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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| 27 | class NewKeyedListSniff extends Sniff |
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| 28 | { |
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| 29 | |||
| 30 | /** |
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| 31 | * Returns an array of tokens this test wants to listen for. |
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| 32 | * |
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| 33 | * @return array |
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| 34 | */ |
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| 35 | public function register() |
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| 42 | |||
| 43 | /** |
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| 44 | * Do a version check to determine if this sniff needs to run at all. |
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| 45 | * |
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| 46 | * @return bool |
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| 47 | */ |
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| 48 | protected function bowOutEarly() |
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| 52 | |||
| 53 | /** |
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| 54 | * Processes this test, when one of its tokens is encountered. |
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| 55 | * |
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| 56 | * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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| 57 | * @param int $stackPtr The position of the current token in the |
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| 58 | * stack passed in $tokens. |
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| 59 | * |
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| 60 | * @return void |
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| 61 | */ |
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| 62 | public function process(\PHP_CodeSniffer_File $phpcsFile, $stackPtr) |
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| 104 | |||
| 105 | |||
| 106 | /** |
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| 107 | * Examine the contents of a list construct to determine whether an error needs to be thrown. |
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| 108 | * |
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| 109 | * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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| 110 | * @param int $opener The position of the list open token. |
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| 111 | * @param int $closer The position of the list close token. |
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| 112 | * |
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| 113 | * @return void |
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| 114 | */ |
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| 115 | protected function examineList(\PHP_CodeSniffer_File $phpcsFile, $opener, $closer) |
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| 127 | |||
| 128 | |||
| 129 | /** |
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| 130 | * Check whether a certain target token exists within a list construct. |
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| 131 | * |
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| 132 | * Skips past nested list constructs, so these can be examined based on their own token. |
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| 133 | * |
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| 134 | * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned. |
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| 135 | * @param int $start The position of the list open token or a token |
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| 136 | * within the list to start (resume) the examination from. |
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| 137 | * @param int $closer The position of the list close token. |
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| 138 | * @param array $targets An array with one or more token constants to look for. |
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| 139 | * |
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| 140 | * @return int|bool Stack pointer to the target token if encountered. False otherwise. |
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| 141 | */ |
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| 142 | protected function hasTargetInList(\PHP_CodeSniffer_File $phpcsFile, $start, $closer, $targets) |
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| 175 | } |
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| 176 |
If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: