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:
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21 | View Code Duplication | class AnnotationDirectoryLoader extends BaseAnnotationDirectoryLoader |
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23 | private $scannedDirectories; |
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25 | public function __construct(FileLocatorInterface $locator, AnnotationClassLoader $loader, array $scannedDirectories) |
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33 | * {@inheritdoc} |
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34 | */ |
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35 | public function supports($resource, $type = null) |
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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: