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 // phpcs:ignore WordPress.Files.FileName |
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15 | class Test_Version_Loading_From_Manifests extends TestCase { |
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16 | |||
17 | /** |
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18 | * A manifest handler. |
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19 | * |
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20 | * @var Manifest_Reader |
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21 | */ |
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22 | private $manifest_handler; |
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23 | |||
24 | /** |
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25 | * Setup runs before each test. |
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26 | * |
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27 | * @before |
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28 | */ |
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29 | public function set_up() { |
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30 | $this->manifest_handler = new Manifest_Reader( new Version_Selector() ); |
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31 | } |
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32 | |||
33 | /** |
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34 | * Tests that the classmap manifest from a single plugin can be handled correctly. |
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35 | */ |
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36 | View Code Duplication | public function test_classmap() { |
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55 | |||
56 | /** |
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57 | * Tests that the PSR-4 manifest from a single plugin can be handled correctly. |
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58 | */ |
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59 | View Code Duplication | public function test_psr4() { |
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78 | |||
79 | /** |
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80 | * Tests that the filemap manifest from a single plugin can be handled correctly. |
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81 | * |
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82 | * @preserveGlobalState disabled |
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83 | * @runInSeparateProcess |
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84 | */ |
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85 | public function test_filemap() { |
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105 | } |
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106 |
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: