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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| 15 | class StockTest extends TestBase  | 
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| 16 | { | 
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| 17 | // /**  | 
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| 18 | // * @depends ProductTest::testCreate  | 
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| 19 | // * @depends testGetSkuInfo  | 
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| 20 | // */  | 
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| 21 | View Code Duplication | public function testAdd()  | 
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| 34 | |||
| 35 | // /**  | 
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| 36 | // * @depends ProductTest::testCreate  | 
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| 37 | // * @depends testGetSkuInfo  | 
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| 38 | // */  | 
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| 39 | View Code Duplication | public function testReduce()  | 
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| 53 | |||
| 54 | public function testGetSkuInfo()  | 
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| 61 | }  | 
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| 62 | 
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVarassignment in line 1 and the$higherassignment in line 2 are dead. The first because$myVaris never used and the second because$higheris always overwritten for every possible time line.