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 CatalogFactoryTest extends PHPUnit_Framework_TestCase  | 
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| 11 | { | 
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| 12 | /**  | 
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| 13 | * @test  | 
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| 14 | */  | 
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| 15 | public function getCatalog_IntegrationTest_CatalogJSONIsValid_CatalogIsReturned()  | 
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| 16 |     { | 
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| 17 | // arrange  | 
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| 18 | $catalogFilePath = "catalog.json";  | 
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| 19 | $filesystem = new Filesystem(new MemoryAdapter());  | 
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| 20 | $catalogJSON = <<<JSON  | 
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| 21 | []  | 
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| 22 | JSON;  | 
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| 23 | $filesystem->write($catalogFilePath, $catalogJSON);  | 
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| 24 | |||
| 25 | $catalogFactory = new CatalogFactory($filesystem, $catalogFilePath);  | 
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| 26 | |||
| 27 | // act  | 
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| 28 | $catalog = $catalogFactory->getCatalog();  | 
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| 29 | |||
| 30 | // assert  | 
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| 31 | $this->assertNotNull($catalog, "The catalog should not be null");  | 
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| 32 | }  | 
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| 33 | |||
| 34 | /**  | 
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| 35 | * @test  | 
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| 36 | * @expectedException Wambo\Catalog\Error\CatalogException  | 
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| 37 | */  | 
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| 38 | public function getCatalog_IntegrationTest_CatalogJSONIsInvalid_CatalogExceptionIsThrown()  | 
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| 39 |     { | 
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| 40 | // arrange  | 
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| 41 | $catalogFilePath = "catalog.json";  | 
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| 42 | $filesystem = new Filesystem(new MemoryAdapter());  | 
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| 43 | $catalogJSON = <<<JSON  | 
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| 44 | [  | 
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| 45 |     { | 
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| 46 | "sku": ""  | 
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| 47 | }  | 
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| 48 | ]  | 
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| 49 | JSON;  | 
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| 50 | $filesystem->write($catalogFilePath, $catalogJSON);  | 
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| 51 | |||
| 52 | $catalogFactory = new CatalogFactory($filesystem, $catalogFilePath);  | 
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| 53 | |||
| 54 | // act  | 
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| 55 | $catalogFactory->getCatalog();  | 
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| 56 | }  | 
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| 57 | }  | 
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| 58 |