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: