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:
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: