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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32 | trait CrudTrait |
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33 | { |
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34 | /** |
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35 | * removes a user from a project. |
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36 | * |
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37 | * @param int $userId |
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38 | * |
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39 | * @return mixed |
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40 | */ |
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41 | 1 | public function unassignUser($userId) |
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45 | |||
46 | /** |
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47 | * Create a new project. |
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48 | * |
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49 | * @param array $input |
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50 | * |
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51 | * @return $this |
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52 | */ |
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53 | 42 | public function createProject(array $input = []) |
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72 | |||
73 | /** |
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74 | * Update project details. |
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75 | * |
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76 | * @param array $attributes |
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77 | * |
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78 | * @return bool |
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79 | */ |
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80 | 1 | public function update(array $attributes = []) |
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90 | |||
91 | /** |
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92 | * Save the project tags. |
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93 | * |
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94 | * @param string $tagString |
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95 | * |
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96 | * @return bool |
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97 | */ |
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98 | public function saveTags($tagString) |
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123 | |||
124 | /** |
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125 | * Assign a user to a project. |
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126 | * |
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127 | * @param int $userId |
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128 | * @param int $roleId |
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129 | * |
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130 | * @return Project\User |
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131 | */ |
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132 | 25 | public function assignUser($userId, $roleId = 0) |
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139 | |||
140 | /** |
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141 | * Delete a project. |
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142 | * |
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143 | * @return void |
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144 | * |
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145 | * @throws \Exception |
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146 | */ |
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147 | 1 | public function delete() |
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158 | } |
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159 |
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.