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 declare(strict_types=1); |
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12 | View Code Duplication | final class JWT implements AuthenticationInterface |
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13 | { |
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14 | /** |
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15 | * @var Token |
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16 | */ |
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17 | private $token; |
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18 | |||
19 | public function __construct(Token $token) |
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23 | |||
24 | public function getOptions(): array |
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39 | } |
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40 |
Let’s assume that you have a directory layout like this:
and let’s assume the following content of
Bar.php
:If both files
OtherDir/Foo.php
andSomeDir/Foo.php
are loaded in the same runtime, you will see a PHP error such as the following:PHP Fatal error: Cannot use SomeDir\Foo as Foo because the name is already in use in OtherDir/Foo.php
However, as
OtherDir/Foo.php
does not necessarily have to be loaded and the error is only triggered if it is loaded beforeOtherDir/Bar.php
, this problem might go unnoticed for a while. In order to prevent this error from surfacing, you must import the namespace with a different alias: