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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| 10 | class NewsletterListCollectionTest extends TestCase |
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| 11 | { |
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| 12 | protected $newsletterListCollection; |
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| 13 | |||
| 14 | public function setUp() : void |
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| 29 | |||
| 30 | /** @test */ |
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| 31 | View Code Duplication | public function it_can_find_a_list_by_its_name() |
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| 39 | |||
| 40 | /** @test */ |
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| 41 | View Code Duplication | public function it_will_use_the_default_list_when_not_specifing_a_listname() |
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| 49 | |||
| 50 | /** @test */ |
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| 51 | public function it_will_throw_an_exception_when_using_a_default_list_that_does_not_exist() |
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| 67 | |||
| 68 | /** @test */ |
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| 69 | public function it_will_throw_an_exception_when_there_are_no_lists_defined() |
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| 82 | |||
| 83 | /** @test */ |
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| 84 | public function it_will_throw_an_exception_when_trying_to_find_a_list_that_does_not_exist() |
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| 90 | } |
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| 91 |
Let’s assume that you have a directory layout like this:
. |-- OtherDir | |-- Bar.php | `-- Foo.php `-- SomeDir `-- Foo.phpand let’s assume the following content of
Bar.php:If both files
OtherDir/Foo.phpandSomeDir/Foo.phpare 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.phpHowever, as
OtherDir/Foo.phpdoes 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: