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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9 | trait ManagesStorageConnection |
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10 | { |
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11 | /** |
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12 | * @return bool |
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13 | */ |
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14 | public function isReady() |
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22 | |||
23 | /** |
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24 | * Sometimes we want to gracefully check up on the cloud storage account without any exceptions |
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25 | */ |
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26 | public function ping() |
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37 | |||
38 | /** |
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39 | * @return bool |
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40 | * @throws StorageUnavailableException |
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41 | */ |
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42 | public function verify() |
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50 | |||
51 | /** |
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52 | * @return mixed |
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53 | */ |
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54 | public function isConnected() |
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58 | |||
59 | /** |
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60 | * @return bool |
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61 | */ |
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62 | public function isEnabled() |
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66 | |||
67 | /** |
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68 | * @return bool |
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69 | */ |
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70 | public function isDisabled() |
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74 | |||
75 | /** |
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76 | * @return bool |
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77 | */ |
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78 | public function isTokenInvalid() |
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82 | |||
83 | /** |
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84 | * @param null $reason |
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85 | * |
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86 | * @return $this |
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87 | */ |
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88 | View Code Duplication | public function disable($reason = null) |
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103 | |||
104 | /** |
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105 | * @return $this |
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106 | */ |
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107 | View Code Duplication | public function enable() |
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119 | } |
This check looks for methods that are used by a trait but not required by it.
To illustrate, let’s look at the following code example
The trait
Idable
provides a methodequalsId
that in turn relies on the methodgetId()
. If this method does not exist on a class mixing in this trait, the method will fail.Adding the
getId()
as an abstract method to the trait will make sure it is available.