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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| 23 | class AggregateAwareDBALEventStore implements EventStoreInterface |
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| 24 | { |
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| 25 | /** |
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| 26 | * @var Connection |
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| 27 | */ |
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| 28 | private $connection; |
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| 29 | |||
| 30 | /** |
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| 31 | * @var SerializerInterface |
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| 32 | */ |
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| 33 | private $payloadSerializer; |
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| 34 | |||
| 35 | /** |
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| 36 | * @var SerializerInterface |
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| 37 | */ |
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| 38 | private $metadataSerializer; |
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| 39 | |||
| 40 | /** |
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| 41 | * @var null |
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| 42 | */ |
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| 43 | private $loadStatement = null; |
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| 44 | |||
| 45 | /** |
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| 46 | * @var string |
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| 47 | */ |
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| 48 | private $tableName; |
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| 49 | |||
| 50 | /** |
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| 51 | * @var string |
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| 52 | */ |
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| 53 | private $aggregateType; |
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| 54 | |||
| 55 | /** |
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| 56 | * @param Connection $connection |
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| 57 | * @param SerializerInterface $payloadSerializer |
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| 58 | * @param SerializerInterface $metadataSerializer |
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| 59 | * @param string $tableName |
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| 60 | * @param mixed $aggregateType |
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| 61 | */ |
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| 62 | public function __construct( |
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| 75 | |||
| 76 | /** |
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| 77 | * {@inheritDoc} |
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| 78 | */ |
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| 79 | public function load($id) |
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| 96 | |||
| 97 | /** |
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| 98 | * {@inheritDoc} |
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| 99 | */ |
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| 100 | public function append($id, DomainEventStreamInterface $eventStream) |
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| 118 | |||
| 119 | /** |
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| 120 | * @param Connection $connection |
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| 121 | * @param DomainMessage $domainMessage |
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| 122 | */ |
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| 123 | private function insertMessage(Connection $connection, DomainMessage $domainMessage) |
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| 137 | |||
| 138 | /** |
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| 139 | * @param Schema $schema |
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| 140 | * @return Table|null |
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| 141 | */ |
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| 142 | public function configureSchema(Schema $schema) |
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| 150 | |||
| 151 | /** |
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| 152 | * @return mixed |
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| 153 | */ |
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| 154 | public function configureTable() |
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| 178 | |||
| 179 | /** |
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| 180 | * @return \Doctrine\DBAL\Driver\Statement|null |
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| 181 | */ |
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| 182 | private function prepareLoadStatement() |
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| 201 | |||
| 202 | /** |
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| 203 | * @param $row |
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| 204 | * @return DomainMessage |
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| 205 | */ |
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| 206 | View Code Duplication | private function deserializeEvent($row) |
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| 216 | |||
| 217 | /** |
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| 218 | * Ensure that an error will be thrown if the ID in the domain messages is |
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| 219 | * not something that can be converted to a string. |
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| 220 | * |
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| 221 | * If we let this move on without doing this DBAL will eventually |
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| 222 | * give us a hard time but the true reason for the problem will be |
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| 223 | * obfuscated. |
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| 224 | * |
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| 225 | * @param DomainEventStreamInterface $eventStream |
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| 226 | */ |
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| 227 | private function guardStream(DomainEventStreamInterface $eventStream) |
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| 234 | } |
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| 235 |
PHP Analyzer performs a side-effects analysis of your code. A side-effect is basically anything that might be visible after the scope of the method is left.
Let’s take a look at an example:
If we look at the
getEmail()method, we can see that it has no side-effect. Whether you call this method or not, no future calls to other methods are affected by this. As such code as the following is useless:On the hand, if we look at the
setEmail(), this method _has_ side-effects. In the following case, we could not remove the method call: