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 | ||
| 15 | View Code Duplication | class ShippingDiscount extends \app\modules\shop\models\AbstractDiscountType | |
| 16 | { | ||
| 17 | /** | ||
| 18 | * getShippingOption | ||
| 19 | * @return ShippingOption | ||
|  | |||
| 20 | */ | ||
| 21 | public function getShippingOption() | ||
| 25 | |||
| 26 | /** | ||
| 27 | * @inheritdoc | ||
| 28 | */ | ||
| 29 |     public function getFullName() { | ||
| 33 | |||
| 34 | /** | ||
| 35 | * @inheritdoc | ||
| 36 | */ | ||
| 37 | public function checkDiscount(Discount $discount, Product $product = null, Order $order = null) | ||
| 38 |     { | ||
| 39 | $odi = $order->orderDeliveryInformation; | ||
| 40 |         if (null === $order || null === $odi) { | ||
| 41 | return false; | ||
| 42 | } | ||
| 43 | |||
| 44 | $q = self::find()->where( | ||
| 45 | [ | ||
| 46 | 'discount_id' => $discount->id, | ||
| 47 | 'shipping_option_id' => $odi->shipping_option_id | ||
| 48 | ] | ||
| 49 | )->count(); | ||
| 50 | |||
| 51 |         if (0 === intval($q)) { | ||
| 52 | return false; | ||
| 53 | } | ||
| 54 | |||
| 55 | return true; | ||
| 56 | } | ||
| 57 | |||
| 58 | /** | ||
| 59 | * @inheritdoc | ||
| 60 | */ | ||
| 61 | public static function tableName() | ||
| 65 | |||
| 66 | /** | ||
| 67 | * @inheritdoc | ||
| 68 | */ | ||
| 69 | public function rules() | ||
| 76 | |||
| 77 | /** | ||
| 78 | * @inheritdoc | ||
| 79 | */ | ||
| 80 | public function attributeLabels() | ||
| 88 | } | ||
| 89 | 
This check compares the return type specified in the
@returnannotation of a function or method doc comment with the types returned by the function and raises an issue if they mismatch.