 193 | * stack passed in $tokens.  | 
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| 194 | * @param array $tokens Token array of the current file.  | 
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| 195 | *  | 
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| 196 | * @return bool  | 
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| 197 | */  | 
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| 198 | private function isTargetPHPErrormsgVar(\PHP_CodeSniffer_File $phpcsFile, $stackPtr, array $tokens)  | 
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| 301 | |||
| 302 | |||
| 303 | }//end class  | 
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| 304 |