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:
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29 | class ManagerFactory |
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30 | { |
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31 | /** |
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32 | * @var MetadataCollector |
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33 | */ |
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34 | private $metadataCollector; |
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35 | |||
36 | /** |
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37 | * @var Converter |
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38 | */ |
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39 | private $converter; |
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40 | |||
41 | /** |
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42 | * @var LoggerInterface |
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43 | */ |
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44 | private $logger; |
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45 | |||
46 | /** |
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47 | * @var LoggerInterface |
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48 | */ |
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49 | private $tracer; |
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50 | |||
51 | /** |
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52 | * @var EventDispatcherInterface |
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53 | */ |
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54 | private $eventDispatcher; |
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55 | |||
56 | /** |
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57 | * @var Stopwatch |
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58 | */ |
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59 | private $stopwatch; |
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60 | |||
61 | /** |
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62 | * @param MetadataCollector $metadataCollector Metadata collector service. |
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63 | * @param Converter $converter Converter service to transform arrays to objects and visa versa. |
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64 | * @param LoggerInterface $tracer |
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65 | * @param LoggerInterface $logger |
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66 | */ |
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67 | public function __construct($metadataCollector, $converter, $tracer = null, $logger = null) |
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75 | /** |
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76 | * @param EventDispatcherInterface $eventDispatcher |
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77 | */ |
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78 | public function setEventDispatcher(EventDispatcherInterface $eventDispatcher) |
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83 | /** |
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84 | * @param Stopwatch $stopwatch |
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85 | */ |
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86 | public function setStopwatch(Stopwatch $stopwatch) |
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91 | /** |
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92 | * Factory function to create a manager instance. |
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93 | * |
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94 | * @param string $managerName Manager name. |
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95 | * @param array $connection Connection configuration. |
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96 | * @param array $analysis Analyzers, filters and tokenizers config. |
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97 | * @param array $managerConfig Manager configuration. |
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98 | * |
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99 | * @return Manager |
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100 | */ |
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101 | public function createManager($managerName, $connection, $analysis, $managerConfig) |
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172 | View Code Duplication | private function dispatch($eventName, $event) |
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180 | } |
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If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: